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A proton exchange membrane increases the electrical performance of a microbial fuel cell (MFC). New inexpensive materials should be sought, especially in a constructed wetland microbial fuel cell (CW-MFC). Here, in a laboratory-scale system of five CW-MFCs, wet clay, wet earth or mud, and non-woven cloth were used as inexpensive separators with long-term stability. The five CW-MFCs were planted with Typha latifolia, fed with synthetic wastewater, and packed with natural porous material. Graphite felt was used as electrodes and the experimental system had a hydraulic residence time of 3 days, operating under shade and natural conditions of temperature and light. Electrodes were connected to current collectors (copper wire) and to an external resistance, with a change every 20 days, starting in open-circuit and following with 20000, 18000, 15000, 10000, 5600, 1000, 560, and 10 Ω. These laboratory-scale CW-MFCs reduced concentrations of nitrates, ammonium ion, and sulfates without inhibiting electricity production. Microbiological analyses indicated that anaerobic, facultative, aerobic, and denitrifying bacteria may have caused these reductions. The reactor with the live plant and with the wet earth or mud separator achieved the highest production of electricity (22.6 mW/m2), and may be worth further attention. [ABSTRACT FROM AUTHOR]

Mosquitoes (Diptera: Culicidae) are one of the most impactful pests to human society, both as a nuisance and a potential vector of human and animal pathogens. Mosquito larvae develop in still aquatic environments. Eliminating these habitats near high human density or managing them to reduce the suitability for mosquitoes will reduce mosquito populations in these human environments and decrease the overall negative impact of mosquitoes on humans. One common source of standing water in urban and suburban environments is the water that pools in stormwater control measures. Previous studies have shown that some stormwater control measures generate large numbers of mosquitoes while others harbor none, and the reason for this difference remains unclear. Our study focuses on elucidating the factors that cause a stormwater control measure to be more or less suitable for mosquitoes. During the summers of 2021 and 2022, we collected and identified mosquito larvae from thirty stormwater control measures across central Ohio to assess variation in mosquito abundance and diversity among sites. Our goal was to determine if specific types of stormwater control measures (retention ponds, detention ponds, or constructed wetlands) harbored different abundances of mosquitoes or different community structures. We also assessed environmental parameters of these sites to elucidate their effects on mosquito abundance and diversity. Overall, we recorded the highest number of mosquito larvae and species in constructed wetlands. However, these sites were dominated by the innocuous species, Culex territans. Conversely, detention ponds held fewer mosquitoes but a higher proportion of known vector species, including Culex pipiens and Aedes vexans. The total number of mosquitoes across all sites was correlated with higher vegetation, more shade, lower water temperatures, and lower pH, suggesting stormwater control measures with these features may also be hotspots for mosquito proliferation. [ABSTRACT FROM AUTHOR]

This study focused on assessing the effectiveness of vertical subsurface constructed wetlands (VSFCW) in purifying integrated poultry and aquaculture wastewater (PAW) in a tropical region. This evaluation encompassed the treatment of physico-chemical, heavy metal, and microbiological pollutants across three distinct climatic seasons and hydraulic retention time (HRT: 21 days). Parameters such as BOD (29.50 mg/L), COD (56.67 mg/L), Zn (2.97 mg/L), Cr (0.24 mg/L), Cu (1.78 mg/L), Pb (0.21 mg/L), total fecal coliform (866.67 cfu/mL), total coliform (1666.67 cfu/mL), E. coli (1133.33 cfu/mL), and Salmonella/Shigella (700 cfu/mL) exceeded the discharge limits for wastewater into nearby surface water bodies. Significant removal efficiencies were observed for all parameters tested in the CW planted with both Phragmites karka and Typha latifolia. The macrophytes showed similar removal efficiencies for all tested parameters, and there was no significant difference in the initial concentrations of the parameters based on the experimental season, except for microbial properties. This suggests that weather conditions did not significantly impact the concentration of physical and chemical properties in the wastewater. Consequently, this study successfully demonstrates the potential of using a VSFCW for effective treatment of PAW. Leveraging the power of nature's green allies, Phragmites karka and Typha latifolia, a Sub-surface Constructed Wetland becomes a dynamic and efficient solution. This innovative strategy not only effectively addresses the wastewater challenge but also promotes sustainability and ecological balance. By harnessing the extraordinary capabilities of these wetland plants, the integrated system showcases its potential to transform waste into a valuable resource while minimizing the environmental footprint. In a world that demands sustainable solutions, this pioneering approach paves the way for a greener future in wastewater treatment for Integrated Poultry and Aquaculture industries. [ABSTRACT FROM AUTHOR]

The efficacy of the lesser duckweed, Lemna aequinoctialis (Welw.), to remediate varying concentrations of cadmium, chromium, lead, and vanadium from an organo-metallic contaminated media was tested in artificial surface wetland mesocosm experiment. A 100 g of fresh-weight duckweed was introduced into each of the mesocosm, except for the control setup and monitored for 120 days while the metals removal rate was quantified using an atomic absorption spectrometer. A time-dependent and partial sorption of metals was observed with the highest removal rate recorded for cadmium (71.96%), followed by lead (69.23%), vanadium (55.22%), and chromium (41.64%). The uptake and bioaccumulation of metals were reflected in the increased plant biomass (p < 0.05, F = 97.12) and relative growth rate (p < 0.05, F = 1214.35) in duckweed. A coefficient (r2) of 0.951, 0.919, 0.970, and 0.967 was recorded for cadmium, chromium, lead, and vanadium respectively, indicating that the remediation of metals followed the first-order kinetic rate model. This study highlights the efficacy of the lesser duckweed to preferentially remediate metals in an organo-metallic complex medium for potential wastewater treatment in the petrochemical industry. Appling ecological or nature-based solutions for the treatment of complex wastewater from the petrochemical industry in Africa remains a challenge due to the paucity of evidence-based science to support the implementation that is acceptable to regulators and the industry. Although laboratory and field-based demonstration of phytoremediation studies has shown the potential of macrophytes for the treatment of organic and inorganic pollutants, studies on the application of duckweed for complex organo-metallic wastewater treatment for heavy metals are few. This study demonstrates the efficacy of the lesser duckweed, Lemna aequinoctialis in the sorption of cadmium, chromium, lead, and vanadium from an organo-metallic complex with potential application in the petrochemical industry. Oil spill releases hydrocarbons and associated metals into the environment. Hydrocarbons are degraded, but heavy metals remain in the environment. Lemna aequinoctialis demonstrated the partial sorption of metals in artificial wetlands. The phytoremediation of metal was time-dependent. The sorption rate fits into the first-order kinetic rate equation. [ABSTRACT FROM AUTHOR]

The Yellow River Delta (YRD), known for its vast and diverse wetland ecosystem, is the largest estuarine delta in China. However, human activities and climate change have significantly degraded the wetland ecosystem in recent decades in the YRD. Therefore, an understanding of the land use modifications is essential for the efficient management and preservation of ecosystems in this region. This study utilized time series of remote sensing data and the extreme gradient boosting method to generate land use maps of the YRD from 2000 to 2020. Several methods, including transition matrix, land use dynamic degree, and standard deviation ellipse, were employed to explore the characteristics of land use transitions. The results underscore significant spatial variations in land use over the past two decades. The most rapid increase was observed in built-up area, followed by terrestrial water and tidal flats, while unutilized land experienced the fastest decrease, followed by forest–grassland. The spatial distribution patterns of agricultural land, built-up area, terrestrial water, and forest–grassland demonstrated stronger directionality compared to other land use types. The wetlands have expanded in size and improved in structure. Unutilized land has been converted into artificial wetlands comprising ponds, reservoirs, salt ponds, shrimp and crab ponds, and natural wetlands featuring mudflats and forest–grassland. The wetland conservation efforts after 2008 have proven very effective, playing a positive role in ecological and environmental preservation, as well as in regional sustainable development. [ABSTRACT FROM AUTHOR]

