Wetlands For Wastewater Treatment Research Articles

Evaluation of the effectiveness of phytoremediation technologies utilizing Lemna minor in constructed wetlands for wastewater treatment

Evaluation of the effectiveness of phytoremediation technologies utilizing Lemna minor in constructed wetlands for wastewater treatment

Bioenergy-producing two-stage septic tank and floating wetland for onsite wastewater treatment: Circuit connection and external aeration

This study designed a two-stage, electrode-integrated septic tank-floating wetland system and assessed their pollutant removal performances under variable operational conditions. The two-stage system achieved mean organic, nitrogen, phosphorus, and coliform removal percentages of 99, 78, 99, and 97%, respectively, throughout the experimental run. The mean metals (chromium, cadmium, nickel, copper, zinc, lead, iron, and manganese) removal percentages ranged between 81 and 98%. Accumulated sludge, filler media, and the hanging root mass contributed to pollutant removals by supporting physicochemical and biological pathways. The mean effluent organic concentration and coliform number across the two-stage system were 20 mg/L and 1682 CFU/100 mL, respectively, during the closed-circuit protocol, which was beneath the open-circuit-based performance profiles, i.e., 32 mg/L and 2860 CFU/100 mL, respectively. Effluent organic, nitrogen, phosphorus, metals, and coliform number ranges across the two-stage system were 9–17 mg/L, 13–24 mg/L, 1–1.5 mg/L, 0.001–0.2 mg/L, and 1410–2270 CFU/100 mL, respectively during intermittent and continuous aeration periods. The air supply rate differences influenced pollutant removal depending on the associated removal mechanisms. The non-aeration phase produced higher effluent pollutant concentrations than the aeration periods-based profiles. The overall mean power density production of the septic tank ranged between 107 and 596 mW/m3; 110 and 355 mW/m3 with the floating wetland. The bioenergy production capacity of the septic tank was positively correlated to external air supply rates. This study demonstrates the potential application of the novel bioenergy-producing septic tank-floating wetland system for wastewater treatment in decentralized areas.

Trace metal transfer to passerines inhabiting wastewater treatment wetlands

Wastewater treatment wetlands are cost-effective strategies for remediating trace metals in industrial effluent. However, biogeochemical exchange between wastewater treatment wetlands and adjacent environments provides opportunities for trace metals to cycle in surrounding ecosystems. The transfer of trace metals to wildlife inhabiting treatment wetlands must be considered when evaluating wetland success. Using passerine birds as bioindicators, we conducted a multi-tissue analysis to investigate the mobilization of zinc, copper, and lead derived from wastewater to terrestrial wildlife in treatment wetlands and surrounding habitat. In addition, we evaluate the strength of relationships between metal concentrations in non-lethal (blood and feathers) and lethal (muscle and liver) sample types for estimation of toxicity risk. From July 2020 to August 2021, 177 passerines of seven species were captured at two wetlands constructed to treat industrial wastewater and two reference wetlands in the coastal plain of South Carolina. Feather, blood, liver, and muscle samples from each bird were analyzed for fourteen metals using inductively coupled plasma mass spectrometry and direct mercury analysis. Passerines inhabiting wastewater treatment wetlands accumulated higher concentrations of zinc in liver, copper in blood, and lead in feathers than passerines in reference wetlands, but neither blood nor feather concentrations were correlated with internal tissue concentrations. Of all the detected metals, only mercury in the blood showed a strong predictive relationship with mercury in internal tissues. This study indicates that trace metals derived from wastewater are bioavailable and exported to terrestrial wildlife and that passerine biomonitoring is a valuable tool for assessing metal transfer from treatment wetlands. Regular blood sampling can reveal proximate trace metal exposure but cannot predict internal body burdens for most metals.

