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Urban stormwater runoff contributes to the deterioration of water quality of urban waterbodies. Development of a cost-effective treatment system that renders the treated effluent suitable for the recharge of receiving waterbodies meeting stringent regulations is required. This study evaluated the performances of the inclined-plate settler (IPS) and activated carbon sponge-cube media filter (ASMF) in treating urban stormwater runoff from an industrial complex area. The stormwater runoff during the first hour of rainfall had significantly high concentrations of suspended solids (SS), chemical oxygen demand (COD), and total nitrogen. The IPS and ASMF bed with hydraulic retention times of 15 ± 5 and < 3 min showed the removal efficiency of 5.4 – 33.2% and 32.8 – 95.1% for SS, turbidity, COD, and TP including < 5 – 20% for TN. The combined IPS/ASMF or biofilm (BF)-ASMF system at filtration velocity of 10 m/h showed removal efficiencies of 46.7 – 99.2% for insoluble fractions such as turbidity, COD, TP and heavy metals including < 40% for TN. The ASMF or BF-ASMF bed coupled with IPS is a cost-effective option for the treatment of urban stormwater runoff, achieving an effluent quality suitable for industrial or multipurpose reuse and for the recharge of waterbodies. [ABSTRACT FROM AUTHOR]

Manganese (Mn) control in surface water systems is a challenge for the drinking water industry, especially through a sustainability framework. Current methods for removing manganese from surface water use strong oxidants that embed carbon and can be expensive and harmful to human health and the environment. In this study, we used a simple biofilter design to remove manganese from lake water, without conventional surface water pre-treatments. Biofilters with aerated influent removed manganese to concentrations below 10 µg/L when receiving influent water containing > 120 µg/L of dissolved manganese. Manganese removal was not inhibited by high iron loadings or poor ammonia removal, suggesting that removal mechanisms may differ from groundwater biofilters. Experimental biofilters also achieved lower effluent manganese concentrations than the full-scale conventional treatment process, while receiving higher manganese concentrations. This biological approach could help achieve sustainable development goals. [ABSTRACT FROM AUTHOR]

This study examined microbiological processes during the bio-drying of municipal wastewater sludge (WS) from the waste treatment facilities of the Moscow region (Russia). In just 21 days of bio-drying, the moisture content of the mixture of WS and wood chips decreased by 19.7%. It was found that members of the genus Bacillus were the main organic matter destructors. In the period from 7 to 14 days, the rates of organic matter mineralization and moisture loss were the highest, and bacteria of the genus Bacillus dominated, accounting for 43.5 to 84.6% of the bacterial community with a total number of 1.20 (±0.09) × 106 to 6.70 (±0.44) × 105 gene copies µg−1. The maximum number of Amaricoccus was (15.7% of the total bacterial community) in the middle of bio-drying. There was an active accumulation of nitrate nitrogen due to the oxidation of nitrogen-containing substances during the same period of time. Bacteria of the genera Sphingobacterium, Brevundimonas, Brucella, Achromobacter and fungi of the genus Fusarium dominated in the biofilter, which removed volatile compounds from the waste air by 90%. The obtained results allow to model the further intensification of bio-drying, as well as its efficiency and safety. [ABSTRACT FROM AUTHOR]

Nitrifying biofilters oxidize harmful ammonia excreted by fish into less toxic nitrate within recirculating aquaculture systems (RAS). Biofilter performance and resulting RAS water quality largely depend on a robust microbiome that effectively converts nitrogenous wastes; however, occasional use of water disinfectants may also be necessary to reduce or eliminate specific fish pathogens. Disinfectants and sanitizers such as peracetic acid (PAA) work by disrupting microbial activity and could unintentionally alter the microbially-driven nitrification biofiltration process if allowed to circulate within an RAS. Furthermore, the target concentration and application method of PAA may influence the level of biofilter disruption. For this study, 12 replicated experimental-scale fluidized sand biofilters were dosed with PAA to achieve target concentrations ranging from 1.0-–2.5 mg/L, a typical low-dose treatment range to reduce or eliminate opportunistic pathogens. Two application methods were compared, including (i) a single pulse of PAA added every other day for five days, and (ii) smaller doses of PAA added every five minutes over four hours. The PAA decay was monitored and predosing and postdosing water quality parameters were assessed. Regardless of the target concentration or application method, PAA addition within the tested range did not cause significant disruption to the biofilters' nitrification processes. This research demonstrates that PAA may be a viable water sanitizer for the RAS industry, although further research to refine safe application protocols is necessary. [ABSTRACT FROM AUTHOR]

Landfill gas emissions cause serious environmental concerns due to the presence of methane (CH 4), an important greenhouse gas (GHG) and several harmful volatile organic compounds (VOCs) such as xylene (X) and ethylbenzene (EB). A series of 9 up-flow biofilters (3 sections of 0.3 m each) packed with inorganic materials were used to eliminate CH 4 as a single pollutant, a binary mixture of X and EB and a ternary mixture of CH 4 , X and EB. The CH 4 concentration range was 2000–10000 ppmv while the VOCs (X and EB) individual concentrations were 200, 400 and 600 ppmv for empty bed residence times (EBRTs) ranging from 2.25 to 9 min over a period of 242 days. The highest CH 4 removal efficiency (RE) in the ternary mixture was 41 ± 3% at a CH 4 concentration of 2000 ppmv and X and EB individual concentrations of 200 ppmv for an EBRT of 9 min. Meanwhile, the highest X and EB-REs of 58 ± 3 and 57 ± 3% were obtained respectively, at the same concentrations of the components but at a shorter EBRT of 4.5 min. Almost 40% of CH 4 biodegradation took place on the top section of the bioreactor while 50–60% of the VOCs biodegradation occurred in the middle section. [ABSTRACT FROM AUTHOR]

This study aimed to compare the performance of biofiltration, constructed wetland, and constructed wetland microbial fuel cell (CW-MFC). The transformation from a biofiltration unit to a hybrid CW-MFC was demonstrated with the advantages of improvement of wastewater treatment while generating electricity simultaneously. The introduction of plants to the upper region of the bioreactor enhanced the DO level by 0.8 mg/L, ammonium removal by 5 %, and COD removal by 1 %. The integration of electrodes and external circuits stimulated the degradation rate of organic matter in the anodic region (1 % without aeration and 3 % with aeration) and produced 5.13 mW/m3 of maximum power density. Artificial aeration improved the nitrification efficiency by 38 % and further removed the residual COD to an efficiency of 99 %. The maximum power density was also increased by 3.2 times (16.71 mW/m3) with the aid of aeration. In treating higher organic loading wastewater (3M), the maximum power density showed a significant increment to 78.01 mW/m3 (4.6-fold) and the COD removal efficiency was 98 %. The ohmic overpotential dominated the proportion of total loss (67-91 %), which could be ascribed to the low ionic conductivity. The reduction in activation and concentration loss contributed to the lower internal resistance with the additional aeration and higher organic loading. Overall, the transformation from biofiltration to a hybrid CW-MFC system is worthwhile since the systems quite resemble while CW-MFC could improve the wastewater treatment as well as recover energy from the treated wastewater. [ABSTRACT FROM AUTHOR]