Rural drainage ditches serve as important sinks for heavy metals and antibiotics. However, the combined effects of heavy metals and antibiotics on ecological processes and functions in ditches remain unclear. We studied the combined effects of cadmium and doxycycline on nitrification, denitrification, anaerobic ammonia oxidation, and nitrous oxide emission rates in constructed ditch wetlands during 84 days. Results show that combined pollution decreased denitrification and anaerobic ammonia oxidation rates, but increased nitrous oxide production rates. The addition of either cadmium or doxycycline decreased the glucokinase and glyceraldehyde-3-phosphate dehydrogenase activities, and their combined pollution had a higher impact on adenosine triphosphate than on nicotinamide adenine dinucleotide. Moreover, the activities of the electron transport system, nitrate reductase, and nitrite reductase were enhanced by short-term pollutant exposure, but inhibited by long-term pollutant exposure. Structural equation modelling further revealed that electron production and transport impacted the rates of denitrification, anaerobic ammonia oxidation, and nitrous oxide production directly and indirectly by changing the activities of nitrate and nitrite reductases. [ABSTRACT FROM AUTHOR]

The generation of faecal sludge (FS) in capitals and urban settings of African countries outpaces the available storage, emptying, transportation and treatment technologies. The low technology-based treatment systems for handling FS are preferable and widely adopted in the African context due to their less associated investment and operation costs. The waste stabilization ponds and constructed wetlands were principally developed as wastewater treatment systems however they are widely adopted for treating FS in urban settings of Africa. Less information is known about the efficiency of these systems in lowering FS pollutant concentrations to meet the design specifications and the allowable discharge limits. This paper reviewed the technical efficacy of waste stabilization ponds and the constructed wetlands in treating FS by evaluating the actual treatment efficiency data against the design efficiencies and the maximum allowable discharge limits. The review results revealed that these technologies are user-friendly although they fail to lower the solids concentrations to meet the design and maximum allowable discharge limits. This failure imposes extra costs on operation and maintenance due to the fast filling of solids in the systems hence leading to short-circuiting issues. So, studies on the adequate dewatering technologies of FS before entering the systems are needed. [ABSTRACT FROM AUTHOR]

This study presents empirical evidence elucidating the utilisation of reed beds by hazel dormice (Muscardinus avellanarius) during their summer activity phase. Historically characterised as an arboreal species confined to woodland and hedgerow habitats, the comprehensive assessment of this strictly protected species within reed beds and analogous wetland ecosystems across Europe has been lacking, presumably due to the presumption of their absence in such locales. This study aimed to employ radio telemetry to monitor hazel dormice and assess their utilisation of a reed bed compared to adjacent woodland for both nocturnal activity and daytime resting. To achieve this aim, eight hazel dormice were fitted with radio transmitters at the boundary between a reed bed and an adjacent woodland and tracked for a minimum of three consecutive nights. Results showed that the animals used the reed bed to a comparable extent to the adjacent woodland during their nocturnal activity. Furthermore, hazel dormice frequently chose resting sites in the reed bed during the day. Although the nesting and breeding behaviour within the reed bed was not thoroughly examined, the discovery of a hazel dormice nest suggests that hazel dormice construct summer nests within the reed bed habitat. Reed beds, particularly when interconnected with adjacent woodland, constitute an integral component of the habitat of the hazel dormouse, a previously overlooked fact. Hence, it is essential to include reed beds in strategies for conservation management and further research aimed at elucidating the habitat requirements of the hazel dormouse. [ABSTRACT FROM AUTHOR]

Significance: While many technologies exist to address the wide variety of sustainability challenges facing humanity, many technologies are not adopted at sufficient scale or are used incorrectly, negating the positive impacts. This commentary introduces the discipline of human factors and ergonomics, demonstrating four features that facilitate the effective design and implementation of eco-socio-technical systems for sustainability. An example of the URBWAT research project, which implemented a nature-based solution in an informal settlement to collect and treat greywater, is given to illustrate how these four features operate in practice. [ABSTRACT FROM AUTHOR]

Wetlands are catchment life support systems with diverse ecological and socio-economic functions. They have played a significant role in the growth of African human civilisations and cultural development, and today contribute billions of US dollars' worth of ecosystem services to the people of Ethiopia. Ethiopia exhibits both natural and man-made wetland types that cover up to 2% of its land surface. They are, however, under threat from excessive pressures that are both ecologically and socially driven. The objective of this study was to analyse the state of ecosystem services provision of the Ethiopian wetlands, with a novel application of Ostrom's Socio-ecological Systems Framework (SESF), taking Boyo Wetland as a case study. Household surveys, focus group discussions and stakeholder analysis methods were applied to satisfy the data needs of SESF. Insufficient knowledge of actors on wetland ecosystem services, weak governance and limited self-organisation among actors are highlighted as the major reasons contributing to the unsustainable use of wetlands. When the use of Boyo Wetland's ecosystem services was evaluated using the SESF, it was evident that unsustainable resource use practices are widespread. These findings could be used to inform national policy on wetlands and local strategies for the sustainable use of wetland resources by direct or indirect users at different levels. [ABSTRACT FROM AUTHOR]

The restoration and construction of wetlands offer opportunities to rewet soils, inhibit decomposition, and enhance nutrient retention in decomposing litters. Here, we report the decomposition rates and nutrient dynamics of macrophyte litters in intact, restored, and constructed wetlands. A 2.1‐year litterbag experiment of four common freshwater macrophytes (Phalaris arundinacea, Phragmites australis, Scirpus cyperinus, and Typha latifolia) was conducted in eight freshwater marshes (three intact, four restored, and one constructed) within three sites in Manitoba and Ontario, Canada, which varied in restoration age, inundation periods, and surrounding land uses. Litter mass loss and N and P dynamics were measured. Litter decomposition rates (k) followed the order of P. arundinacea (0.42 ± 0.03 year−1) > T. latifolia (0.31 ± 0.03 year−1) > P. australis (0.19 ± 0.01 year−1) > S. cyperinus (0.13 ± 0.01 year−1) in most wetlands and were positively correlated to the initial litter N concentration. Litters decomposed fastest under seasonally inundated conditions rather than permanent inundation. N and P retention in litters were significantly affected by both initial litter N and P concentration and wetland surrounding land uses. After 2.1 years of decomposition, the N:P ratio of all litters converged to 20 to 28:1, regardless of the initial litter N:P ratio or N or P concentrations. The effectiveness of wetland restoration in slowing decomposition and enhancing nutrient accumulation depends on the quality of the input litters and wetland characteristics, including inundated periods and surrounding anthropogenic disturbances. [ABSTRACT FROM AUTHOR]

Wetlands are important habitats for insectivorous bats, as the presence of water promotes insect abundance and provides drinking water for wildlife, and therefore could promote bat conservation. Research on bats and wetlands has mainly focused on constructed wetlands, and with a geographical emphasis on eastern United States and central Europe, whereas relatively little is known about the effects of wetland restoration on bats, especially in the boreal zone. We conducted a Before‐After‐Control‐Impact (BACI) study in 21 wetlands. Using acoustic survey techniques, we collected information on bats both before and after restoration, with 7 of the 21 wetlands acting as control sites and 14 as impact (i.e., restored) sites. Acoustic surveys were conducted in May–September in the years 2018, 2019 (before restoration) and in 2021 and 2022 (after restoration). Species detection for each night was assessed by automated analysis of audio recordings. We assessed the presence and number of active minutes of the Northern bat (Eptesicus nilssonii) and the Myotis species group, using a generalized linear mixed model. Wetland restoration increased the acoustic activity of both taxa, but not their presence. Thus, restoration increased the usage of wetlands as a feeding site for bats. Our BACI study provides strong evidence that wetland restoration caused an increase in bat activity, and can be used as an effective tool for bat conservation. [ABSTRACT FROM AUTHOR]