Study on the performance of accessory microbial fuel cell (MFC) integrated to the constructed wetlands (CWs) for deep wastewater treatment

Deep nitrogen removal is difficult due to inefficient organic carbon sources in tail water from sewage treatment facilities. Microbial fuel cell integrated with constructed wetlands (MFC-CWs) filled with high density polyethylene (HDPE) as the biocarriers were constructed for deep denitrification of tail water, and was compared with MFC and CW. The influences of electrode gap and hydraulic retention time (HRT) on denitrification as well as electricity generation performance were investigated. It was found that appropriate electrode gap extension might enhance chemical oxygen demand (COD) and nitrogen removal, and MFC-CW got the highest electricity generation and nitrogen removal with the electrode gap at 25 cm. Extending HRT promoted deep denitrification, resulting in an initial increase followed by a subsequent decrease in power generation performance. The maximum power density of MFC-CW attained 1.95 mW/m2 with an HRT of 2 d. It was found that microbial abundances in the upper cathode of the systems were higher, and the growth and metabolisms of microorganisms were enhanced in MFC-CWs. Saccharimonadales and SBR1031 in MFC-CW were the dominant genera, which promoted nitrogen removal. The results provide a reference for the study of synchronous denitrification and electricity generation performance in MFC-CW with HDPE as bio-fillers.

Organic Pollutants Removal in a Hybrid Constructed Wetland Wastewater Treatment Plant with an Aeration System

This study presents the efficiency of TSS and organic pollutants (BOD5 and COD) removal in a hybrid constructed wetland wastewater treatment plant (VF-HF type) with an aeration system. This study was conducted over 6 years (2017–2022) in a facility with a capacity of 4.5 m3/day located in southeastern Poland and designed to treat real domestic wastewater from a school building. The studied facility consists of a three-chambered septic tank, a pumping station with an aeration system, and two beds with vertical and horizontal flow planted with giant miscanthus and willow. As a result of artificial aeration, the dissolved oxygen concentration in wastewater after mechanical treatment increased significantly, by an average of 1.18 mg O2/L, and was negatively correlated with wastewater temperature. The cumulative pollutant removal effects of the treatment plant (primary settling tank + VFCW + HFCW) were 81% for TSS, 98% for BOD5, and 89% for COD. There was no statistically significant effect of aeration on the organic pollutant removal effects in the VF bed, and such an effect was found for the temperature of wastewater entering the VF bed. The TSS, BOD5, and COD removal effects in the VF bed and BOD5 in the VF-HF system were positively correlated with air temperature. The technological reliability of the treatment plant was 98% for TSS and 100% for BOD5 and COD. The use of artificial aeration of wastewater makes it possible to achieve high organic pollutant removal efficiency in SSF CWs and to compensate for limitations due to the reduction in the area of constructed wetland beds.

Greenhouse gas production from an intermittently dosed cold-climate wastewater treatment wetland

This study explores the greenhouse gas (GHG) fluxes of nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) from a two-stage, cold-climate vertical-flow treatment wetland (TW) treating ski area wastewater at 3 °C average water temperature. The system is designed like a modified Ludzack-Ettinger process with the first stage a partially saturated, denitrifying TW followed by an unsaturated nitrifying TW and recycle of nitrified effluent. An intermittent wastewater dosing scheme was established for both stages, with alternating carbon-rich wastewater and nitrate-rich recycle to the first stage. The system has demonstrated effective chemical oxygen demand (COD) and total inorganic nitrogen (TIN) removal in high-strength wastewater over seven years of winter operation. Following two closed-loop, intensive GHG winter sampling campaigns at the TW, the magnitude of N2O flux was 2.2 times higher for denitrification than nitrification. CH4 and N2O emissions were strongly correlated with hydraulic loading, whereas CO2 was correlated with surface temperature. GHG fluxes from each stage were related to both microbial activity and off-gassing of dissolved species during wastewater dosing, thus the time of sampling relative to dosing strongly influenced observed fluxes. These results suggest that estimates of GHG fluxes from TWs may be biased if mass transfer and mechanisms of wastewater application are not considered. Emission factors for N2O and CH4 were 0.27 % as kg-N2O-N/kg-TINremoved and 0.04 % kg-CH4-C/kg-CODremoved, respectively. The system had observed seasonal emissions of 600.5 kg CO2 equivalent of GHGs estimated over 130-days of operation. These results indicate a need for wastewater treatment processes to mitigate GHGs.