Emerging contaminants (ECs) are causing negative effects on the environment and even on people, so their removal has become a priority worldwide. Adsorption and the associated technologies where this process occurs (filtration/biofiltration) have gained great interest, due to its low cost, easy operation, and effectiveness mainly in the removal (up to 100%) of lipophilic ECs (log Kow > 4). Activated carbon continues to be the most efficient material in the removal of ECs (>850 mg/g). However, other conventional materials (activated carbon, clays, zeolites) and non-conventional materials (agro-industrial/forestry/industrial residues, nanomaterials, among others) have shown efficiencies greater than 90%. Adsorption depends on the physicochemical properties of the materials and ECs. Thus, physical/chemical/thermal modifications and nanomaterial synthesis are the most used procedures to improve adsorption capacity. A material with good adsorptive properties could be used efficiently in filtration/biofiltration technologies. Agro-industrial residues are promising alternatives to be used in these technologies, due to their high availability, low toxicity, and adsorption capacities (up to 350 mg/g). In filtration/biofiltration technologies, the material, in addition to acting as adsorbent, plays a fundamental role in operation and hydraulics. Therefore, selecting the appropriate material improves the efficiency/useful life of the filter/biofilter. [ABSTRACT FROM AUTHOR]

Brominated disinfection byproducts (DBPs) are a concern to drinking water utilities due to their toxicity and increasing prevalence in water systems. Haloacetic acids (HAAs) are a class of DBPs that are partially regulated by the United States Environmental Protection Agency (USEPA), but regulations are likely to increase as evidenced by the brominated HAAs listed on the USEPA Fourth Unregulated Contaminant Monitoring Rule and Fifth Contaminant Candidate List. Utilities often use a pre-oxidant to assist in their treatment training, but this can lead to increased HAA formation during treatment. In this study, tap water was spiked with bromine (Br2) at varying concentrations to simulate bromine-to-chlorine ratios found in the natural environment and the DBPs that may be formed from those waters. The water was fed through a bench-scale biological filter (biofilter) with a small layer of fresh granular activated carbon (GAC) media followed by acclimated anthracite media. The HAA species studied were found to be removable by an average of 89.5% through combined GAC filtration and biofiltration. Biodegradation occurred predominantly in the first five minutes for the acclimated anthracite, with minimal additional removal observed at longer empty bed contact times (15 and 30 min EBCT). This study provides recommendations on biofilter parameters for utilities to reduce the formation of both regulated and unregulated HAAs during the drinking water treatment process. [ABSTRACT FROM AUTHOR]

Key Takeaways: Research and operational experience have proved biofiltration's success, answering many questions that utilities considering it for treatment may have. Determining treatment objectives is the best starting point for water providers that are new to biofiltration. Upon full‐scale implementation, operations staff should be familiar with maintenance strategies unique to biofiltration to prevent biological overgrowth. Understanding biofiltration's benefits and applications is an evolving process. [ABSTRACT FROM AUTHOR]

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The ability of a commercial‐scale Cyclobio fluidized sand filter was evaluated for ammonia and nitrite removal by dosing with ammonia chloride, NH4Cl, as part of the water treatment unit for the U.S. Department of Agriculture Agricultural Research Service Warmwater Aquaculture Research Unit's (WARU) catfish hatchery in Stoneville, Mississippi, USA. Treatment system water was recirculated through the Cyclobio filter for several months without any feed inputs; thus, our objective was to investigate how quickly a full‐scale Cyclobio fluidized sand filter could be reactivated with NH4Cl substrate dosing in preparation for the upcoming spawning season. A second objective of the study was to examine the decline of the filter's nitrification ability when the supplementary NH4Cl substrate dosings were removed or limited. The effects of daily and weekly substrate additions were evaluated over a 14‐week winter period, with the system water temperature ranging between 20° and 23°C. Total ammonia nitrogen (TAN) concentration decreased within hours of initial dosing. After approximately a 2‐h lag period, the nitrite–nitrogen concentration peaked and then decreased. The rate of TAN nitrification followed a simple first‐order reaction kinetics and increased over time during the 4 weeks of daily NH4Cl substrate dosing. The return to a weekly substrate dosage resulted in a decrease in the kinetic reaction rate, but adequate to maintain the filter during periods of system inactivity. The once‐daily substrate dosage was consumed within hours of the initial dosing and was sufficient for current system loading. [ABSTRACT FROM AUTHOR]

In coastal environments, strong feedback can exist between benthic fauna and sediment dynamics. Benthic populations can modify sediment dynamics through biofiltration and bioturbation, while hydro- and sediment dynamics directly determine local environmental conditions for benthic organisms. However, these complex feedbacks are difficult to study in situ. Here, we carried out mesocosm experiments to characterize the effects of a benthic species (the gastropod Crepidula fornicata) on mud dynamics under hydrodynamic conditions representative of their natural habitat. Different experimental tests related to the inclusion (or not) of dead or live crepidula reveal that biofiltration can increase particle settling up to 40%. Flocculation, which is strengthened by organic matter enrichment in shell beds, also substantially increases particle settling. Thus, both processes enhance sedimentation above live crepidula habitats. Furthermore, these experiments highlight serious technical, physical and biological challenges that have to be tackled for properly investigating bio-physical interactions. [ABSTRACT FROM AUTHOR]

Sustainable production of drinking water requires safe and efficient production, operation, and maintenance of the entire production line. Rapid gravity granular filters in water production require periodic backwash to ensure water quantity and quality. Therefore, an efficient backwash strategy plays a key role in ensuring a sustainable operation of the filters. In this study, a real-time monitoring method based on electrical resistivity tomography has been developed and tested at full scale for a period of six months in a rapid gravity granular filter during drinking water production. It provides proof of concept for a developed equipment and monitoring strategy within the given production environment. The time series of collected data, with different depth sensitivities of the upper 40 cm filter bed, demonstrates the temporal and spatial resolution capability of the method. Results show temporal development related to dynamic operation and backwash which in this study is combined with snapshot diagnostic tools and operational parameters to increase the spatial understanding of the active processes within the filter. These results suggest electrical resistivity tomography to be a suitable method for monitoring backwash efficiency. HIGHLIGHTS Spatial variation within rapid sand filtration is monitored in real time.; The applied electrical resistivity tomography monitoring strategy reveals vertical and temporal variations directly related to the operational and physical state of the filter.; Good and bad backwash efficiency can be differentiated based on the real-time monitoring data.;

Live Freshwater Mussels (FMs) have remarkable characteristics to support other species and the ecosystem. The objective of the study was to identify the planktonic composition; dye absorbance by living FMs; analyze the water quality indicators; and determine the heavy metals from FMs of different rivers in Bangladesh. In order to assess the planktonic composition, planktons were collected from the experimental ponds and then identified under the microscope. Methyl blue (MB) and methyl red (MR) dye absorbance were assessed using live FMs. After co-cultivating Silver barb (Barbonymus gonionotus) with FMs, water quality indicators (including pH, DO, hardness, total dissolved solids, ammonia, nitrite, and nitrate) were recorded. For determining heavy metals (Cu, Cr, Cd, Pb, Zn), mussels (Lamellidens marginalis) samples were collected from different rivers of Bangladesh. The findings of the study showed that the planktons were significantly (p

