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Heavy metal pollution such as cadmium and arsenic in water seriously threatens human health and safety, and the removal of Cd/As combined pollution is more difficult. In this work, the performance of mechanically activated calcite composite FeSO4 to remove Cd/As combined pollution was investigated by Cd/As combined pollution removal test in water. It was found that mechanically activated calcite can significantly improve the removal efficiency of Cd/As combined pollution in water. The results showed that the removal rate of Cd and As can reach 99% in 30 min by activated calcite composite FeSO4. The removal mechanism of Cd/As combined pollution in water by activated calcite and FeSO4 was studied by SEM-EDS, XPS, and XRD. The results showed that the crystallinity and dissolution activity of calcite were changed by mechanical activation, and the hydrolysis of calcite to produce CO32- and OH- was enhanced. OH- promoted the formation of a stable iron oxide bound precipitate of FeSO4 with arsenic, and CO32- binded with cadmium to form a stable precipitate of cadmium carbonate.

The ecological restoration of submerged plants is one of the most widely used technologies in the remediation of eutrophic water bodies. This technology mainly removes nitrogen, phosphorus, and other nutrients in water through the absorption effects of plant roots, stems, and leaves and the biotransformation of microorganisms attached to their surfaces. Root exudates can directly affect root-attached microorganisms and other aquatic organisms, thus significantly influencing water remediation by submerged plants. At present, there are few reviews on the root exudates of submerged plants and their effects on aquatic organisms. In this study, the composition, collection, and methods of detecting the root exudates of submerged plants are reviewed. Factors affecting the release of root exudates from submerged plants are analyzed, including abiotic (light, temperature, and nutritional status) and biotic factors (rhizosphere microorganisms). The positive or negative effects of root exudates on phytoplankton, zooplankton, and microorganisms are also discussed. The results show that plant species, growth stages, and environmental factors (light, temperature, and nutritional status) are crucial factors affecting root exudates. In addition, submerged plants can significantly influence phytoplankton, zooplankton, and microorganisms by releasing allelochemicals or other root exudates. Based on the results of this study, the influencing mechanisms of root exudates on ecological restoration processes by submerged plants are clarified. This review provides important guiding significance for applying submerged macrophytes in water restoration. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Hydrobiology / Shuisheng Shengwu Xuebao is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Submerged plants are often used in the ecological restoration of polluted water, and they have good water purifying effect. In the process of water restoration, submerged plants are faced with insufficient light due to high turbidity or water depth. Therefore, we proposed a new model of artificial light assisted submerged plants to purify water nutrients. In this paper, we investigated the effects of locations and light intensities on the growth of V.spinulosa Yan and its water purification effect. The results showed that the light location of the underwater supplemental light was more important than the light intensity. The top supplemental light may provide an excellent environment for algae on the water surface. Excessive algae or epiphytic microorganisms might prevent the V.spinulosa Yan from obtaining light. When the PAR= 109 μmol m−2 s−1, V.spinulosa Yan had a higher biomass (145.39 dw/m2) than before (65.2 dw/m2). When the PAR > 280 μmol m−2 s−1, the clonal reproduction of V.spinulosa Yan was reduced. The main effect of supplemental underwater light on the water restoration process was enhancing the photosynthesis of V.spinulosa Yan by changing ETR max and Fv/Fm of V.spinulosa Yan leaves. It significantly increased V.spinulosa Yan biomass and improved dissolved oxygen. Improvement of the water environment possibly altered the microbial environment and promoted the removal of water nutrients. [Display omitted] [ABSTRACT FROM AUTHOR]