The degradation and loss of natural wetlands has caused severe crises for wetland taxa. Meanwhile, constructed wetlands are expanding significantly and facing dramatic environmental changes. Exploring the responses of wetland organisms, particularly zooplankton, may have important implications for the management of wetlands. Environmental and zooplankton samples were collected from 34 subsidence wetlands created by underground coal mining across the North China Plain in August 2021. We used generalized linear models and redundancy analysis to test zooplankton responses to environmental variables, with the relative importance quantified by variation partitioning. We identified 91 species, divided into 7 functional groups, with the highest density of rotifer filter feeders (RF, 2243.4 ± 499.4 ind./L). Zooplankton species richness was negatively correlated with electrical conductivity (EC), chlorophyll-a, total phosphorus, and pH. The Shannon–Weiner and Pielou evenness indices were positively correlated with transparency and negatively correlated with the photovoltaic panel area (AS). Rotifer predators (RCs) and RF densities were positively correlated with cropland area and dissolved oxygen, but negatively correlated with AS. Small crustacean filter feeders positively correlated with AS, whereas medium crustacean feeders (MCFs) positively correlated with EC. AS was the most critical variable affecting the zooplankton community. Our study showed that the spatial pattern of zooplankton communities was shaped by environmental heterogeneity across the subsidence wetlands, providing implications for the management and conservation of these constructed wetlands. [ABSTRACT FROM AUTHOR]

The cheese making and vegetable processing industries generate immense volumes of high‐nitrogen wastewater that is often treated at rural facilities using land applications. Laboratory incubation results showed denitrification decreased with temperature in industry facility soils but remained high in soils from agricultural sites (75% at 2.1°C). 16S rRNA, phospholipid fatty acid (PLFA), and soil respiration analyses were conducted to investigate potential soil microbiome impacts. Biotic and abiotic system factor correlations showed no clear patterns explaining the divergent denitrification rates. In all three soil types at the phylum level, Actinobacteria, Proteobacteria, and Acidobacteria dominated, whereas at the class level, Nitrososphaeria and Alphaproteobacteria dominated, similar to denitrifying systems such as wetlands, wastewater resource recovery facilities, and wastewater‐irrigated agricultural systems. Results show that potential denitrification drivers vary but lay the foundation to develop a better understanding of the key factors regulating denitrification in land application systems and protect local groundwater supplies. Practitioner Points: Incubation study denitrification rates decreased as temperatures decreased, potentially leading to groundwater contamination issues during colder months.The three most dominant phyla for all systems are Actinobacteria, Proteobacteria, and Acidobacteria.The dominant class for all systems is Nitrosphaeria (phyla Crenarchaeota).No correlation patterns between denitrification rates and system biotic and abiotic factors were observed that explained system efficiency differences. [ABSTRACT FROM AUTHOR]

Abstract\nNOVELTY STATEMENTBrassware industry constitutes the second most polluting industrial sector in Fez city, Morocco, owing to its high heavy metal load. The aim of this study is to examine and evaluate the performance of vertical flow constructed wetlands in treating brassware effluents using various plant species. Ten treatment systems were planted with four types of plants: Chrysopogon zizanioides, Typha latifolia, Phragmites australis, and Vitex agnus-castus, while another system remained unplanted. These systems underwent evaluation by measuring various parameters, including pH, electrical conductivity, suspended solids, chemical oxygen demand, biological oxygen demand, sulfates, orthophosphates, total Kjeldhal nitrogen, ammonium, nitrates, nitrites, and heavy metals such as silver, copper, and nickel, using standard methods over of ten weeks. The results obtained demonstrate effectiveness of these systems. When planted with Ch. zizanioides, the systems achieved elimination rates of 83.64%, 98.55%, 91.48%, 86.82%, 80.31%, 96.54%, 98%, and 98.82% for suspended solids, ammonium, nitrites, BOD5, sulfates, orthophosphates, silver, and nickel, respectively. System with V. agnus-castus showed significant reductions in nitrate and copper, with rates of 84.48% and 99.10%, respectively. Considerable decrease in pH and electrical conductivity values was observed in all systems, with a notable difference between planted and control systems regarding effectiveness of treatment for other parameters.The novelty of this study lies in the application of constructed wetlands for the treatment of brassware effluents in the city of Fez, Morocco. Consequently, a comparison was conducted to assess the removal efficiency of Chrysopogon zizanioides (L.) Roberty and Vitex agnus-castus L., in comparison to Typha latifolia L. and Phragmites australis (Cav.) Trin. These four plant species were specifically chosen for their high elimination capacity and resistance to the toxicity of the pollutants. Notably, this study represents an unexplored aspect in the existing literature. Nevertheless, T. latifolia and P. australis have been extensively utilized in constructed wetlands for treating diverse wastewaters. The findings from this study can also be extrapolated to pilot-scale constructed wetlands, offering valuable insights for the removal of pollutants from brassware wastewater. [ABSTRACT FROM AUTHOR]

The primary objective of the present study is to enhance the denitrification process in constructed wetlands (CWs), employed as an ecological and natural technology for wastewater treatment. Eco-friendly approaches have been tested to improve the nitrate removal efficiency in pilot-scale subsurface flow CWs. Initially, the system's performance was enhanced by using a natural substrate, namely cork, as a filter medium. Another approach is bio-inoculation into the rhizosphere of a bacterial strain with the potential capacity for nitrate removal, thereby reinforcing the synergy between the plant and microorganisms. Finally, the approaches were combined, and nitrate removal was assessed. The main results showed that the most effective nitrate removal from wastewater was achieved with cork (80%) compared to gravel (60%). Bio-inoculation into the rhizosphere of denitrifying bacteria significantly improved nitrate removal. Indeed, the nitrate removal rate by the inoculated CW filled with gravel, was higher than the non-inoculated system, with rates of 78% and 60%, respectively. Moreover, the highest removal rate of 99.77% was obtained with the inoculated system filled with cork. [ABSTRACT FROM AUTHOR]

This work presents an engaging hands-on activity designed to teach school students about nature based solutions (NBS) and their role in achieving high-quality water systems within a sustainable circular economy. Through this activity, students actively participate in building a small constructed wetland (CW) and test its effectiveness under various contamination scenarios. The activity was tested with school teachers, undergoing refinements based on their feedback. This iterative development process has ensured the activity’s effectiveness in engaging both school students and the public. Further, the CW model can be scaled-up for specific school projects focused on improving water quality. This activity offers valuable opportunities to enhance ocean literacy, promote understanding on NBS and raise awareness about aquatic ecosystems contamination and the importance of environmental sustainability. [ABSTRACT FROM AUTHOR]

Wastewater treatment in a constructed wetland is achieved by the presence of plant species, the metabolism of microorganisms, and the enzyme activities. Three small‐scale hybrid subsurface flow constructed wetlands (HSFCWs) planted with Arundo donax and one unplanted HSFCW were constructed near a water resource recovery facility at Guru Gobind Singh Indraprastha University. The purpose of the study was to determine the correlation between soil enzymatic activities and the removal of contaminants from domestic wastewater. Enzyme activity of phosphatase, protease, urease, and cellulase increased with an increase in temperature. A strong correlation between enzyme activities and TKN and surfactant removal was observed, whereas moderate correlation was observed with phosphate in planted HSFCW during the study. The correlation between COD removal and enzyme activities was low to moderate. In unplanted HSFCW, the correlation between enzyme activities and COD removal was negative, negligible to moderate to strong in the case of TKN, low to moderate in the case of phosphate, and negligible to low in the case of surfactants. The increased removal efficiency of the planted system compared with that of the unplanted system indicated a positive impact on enzyme activities with the growth of plants and their roots. Practitioner Points: Protease, urease, and cellulase activities:Planted HSFCW exhibited higher protease, urease, and cellulase activities than unplanted, signifying enhanced breakdown.July displayed maximum enzyme activities, correlating with heightened biological breakdown in both systems.Fluctuations in enzyme activities reflected seasonal changes, influencing nutrient degradation rates.Planted HSFCW consistently showed higher enzymatic activities across protease, urease, and cellulase than unplanted. [ABSTRACT FROM AUTHOR]