Biofiltration for drinking water treatment has several water quality benefits but questions remain about biofilter start‐up in temperate climates where temperature and water quality changes can impact performance. A year‐long full‐scale demonstration was performed with biofilters operated in parallel to chlorinated filters to (O1) monitor the development of the biofilter microbiota across the acclimation period with respect to removal of Mn and total organic carbon, and (O2) determine the impact of depth and backwash events on the microbial community composition and function. Biofilter media biomass increased for the first 6 months of operation and after about 9 months the biofilters achieved comparable Mn removal to the chlorinated filters. Prokaryotic diversity decreased when the water temperature dropped. Backwash resulted in an increase in microbial diversity deeper in the biofilter. By the next sampling (30 h post backwash), 16S rRNA gene copies were again more abundant in the upper layers. Metagenomic sequencing confirmed the presence of moxA and mofA, Mn oxidizing genes. The results presented can help inform expected performance of full‐scale biofilters in temperate climates. [ABSTRACT FROM AUTHOR]

Short-term N-NH4+ and N-NO3− removal by Ulva pseudorotundata under different initial nutrient concentrations and biomass stocking densities were investigated, monitoring in parallel photosynthetic parameters obtained by Pulse-Amplitude-Modulation (PAM) fluorometry of chlorophyll-a and evaluating biomass characteristics (CHN, proteins, carbohydrates). The results showed that U. pseudorotundata cultivated under solar radiation in a land-based outdoor pilot scale system was efficient in removing N-NH4+ and N-NO3− even in concentrations as high as 500 µmol L–1 ensuring complete water remediation in a period of 24 h and in all experimental conditions tested, however differences were observed depending on the stocking density and type of N-source. Treatments with N-NH4+ showed faster N removal than those with N-NO3−, whilst treatments with N-NO3− required more photosynthetic energy. Part of the ammonium removed in the respective treatments may have been volatilized as a combined effect of the pH increase related to photosynthesis and aeration in the tanks. The results presented here establish the fundamental parameters for the use of U. pseudorotundata as a biofiltering organism for effluents with high concentrations of N-NH4+ and N-NO3−. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine the efficiency of a biofilter treating waste gas containing a mixture of cyclohexanol (CHXOH), cyclohexanone (CHXO) and butanol (BL) and to assess the impact of the process parameters on the microorganisms and their enzymatic activities. The biofilter was packed with compost made from green waste mixed with compost made from municipal wastes and polyethylene carriers with immobilized biomass of bacteria. A linear correlation between pollutant loading rate and biofilter elimination capacity was obtained. At a hydraulic load of the biofilter bed of 127.3 m3/(m3 × h), the average elimination capacities were 14.6 g CHXOH/(m3 × h), 3.6 g CHXO/(m3 × h) and 3.8 g BL/(m3 × h). The microbiological and enzymatic analyses of the biofilter bed indicated that high loading rates of pollutants can have significant effects on microbial growth and enzymatic activity. [ABSTRACT FROM AUTHOR]

Most countries around the world have experienced water scarcity in recent decades as fresh water consumption has increased. However, untreated wastewater is routinely discharged into the environment, particularly in developing countries, where it causes widespread environmental and public health problems. The majority of wastewater treatment method publications are heavily focused on high-income country applications and, in most cases, cannot be transferred to low and middle-income countries. An experimental study was conducted to evaluate the performance efficiency of pilot-scale physicochemical and biological treatment methods for the treatment of household greywater in Jimma, Ethiopia. During the experiment, grab samples of greywater were taken from the combined treatment system's influent and effluent every 7 days for 5 weeks and analyzed within 24–48 hours. Temperature, DO, EC, turbidity, TDS, and pH were measured on-site, while BOD, COD, TSS, TP, TN PO4−3-P, NO3-N, NH4-N, Cl−, and FC were determined in the laboratory. During the five-week pilot-scale combined treatment system monitoring period, the combined experimental and control system's mean percentage reduction efficiencies were as follows: turbidity (97.2%, 92%), TSS (99.2%, 97.2%), BOD5 (94%, 57.4%), COD (91.6%, 54.7%), chloride (61%, 35%), TN (68.24, 42.7%), TP (71.6%, 38.7%), and FC (90%, 71.1%), respectively. Similarly, the combined experimental and control systems reduced PO4−3-P (12.5 ± 3 mg/L), NO3-N (4.5 ± 3 mg/L), and NH4-N (10.19 ± 2.6 mg/L) to PO4−3-P (3.5 ± 2.6 mg/L, 7.5 ± 1.6 mg/L), NO3-N (0.8 ± 0.5, 3.6 ± 2.3 mg/L), and NH4-N (7 ± 2.9 mg/L, 15.9 ± 3.9 mg/L), respectively. From the biofiltration and horizontal subsurface flow constructed wetland combined systems, the experimental combined technology emerged as the best performing greywater treatment system, exhibiting remarkably higher pollutant removal efficiencies. In conclusion, the combined biofiltration and horizontal subsurface flow constructed wetland treatment system can be the technology of choice in low-income countries, particularly those with tropical climates. [ABSTRACT FROM AUTHOR]

Full‐scale sampling at 16 facilities illustrated that NDMA precursor concentrations, measured by adding chloramine under Uniform Formation Conditions (NDMAUFC), increased across biofiltration at 7 of 16 facilities (by 3–48 ng/L or 12%–296%) but stayed the same or decreased (by up to 5 ng/L or 24%) at the other nine facilities. Increases in NDMAUFC concentrations were attributed to both particulate and soluble precursors. Only two facilities had an increase in NDMAUFC greater than 10 ng/L. However, NDMAUFC concentrations in the biofilter effluent from five facilities exceeded 10 ng/L during one or more sampling events. For these facilities, testing at multiple scales showed that mitigation steps could include pretreatment with ozone (which resulted in overall lower NDMAUFC), increased free chlorine contact time prior to ammonia addition, and/or optimized biofilter design and operation. [ABSTRACT FROM AUTHOR]

Introduction: Volatile organic compounds are the most common pollutants in the air, and among them, toluene is the most common form, which is toxic resulting in liver and kidneys damages. Regarding the fact that this compound is widely used in various chemical industries, implementing an efficient method for controlling its concentration is of great importance. The comparative survey of the capability of virgin activated carbon with the one immobilized by pseudomonas putida PTCC, and also the performance of the biofiltration system involving pseudomonas putida bacteria immobilized on activated carbon for the adsorption and degradation of toluene from the air as well as regenerating the activated carbon were aimed in the present study. Material and Methods: The microbial growth process was initiated by incubation of pre-culture in a rotary shaker, at 150rpm overnight. After 4 days, the strain pseudomonas putida, PTCC No: 1694 was immobilized on a certain amount of activated carbon. Subsequently, an airstream containing toluene was introduced into the biofilter, and the inlet and outlet concentrations of toluene were measured. Results: The obtained results illustrated that the increase in the volume of the media and decrease in the gas flow rate significantly enhances efficiency. The great performance of the biofilter was confirmed by the high efficiency of the immobilized activated carbon which exhibited 89% yield during 14 hours. On the second cycle, the biofiltration system was able to adsorb toluene at an efficiency of 81%, while the virgin activated carbon exhibited far less efficiency with the value of 28%. Conclusion: The provided results demonstrated the feasibility and reusability of the biofilter system for toluene removal. The proposed technique also extends the activated carbon’s capacity, which could be a potential solution to re-use the activated carbon in industrial applications.