Mine ecological restoration has experienced a long-term development process in China, in which various technologies have been constantly developing and integrating. Based on the related theoretical research and field program, the technical system of mine ecological restoration was constructed, and the characteristics of key technologies were specifically grasped. In this research, the environment, including natural elements and the spatial environment, is the object of mine ecological restoration, which requires further long-term investigation and monitoring. Therefore, natural element restoration technology, space environment restoration technology, and environmental survey and restoration monitoring technology should be considered when establishing technical systems. The research showed that： ① In mine natural element restoration, where soil and water are important, traditional technologies like pollution abatement with physical, chemical, and biological methods have been extensively used. Meanwhile, artificial soil reconstruction and multi-technology joint remediation became the main study focus in soil restoration and artificial wetlands have been gradually constructed as a new method in water restoration, covering water system restoration and pollution control. ② The two tasks of space environment restoration were geological disaster prevention and vegetation re-greening. Major technologies of the former were applied to surface mine slope treatment and mining subsidence area control, the latter of which could be divided into three technical links： vegetation selection, construction, and maintenance. Although many technologies are valid, a few frontiers need to be further pursued. ③ The mine environmental investigation and restoration monitoring were based on 3S technologies, containing GIS, GPS, and RS, all of which are developing rapidly but still have a large space for integration and innovation.

[Display omitted] • Copper content influences the structural, optical, morphological, and photocatalytic properties of doped gallium oxides. • Cu-doped gallium oxides show photocatalytic activity in the visible region of the spectrum. • Acetaminophen degradation percentages between 80 - 90 % and mineralization up to 80 % is reached. • The highest degradation and mineralization were obtained with Cu concentrations of 5 and 7 %. This work addresses the effect of copper content on the synthesis and application of copper-doped gallium liquid metal-based photocatalysts. Ga 2 O 3 -copper ion doped were synthesized at 0, 5, 7, and 10% wt by the ultrasonic transducer. Characterization was done by TGA, XRD, XPS, SEM/EDS, ATR-FTIR, and UV–vis-NIR diffused reflectance. Additionally, we study the photocatalytic activity in degrading and mineralizing acetaminophen under visible light. Results show that the copper content influences the structural, optical, morphological, and photocatalytic properties. [ABSTRACT FROM AUTHOR]

Endocrine disruptors (EDCs) are widely detected in water resources owing to the abuse of plastic products, posing a serious global concern. Unfortunately, the rapid, effective, and economical removal of trace EDCs from water remains a significant challenge. Herein, a novel adsorptive membrane (PVPM) with excellent recyclability and stability is prepared by the UV‐initiated grafting of poly(N‐vinylpyrrolidone) (PNVP) onto the surface of polypropylene fibrous membrane (PPM). The PVPM exhibits high flux, low‐pressure drop, and excellent adsorption performance. It can efficiently capture trace (10 µg L−1) EDCs with a removal efficiency of 99%. Notably, the adsorption performance of the PVPM remains unchanged even in river water. A mechanism for the adsorption is proposed based on adsorption kinetics and thermodynamics. Specifically, dynamic hydrophobic microdomains are generated between amphiphilic PNVP and EDCs and form co‐aggregates on the PPM substrate. This co‐aggregation is responsible for the large adsorption capacity for EDCs. A large decrease in the free energy (−16.65 kJ mol−1) of the adsorption process provides additional evidence for the strong adsorption affinity of the PVPM to EDCs. This study introduces a new pathway for designing low‐cost and high‐performance membrane adsorbents for prompt and efficient capture of trace EDCs from water. [ABSTRACT FROM AUTHOR]

Aquaculture is an important source of animal protein and a key contributor to global food security. However, aquaculture can exert a negative effect on the aquatic environment due to the release of effluents containing high nutrient levels. In integrated multi-trophic aquaculture (IMTA), the waste produced by one species is the input for another, referred to as extractive species (ES). Potential ES include plants. In the present study, it was explored whether Lemna minor can be used to remove nitrogen and phosphorus from aquaculture wastewater. A representative synthetic wastewater was designed based on the composition of aquaculture effluents found in the literature. Synthetic wastewater was found to be a suitable medium for growth of Lemna minor, and plants readily took up NH4+-N, NO3-N and PO43--P. In particular, NH4+-N concentrations rapidly decreased. The highest removal rates per square meter of water surface, calculated for NH4+-N, NO3-N and PO43--P, were, respectively, 158, 206 and 32 mg·m-2·day-1, and these rates were achieved at a plant surface density of 80%. As removal of nutrients is essentially a surface area–related process, the effect of plant density on nutrient uptake was determined. Uptake of nutrients per square meter of surface area was highest at the highest plant density. Yet, when uptake rates were calculated per square meter of water area covered by Lemna fronds, the highest removal rates were found at the lowest plant density, and this is likely to be associated with a reduced intraspecific competition. The present work enables the calculation of potential nutrient uptake by Lemna minor and lays the foundation for a more scientific approach to the design of duckweed-based aquaculture wastewater treatment systems. [ABSTRACT FROM AUTHOR]