Nature-based solutions (NbSs) are considered to form an innovative stormwater management approach that has living resolutions grounded in natural processes and structures. NbSs offer many other environmental benefits over traditional grey infrastructure, including reduced air pollution and climate change mitigation. This review predominantly centers on the hydrological aspect of NbSs and furnishes a condensed summary of the collective understanding about NbSs as an alternatives for stormwater management. In this study, which employed the CIMO (Context, Intervention, Mechanism, Outcome) framework, a corpus of 187 NbS-related publications (2000–2023) extracted from the Web of Science database were used, and we expounded upon the origins, objectives, and significance of NbSs in urban runoff and climate change, and the operational mechanisms of NbSs (including green roofs, permeable pavements, bioretention systems, and constructed wetlands), which are widely used in urban stormwater management, were also discussed. Additionally, the efficacy of NbSs in improving stormwater quality and quantity is discussed in depth in this study. In particular, the critical role of NbSs in reducing nutrients such as TSS, TN, TP, and COD and heavy metal pollutants such as Fe, Cu, Pb, and Zn is emphasized. Finally, the main barriers encountered in the promotion and application of NbSs in different countries and regions, including financial, technological and physical, regulatory, and public awareness, are listed, and future directions for improving and strategizing NbS implementation are proposed. This review gathered knowledge from diverse sources to provide an overview of NbSs, enhancing the comprehension of their mechanisms and applications. It underscores specific areas requiring future research attention. [ABSTRACT FROM AUTHOR]

The wastewater from underground coal gasification (UCG) process has extremely complex composition and high concentrations of toxic and refractory compounds including phenolics, aliphatic and aromatic hydrocarbons, ammonia, cyanides, hazardous metals and metalloids. So, the development of biological processes for treating UCG wastewater poses a serious challenge in the sustainable coal industry. The aim of the study was to develop an innovative and efficient wetland construction technology suitable for a treatment of UCG wastewater using available and low-cost media. During the bioremediation process the toxicity of the raw wastewater decreased significantly between 74%—99%. The toxicity units (TU) ranged from values corresponding to very high acute toxic for raw wastewater to non-toxic for effluents from wetland columns after 60 days of the experiment. The toxicity results correlated with the decrease of some organic and inorganic compounds such as phenols, aromatic hydrocarbons, cyanides, metals and ammonia observed during the bioremediation process. The removal percentage of organic compounds like BTEX, PAHs and phenol was around 99% just after 14 days of treatment. A similar removal rate was indicated for cyanide and metals (Zn, Cr, Cd and Pb). Concluded, in order to effectively assess remediation technologies, it is desirable to consider combination of physicochemical parameters with ecotoxicity measurements. The present findings show that wetland remediation technology can be used to clean-up the heavily contaminated waters from the UCG process. Wetland technology as a nature-based solution has the potential to turn coal gasification wastewater into usable recycled water. It is economically and environmentally alternative treatment method. [ABSTRACT FROM AUTHOR]

A robust understanding of the interactions between global and local anthropogenic stressors is crucial for ecosystem management in the Anthropocene. Manipulative experiments in the laboratory or in the field can be used to build knowledge about the physiological and ecological effects of stressors, but predicting the combined landscape‐scale effects of global stressors such as climate change, and local stressors such as land‐use change requires a different approach.Here we used water quality and hydrology process‐based models of entire river catchments in combination with a large biomonitoring dataset to predict the responses of macroinvertebrate communities under different climate change and land‐use change scenarios. Using the River Thames in the U.K. as a model system, we predicted changes in water quality (temperature, flow, phosphorus [P], nitrogen, dissolved oxygen [DO]) and subsequent changes in macroinvertebrate communities for two climate change scenarios, individually and in combination with intensified agriculture and reduced P pollution (representing improved wastewater treatment).Our models predicted that water‐quality changes associated with climate change may not influence total species richness, but that community composition will shift towards more pollution‐tolerant and common taxa based on responses of community indices and taxon‐specific responses. We also found that the negative impacts of climate change on water quality (e.g., increased P concentration, decreased DO concentration) accumulate through the catchment, but that local land‐use practices influencing P dynamics can modify this trend. Furthermore, although the intensified agriculture scenario was predicted to have minimal impacts on macroinvertebrate communities (a result potentially related to shifting baselines as the Thames is already heavily polluted), we found that reduced P pollution resulting from improved wastewater treatment was able to mostly offset the negative impacts of climate change on macroinvertebrate communities.Our results demonstrate that using process‐based models to study networks of interacting stressors at a landscape scale can provide useful insights into the ecological impacts of anthropogenic global change, and adds support to the idea that management of local stressors has the potential to mitigate some of the impacts of climate change on ecosystems. [ABSTRACT FROM AUTHOR]

Subsurface-flow constructed wetlands (SSF CWs), which include horizontal subsurface–flow constructed wetlands (HSSF CWs) and vertical subsurface–flow constructed wetlands (VSSF CWs), have become increasingly popular for the treatment of various waste streams such as wastewater, landfill leachate, and stormwater runoff. These wetlands utilize a variety of natural physical, chemical, and microbial processes to effectively remove contaminants. This article aims to provide valuable insights into the application of subsurface-flow wetlands for the treatment of stormwater runoff by collecting and reviewing relevant articles. Within the realm of stormwater contaminants, this review primarily focuses on nutrients, heavy metal, and per- and polyfluoroalkyl substances (PFAS), which are commonly found in stormwater runoff worldwide. The removal percentages of these contaminants vary across different studies, depending on factors such as the characteristics of the contaminants, the type and scale of the subsurface-flow wetland, as well as the selection of plants and substrates used. This study provides valuable insights into the various processes that significantly contribute to the removal of contaminants, including adsorption, plant uptake, and biodegradation. The removal percentage of PFAS ranges from 1% to 99% in constructed wetlands. The wide range of PFAS removal comes from differences between PFAS category, plant and soil type, wetland configuration, and matrix effects. Additionally, this paper brings attention to the current gaps and limitations present in the research conducted within this field. It is imperative to conduct further studies utilizing real-world or synthetic stormwater runoff to deepen our comprehension in this domain. Furthermore, considering that each category of PFAS possesses unique properties, conducting individual studies on each group becomes crucial to attain a comprehensive understanding of the behavior and transformation of PFAS in CWs. [ABSTRACT FROM AUTHOR]

Coastal marshes mitigate allochthonous nitrogen (N) inputs to adjacent marine habitat; however, their extent is declining rapidly. As a result, marsh restoration and construction have become a major foci of wetland management. Constructed marshes can quickly reach similar plant biomass to natural marshes, but biogeochemical functions like N removal and retention can take decades to reach functional equivalency, often due to lags in organic matter (OM) pools development in newly constructed marshes. We compared denitrification and dissimilatory nitrate reduction to ammonium (DNRA) rates in a 32 year-old constructed marsh and adjacent reference marsh in the Northern Gulf of Mexico. Marsh sediments packed into 3 mm "thin discs" were subjected to three OM quality treatments (no OM addition, labile OM, or recalcitrant OM) and two N treatments (ambient nitrate or elevated nitrate) during a 13 day incubation. We found that OM addition, rather than marsh type or nitrate treatment, was the most important driver of nitrate reduction, increasing both denitrification and DNRA and promoting DNRA over denitrification in both marshes. Fungal and bacterial biomass were higher in the natural marsh across treatments, but recalcitrant OM increased fungal biomass in the constructed marsh, suggesting OM-limitation of fungal growth. We found that constructed marshes are capable of similar denitrification and DNRA as natural marshes after 30 years, and that labile OM addition promotes N retention in both natural and constructed marshes. Conceptual figure highlighting the findings of this experiment. Under control treatment with no C addition (bottom panel), constructed and natural marshes have similar rates of both DNRA and denitrification. The natural marsh has higher fungal and bacterial biomass, while fungal biomass is not detectable in the constructed marsh. Under labile OM additions (upper left panel), rates of both DNRA and denitrification are increased and DNRA becomes favored over denitrification in both marshes. Recalcitrant OM additions (upper right) increase denitrification, but do not affect DNRA or % denitrification. The addition of recalcitrant OM also increases the detectability of fungal biomass in the constructed marsh. [ABSTRACT FROM AUTHOR]

Wetlands within dryland regions are highly sensitive to climate change and human activities. Based on three types of land use data sources from satellite images and a spatial data analysis, the spatiotemporal characteristics of wetland evolution in China's drylands and their relationship with human interference and climate change from 1990 to 2020 were analyzed. The results were as follows: (1) The wetlands within China's drylands expanded, including rivers, lakes, and artificial wetlands, apart from marshes, which shrunk. Meanwhile, wetland fragmentation increased, with rivers being particularly severely fragmented. (2) Temperature and precipitation showed an increasing trend from 1990 to 2020 in China's drylands. Lakes and rivers expanded with regional differences due to the uneven distribution of precipitation and rising temperature. (3) Human activities, more than climate change, became the key driving factor for the changes in wetland patterns in China's drylands. The increased areas of farmland and grassland along with increased levels of drainage and irrigation activities led to the shrinkage of marshes and the fragmentation of rivers. The increase in the number of artificial reservoirs was the main reason for the expansion of artificial wetlands. This study clarifies the specific driving factors of different types of wetlands within China's drylands, which is of great use for better protecting wetlands and the gradual restoration of degraded wetlands. [ABSTRACT FROM AUTHOR]