Composting of the organic fraction of municipal solid waste (OFMSW) is accompanied by the emission of large volumes of harmful, hazardous and foul-smelling volatile organic compounds (VOCs). To improve the efficiency of terpenes removal, which constitute a significant part of VOCs, pure cultures of microorganisms dominating in its microbiota were isolated from the microbial community of the biofilter, which has been cleaning such emissions for a long time. Seven pure cultures were isolated and then tested for being able to grow on a mineral medium in the presence of terpene vapor as the only source of carbon and energy. Three of the most actively growing cultures were selected, characterized and identified by the 16S rRNA gene as Rhodococcus erythropolis CA1, Rhodococcus pyridinivorans CA3 and Gordonia sp. CA6. Three identical laboratory biofilters (BF) were inoculated with a mix of these cultures to test the possibility of more complete removal of terpenes. Biofilters were adapting to clearing the model mix of terpineols and geraniol vapors for 45 days. During 45 days the purification efficiency of the model mix reached an average of 91.5% with a contact time (CT) of 3.7 ± 0.2 s and the terpene vapors concentration of 14 ± 2 mg m−3. Then the biofilters number BF2.1 and BF3.1 were connected to real emission from composting OFMSW. The biofilter BF2.1 purified the emission directly, whereas BF3.1 purified similar discharge after the intermediate biofilter of the 1st stage of purification (BF0.0). The BF1.0 was left connected to purification of the model mix as a control. The effectiveness of biofiltration of hard-to-remove terpenes was evaluated by gas chromatography of samples taken at the inlet and outlet of biofilters. The average efficiency of removing terpenes from real emissions by BF2.1 was 93.1 % (CT = 5.5 s). The total efficiency of removing terpenes by (BF0.0 + BF3.1) complex was 93.2 % (total CT = 7.4 s). A study of the microbiota of inoculated biofilters after 60 and 90 days of purification the real emission by cultivation from dilutions, identification by the 16S rRNA gene and fingerprinting showed that in BF2.1 and BF3.1 Rhodococcus erythropolis CA1 and Rhodococcus pyridinivorans CA3 were preserved among living cells at a level of 6.5–12.4 %, and genetically fully corresponded to the original cultures. These results could have a positive impact on improving the results of deodorization of emissions from OFMSW composting by biofiltration, simplifying the design of the biofiltration facility (one stage instead of two) and reducing the total time for effective biofiltration. This, in turn, would contribute to the wider introduction of highly efficient emission purification methods at OFMSW composting facilities in order to create more comfortable and ecologically clean environmental conditions around them. [Display omitted] • Three cultures using hard-to-decompose terpenes have been isolated and identified. • Biofilters with high and stable efficiency of terpenes removal have been obtained. • Isolated cultures are constantly present in microbiota of inoculated biofilters. • Comparable results of 1- and 2-stage biofiltration of terpene mixture have been fixed. [ABSTRACT FROM AUTHOR]

Urban areas face increasing pressures on water resources, necessitating innovative approaches to climate adaptation and water quality management. Nature-based Solutions (NbS) offer a sustainable pathway, yet their integration with existing infrastructure in urban settings remains occasional. This study presents a novel hybrid system—Sequential Sedimentation Biofiltration System (SSBS)—designed for stormwater treatment within confined urban spaces. The system was adjusted to the existing stormwater infrastructure by integrating a sedimentation tank (SED), three Permeable Reactive Barriers (PRBs), and a biofiltration zone (BIO). The SSBS was evaluated for its efficiency in removing nutrients and sediments, focusing on the performance of PRBs. Our findings showed limited sediment removal in SED and PRBs due to spatial constraints and a high Hydraulic Loading Rate (HLR = 1.31 m/d), achieving an average of 13.6% Total Suspended Solids (TSS) removal. However, PRBs demonstrated effective removal of ammonium (43.4%) and phosphate (59.3%), potentially due to sorption and biofilm activity, with dominant microbial communities including Proteobacteria, Bacteroidetes, and nutrient-transforming taxa such as Nitrospirae. Interestingly, PRBs increased nitrite levels (57.1%) but did not significantly impact nitrate, chloride, or TSS. The BIO zone further enhanced nutrient retention (56% PO 4 –P) and served as a sink for TSS (52%). This study underscores the potential for integrating traditional urban infrastructure with NbS in a sequential stormwater treatment system, demonstrating its effectiveness in space-constrained urban environments. [Display omitted] • A hybrid SSBS was implemented for stormwater treatment within an urban area. • The system effectively removed TSS, N, and P despite space constraints. • Permeable Reactive Barriers maintained their efficiency after 110 days of operation. • Biofilms with potential nutrient-cycling bacteria developed on sorption materials. [ABSTRACT FROM AUTHOR]

Biofiltration systems can fail over time due to clogging by fine sediments in stormwater. Infiltration can be maintained by plant roots, but species selection for biofiltration to date has largely been driven by pollutant removal efficiency and tolerance of conditions. As a result, plant species diversity in biofilters is typically low and dominated by sedges and rushes. Increased use of woody species could in theory improve plant diversity, aesthetic appeal, infiltration under high sediment loads and volumetric runoff reduction via higher evapotranspiration, without jeopardising nutrient pollutant removal. We tested whether shrubs could maintain infiltration and evapotranspiration in biofiltration profiles treated with a high sediment load, by comparing them with biofilters subjected to tap water without sediment. Following sediment application, biofilter columns planted with shrubs with high total biomass and total root length showed higher infiltration and evapotranspiration than those receiving tap water. These results indicate that shrub species are likely to alleviate clogging and increase stormwater retention in biofiltration systems. However, shrubs with a high root diameter also had low total biomass and total root length and showed 33–51 % lower infiltration rates after sediment application compared with those receiving tap water. As all shrubs had higher root diameters than typical sedges and rushes, we suggest that shrubs need a combination of higher total biomass, total root length and average root diameter to effectively maintain infiltration. While shrubs which maintained infiltration had traits associated with high nutrient removal, nutrient removal efficiency of shrubs needs to be quantified. Although root traits were related to maintenance of infiltration, above-ground stems likely created flow pathways through sediment which requires further investigation. Overall, selecting shrub species with high total biomass has the potential to maintain infiltration and increase evapotranspiration in biofiltration systems impacted by high sediment loads. [ABSTRACT FROM AUTHOR]

Various harmful gas emissions are a major controversial issue globally, and open dumpsites have become a leading contributor to atmospheric pollution. The study aims to introduce a high-performance landfill gas purification substrate using laterite soil, an iron, and aluminum-rich, highly available soil type in tropical countries; the final suggested substrate contained uniformly mixed laterite soil and compost with a 4:1 fraction by volume. A self-design setup that can maintain moisture content and aerobic conditions was used with an active landfill gas collection system through the gas wells established on the Karadiyana landfill in Sri Lanka under a tropical climate. The elimination capacity of CH 4 , NH 3 , VOCs, and H 2 S were 202860 ± 51595, 91 ± 30, 75 ± 27, and 6 ± 3 mg m−3 h−1 with 91 ± 3, 96 ± 1, 93 ± 3 and 83 ± 4% of removal efficiencies respectively at a 9.4 min empty bed residence time (EBRT). Selected laterite soil acts as an adsorption material and provides a better bio-filtering substrate with compost due to its specific characteristics. The hybrid gas purification process, absorption, and biofiltration within the proposed material were the reasons for higher performance, and the setup may be successful under the industrial waste gas streams. Further investigation should be carried out to study the medium's effectiveness as the covering layer on the dump with the successful lowest thickness, regarding secondary pollutants, and industrial applicability under unique specific conditions. [ABSTRACT FROM AUTHOR]