Water reservoir restoration process is of a holistic nature and requires the application of many reclamation and remediation methods. The final result should be the restoration of the state of the primary aquatic environment that occurred before the adverse anthropogenic changes. The condition of many water reservoirs in the world requires taking redegradation method to restore the water quality. Water rehabilitation activities conducted by specialized companies or expert teams are colloquially called “water restoration”. The author presented the problem of incorrect naming of water restoration processes in the aspect of “water restoration” process. He pointed to selected examples of scientific and industry articles, of incorrect use of the word "reclamation" and suggested the proper naming in relation to the nature of the corrective actions taken. Commercialization of the f “water restoration” word is undoubtedly the cause of its abuse and misuse in many activities, which in the end do not meet the objectives of lake restoration.

Crop abandonment is a factor responsible for soil degradation in semi-arid regions. The effects of crop abandonment on soil restoration may depend on soil properties and climatic conditions of an area. In particular, soil hydraulic properties affect the vegetation recovery process. The objective of this study was to investigate the succession changes in water flow as a result of changes in soil hydraulic properties after crop abandonment under drought and non-drought conditions, and under water uptake by co-occurring perennial plants to clarify the observation that typical perennial grass species are seldom observed in abandoned fields. Soil hydraulic properties were measured in croplands which had been abandoned for different periods (2, 9, and 18 years ago) and in a grazed grassland site (control site). Hydrological processes in the soil profiles were simulated with soil hydraulic properties under drought and non-drought summer conditions with water uptake from perennial grass species. Suctioning the surface soils increased with the period of abandonment, with this trend being particularly obvious in a drought year. Soil water appears to be restricted in the later succession stage of abandoned fields and in grazed grassland for drought-tolerant plants. Dry soil and climate conditions are important factors determining the intrusion of the typical perennial grass, Stipa krylovii, into degraded abandoned fields. A water availability with low pressure (plant can use with low pressure) made difficult the intrusion of typical perennial grasses to abandoned cropland. This abiotic relation between soil hydraulic properties and climate conditions may play an important role for plant succession in abandoned cropland. [ABSTRACT FROM AUTHOR]