The filling of constructed wetlands (CWs) affects the efficiency of sewage treatment and proper operation. Mineral aggregates are most often used as filling materials. Significant environmental burdens from mineral mining operations justify the search for waste fill. This study aimed to determine the possibility of increasing the efficiency of CW by using a Certyd aggregate as a new filling. Certyd is produced in the sintering process of coal ash, a waste from combined heat and power (CHP) plant operation. Comprehensive two-year studies were conducted using two real-scale subsurface vertical flow (SS VF) CWs supplied with domestic sewage. One bed was filled with a Certyd and the other was filled with appropriate fractions of a mineral aggregate. Both beds worked in parallel, and to compare their effectiveness, account seasonality was taken into account. The SS-VF Certyd-filled bed achieved an average efficiency of 88.0% for biological oxygen demand (BOD5), 80.2% for chemical oxygen demand (COD), 80.4% for suspended solids (SSs), 80.2 for ammonia nitrogen (N-NH4), 72.2% for total nitrogen (TN), and 55.3% for total phosphorus (TP), while the gravel-filled bed achieved 84.5%, 77.0%, 86.9%, 74.2%, 69.4%, and 57.8% for the whole research period, respectively. A higher effect of the removed unit load was achieved in the bed filled with Certyd (36.2 g BOD5 m−2 d−1, 50.0 g COD m−2 d−1, 5.88 g SS m−2 d−1, 7.1 g TN m−2 d−1, 7.9 g N-NH4 m−2 d−1, 0.79 g TP m−2 d−1) compared to the gravel-filled bed (34.7 g BOD5 m−2 d−1, 47.0 g COD, 6.35 g SS m−2 d−1, 6.9 g TN m−2 d−1, 7.3 g m−2 d−1 N-NH4, 0.83 g TP m−2 d−1). [ABSTRACT FROM AUTHOR]

This research shows efficiency of constructed wetlands (CWs) to purify waste water in the case of Biochemical Oxygen Demand (BOD). CWs such as surface flow (SF), subsurface flow (SSF), and hybrid (HYB) systems have been compared to provide an analysis about which system has better performance for BOD removal efficiency. Data were collected from different scientific articles and from all over the world. Meta-analysis technique was employed to aggregate data from scientific sources, facilitating hypothesis testing, and comparisons between different types of CWs. All the systems of CWs show satisfactory removal efficiency. HYB systems are shown to be the most efficient. One-way analysis of variance (ANOVA) has been applied to analyze differences between respective CWs using R software. It shows that there is a statistically significant difference between different types of CWs. Post-hoc Tukey's Honestly Significant Different (HSD) analysis demonstrates a statistically significant difference between SF and HYB systems in the case of BOD removal efficiency. Also, Post-hoc Tukey's HSD shows statistically significant difference between SSF and SF CWs. On the other hand, Post-hoc Tukey's HSD does not show statistically significant difference between HYB and SSF CWs. The significant reduction rates for BOD removal efficiency, demonstrates that CWs can be used to diminish this kind of pollution. [ABSTRACT FROM AUTHOR]

Microorganisms, in particular prokaryotic cells, thanks to their small dimensions, wide metabolic abilities and fast reproduction, adapt continuously to environmental changes. Bacteria and Archaea are ubiquitous and develop promptly resistance to toxic effects of contaminants and capability of removing them through aerobic and anaerobic pathways. They can be used for bioremediation purposes both in bulk soil and in rhizosphere. The rhizosphere is a microhabitat, comprising roots and few millimeter soil/sediment immediately surrounding them, where an intense chemical dialog between plants and microorganisms occurs. Plants and microorganisms can interact so closely, which they can be considered as a metaorganism. Synergic interactions between plant and the microbiome improve the ecosystem's homeostatic response to a number of disturbances and enable effective purification of soil and water, and removal of contaminants. This chapter describes some examples of nature-based solutions (e.g. Plant assisted-bioremediation, constructed wetlands and Plant-microbial fuel cells) that rely on plant and microorganisms as a unique metaorganism. [ABSTRACT FROM AUTHOR]

The purpose of this review article is to present the primary factors that cause clogging of substrate in Constructed wetlands (CWs), as well as the consequences and possible solutions. A wide range of sources, including books, scholarly and internet articles, were used in the literature study. Substrate clogging is a major problem in CWs, which results in slowing down the flow of water and, finally, a significant reduction in the system's treating wastewater effectiveness. The deposition of suspended matter, the development of sludge, precipitation of chemicals and deposition inside the pore spaces, the growth of plant root systems, the production of gas, and the compaction of the clogging layer all contribute to this technical and operational challenge. Evaluating the extent of substrate clogging in CWs is a difficult task because this phenomenon is influenced by several factors. Clogging impact can be assessed using a variety of methods, including tracer testing, hydraulic conductivity measurements, and clogging matter characterization. A preventive or restorative strategy can be used to address this issue. Pre-treatment of wastewater, proper substrate and aquatic plant selection, earlier removal of leaves and dead roots, and backwashing are some of these strategies. [ABSTRACT FROM AUTHOR]

The effectiveness of constructed wetlands (CWs) created to improve water quality has been demonstrated. However, their role in enhancing biodiversity, such as in plankton communities, is still understudied. To assess this, we analysed, over two years, the plankton of three structurally different CWs which are intermediaries between low-quality waters and a protected Mediterranean wetland (Albufera de València Natural Park). We estimated the alpha-diversity of each CW and the beta-diversity among their different sectors. In two CWs, the diversity decreased as water flowed from the Inlet (a species mix from anthropically disturbed environments) to the Outlet, due to natural assembly processes. In the other CW, as it received water dominated by a few species, the emerging assemblages increased the diversity. Moreover, comparing the three CWs, the most divergent communities were those in the outlets (due to the emergence of exclusive species, biovolume differences, etc.). Therefore, they contributed to beta-diversity as they acted as generators of communities, which were characterized by the loss of cyanobacteria and chlorophytes, the dominance of large copepods or cladocerans and the presence of unshared species. We emphasize the importance of having structurally and functionally different CWs to enhance biodiversity and improve biological water quality in natural parks. [ABSTRACT FROM AUTHOR]

Increasing water and energy demand in agriculture due to changing climatic conditions and high resource consumption is widespread in Central Asia. Under these constraints, compounded by lack of irrigation water, farmers are opting to use drainage water for crop production, with negative consequences. Focusing on Uzbekistan, we evaluate the governance of farmer adoption of selected technological innovations (i.e., constructed wetlands and biogas) to improve crop productivity while providing water and energy savings. We build upon farmers' expressed views of the strategic decisions they would take regarding constructed wetlands and biogas plants. We use institutional analysis to identify relevant action situations, highlight potential institutional complementarity between these situations, and indicate promising areas for policy intervention. [ABSTRACT FROM AUTHOR]

The research stems from a growing concern about the negative impact of leachates, which are highly contaminated and complex liquids, on public health and the environment. Through detailed analysis and technical data collection, including on-site evaluation of the plant, deficiencies in the current treatment were identified. The study included estimation of the leachate flow rate using the volumetric method based on height differentiation. A detailed leachate characterization was performed to determine the efficiency of the existing treatment, focusing on the removal of Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD) and Turbidity. In addition, a treatability test was conducted using a specific flocculation and agitation process. The results revealed a deficient operation of the plant, with a daily production of 26 m3 of leachate that was not adequately treated. Therefore, the design of a vertical subsurface artificial wetland was proposed, meticulously calculating its surface area, retention time, dimensions and the amount of filter media required. It is concluded that there is an imperative need to redesign and optimize all the treatment phases of the plant. [ABSTRACT FROM AUTHOR]