Bentho-pelagic coupling is a key determinant of multifunctionality in marine ecosystems, influencing critical processes such as production and trophic dynamics. However, knowledge gaps regarding biotically mediated bentho-pelagic coupling limit our understanding of ecosystem responses to global change, and the functional significance of biota nested therein. This is especially relevant for endobenthic ecosystem engineers, which rank amongst the most dynamic of sediment and porewater manipulators in marine systems. Based on this rationale, we tested the consequences of ecosystem engineering by South African endobenthic deposit-feeding crustaceans (sandprawns) for pelagic microbial assemblages, to make inferences about bentho-pelagic coupling. Findings from a factorial 18-day mesocosm experiment indicated a density-dependent, sandprawn-induced decline in phytoplankton relative abundance, but negligible effects on bacterial groups. Picophytoplankton appeared more susceptible than nanophytoplankton to sandprawn density, since relative abundance of the former group declined more in the presence of sandprawns than the latter. By the end of the experiment, there was evidence of a trait shift in phytoplankton assemblages in response to sandprawn presence, with nanophytoplankton being more dominant in the presence of sandprawns. Our findings suggest that pelagic microbes may have differential susceptibilities to endobenthic deposit-feeders and provide useful information on pathways by which these engineers influence bentho-pelagic coupling. These pathways need further evaluation to better understand secondary food-web ramifications and ecosystem responses to global change. • Sandprawn bioturbation influences bentho-pelagic coupling by altering ratios of pelagic trophic resources. • Sandprawn presence resulted in reduced relative abundance of phytoplankton. • Picophytoplankton was more susceptible to sandprawns than nanophytoplankton. • Sandprawn presence led to a shift towards nanoplankton dominance in phytoplankton assemblages. [ABSTRACT FROM AUTHOR]

A multi-channel capillary bioreactor devoted to the continuous abatement of hydrophobic volatile organic compounds (VOCs) by a bacterial and bacterial/microalgae consortium was investigated for 200 days. Toluene, α-pinene and hexane removal in the capillary bioreactor was up to 99 %, 98 %, and 55 %, respectively, which is remarkably high considering the low gas contact time of less than 1 second. Addition of silicone oil increased the removal efficiency (RE) of α-pinene within two days from 45 ± 6 % to 98 ± 2 %, probably through alleviation of biokinetic inhibition provided by the oil acting as buffer for the α-pinene and/or its metabolites. The RE of toluene increased after silicone oil addition over a period of about eight weeks from 81 ± 3 % to 99 ± 1 %, most likely via microbial adaptation. On the contrary, the removal of hexane did not increase following silicone oil addition, potentially due to the inhibition of hexane or its metabolites as the bioreactor was deliberately operated without replenishing the recirculation liquid. Interestingly, biomass adhered to the silicone oil phase rather than residing in the water phase. The bacterial diversity was substantially enhanced, and probably contributed to the observed stable performance of the capillary bioreactor. After the introduction of microalgae on day 150, lower CO 2 concentrations at the outlet compared to the inlet were observed immediately. A net CO 2 consumption was recorded, achieving complete carbon sequestration from the removed VOCs, along with additional CO 2 removed from the inlet ambient air. [Display omitted] • A multi-channel capillary bioreactor with up to 10 %(v/v) silicon oil was studied. • Hydrophobic VOCs removal up to 99 % achieved at less than 1 second gas contact time. • The capillary bioreactor displayed stable operation for the 200 days period. • Biomass adhered to the silicone oil phase rather than residing in the water phase. • VOC-CO 2 co-abatement via algal-bacterial synergism gave complete carbon sequestration. [ABSTRACT FROM AUTHOR]

In drinking water production from groundwaters, biological rapid sand filters (RSFs) can be used for ammonium and manganese removal in aerobic conditions. However, in some boreholes, a start-up duration of several months is required to reach the required removal capacity, leading to significant water losses. Moreover, in specific industrial cases, no exogenous biomass under the form of backwash water or activated sludge can be added to accelerate the process, and different approaches are seldom considered in the literature. With the aim of saving water, start-up strategies coupling water temperature increase and substrate dosing were studied to accelerate the installation of biological activities in a pilot plant fed with borehole water. These set-ups enabled a substantial acceleration of nitrification but no improvement of manganese oxidation in the experimental conditions, although the experiments showed no clear negative influence of nitrification, through nitrite accumulation, on biological manganese oxidation. To further save energy and reduce water loss, outlet water recirculation at a rate of 75% during the start-up phase was validated. The proposed start-up strategy enabled the complete installation of active biofilms with a mean start-up time reduction of 36% and water use reduction of 84% compared to the reference natural conditions. HIGHLIGHTS The accelerated start-up strategy designed for the production of drinking water yielded up to 90% of water saved in the best tested configuration.; Temperature increase and substrate dosing have a better impact on nitrification than on manganese oxidation.; No clear negative interaction between nitrification and manganese oxidation was observed.;

Ulva ohnoi has a big potential in IMTA-RAS fish–seaweed systems. In order to design the best production strategy in these systems, the effect of the main environmental factors, such as pH, nutrient concentration (N, P, and N: P ratios) and dissolved inorganic carbon (DIC), on the productivity, bio filtration capacity, and quality of the biomass obtained was studied. It is concluded that in closed systems, strong pH variations (7.9–10.1) do not influence the growth of U. ohnoi and growth is slowed down due to the depletion of DIC. This fact would not be a problem in IMTA-RAS fish–macroalgae systems, due to the physiological activity of the fish contributing CO2 to the medium and replenishing it. The results obtained in the wide range of N: P ratios tested (2–410), allow us to conclude that this ratio should not be a limiting factor for the cultivation of Ulva ohnoi in IMTA-RAS systems. Based on those results, the best strategy to follow in an IMTA-RAS sole–sea lettuce would be to maintain the algae with highest level of nitrogen. This procedure implies a high rate of water renewal, which would also guarantee the maintenance of an adequate DIC and the best commercial quality of seaweed. [ABSTRACT FROM AUTHOR]

Biotrickling filtration is a well-established technology for the treatment of air polluted with odorous and volatile organic compounds (VOCs). Besides dozens of successful industrial applications of this technology, there are still gaps in a full understanding and description of the mechanisms of biotrickling filtration. This review focuses on recent research results on biotrickling filtration of air polluted with single and multiple VOCs, as well as process modeling. The modeling offers optimization of a process design and performance, as well as allows deeper understanding of process mechanisms. An overview of the developments of models describing biotrickling filtration and conventional biofiltration, as primarily developed and in many aspects through similar processes, is presented in this paper. [ABSTRACT FROM AUTHOR]