A phytoremediation project involving the large-scale cultivation of water hyacinths (Eichhornia crassipes (Mart.) Solms) was conducted in Lake Caohai (China) from May to November during 2011–2013 to remove pollutants and decrease eutrophication. Water hyacinths were cultivated in two areas of Lake Caohai, Neicaohai, and Waicaohai, which are connected and function as a relatively independent water body. The areas for macrophyte growth varied in size from 4.30 km2 in 2011 to 0.85 km2 (2012) and 1.15 km2 (2013). Compared with historical data from 2007, the concentrations of total phosphorus decreased significantly, while dissolved oxygen concentrations increased slightly. After plant cultivation in 2011, the average concentrations of total phosphorus, total dissolved phosphorus, and phosphate anions decreased from 0.54, 0.35, and 0.23 mg L−1 upstream (river estuaries) to 0.15, 0.13, and 0.08 mg L−1 downstream (Xiyuan Channel), respectively. The amount of phosphorus assimilated by the macrophytes (44.31 t) was more than 100% of the total removed phosphorus (40.93 t) from lake water when water hyacinths covered 40.9% of the area, which could indicate sedimentary phosphorus release. Our study showed the great potential of utilizing water hyacinth phytoremediation to remove phosphorus in eutrophic waters. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Polonorum. Formatio Circumiectus is the property of Wydawnictwo Uniwersytetu Rolniczego im. Hugona Kollataja w Krakowie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Globally, fluvial heavy metal (HM) pollution has recently become an increasingly severe problem. However, few studies have investigated the variational characteristics of fluvial HMs after rain over long periods (≥1 year). The Dakan River in Xili Reservoir watershed (China) was selected as a case study to investigate pollution levels, influencing factors, and sources of HMs under different rainfall conditions during 2015 and 2016. Fluvial HMs showed evident spatiotemporal variations attributable to the coupled effects of pollution generation and rainfall diffusion. Fluvial HM concentrations were significantly associated with rainfall characteristics (e.g., rainfall intensity, rainfall amount, and antecedent dry period) and river flow, which influenced the generation and the transmission of fluvial HMs in various ways. Moreover, this interrelationship depended considerably on the HM type and particle size distribution. Mn, Pb, Cr, and Ni were major contributors to high values of the comprehensive pollution index; therefore, they should be afforded special attention. Additionally, quantitative source apportionment of fluvial HMs was conducted by combining principal component analysis with multiple linear regression and chemical mass balance models to obtain comprehensive source profiles. Finally, an environment-friendly control strategy coupling “source elimination” and “transport barriers” was proposed for aquatic environment protection. [ABSTRACT FROM AUTHOR]

In recent years, the Chinese government has strengthened its efforts in surface water protection and restoration through strict policies and heavy investments. A clear understanding of the impacts of land use on water quality is necessary in order to ensure an effective and efficient implementation of the ongoing surface water restoration program in China. To this end, four small watersheds (less than 5000 ha) in southeastern China, which have clear gradients in the intensities of agriculture (17.0–45.4%), forest (35.2–73.6%) and built-up area (3.3–8.5%), were investigated regarding the impacts of land use on water quality. In addition to the general water quality indices, characteristic components derived by fluorescence excitation-emission matrices (FEEMs) coupled with parallel factor analysis (PARAFAC) were employed to explore a more accurate association between land use and water quality. The results show that agricultural intensity has significant effects by elevating the concentrations of dissolved organic carbon (DOC, an approximate six-fold increase) and total phosphorous (TP, an approximate four-fold increase) in the surface waters. A total of five PARAFAC components representing terrestrial (three components) and protein-like (two components) substances were identified. The PARAFAC results indicate that land-use patterns affected the dissolved organic matter (DOM) in the aspects of both amount and composition. The intensity (R.U.) of the terrestrial components showed a strong correlation (r 2  = 0.95, p  = 0.01) with agricultural land percentage. Moreover, although the proportion of built-up area varies with a relatively small range, a protein-like component could predict its impact with excellent sensitivity (r 2  = 0.94, p  = 0.02), whereas the general water quality indices were incapable of predicting the impact due to their multiple sources. The results of this study demonstrate that the FEEMs-PARAFAC technique provides an inexpensive and effective tool for policy makers to overcome the insensitivity of general water quality indices, particularly for the restoration of watersheds with complex land-use patterns. [ABSTRACT FROM AUTHOR]

The Billion Oyster Project is a New York City-wide effort to reintroduce eastern oysters back into the New York Harbor and help improve water quality by reducing heavy metal concentrations in the environment. In particular, the bioaccumulation of mercury in oyster tissue was investigated in the New York Harbor oysters acquired from two sites. Mercury levels exceed the standard Environmental Protection Agency-recommended levels as the New York Harbor oysters exhibit mercury levels ranging from 0.36 ± 0.05 to 0.55 ± 0.08 μg Hg g dry weight. In an ideal scenario, one billion of these oysters are roughly projected to capture a maximum of 110 g of mercury from the New York Harbor by 2030, assuming an average uptake of 0.55 μg Hg g dry weight for every oyster added to the reef. In addition to the bioaccumulation of mercury within the oyster tissue, stunted physical growth of the oysters and abnormal discoloration of the tissue indicate the presence of other heavy metals. This study demonstrates the promising role that eastern oysters play in removing heavy metals, such as mercury, from their water environment and preview significant and measurable impacts on the ecosystem. Graphical Abstract: [ABSTRACT FROM AUTHOR]