Considering the potential threat of perfluorooctanoic acid (PFOA) on constructed wetlands (CWs), nano zero valent iron (nZVI) has been employed to promote ecological factors in CWs to enhance the operation performance. Nevertheless, effectiveness of iron-promotion on carbon and phosphorous metabolism with nZVI at various dosage should be investigated. In this study, the most significant enhancement on TP removal was found by 30 mg/L nZVI, with removal efficiency 1.46–12.89% higher than control level. It was consistent to the highest phosphatase activity on this condition. Whereas, lower abundance of key phyla involved in phosphorous metabolism like Proteobacteria , Actinobacteria and Chloroflexi with 30 mg/L nZVI indicated that microbial stimulation was not the dominant manner for strengthening phosphorous removal. In contrast to phosphorous metabolism, the highest increase of PFOA removal by 11.56% was uncovered with 10 mg/L nZVI, and such promotion was reduced by 2.76% since nZVI dosing rising to 30 mg/L. Analogously, inhibition on COD removal was even observed due to higher nZVI concentration. Lower dosage of nZVI generally contributed to more reinforcement on secreting polysaccharide and humus. As for plants, the most obvious improvement of chlorophyll (increased by 33.34–36.85%) and the highest reduction on catalase and malondialdehyde (declined by 221.16% and 45.24% in maximum) were all discovered with 30 mg/L nZVI introduction. It revealed the more potential of nZVI at higher concentration to restore plants under PFOA stress. Information in this study enriched investigation on iron-promoted CWs for treating wastewater containing per- and perfluoroalkyl substances. [Display omitted] [ABSTRACT FROM AUTHOR]

Livestock farming wastewater is complex in composition, containing a large number of pathogenic microorganisms and ammonia nitrogen (NH 4 +-N) with high concentration, which makes biological treatment difficult. In this study, tidal flow constructed wetlands were applied to treat piggery biogas slurry. Compared with a continuous flow constructed wetland, two tidal influent modes (hydraulic retention time: idling time for 12 h:12 h and 20 h:4 h, namely TFCW1 and TFCW2) were set up to explore treatment performances on chromaticity, turbidity, chemical oxygen demand (COD), total nitrogen (TN), NH 4 +-N and total phosphorus (TP), and determine the relationship between nitrogen transfer and dissolved oxygen (DO) contents. The fluorescence spectra of dissolved organic matter (DOM) in constructed wetlands were analyzed by excitation-emission matrix spectroscopy-parallel factor analysis to reveal its composition and content of humus. The results showed that tidal flow constructed wetlands obviously improved the removal of chromaticity and turbidity by 44.6% and 10.1%, in comparison to continuous flow constructed wetland. TFCW2 had enhanced reduction on pollutants, with removal efficiencies of COD, NH 4 +-N and TP at 78.6%, 82.1% and 84.0%, respectively. Furthermore, three fluorescent components were detected in TFCW2, and the value of Fmax was increased in the effluent, among which the Fmax of C3 (Humic-like substances) increased obviously from 0.320 to 9.39. The ratio of C2 (Aquatic fulvic acids) to C3 showed a slow increasing trend in the daily outflow of TFCW2, while C1 (dark-incubation substances) remained relatively constant. Fluorescence index (FI), humification index (HIX) and biological index (BIX) increased from 1.35 to 2.09, 0.210–1.51, and 0.240–1.05, respectively, showing that the effluent from the tidal flow constructed wetland had a high microbial activity. This study provided a new insight for the advanced treatment of livestock biogas slurry with a high NH 4 +-N content. [Display omitted] • Actual piggery biogas slurry was treated by tidal flow constructed wetland. • The changes of DO and pollutant concentrations along the system were detected. • 82.1% of NH 4 +-N and 84.0% of TP were removed by tidal flow constructed wetlands. • Dark-incubation substances, aquatic fulvic acids and humic-like substances were three main components in DOM. [ABSTRACT FROM AUTHOR]

The main objective of this study was to analyze the efficiency of CWs for purifying swine wastewater in order to reduce its pollutant load. The system included a pretreatment module (raw swine wastewater tank, phase separator, and settlement tank), and three constructed wetlands connected in series and planted with Phragmites australis and Suaeda vera. Three treatment cycles were carried out with a total hydraulic retention time in the wetland of 21 days for each cycle. Pig slurry samples were collected in triplicate after each treatment module, and physical–chemical analyses were performed. The results showed that the phase separator decreased the suspended solids, turbidity, and the chemical oxygen demand in the treated swine wastewater. The system enabled considerable nitrogen reductions (Kjeldahl nitrogen, NH4+, and organic nitrogen), and the highest removal was reported in the wetlands. However, the cations and anions showed different efficiencies. In some cases (Ca, Mg, and Na), the final concentrations were increased, which could be explained by their release from the substrate; however, there were no statistical differences among the CW effluents and the raw pig slurry. Therefore, the integral pig slurry treatment system with constructed wetlands increased the quality of the treated swine wastewater and thus can be used for its sustainable agronomic valorization. This thereby enables savings in inorganic fertilizers and irrigation water. [ABSTRACT FROM AUTHOR]

The identification and assessment of plant stress using wetland satellite images is a major task in remote sensing. In this study, one of the largest constructed wetlands (CWs) in the world, located in the Sultanate of Oman, was examined, assessed, and evaluated using remote sensor data from Sentinel-2. This CW system treats produced water generated during oil exploration activities in a desert environment; thus, CW vegetation is subjected to stress induced by oil hydrocarbons and water salinity. This study examined the plant stress and detected changes between the years of 2017 and 2019. Sentinel satellite images were evaluated for vegetation status extraction. The Normalized Difference Vegetation Index (NDVI), Modified Soil-Adjusted Vegetation Index (MSAVI), and Normalized Difference Salinity Index (NDSI) were used to evaluate the vegetation change. The results showed a comprehensive mapping identification of the plant stress and water flow parameter factors including oil in water contamination (OIW), dissolved oxygen (DO), water temperature (WT), and water conductivity (COND). Among the three indices, it was found that the NDVI showed a very good correlation with all parameters in both years with average R2 = 0.78, 0.67, 0.75, and 0.60 for OIW, DO, WT, and COND, respectively. The same trend was found for MSAVI but with R2 = 0.59, 0.48, 0.55, and 0.56 for OIW, DO, WT, and COND, respectively. This shows that the NDVI performed better than the MSAVI in evaluating the water flow parameters. On the other hand, the NDSI showed a strong correlation with one flow parameter, that is, water conductivity, especially at the outlet cells of the CW with R2 = 0.86 and 0.82 for winter time and summer time, respectively. The synchronization and correlation between the water flow parameters and remote sensing vegetation indices in this study lead to a new approach to large-scale landscape wetland monitoring that improves and helps predict any degradation or stress on vegetation growth. Furthermore, the results of this work can help decision makers potentially modify the wetland design and water flow path to improve future expansion phases. The mapping of such a critical and massive industrial CW should consider the use of high spatial resolution sensors where identifications and classifications are further improved. In summary, this research demonstrates that it is feasible to estimate vegetation stress within the constructed wetland using remote sensing techniques across extensive regions when an ample dataset comprising field data, satellite imagery, and supporting information is accessible. [ABSTRACT FROM AUTHOR]

Constructed wetlands (CWs) represent a natural wastewater treatment process, offering economic and environmental advantages. These systems can remove several components that may cause negative impacts on the environment. Media types and plant species are crucial influencing factors for the removal of contaminants in CWs. The goal of this study is to evaluate the capacity of a CW using Tamarix spp. with three filter media to treat FGD wastewater. Planted and unplanted CWs were set up with varying types of biofilm support media: 3 bioreactors were operated with 50% gravel and 50% zeolite (v/v), 3 with 100% gravel, and 3 with 50% gravel, 25% zeolite, and 25% silage. Planted CWs had the greatest potential to reduce the concentrations of B, K, and NH4+-N in 64.9%, 91.1%, and 92.5%, respectively, when used in addition to the filter composed by 50% gravel + 50% zeolite, which was the only media keeping the plants alive for 60 days. The results showed that the optimal selection of filter media depends on the purpose for which the treatment has been projected for, considering that the types of substrates influenced the nature of the contaminant removal in the CW. Salinity impact on Constructed wetlands (CWs) is still scarce in the literature. The novelty is the choice of a salt cedar (Tamarix spp.) combined with three filter media types ((1) gravel; (2) gravel and zeolite; (3) gravel, zeolite, and silage) to treat flue gas desulfurization wastewater in CWs. Our findings demonstrate that filter media containing 50% gravel + 50% zeolite can decrease the toxicity of contaminants from FGD wastewater in plants. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the performance of a laboratory-scale Hybrid Constructed Wetland (HCW) for industrial wastewater treatment planted with different macrophytes at different hydraulic retention times (HRT). The results revealed that the HCW planted with Phragmites australis and Lemna minor (PA/LMs), and the HCW planted with Typha latifolia and Lemna minor (TL/LMs) were able to improve the physicochemical proprieties of industrial wastewater, and were efficient enough to remove the heavy metals. [ABSTRACT FROM AUTHOR]