Urban water managers regard stormwater runoff and its treatment as one of the greatest challenges, due to its diffused nature and pollutant range. In response, plant biofiltration, a water-sensitive urban design technology, is increasingly preferred. However, due to varying removal performances influenced by design and operational conditions, as well as pollutant removal process complexity, it is under-utilised. This note reviews relevant pollutant removal processes and pathways; and subsequently proffers a first step summary of fundamental processes and pathways applicable to generic plant biofiltration for removal of typical stormwater pollutants. The treatment model combines relevant existing models applicable to the removal pathways of organics, NH3, NO3-, PO43- and metal pollutant change, as well as recommends further refinements. Advancing the understanding of plant biofilter complexity represents a significant in the urban drainage management strategy, from simple flood reduction to the recognition of the stochastic nature of interactions influencing water quality. A summary of the complex nutrient and metal removal processes and pathways in a plant biofilter is given. A deterministic model based on a biofilm reactor for application to a standard plant biofilter is presented. Model refinements for numerical solving are suggested. [ABSTRACT FROM AUTHOR]

A cost-efficient and environmentally friendly biofiltration system is essential for desulfurization to recover elemental sulfur and sulfate for extensively remediating H 2 S. This work investigated the H 2 S removal capacity, accumulation of desulfurization products, sulfur balance, microbial community, and the pathway for sulfide oxidation under different O 2 doses (1%, 3%, 5%, and 10%). The results showed that the removal efficiency of H 2 S increased from 94.1% to 100.0% with the increase of O 2 dose. At 1% O 2 , the elimination capacity (EC) was 5.72 ± 0.33 gH 2 S m–3 h–1, and about 78.13% of S0-S was generated. However, with stepwise increase of O 2 concentration to 10%, the EC became 6.00 ± 0.35 gH 2 S m–3 h–1, and SO 4 2–-S was the dominant product at 80.39%. Furthermore, the sulfur balance was verified by calculating the proportion of sulfur compounds (S0-S, SO 4 2−-S, and SO 3 2−-S) and comparing the microstructure of packing material in the biotrickling filter. Moreover, 16 S rRNA high-throughput sequencing analysis showed that the cooperation of sulfur-oxidizing bacteria in the biofiltration system was the key to the stable and efficient removal of H 2 S. In addition, possible reaction pathways in which H 2 S was transformed to S0 and SO 4 2− were proposed. [Display omitted] [ABSTRACT FROM AUTHOR]

Wastewater treatment plants (WWTPs) are confirmed sources of bioaerosols and can be a hotspot for both antibiotic-resistant bacteria and antibiotic-resistant genes (ARGs). Bioaerosols can be a source of dispersion for bacteria and ARGs into the environment. Biofiltration is one of the most effective technologies to mitigate odors from WWTPs. The objective of this study was to evaluate the capacity of an odor biofiltration system designed to remove volatile compounds, to influence the airborne bacterial diversity and to reduce the aerosolized microbial and ARG concentrations. In total, 28 air samples were collected before and after treatment of an interior WWTP. Overall, air samples collected upstream had higher total bacterial concentrations, and a shift in bacterial diversity was observed. Legionella and Mycobacterium were detected in low abundance upstream and downstream, whereas Legionella pneumophila was detected but not quantifiable in two samples. Of the 31 ARGs and mobile genetic elements detected by quantitative polymerase chain reaction, 15 exhibited a significant reduction in their relative abundance after biofiltration, and none were significantly higher in the effluent. Overall, these results show the benefits of odor biofiltration systems to reduce bacterial and antimicrobial resistance in treated air, a promising application to limit environmental dispersion. [ABSTRACT FROM AUTHOR]

Identification of ecosystem services, i.e. the contributions that ecosystems make to human well‐being, has proven instrumental in galvanising public and political support for safeguarding biodiversity and its benefits to people. Here we synthesise the global evidence on ecosystem services provided and disrupted by freshwater bivalves, a heterogenous group of >1200 species, including some of the most threatened (in Unionida) and invasive (e.g. Dreissena polymorpha) taxa globally. Our systematic literature review resulted in a data set of 904 records from 69 countries relating to 24 classes of provisioning (N = 189), cultural (N = 491) and regulating (N = 224) services following the Common International Classification of Ecosystem Services (CICES). Prominent ecosystem services included (i) the provisioning of food, materials and medicinal products, (ii) knowledge acquisition (e.g. on water quality, past environments and historical societies), ornamental and other cultural contributions, and (iii) the filtration, sequestration, storage and/or transformation of biological and physico‐chemical water properties. About 9% of records provided evidence for the disruption rather than provision of ecosystem services. Synergies and trade‐offs of ecosystem services were observed. For instance, water filtration by freshwater bivalves can be beneficial for the cultural service 'biomonitoring', while negatively or positively affecting food consumption or human recreation. Our evidence base spanned a total of 91 genera and 191 species, dominated by Unionida (55% of records, 76% of species), Veneroida (21 and 9%, respectively; mainly Corbicula spp.) and Myoida (20 and 4%, respectively; mainly Dreissena spp.). About one third of records, predominantly from Europe and the Americas, related to species that were non‐native to the country of study. The majority of records originated from Asia (35%), with available evidence for 23 CICES classes, as well as Europe (29%) and North America (23%), where research was largely focused on 'biomonitoring'. Whilst the earliest record (from 1949) originated from North America, since 2000, annual output of records has increased rapidly in Asia and Europe. Future research should focus on filling gaps in knowledge in lesser‐studied regions, including Africa and South America, and should look to provide a quantitative valuation of the socio‐economic costs and benefits of ecosystem services shaped by freshwater bivalves. [ABSTRACT FROM AUTHOR]