The role of algae-based wastewater treatment systems: A comprehensive review

Algae-based wastewater treatment systems have gained significant attention as sustainable and efficient solutions for nutrient removal, organic pollutant degradation, and biomass production. This comprehensive review explores the role of algae-based systems in wastewater treatment, covering key aspects such as nutrient uptake mechanisms, cultivation techniques, system design considerations, and environmental sustainability implications. Algae offer unique advantages for wastewater treatment, including high nutrient removal rates, CO2 sequestration, and the production of valuable biomass for biofuel production and nutrient recycling. Various cultivation methods, including open ponds, raceways, photobioreactors, and wastewater treatment wetlands, are evaluated for their suitability in different wastewater treatment scenarios. The integration of algae-based systems with conventional wastewater treatment processes, such as activated sludge and membrane bioreactors, is discussed to enhance treatment efficiency and resource recovery. Furthermore, the environmental sustainability of algae-based systems, including carbon footprint, water footprint, and ecosystem impacts, is assessed to identify opportunities for mitigating environmental impacts and promoting ecosystem resilience. Future research directions in algae-based wastewater treatment systems, such as optimization of cultivation conditions, development of novel algal strains, and techno-economic analysis of large-scale implementation, are proposed to address remaining challenges and accelerate the adoption of algae-based technologies in wastewater treatment practices. Overall, this review provides valuable insights into the role of algae-based systems as sustainable and versatile tools for wastewater treatment, highlighting their potential to address the growing challenges of nutrient pollution and water scarcity in the 21st century.

Research status of low-temperature operation effect and strengthening measures of constructed wetlands

Constructed wetlands are a new method of wastewater treatment, which has the advantages of low cost, ease of implementation, and high ecological benefits, and has been applied in many scenarios. However, this method also has certain limitations, manifested in reduced purification efficiency or even complete failure under low temperatures. This article analyzes the influencing factors of low-temperature operation of constructed wetlands, explores its operational effectiveness in low-temperature areas, and summarizes previous research experience, and then proposes some suggestions for the current situation. The research in this article can provide theoretical references for wetland wastewater treatment, and also provide references for subsequent similar research.

Anaerobic baffled reactor followed by up-flow constructed wetland for treatment of municipal wastewater

A laboratory-scale anaerobic baffled reactor followed by up-flow constructed wetland are designed and developed with different filter media, and emergent plants. The effectiveness of an anaerobic baffle reactor (ABR) for settling down inorganic and treatment of the organic matter is observed in the present study. Further, two up-flow constructed wetland (UCW) units filled with Autoclaved Aerated Concrete (ACC) blocks and coconut shells as a filter media and wetland plants are combined for bio-phyto treatment. The performance of the treatment system is analyzed with hydraulic retention times (HRTs) of 12 h, 18 h, and 24 h. The removal of TSS, COD, TN, and TP are found to be 96 %, 84 %, 68 %, and 65.5 %, respectively, with 24 h HRT, which complied with the discharge standards. Due to the simplicity of construction as well as low operation and maintenance, the present treatment combination is considered eco-friendly, sustainable, and a cost-effective option for households or communities prior to its safe discharge. The treated water is ready to use for irrigation, gardening, floriculture, cleaning, and flushing.

Opposite response of constructed wetland performance in nitrogen and phosphorus removal to short and long terms of operation

Constructed wetlands (CWs) have been widely used for treating polluted water since the 1950s, with applications in over 50 countries worldwide. Most studies investigating the pollutant removal efficiency of these wetlands have focused on differences among wetland designs, operation strategies, and environmental conditions. However, there still remains a gap in understanding the variation in wetland pollutant removal efficiency over different time scales. Therefore, the main aim of the study is to address this gap by conducting a global meta-analysis to estimate the variation in nitrogen (N) and phosphorus (P) removal by wetland in short- and long-term pollutant treatment. The findings of this study indicated that the total efficiencies of N and P removal increased during short-term wetland operation but decreased during long-term operation. However, for surface flow CWs specifically, the efficiencies of N and P removal increased during short-term operation and remained stable during long-term operation. Moreover, the study discovered that wetland N removal efficiency was influenced by seasons, with an increase in spring and summer and a decrease in autumn and winter. Conversely, there was no significant seasonal effect on P removal efficiency. Additionally, high hydraulic load impaired wetland N and P removal efficiency during long-term operation. This study offers a critical review of the role of wetlands in wastewater treatment and provides valuable reference data for the design and selection of CWs types during wastewater treatment in the aspect of sustainability.