The T-type submerged dam based on zeolite and ecological floating bed was set up in Zhujiabang River, a tributary of the Zhihugang River (north of the Taihu Lake), together with ecological restoration measures such as aeration and slope wetland. From the perspective of phytoplankton community, the restorative effect of ecological restoration project on rural contaminated rivers was investigated. The results showed that (i) ecological restoration changed the community structure and succession tendency of phytoplankton, the dominant state of Cyanophyta and Cryptophyta was replaced by some species of Bacillariophyta, Chlorophyta and Pyrrophyta; (a) ecological engineering restrained the standing stock of phytoplankton community greatly, total biomass of phytoplankton during the restoration period was less than 6 mg/L; (iii) biodiversity of phytoplankton during the ecological restoration maintained at a higher level (mean Shannon-Weiner index was 2.32). Considering the correlation between efficiency of ecological restoration project in purifying water, standing stock of phytoplankton and nutrient level of water, removal of nutrients by ecological restoration project was one of the major factors triggering the change of phytoplankton community characteristics. [ABSTRACT FROM AUTHOR]

To achieve the goals of harmful cyanobacterial bloom control and nutrient removal, an eco-engineering project with water hyacinth planted in large-scale enclosures was conducted based on meteorological and hydrographical conditions in Lake Dianchi. Water quality, cyanobacteria distribution, and nutrient (TN, TP) bioaccumulation were investigated. Elevated concentrations of N and P and low Secchi depth (SD) were relevant to large amount of cyanobacteria trapped in regions with water hyacinth, where biomass of the dominant cyanobacteria Microcystis (4.95 × 10 cells L) was more than 30-fold compared with values of the control. A dramatic increase of TN and TP contents in the plants was found throughout the sampling period. Results from the present study confirmed the great potential to use water hyacinth for cyanobacterial bloom control and nutrient removal in algal lakes such as Lake Dianchi. [ABSTRACT FROM AUTHOR]

ZIF-8 exhibits poor visible light response and rapid electron-hole recombination. To address these problems, we constructed an N-CQD/ZIF-8 framework by in-situ synthesis method, then prepared a novel Z-scheme heterostructure photocatalyst (Cu 2 O/N-CQD/ZIF-8) by reduction precipitation method for the efficient photocatalytic reduction of Cr(Ⅵ). Cu 2 O/N-CQD/ZIF-8 (with a 10% Cu 2 O loading) had a unique heterostructure and exhibited significantly improved performance for Cr(Ⅵ) photoreduction. This photocatalyst successfully reduced 98.99% of the Cr(Ⅵ) in a pH = 3 solution system, which was 6 times higher than that of ZIF-8. Meantime, due to its stable interfacial adhesion, the reduction efficiency of Cr(Ⅵ) by Cu 2 O/N-CQD/ZIF-8 still reached 97.13% after five cycles. Therefore, Cu 2 O/N-CQD/ZIF-8 exhibited superior photocatalytic activity and recyclability compared with unmodified ZIF-8. The charge transfer path of this Z-scheme heterojunction was verified by free radical trapping experiments and X-ray photoelectron spectroscopy. Moreover, a possible charge transfer mechanism was proposed. N-CQD provided a potential driving force for the construction of the internal Z-scheme charge transfer system. Moreover, the synergistic effect between Cu 2 O and ZIF-8 inhibited the rapid recombination of photogenerated electron-hole pairs. This work provides potential insights for the innovative design of high-performance photocatalysts based on metal-organic frameworks for the restoration of Cr(Ⅵ)-containing wastewater. [Display omitted] • Cu 2 O/N-CQD/ZIF-8 catalyst was proposed for photocatalytic reduction of Cr(VI). • The prepared composite photocatalyst has Z-scheme heterojunction. • The instability of photocatalytic performance of ZIF-8 was solved. • The photocatalytic reduction efficiency of Cr(VI) was up to 99 %. • After five cycles, the reduction rate of Cr(VI) can still reach 97.13 %. [ABSTRACT FROM AUTHOR]