Constructed wetlands (CWs) are a kind of green environmental protection technology, which are widely used in sewage treatment. Traditional CWs are faced with the problem of a low treatment effect of high-concentration sewage. In recent years, biochar, as a new type of adsorption material, has been used in CWs because of its advantages of large specific surface area, strong adsorption capacity, and wide material sources. This paper systematically summarized the characteristics of biochar and the preparation of biochar by studying the changes in microorganisms added to CWs and compared the effects of different treatment methods coupled with biochar on the treatment performance of CWs. The effects of biochar coupled with CWs on enzyme activity, functional genes, metabolites, and microbial communities were investigated. This review summarizes how different preparation methods affect the properties of biochar and how these biochar properties cause changes in the microorganisms added to CWs. It provides a new theoretical basis for the treatment of pollutants in CWs. [ABSTRACT FROM AUTHOR]

Sediments in aquatic systems often act as a major sink for contaminants. Diffusive gradient in thin films (DGTs) and in situ equilibrium dialysis samplers (peepers) are two major in situ pore water sampling devices that overcome the problems associated with conventional pore water sampling methods. In the present study, DGTs and peepers were used to study the spatial and seasonal effects (cool months, October–February; warm months, May–September) on metal bioavailability in the H‐02 constructed wetland and the sink versus source role of the sediments by calculating the metal resupply capacity. Data showed similar seasonal trends in metal concentrations using passive samplers, peepers, and DGTs. Pooled Cu and Zn concentrations measured using DGTs were lower in warm months (1.67 ± 1.50 and 2.62 ± 0.68 μg L–1, respectively, p < 0.001) versus in cool months (2.12 ± 0.65 and 5.58 ± 1.33 μg L–1, respectively, p < 0.001; mean ± 95% confidence interval). Sulfate (SO42−) concentrations were significantly (p = 0.0139) lower in warm months (averaged at 0.22 ± 0.05 mg L–1) compared to in cool months (0.16 ± 0.05 mg L–1). The increase in SO42− concentration is an indicator of the lower activity of sulfate‐reducing bacteria, which need SO42− during anaerobic respiration, in which SO42− is reduced to sulfide (S2–) that forms insoluble salts with Cu and Zn, which could partially explain the higher bioavailability of these metals in the cool season. Metal resupply capacity of the sediments was mostly <0.2 for Cu and Zn. Taken together, the H0‐2 wetland sediments mostly acted as a sink to both Cu and Zn over the course of the present study. Environ Toxicol Chem 2023;42:2726–2736. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Naphthenic acids (NAs) are a complex mixture of organic compounds released during bitumen extraction from mined oil sands that are important contaminants of oil sands process-affected water (OSPW). NAs can be toxic to aquatic organisms and, therefore, are a main target compound for OSPW. The ability of microorganisms to degrade NAs can be exploited for bioremediation of OSPW using constructed wetland treatment systems (CWTS), which represent a possible low energy and low-cost option for scalable in situ NA removal. Recent advances in genomics and analytical chemistry have provided insights into a better understanding of the metabolic pathways and genes involved in NA degradation. Here, we discuss the ecology of microbial NA degradation with a focus on CWTS and summarize the current knowledge related to the metabolic pathways and genes used by microorganisms to degrade NAs. Evidence to date suggests that NAs are mostly degraded aerobically through ring cleavage via the beta-oxidation pathway, which can be combined with other steps such as aromatization, alpha-oxidation, omega-oxidation, or activation as coenzyme A (CoA) thioesters. Anaerobic NA degradation has also been reported via the production of benzoyl-CoA as an intermediate and/or through the involvement of methanogens or nitrate, sulfate, and iron reducers. Furthermore, we discuss how genomic, statistical, and modeling tools can assist in the development of improved bioremediation practices. [ABSTRACT FROM AUTHOR]

Wetlands, as temporary or permanent water reservoirs, provide various benefits for the ecosystem, such as water supply, waste water treatment, and dust control. By the end of 2023, the Iranian government and the Ramsar Convention have registered 25 international and 226 national wetlands. West Azerbaijan and Mazandaran provinces have more wetland ecosystems than any other provinces. Semnan, Yazd, and Zanjan provinces have no wetlands. According to the Ramsar Convention of 1971, Iran has 32 aquatic ecosystems that have the potential to become wetland. In addition, according to the available data and the WHO standard, eight wetlands have the highest probability of producing dust and should be given more attention and care. We recommend the wetland management plan, which ensures their water requirements, protects them from degradation and pollution, and promotes their ecological restoration. Satellite image analysis can help explore how climate change affects dust intensity, considering the role of wetlands in dust control. [ABSTRACT FROM AUTHOR]

This study reports a literature review of the state of the art, 2000-2020, on the substrates that are used as support media in constructed wetlands with subsurface flow. Its importance compared to the most used substrates worldwide and its economic feasibility as a substrate in CW. 13 different types of substrates have been identified in 155 different studies, but the most used substrates were gravel (32%) and sand (23%) for the development of bacterial associations. However, gravel and sand used in full-scale CW are expensive (10–35 $USD/m3), for wastewater treatment in small communities with economic difficulties. The tendency is to use substrates such as gravel (32%), sand (23%), sediments (13%), limestone or river rock (11%), granite (8%), zeolite (6%) and other alternative materials (7%). Among these we can mention: ceramics, pumice, steel, bricks, shells of different local aquatic fauna and some stone materials easily found in the study area. Therefore, the development of substrates of lower commercial value, reused material and material of easy operation is important, especially in developing countries where economic resources are one of the main constraints in the implementation of wastewater treatment systems. The use of treatment wetlands with economic materials detected in this study indicate that the future in wastewater treatment is this technology, because present multiple objectives, which include water treatment, fertilizer production, enhancement of biodiversity and cooling, vegetation production for handicraft, etc. CW are a technology with future role in circular economy that want to respond to sanitation worldwide. [ABSTRACT FROM AUTHOR]

Floating treatment wetlands (FTWs) are a cost-effective ecological engineering tool for the restoration of polluted water bodies. The aims of this work were to evaluate the removal of Cr(III) and Cr(VI) by FTWs using Typha domingensis, and to assess Cr accumulation and distribution in plant tissues and sediment. Treatments were 5 and 10 mg L−1 of Cr(III), and 5 and 10 mg L−1 of Cr(VI), with and without FTWs, and biological control (BC) with FTW without Cr addition. Both Cr species were efficiently removed from water in all treatments (Cr removal > 80%). Cr concentration in sediments of treatment without FTWs was significantly higher than in sediments of treatments with FTWs, indicating that T. domingensis was directly involved in Cr removal. In sediment, Cr was mainly bound to the organic matter in all treatments with a low risk of future release under FTW conditions. T. domingensis demonstrated tolerance to both Cr species at 5 and 10 mg L−1 with Cr accumulated mainly in the roots in all treatments. The use of FTWs planted with T. domingensis is a suitable tool to remediate water bodies contaminated with Cr. This study evaluates the removal efficiency of Cr(III) and Cr(V) in Floating Treatment Wetlands planted with Typha domingensis in greenhouse experiments. Cr accumulation and distribution in plant tissues and different sediment fractions were also assessed [ABSTRACT FROM AUTHOR]