Integrated Process of Immediate One-Step Lime Precipitation, Atmospheric Carbonation, Constructed Wetlands, or Adsorption for Industrial Wastewater Treatment: A Review

The transition from the linear economy paradigm to the circular economy in industrial wastewater treatment systems is on the global agenda. The search for new simple, eco-innovative, and low-cost processes for treating industrial wastewater, which can also be used by small and medium-sized industries, has been a constant challenge especially when environmental sustainability is considered. So, a new integrated industrial wastewater treatment system has been developed that includes the immediate one-step lime precipitation process (IOSLM) and atmospheric carbonation (AC), followed by constructed wetlands (CWs) or adsorption. The current review provides an overview of industrial wastewater treatment strategies for high- and low-biodegradable wastewater. A background on functionality, applicability, advantages and disadvantages, operating variables, removal mechanisms, main challenges, and recent advances are carried out for each process that makes up the IOSLM+AC+CW/adsorption integrated system. The prospects of the IOSLM+AC+CW/adsorption integrated system are also discussed. Not neglecting the improvements that still need to be made in the integrated treatment system as well as its application to various types of industrial wastewater, this review highlights that this treatment system is promising in industrial wastewater treatment and consequent by-product recovery. The IOSLM+AC integrated system showed that it can remove high amounts of organic matter, total suspended solids, oils and fats, phosphorus, and ammonium nitrogen from industrial effluents. On the other hand, constructed wetlands/adsorption can be alternatives for refining effluents still containing organic matter and nitrogen that were not possible to remove in the previous steps.

Horizontal flow aerated constructed wetlands for municipal wastewater treatment: The influence of bed depth

The influence of bed depth on the performance of aerated horizontal constructed wetlands was investigated at the pilot plant scale. Two horizontal flow subsurface constructed wetlands (HF) intensified units of different bed depth (HF1: 0.90 m and HF2: 0.55 m, 0.8 m and 0.5 m water level, respectively) were fitted with forced aeration, while a third one (HFc, 0.55 m bed depth, 0.5 m water level) was used as control and not aerated. The three HF units were operated in parallel, receiving the same municipal wastewater pre-treated in a hydrolytic up-flow sludge blanket anaerobic digester. Applied surface loading rates (SLR) ranged from 20 to 80 g biochemical oxygen demand (BOD5)/m2·d and from 3.7 to 6.7 g total nitrogen (TN)/m2·d, while it ranges from 6 to 23 g BOD5/m2·d and from 1.1 to 1.7 g TN/m2·d in the control unit. Removal of total suspended solids (TSS) and BOD5 was usually close to a 100 % in all units, whilst chemical oxygen demand (COD) removal was higher for the HF1 unit (97 % on average, range of 96–99 %) than for HF2 (92 %, 82–98 %) and HFc (94 %, 86–99 %). TN removal reached on average 33 % (16–43 %) in HFc, 37 % (10–76 %) in HF2 and 51 % (21–79 %) in HF1. High TN removal required a longer aeration time for nitrification and higher effluent recirculation ratio to enhance denitrification. The results indicate that artificial aeration and a high bed depth allows to increase the SLR by a factor of 4 in HF1 but only by a factor of 2 in HF2.

Distribution and migration of heavy metals in the sediment-plant system: Case study of a large-scale constructed wetland for sewage treatment

Constructed wetlands are extensively applied in wastewater treatment and water ecosystem restoration. However, the characteristics of heavy metals accumulation and migration in a long-running large-scale constructed wetland for wastewater treatment remain unclear. In this study, the variation of heavy metals (Cu, Zn, Pb, Cd, Cr, and As) in the sediment-plant system of a wetland that has been operating for 14 years was quantified. Results show that the sediments of the constructed wetland were the sink for heavy metals. All heavy metals, except As, significantly increased (P < 0.05) in sediments within 0–40 cm depth, and Zn and Cr had leaked to 40–60 cm depth (P < 0.05). Along with the surface flow direction, heavy metal concentrations mostly showed a declining trend, and in comparison, Cu and Cr transported longer distances. Bioconcentration factors show that the two common wetland plants, Phragmites australis and Typha latifolia, exhibited obvious differences in enrichment performance of heavy metals, with the orders of Zn > Cr > Cd > Cu > Pb > As and Cd > Zn > Cr > Cu > As > Pb, respectively. The translocation factors of the two kinds of plants were less than 1 suggesting that they are suitable for phytostabilization. Redundancy analysis indicates that sediment organic matter was the primary environmental factor affecting the distribution and migration of heavy metals in the wetland system. The discrepancy in the migration characteristics of pollutants, especially heavy metals, should be seriously considered in the design and management of wetland systems, including highly-enrichment plants, appropriate hydraulic residence time, and effective surficial filling medium.