Environmental impacts of small scale projects are often assessed poorly, or not assessed at all. This paper examines the usability of the Rapid Impact Assessment Matrix (RIAM) as a tool to prioritize project proposals for small scale water restoration projects in relation to proposals' potential to improve the environment. The RIAM scoring system was used to assess and rank the proposals based on their environmental impacts, the costs of the projects to repair the harmful impacts, and the size of human population living around the sites. A four-member assessment group (The expert panel) gave the RIAM-scores to the proposals. The assumed impacts of the studied projects at the Eastern Finland water systems were divided into the ecological and social impacts. The more detailed assessment categories of the ecological impacts in this study were impacts on landscape, natural state, and limnology. The social impact categories were impacts to recreational use of the area, fishing, industry, population, and economy. These impacts were scored according to their geographical and social significance, their magnitude of change, their character, permanence, reversibility, and cumulativeness. The RIAM method proved to be an appropriate and recommendable method for the small-scale assessment and prioritizing of project proposals. If the assessments are well documented, the RIAM can be a method for easy assessing and comparison of the various kinds of projects. In the studied project proposals there were no big surprises in the results: the best ranks were received by the projects, which were assumed to return watersheds toward their original state. [ABSTRACT FROM AUTHOR]

Abstract: The biosorption capacity of different cortex fruit wastes including banana (Musa paradisiaca), lemon (Citrus limonum) and orange (Citrus sinensis) peel were evaluated. In order to perform these experiments, grinded dried cortexes were used as package in 100mm high, 10mm i.d. columns. The grinded material was powdered in a mortar and passed through a screen in order to get two different particle sizes, 2 and 1mm, for all powders. To estimate the biosorption capabilities of the tested materials, different heavy metals were passed through the columns and the elution filtrate reloaded different times to increase the retention of metals. The heavy metals used were prepared as synthetic samples at 10mg/L of Pb(NO3)2, Cd(NO3)2, and Cu(NO3)2·6H2O using primary standards. In preliminary experiments using banana cortex, it was found that material with 1mm of particle size showed higher retention capability (up to12%) than the material with 2mm of particle size. Considering these results, 1mm particle size material was used in further experiments with the other waste materials. It was found that for Pb and Cu removal, lemon and orange cortex showed better biosorption capability when compared with banana cortex (up to 15% less for Pb and 48% less for Cu). For Cd, banana cortex showed better biosorption capability 57% (67.2mg/g of cortex) more than orange (28.8mg/g of cortex), and 82% more than lemon (12mg/g of cortex). Reload of the columns with the filtrate after passing through the column improved the removal capability of all the materials tested from 10% to 50% depending on the cortex and metal tested. [Copyright &y& Elsevier]

Changes in tissue structure, rheological property and water content of dry abalone meat in the process of water restoration were studied. The weight and volume of dry abalone meat increased with water restoration. When observed under a light microscope, structural change in myofibrils was obvious and a distinct network was found. When water restoration time increased from 24 h to 72 h, the instantaneous modulus E 0 and viscosity η 1 increased, whereas the rupture strength and relaxation time ( τ 1) were reduced. There were no significant changes of rheological parameters ( E 0, η 1, τ 1, rupture strength) from 72 h to 96 h of water restoration. Therefore, the dry abalone meat was swollen enough at the time of 72 h. The rheological parameters were obviously influenced by the structural changes. [ABSTRACT FROM AUTHOR]