Nutrients such as nitrogen and phosphorus are typically considered detrimental to wetland values, but waterfowl can be numerous on nutrient-rich wetlands. Waterfowl were counted three to six times per year on nine treatment lagoons and associated wetlands (2,025 ha) at the Western Treatment Plant (south-east Australia) from 2000, to help maintain ecological values of this Ramsar-listed wetland as well as treating sewage for a large city (Melbourne). Up to 185,000 waterfowl were counted, varying with season, continental rainfall and lagoon operation. Nutrient levels were reduced on Lake Borrie lagoon in 2005 (as part of an Environmental Improvement Program) and restored in 2015. Waterfowl declined on Lake Borrie lagoon from 2005 when it received treated effluent not raw sewage, and increased in 2015 when it received partially treated sewage. This pattern was highly significant for total waterfowl and most species and guilds at Lake Borrie but was not replicated on other lagoons. Modelling revealed positive relationships between waterfowl numbers and nutrient concentrations, including ammonia and nitrite, to moderate levels. This shows that with careful management nutrient enrichment can have positive benefits, allowing artificial wetlands such as wastewater treatment plants to support high densities of waterbirds and the food webs that sustain them. [ABSTRACT FROM AUTHOR]

Recently, lightweight expanded-clay aggregates (LECAs) have emerged as a promising material for various geoenvironmental applications. This study aimed to explore the potential of LECAs as an adsorbent in a laboratory-scale constructed wetland to mitigate the impact of antibiotics, specifically erythromycin (ery) and doxycycline (doxy). The physical characteristics of LECA were determined, including hydraulic conductivity of 1.12×10−3 m/s , a specific surface area of 2,890 m2/kg , and a pH value of 7.6. In the laboratory-scale batch study, Langmuir (KL=3.2565 L/mg) and Freundlich [ Kf=0.2376 (mg/g) (L/mg)] isotherm models provided the best fit for doxy and ery, respectively. Additionally, the pseudo-second-order kinetic model exhibited the best fit for both antibiotics. The adsorption of doxy was primarily attributed to π–π interactions and hydrogen bonding, explaining why it followed the Langmuir isotherm with most sorbents. On the other hand, ery exhibited electrostatic sorption and cation exchange as the dominant mechanisms, potentially demonstrating its multilayer sorption behavior. A shift from an acidic to an alkaline pH significantly enhanced the adsorption of both doxy (16% to 94%) and ery (45% to 89%). Similarly, raising the temperature from 5°C to 45°C increased the sorption capacity to 83% for doxy and 88% for ery. In the one-dimensional vertical-column study using LECA as the adsorbent, the exhaustion time for ery and doxy was determined to be 70 and 84 h, respectively. These results aligned well with the findings obtained from the HYDRUS model. Constructed wetlands employing LECA beds demonstrated remarkable removal efficiencies, with doxy removal from 93% to 96% and ery removal from 92% to 97%. A long-term study on LECA after pouring studied antibiotics solution in cycles revealed an appreciable drop in removal efficiencies at the end of an extensive period. Based on these observations, it can be concluded that LECA possesses a significant adsorption capacity against doxy and ery due to high in situ pH, specific surface area, and hydraulic conductivity. Under acidic conditions, ery exhibited higher sorption capacity in comparison to doxy because of the preponderance of H+ ions. However, in an alkaline state, the abundance of OH− ions hindered the release of H+ ions, resulting in minimal changes in the adsorption capacity of ery, unlike doxy, which displayed a steady increase. Furthermore, elevated temperatures enhanced the adsorption capacity by accelerating intraparticle diffusion. The use of LECA in constructed wetlands has emerged as a cost-effective, sustainable, and highly efficient strategy for mitigating the release of antibiotic-laden wastewater into the environment, particularly water bodies. Extensive research has already established LECA as an exceptional sorbent, and this study further reinforces its remarkable efficacy in adsorbing antibiotics from aqueous solutions. These findings position LECA as a leading candidate for implementation as bed material in scaled-up constructed wetland systems in actual field conditions. The long-term advantages of utilizing LECA are manifold. First, it offers easy production, ensuring a readily available supply. Additionally, LECA exhibits a long life span, durability, and the ability to withstand changes in pH and temperature without degradation or decomposition. These characteristics make it a reliable and robust material for sustained use in constructed wetlands. Moreover, the simplicity of the approach, requiring minimal expertise for setup and maintenance, makes LECA an attractive option for government organizations, pharmaceutical industries, and rural communities alike. The broad applicability of LECA extends beyond antibiotic removal, because it effectively eliminates contaminants from wastewater, thereby safeguarding surface and groundwater bodies from pollution. Thus, LECA is an ideal solution for removing antibiotics and other pollutants from wastewater in constructed wetland systems. Its low-cost production, longevity, resilience, and user-friendly nature make it an appropriate choice for large-scale implementation. By adopting LECA, the impact of antibiotic contamination on the environment can be significantly reduced and can help preserve the integrity of precious water resources. [ABSTRACT FROM AUTHOR]

This paper reviews the current research and status of CWs for terminal effluent of WWTPs, mainly focusing on substrate selection, microbial enhancement, plant cultivation, structure optimization, electrochemical coupling, and the core still remains to strengthen the nitrogen removal efficiency of CWs・ In the future, it is necessary to build a "basic databasebased on substrate and aquatic plant options, engineering operation mon让oring, etc・ 'further reveal the biological deri让rification mechanism of terminal effluent of WWTPs, and promote the suitability and economic performance of the engineering ・ [ABSTRACT FROM AUTHOR]

This study investigated a feasible model for treating actual shrimp farm wastewater at a pilot scale that could be applied to farms in the Mekong Delta area. The research was carried out using a hybrid constructed wetlands (HCWs) model, which included a floating constructed wetland (FCW, total area of 1,500 m2) and a horizontal sub-surface constructed wetland (HSCW, total area of 400 m2). The HCWs were cultivated with native plants including: Scirpus littoralis Schrab, Cyperus alternifolius, and Paspalum vaginatum. These plants are all adapted to the high salinity levels of shrimp farm wastewater. The system was operated for 30 days to treat shrimp farm effluent. Results indicated that the model effectively removed organic matter and nitrogen compounds from the wastewater. The treated wastewater had low concentrations of COD (10.0-15.4 mg/L), BOD5 (7.1-12.5 mg/L), NH4 + -N (0.04-1.11 mg/L), and TN (0.17-1.83 mg/L), which met the reliable conditions for reuse or safety requirements for discharge to aquatic systems. The findings of this study have significant implications for the sustainable management of shrimp farm wastewater in the Mekong Delta area. The HCWs model is a feasible and effective way to treat this type of wastewater, and it could be adapted to other regions facing similar challenges. [ABSTRACT FROM AUTHOR]

The vertical flow constructed wetlands (VFCW) for the treatment of domestic wastewater has become a conventional and cost effective treatment system with one of the major disadvantage of elevated nitrate concentrations. The present study makes an effort in providing a new design of anaerobic denitrification unit termed as anaerobic chamber (AC) which was introduced after two-stage VFCW to remove nitrates from the treated wastewater (WW). The AC provided all the essential conditions of effective denitrification such as anaerobic environment with enough carbon and nitrogen source. To understand the pollutant removal mechanism in AC, microbial diversity and functional annotation was studied by metagenomic analysis of sequences obtained from biofilm formed in AC. The efficiency of AC was measured with respect to physicochemical wastewater quality parameters. The removal efficiencies were 88, 65, 43 and 27% for total nitrogen, nitrate (NO3), ammoniacal-nitrogen (NH4) and ortho-phosphate respectively. The microbial flora was much more diverse and unique pertaining to anaerobic microbes in AC compared to WW with total of 954 and 1191 genuses respectively with minimum abundance of 10 hits. The metagenomes exhibited 188% more Archaea in the AC than WW where Crenarchaeota, Euryarchaeota, Korarchaeota, Nanoarchaeota and Thaumarchaeota were major phyla with 60 genuses. The nitrogen metabolism was reported in terms of assimilatory nitrate reductase. As the class, Proteobacteria, Actinobacteria were prominent in WW, whereas Proteobacteria, Chloroflexi in AC were abundant. From functional annotation of sequences, the microbial flora in AC has the potential of removal of pollutants present in the form of carbon, nitrogen, and phosphorus. [ABSTRACT FROM AUTHOR]