Composting is an effective method for recycling resources in waste management. However, significant nitrogen loss can hinder the overall effectiveness of the composting process. Biofiltration is a promising method for conserving nitrogen in composting owing to its ability to efficiently trap and convert gaseous emissions. This study investigated the efficiency and mechanisms of a composting-biofiltration system to enhance nitrogen retention in distilled grain waste (DGW) compost using pre-composted DGW as biofilter media. The DGW composting-biofiltration system exhibited a lower nitrogen loss (24.9%) than the mono-composting system (40.1%). Additionally, this DGW system achieved a high NH 3 removal efficiency of 94.7%-97.7%, while NO 3 - concentration continuously increased in the biofilter, indicating that biofiltration mainly conserved nitrogen through the conversion of NH 3 emitted from the composter. The analysis of the microbial community and key functional enzymes involved in nitrogen metabolism revealed a significant increase in both nitrification and ammonia assimilation within the biofilter. This resulted in the accumulation of NO 3 - and the formation of organic nitrogen, thereby facilitating nitrogen retention. Genera such as Chryseolinea, Anseongella, Parapusillimonas, Bacillus, and Urebacillus mainly contributed to the generation of NO 3 - and organic nitrogen. The structural equation model analysis revealed that nitrogen retention in DGW compost was mainly facilitated by enhanced nitrification and ammonia assimilation in the biofilter. These results provide insights into underlying mechanisms for enhancing nitrogen retention through a composting-biofiltration approach and present guidance for improving compost quality., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Biofiltration is a simple and low-cost method for the cleanup of contaminated water. However, the reduced availability of dissolved chemicals to surface-attached degrader bacteria may limit its efficient use at certain hydraulic loadings. When a direct current (DC) electric field is applied to an immersed packed bed, it invokes electrokinetic processes, such as electroosmotic water flow (EOF). EOF is a surface-charge-induced plug-flow-shaped movement of pore fluids. It acts at a nanometer distance above surfaces and allows the change of microscale pressure-driven flow profiles and, hence, the availability of dissolved contaminants to microbial degraders. In laboratory percolation columns, we assessed the effects of a weak DC electric field ( E = 0.5 V·cm -1 ) on the biodegradation of waterborne naphthalene (NAH) by surface-attached Pseudomonas fluorescens LP6a. To vary NAH bioavailability, we used different NAH concentrations ( C 0 = 2.7, 5.1, or 7.8 × 10 -5 ) and Darcy velocities typical for biofiltration ( U ¯ = 0.2-1.2 × 10 -1 ) and Darcy velocities typical for biofiltration ( U ¯ = 0.2-1.2 × 10 -4 m·s -1 ). In DC-free controls, we observed higher specific degradation rates ( q c ) at higher NAH concentrations. The q c depended on U ¯ , suggesting bioavailability restrictions depending on the hydraulic residence times. DC fields consistently increased q c and resulted in linearly increasing benefits up to 55% with rising hydraulic loadings relative to controls. We explain these biodegradation benefits by EOF-altered microscale flow profiles allowing for better NAH provision to bacteria attached to the collectors even though the EOF was calculated to be 100-800 times smaller than bulk water flow. Our data suggest that electrokinetic approaches may give rise to future technical applications that allow regulating biodegradation, for example, in response to fluctuating hydraulic loadings.

The present study evaluated engineered media for plant biofilter optimisation in an unvegetated column experiment to assess the performance of loamy sand, perlite, vermiculite, zeolite and attapulgite media under stormwater conditions enriched with varying nutrients and metals reflecting urban pollutant loads. Sixty columns, 30 unvegetated and 30 Juncus effusus vegetated, were used to test: pollutant removal, infiltration rate, particulate discharge, effluent clarity and plant functional response, over six sampling rounds. All engineered media outperformed conventional loamy sand across criteria, with engineered attapulgite consistently among the best performers. No reportable difference existed in vegetation exposed to different material combinations. For all media, the results show a net removal of NH3-N, PO43−-P, Cd, Cu, Pb and Zn and an increase of NO3−-N, emphasizing the importance of vegetation in biofilters. Growth media supporting increased rate of infiltration whilst maintaining effective remediation performance offers the potential for reducing the area required by biofilters, currently recommended at 2% of its catchment area, encouraging the use of small-scale green infrastructure in the urban area. Further research is required to assess the carrying capacity of engineered media in laboratory and field settings, particularly during seasonal change, gauging the substrate's potential moisture availability for root uptake. HIGHLIGHTS This is the first study to investigate the novel addition of attapulgite media for urban pollutant removal from stormwater in biofilters.; The experiment reported consistent and effective removal of ammonia, orthophosphate an heavy metals.; The paper reports a time-lapse of photographic evidence illustrating the change in sediment discharge from new biofilters.; Infiltration rate enhanced, while pollutant removal performance was maintained.;

Background: Controlling excess biomass accumulation and clogging is important for maintaining the performance of gas biofilters and reducing energy consumption. Interruption of bacterial communication (quorum quenching) can modulate gene expression and alter biofilm properties. However, whether the problem of excess biomass accumulation in gas biofilters can be addressed by interrupting bacterial communication remains unknown. Results: In this study, parallel laboratory-scale gas biofilters were operated with Rhodococcus sp. BH4 (QQBF) and without Rhodococcus sp. BH4 (BF) to explore the effects of quorum quenching (QQ) bacteria on biomass accumulation and clogging. QQBF showed lower biomass accumulation (109 kg/m3) and superior operational stability (85–96%) than BF (170 kg/m3; 63–92%) at the end of the operation. Compared to BF, the QQBF biofilm had lower adhesion strength and decreased extracellular polymeric substance production, leading to easier detachment of biomass from filler surface into the leachate. Meanwhile, the relative abundance of quorum sensing (QS)-related species was found to decrease from 67 (BF) to 56% (QQBF). The QS function genes were also found a lower relative abundance in QQBF, compared with BF. Moreover, although both biofilters presented aromatic compounds removal performance, the keystone species in QQBF played an important role in maintaining biofilm stability, while the keystone species in BF exhibited great potential for biofilm formation. Finally, the possible influencing mechanism of Rhodococcus sp. BH4 on biofilm adhesion was demonstrated. Overall, the results of this study achieved excess biomass control while maintaining stable biofiltration performance (without interrupting operation) and greatly promoted the use of QQ technology in bioreactors. 3zfTX8KHj1tCkn3P9YoqjH Video Abstract [ABSTRACT FROM AUTHOR]

Biofiltration is a water purification technology playing a pivotal role in producing safe drinking water. This technology attracts many interests worldwide due to its advantages, such as no addition of chemicals, a low energy input, and a high removal efficiency of organic compounds, undesirable taste and odours, and pathogens. The current review describes the microbial ecology of three biofiltration processes that are routinely used in drinking water treatment plants, i.e. (i) rapid sand filtration (RSF), (ii) granular activated carbon filtration (GACF), and (iii) slow sand filtration (SSF). We summarised and compared the characteristics, removal performance, and corresponding (newly revealed) mechanisms of the three biofiltration processes. Specifically, the microbial ecology of the different biofilter processes and the role of microbial communities in removing nutrients, organic compounds, and pathogens were reviewed. Finally, we highlight the limitations and challenges in the study of biofiltration in drinking water production, and propose future perspectives for obtaining a comprehensive understanding of the microbial ecology of biofiltration, which is needed to promote and optimise its further application. Key points: • Biofilters are composed of complex microbiomes, primarily shaped by water quality. • Conventional biofilters contribute to address safety challenges in drinking water. • Studies may underestimate the active/functional role of microbiomes in biofilters. [ABSTRACT FROM AUTHOR]

The rapid development of aquaculture makes it desirable to use environment-friendly methods of purifying the wastewater effluent. Seaweed is often cultured for the dual purpose of useful algal biomass production and its bioremediation potential. This paper offers a survey on growth characters and ecological functions of the macroalgae Gracilaria gracilis (Steentoft, L.M. Irvine & Farnham, 1995), collected from Ganzirri lagoon (Messina, Italy). The results obtained provided promising data in terms of growth rates, biomass and biofiltering potential of G. gracilis. A daily growth rate (DGR) of 0.70%/g and biomass 36,05 g/m3 was obtained using tanks with lower lighting. Its biofiltration efficiency was demonstrated by the strong correlation between the algal growth parameters (Y and DGR) and the concentration decrease of dissolved nutrients. Results provided in this study indicated that G. gracilis can find application in aquaculture systems as a biofilter and that biomass produced offers a valid resource for further biotechnological applications. [ABSTRACT FROM AUTHOR]