We examined the capacity for physiological recovery from the effects of desiccation in five replicate populations of Drosophila melanogaster that have been selected for enhanced desiccation resistance (D populations) and in five replicate control populations (C populations). The capacity to recover was signified by the ability to restore three somatic components, namely whole-body water, dry mass and sodium content, all of which are reduced during desiccation. Throughout a period of recovery following a bout of desiccation, the flies were offered one of three fluids: distilled water, saline solution, or saline+sucrose solution. Our findings indicate that, when allowed to recover on saline+sucrose solution, D populations have the capacity to restore water at a greater rate than C populations and are able to fully restore dry mass and sodium content to the levels observed in non-desiccated, hydrated D flies. When provided with this same solution during recovery, C flies are unable to restore dry mass and are faced with an elevated sodium load. Desiccation resistance of the flies subsequent to recovery was also examined. We provide evidence that the greatest desiccation resistance in the D populations is associated with the restoration of all three somatic components, suggesting that not only water content, but also dry mass and sodium, may contribute to the enhanced desiccation resistance that has evolved in these populations. [ABSTRACT FROM AUTHOR]

Ammonium is a paradoxical chemical because it is a nutrient but also damages ecosystems at high concentration. As the most eco-friendly method of water restoration, phytoremediation technology still faces great challenges. To provide more theoretical support, we exploited six common submerged macrophytes and selected the most ammonium-tolerant and -sensitive species; then further explored and compared the mechanisms underlying ammonium detoxification. Our results showed the activity of glutamate dehydrogenase (GDH) in the ammonium-tolerant species Myriophyllum spicatum leaves performed a dose-response curve (increased 169% for NADH-dependent GDH and 103% for NADPH-dependent GDH) with the [NH 4 +-N] increasing from 0 to 100 mg/L while glutamine synthetase (GS) activity slightly changed. But for the ammonium-sensitive species, Potamogeton lucens , the activity of GDH recorded no major changes, while the GS increased slightly (17%). Based on this, we conclude that the alternative pathway of GDH is more important than the pathway catalyzed by GS in determining the tolerance of submerged macrophytes to high ammonium concentration (up to 100 mg N/L). Our present study identifies submerged macrophytes that are tolerant of high concentrations of ammonium and provides mechanistic support for practical water restoration by aquatic plants. Unlabelled Image • Ammonium-tolerant and -sensitive submerged macrophytes were identified. • The mechanisms for ammonium detoxification in macrophytes are clarified. • Glutamate dehydrogenase enhances the ability of plants to ammonium assimilation. • Theoretical supports and ideal species for water restoration are provided. [ABSTRACT FROM AUTHOR]

Constructed wetlands can play an active role in improving the water quality of urban rivers. In this study, a sequential series system of the floating-bed constructed wetland (FBCW), horizontal subsurface flow constructed wetland (HSFCW), and surface flow constructed wetland (SFCW) were constructed for the urban river treatment in the cold regions of North China, which gave full play to the combined advantages. In the Yitong River, the designed capacity and the hydraulic loading of the system was 100 m3/d and 0.10 m3/m2d, respectively. The hydraulic retention time was approximately 72 h. The monitoring results, from April to October in 2016, showed the multiple wetland ecosystem could effectively remove chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), total nitrogen (TN), total phosphate (TP), and suspended solids (SS) at average removal rates of 74.79%, 80.90%, 71.12%, 78.44%, and 91.90%, respectively. The removal rate of SS in floating-bed wetland was the largest among all the indicators (80.24%), which could prevent the block of sub-surface flow wetland effectively. The sub-surface flow wetland could remove the NH4-N, TN, and TP effectively, and the contribution rates were 79.20%, 64.64%, and 81.71%, respectively. The surface flow wetland could further purify the TN and the removal rate of TN could reach 23%. The total investment of this ecological engineering was $12,000. The construction cost and the operation cost were $120 and $0.02 per ton of polluted water, which was about 1/3 to 1/5 and 1/6 to 1/3 of the conventional sewage treatment, respectively. The results of this study provide a technical demonstration of the restoration of polluted water in urban rivers in northern China. [ABSTRACT FROM AUTHOR]