Bacterial communities structure in constructed wetlands for municipal and industrial wastewater treatment in Tanzania

Abstract Bacteria are the largest and most essential microorganisms in wastewater treatment systems. Despite the vital role bacteria play in enhancing wastewater treatment, its community structure and diversity remain poorly known. This study elucidated bacterial diversity and community structure in constructed wetlands (CWs) for municipal and industrial wastewater treatment using a culture-independent approach. Analysis of physicochemical parameters and Illumina high-throughput sequencing of V3 and V4 hypervariable regions of 16S rRNA gene bacterial community was performed. The results showed that the Proteobacteria were dominant (48.66%) phyla across all CWs. The Gammaproteobacteria class (27.67%), family Comamonadaceae (35.79) and Genus Flavobacterium (4.35%) were dominant across studied CWs. Bacterial abundance increased from the inlet to the outlet, with CWs having a higher abundance around the outlet, showing a good performance. The Shannon–Wiener index showed the highest species diversity (H = 1.45) in Banana Investment Limited CWs treating industrial wastewater. This study found significant bacterial diversity across studied CWs, with higher abundance and diversity at the outlet indicating better performance than those with low abundance and diversity at the outlet. We recommend a longitudinal investigation at each CWs section to confirm and establish the role of bacterial diversity on the performance pattern of CWs.

Cost benefit analysis of integrated constructed wetland microbial fuel cell system for sustainable and economic domestic wastewater treatment

Wastewater treatment with integrated constructed wetland–microbial fuel cell technology has attracted serious attention from researchers. The economic sustainability of any potential technology is the key to its commercialization from laboratory to field application, which is fulfilled through an exhaustive assessment of the related costs and benefits. This article presents a comparative cost-benefit analysis of three reactors: constructed wetland (R1), integrated CW-MFC (R2), and unplanted CW-MFC (R3) for domestic wastewater treatment and economic sustainability assessment. The study was conducted with 36 h and 24 h hydraulic retention times of the reactors and the respective cost-benefit ratio was determined. Results revealed that R2 was the most sustainable option with maximum economic benefits during Phase 1 and Phase 2 without effluent disinfection. With effluent disinfection in place, R1 emerged with the best cost-benefit ratio due to less investment cost and low revenue from electricity production in R2 and R3. Sensitivity analysis with net investment cost, power density, electrode area, effective reactor volume, and hydraulic retention time; showed power density was the most influential parameter affecting the cost-benefit ratio. Revenue from wastewater treatment was found essential for economic sustainability which shows the importance of producing high-quality effluent and greater power density to make CW-MFC technology economically attractive.

Comparing the potential treatment of biogas effluent by two artificial wetland wastewater treatment systems

Comparing the potential treatment of biogas effluent by two artificial wetland wastewater treatment systems

Research Progress on the Decomposition Process of Plant Litter in Wetlands: A Review

Wetland is a transitional area where terrestrial ecosystems and aquatic ecosystems interact and influence each other, and it is an important ecosystem on the Earth’s surface. Due to the special characteristics of wetland ecology, the decomposition of wetland plant litter is slightly different from litter in forests, grasslands, and meadows and other traditional areas. The role of litter mineralization in the wetland ecological C cycle and the functional role of plant litter have been neglected. This study analyzes the decomposition mechanism and decomposition model of wetland litter material and focuses on the effects of the decomposition process of wetland litter material on the structure of the soil fauna community, decomposition of soil organic matter, sediment properties, and the dynamic changes in the C cycle of the biological system by combining domestic and international studies from recent years. Finally, we propose that the direction of future research on wetland litter decomposition should be to reveal the mechanism of wetland biodiversity and ecology, as well as the ecological correlation between aboveground and belowground biodiversity, with a view to providing a decision-making basis for wetland phytoremediation and wetland wastewater treatment.

Performance evaluation of a lab-scale subsurface flow-constructed wetland system for textile industry wastewater treatment.