An integrated recirculation aquaculture system (RAS) was designed and developed using bacteria, echinoderms (Athyonidium chilensis), and mollusks (Mytilus chilensis) to maintain water quality. Photovoltaic panels were employed to reduce the energy costs of the crop. The evaluation of survival and growth of adults (2-month olds) and juveniles (7-month olds) of Seriola lalandi fish, fed with commercial pellets, was carried out. Different water parameters (temperature, humidity, irradiance, oxygen, pH, ammonium, nitrite, nitrate, etc.) were recorded. The distribution of trophic levels maintained the quality of the water in the system. The photovoltaic panels allowed autonomy of 4 h of disconnection from the electrical network. The weight gain was optimal in adults for the species (initial 1496 g, final 1698 g) and juveniles (initial 24 g, final 588 g). The survival of 100% of adults and 39% of juveniles was documented. The analysis of the fillet helped ascertain its quality for human consumption. This cultivation system depended only on a reservoir to supply water. Operating the system does not require highly specialized personnel and the use of biofilters/photovoltaic panels reduces operating costs. Finally, the production of commercially important marine organisms in efficient and sustainable cultivation systems may help solve global challenges such as the availability of food. [ABSTRACT FROM AUTHOR]

Direct anaerobic sewage treatment is increasingly adopted in several intertropical developing countries. The reduced carbon footprint of such facilities is based on its low electricity requirements and potential energy (biogas) recovery; however, if dissolved CH 4 in the effluent is not controlled, this advantage will be drastically reduced. A suitable option to overcome this situation is to adopt CH 4 desorption by an air stream, followed by bio-oxidation in compost biofilters. In such systems, the methanotrophic activity will increase the temperature in the biofilter to inhibiting values (above 40 °C), reducing the active volume of the compost media and its removal efficiency. This work addresses this process limitation, aiming to assess the temperature variations in the filter media and their effects on methane oxidation performance under different operating conditions. A comprehensive mathematical 2-D porous-medium based model was developed and then calibrated and validated with experimental data. The model considers heat, momentum, and mass balances under non-steady-state conditions, including heat exchange at the biofilter container wall influenced by daily ambient temperature fluctuations and solar radiation. Results obtained from 6 model simulations at different operating conditions show that temperatures above 40 °C are reached at the center-upper zones of the compost biofilter due to the heat transported from the methanotrophic active zones located at the bottom (inlet) and container wall. At midday (12 – 14 h), solar radiation on the wall contributes 14% of the total heat gained in a non-covered biofilter. The model highlights the importance of facilitating heat transport from the compost media to the surroundings; some practical recommendations are presented for that purpose. [ABSTRACT FROM AUTHOR]

The effect of the partition coefficient on the simulation of the operation of a biotrickling filter treating a mixture of sulfur compounds was analyzed to evaluate the pertinence of using Henry's law in determining its removal capacity. The analysis consisted of the simulation of a biotrickling filter that bio-oxides hydrogen sulfide (H2S), dimethyl sulfide (DMS), methyl mercaptan (MM) and dimethyl disulfide (DMDS) using different types of models for determining the partition coefficient: Henry's law for pure water, Henry's law adjusted from experimental data, a mixed model (Extended UNIQUAC) and a semi-empirical model of two-parameters. The simulations were compared with experimental data. It was observed that Henry's law for pure water could produce significant deviations from empirical data due to the liquid phase not being pure water. The two-parameter model better fits with similar results compared to the extended UNIQUAC model, with a lower calculation cost and necessary parameter amount. It shows that semi-empirical models can considerably improve simulation accuracy where complex phase interactions are present. [ABSTRACT FROM AUTHOR]

Biofilters (BFs) and biotrickling filters (BTFs) are two types of bioreactors used for treatment of volatile organic compounds (VOCs). Both BFs and BTFs use packing materials in which various microorganisms are immobilised. The water phase in BFs is stationary and used to maintain the humidity of packing materials, while BTFs have a mobile liquid phase. Optimisation of irrigation of packing materials is crucial for effective performance of BFs and BTFs. A literature review is presented on the influence of water content of packing materials on the biofiltration efficiency of various pollutants. Different configurations of BFs and BTFs and their influence on moisture distribution in packing materials were discussed. The review also presents various packing materials and their irrigation control strategies applied in recent biofiltration studies. The sources of this review included recent research articles from scientific journals and several review articles discussing BFs and BTFs. [ABSTRACT FROM AUTHOR]

Nature-based solutions (NBS) are increasingly proposed for effectively and adaptively addressing societal challenges such as water security and natural disasters. However, NBS that are exclusively reliant on natural processes are not fit-for-purpose for the provision of safe drinking water – some range of built technology is required. There is a wide spectrum of techno-ecological NBS – ‘green technologies’ – that are fit-for-purpose in the treatment and distribution of safe drinking water. A framework was developed to enable an accurate and transparent description of the ‘green’ attributes of technology – including green infrastructure – in the water industry. The framework differentiates technology ‘greenness’ by relatively examining key attributes that may cause environmental impacts across the technology's life cycle through the lens of the environmental setting in which it is applied. In the water industry, green technology can be described by four main attributes: natural-resource basis, energy consumption, waste production, and footprint. These attributes are closely linked and must be considered relative to the biophysical and human environments in which they are applied and the other technologies to which they are being compared. The use of the framework can facilitate techno-ecological decision-making that strives to address diverse stakeholder priorities – including the influence of sociocultural factors on the green technology preferences of individuals, groups, or communities. HIGHLIGHTS NBS exclusively reliant on natural processes are not fit-for-purpose for the provision of safe drinking water.; Green technology falls on a spectrum.; The four main attributes of green technology are natural-resource basis, energy consumption, waste production, and footprint.; Operational control is often reduced as technology ‘greenness’ increases.; Biofiltration is an underutilized, green drinking water treatment technology.;

Biogas is a valuable green energy source. Hydrogen sulfide removal is essential for biogas upgrading for high-end applications. This work provides a comprehensive review of biogas biodesulfurization technologies for industrial applications, focusing on aerobic and anoxic biofilters, biotrickling filters, and bioscrubbers. Key topics include removal mechanisms, system design, performance, operating factors, best-fit applications, and design-based cost analysis. Biodesulfurization technologies are highly efficient, achieving up to 99 % removal efficiency at full scale, particularly in bioscrubbers and biotrickling filters due to improved design configurations. Performance is largely affected by operating conditions and the composition, activity, and robustness of sulfur-oxidizing microorganisms. While kinetic models are widely used to study performance, further research is needed to advance the application of computational fluid dynamics for system modeling. Biodesulfurization technologies prove to be environmentally sustainable and may be more economically viable in large-scale, commercial applications. Reducing energy and packing material replacement costs would further improve economic viability. While biodesulfurization technologies are safe, precautions must be taken to avoid explosion risks from methane/oxygen mixtures and hydrogen sulfide gas poisoning. Ultimately, selecting suitable biodesulfurization technology for industrial applications depends on the volume of biogas to be treated, the choice of sulfur microorganisms, system stability, and the intended biogas end-use. [Display omitted] • This review features biodesulfurization technologies for commercial applications. • Addresses the sustainability aspect of biogas biodesulfurization technologies. • Highlights environmental benefits and viability of biodesulfurization technologies. • Highlights high removal efficiency of biodesulfurization technologies (up to 99 %). • Suggests sustainability assessment, modeling, and simulations for further research. [ABSTRACT FROM AUTHOR]