This study compares biochar (BCW) systems' pollutant removal effectiveness to conventional subsurface flow (CCW) in constructed wetland systems to treat textile wastewater. The two systems were identical in construction, but the biochar was 0.1 m thick over gravel and sand (maximum flow rate of 0.021 m3 h-1) as the primary medium over CCW (flow rate of 0.02 m3 h-1). The results revealed that the BCW approach was more efficient than the CCW system (pebble over sand and gravels) in removing and lowering heavy metals below thresh hold limits such as Cr, Cd, Cu, Pb, Ni, and Zn. The alkaline nature of textile water achieves neutrality in both CCW and BCW. However, BCW is more efficient due to a larger active surface area and the ability to filter out more metal and organic ions. TDS reduction efficiency in BCW was 53.07%, compared to 40.04% in CCW. Heavy metal removal was 100% in BCW at 3 to 12 h, whereas it takes 6 to 24 h in CCW (82% for Cr to 93% for Cu). The quick removal of Na from textile wastewater by BCW was reversed and achieved equilibrium in 24 h in contrast to the CCW system (> 24 h). The findings obtained at the lab scale level demonstrated that the BCW system was more effective in reducing TDS, neutralizing the alkalinity of textile wastewater, and removing heavy metals. This study strongly supports the potential application of biochar-constructed wetlands for textile wastewater treatment.

Impact of the electrode, aeration strategies, and filler material on wastewater treatment in tidal flow wetlands

The present work reports the pollutants removal performance of the waste material-based non-aerated, intermittently, and continuously aerated normal and electrode-integrated tidal flow wetlands that received municipal wastewater. The tidal flow wetlands were operated under variable wastewater contact periods. The mean biochemical oxygen demand (BOD), ammonium‑nitrogen (NH4-N), total nitrogen (TN), total phosphorus (TP), and coliform removal percentage ranges were 74–99 %, 58–87 %, 65–85 %, 62–93 %, and 56–96 %, respectively. Nutrient removals declined in all tidal flow wetlands during the longest wastewater contact period. An opposite trend was observed with organic and coliform removals. The aerated tidal flow wetlands achieved better organic and nutrient removal than the non-aerated systems. Nutrient accumulation percentage in plant tissues ranged between 0.01 and 0.7 %. Power density production within the electrode-integrated tidal flow wetlands ranged between 4474 and 8199 mW/m3. This study demonstrates the necessity of external aeration to improve the performance of the normal and electrode-integrated tidal flow wetlands.

Assessment of contaminants, health and survival of migratory shorebirds in natural versus artificial wetlands – The potential of wastewater treatment plants as alternative habitats

The rapid destruction of natural wetland habitats over past decades has been partially offset by an increase in artificial wetlands. However, these also include wastewater treatment plants, which may pose a pollution risk to the wildlife using them. We studied two long-distance Arctic-breeding migratory shorebird species, curlew sandpiper (Calidris ferruginea, n = 69) and red-necked stint (Calidris ruficollis, n = 103), while on their Australian non-breeding grounds using an artificial wetland at a wastewater treatment plant (WTP) and a natural coastal wetland. We compared pollutant exposure (elements and per- and poly-fluoroalkyl substances/PFASs), disease (avian influenza), physiological status (oxidative stress) of the birds at the two locations from 2011 to 2020, and population survival from 1978 to 2019. Our results indicated no significant differences in blood pellet pollutant concentrations between the habitats except mercury (WTP median: 224 ng/g, range: 19–873 ng/g; natural wetland: 160 ng/g, 22–998 ng/g) and PFASs (total PFASs WTP median: 85.1 ng/g, range: <0.01–836 ng/g; natural wetland: 8.02 ng/g, <0.01–85.3 ng/g) which were higher at the WTP, and selenium which was lower at the WTP (WTP median: 5000 ng/g, range: 1950–34,400 ng/g; natural wetland: 19,200 ng/g, 4130–65,200 ng/g). We also measured higher blood o,o′-dityrosine (an indicator of protein damage) at the WTP. No significant differences were found for adult survival, but survival of immature birds at the WTP appeared to be lower which could be due to higher dispersal to other wetlands. Interestingly, we found active avian influenza infections were higher in the natural habitat, while seropositivity was higher in the WTP, seemingly not directly related to pollutant exposure. Overall, we found limited differences in pollutant exposure, health and survival of the shorebirds in the two habitats. Our findings suggest that appropriately managed wastewater treatment wetlands could provide a suitable alternative habitat to these migratory species, which may aid in curbing the decline of shorebird populations from widespread habitat loss.