Organic Matter Removal Efficiency Research Articles

Wastewater Treatment using the “Sulfate Reduction, DenitrificationAnammox and Partial Nitrification (SRDAPN)” Process

Although nitrogen removal from wastewater is essential to prevent eutrophication, the biological processes employed to this end are characterized by several disadvantages, including high energy consumption and the production of large quantities of sludge. Thus, in this study, the organic matter and nitrogen removal efficiencies of the new sulfate reduction, denitrification/anammox and partial nitrification (SRDAPN) process were examined using an anaerobic-anoxic-oxic biofilter reactor. The results showed that the organic matter removal efficiency of the new process at loading rate 1.0 kg COD/m3 per day was 97%. With a circulation flow from the oxic to the anoxic column that was 3 times influent, the nitrogen removal efficiency of the sulfur denitrification and nitrification (SRDN) process without anammox, was 66%, while that of the SRDAPN process with anammox was 76%. Additionally, nitrogen consumption by the anammox reaction in the anoxic column was 13.8% for nitrite-nitrogen and 10.5% for ammonium-nitrogen, and the withdrawal of excess sludge was not required throughout the 170 days of operation. Microbial community analysis showed that acetogenic sulfate reducing bacteria and acetoclastic methanogens coexisted in the anaerobic column, and in the anoxic column, the total relative abundance of anammox bacteria, including Candidatus Brocadia, which coexisted with heterotrophic denitrifying bacteria and sulfur denitrifying bacteria, was 17-18%. Thus, this study established the SRDAPN process as an energy saving and high removal efficiency process.

Kinetics of a fixed bed reactor with immobilized microorganisms for the removal of organic matter and phosphorous.

The biodegradation of domestic wastewater contaminants has been carried out using microorganisms immobilized in sodium alginate gel (Alg-Na). A fixed bed reactor with immobilized microorganisms was used for the treatment of domestic wastewater. A wastewater pretreatment was carried out to remove the larger particulate matter, which consisted of a reactor packed with different materials (anthracite, zeolite, and activated carbon). Later, a second reactor packed with balls with immobilized microorganisms was used to eliminate organic matter and nutrients. 2.5% w/v of Alg-Na was used as a support to immobilize the microorganisms. According to the results, a total phosphorus (TP) and chemical oxygen demand (COD) removal of 94.26% and 78.25% was obtained, respectively. In addition, the degradation rate for both organic matter and phosphorous was studied by using the kinetic model for fix bed reactor. © 2020 Water Environment Federation PRACTITIONER POINTS: Phosphorous and organic matter removal by adsorption and immobilized microorganisms. High removal efficiency of phosphorous and organic matter was found. An innovative wastewater treatment alternative is proposed. Kinetic model for fixed bed reactor is also proposed for scaling-up purposes.

Evaluation of TiO2 and SnO Supported on Graphene Oxide (TiO2-GO and SnO-GO) Photocatalysts for Treatment of Hospital Wastewater

The effectiveness of two photocatalysts, TiO2 and SnO, supported on graphene oxide (TiO2-GO and SnO-GO) on the removal of organic matter from hospital wastewater effluent was evaluated at laboratory scale. The results of the experimental design allow us to conclude that variables such as catalyst type and catalyst concentration have a significant effect on the organic matter removal efficiency of the photocatalytic process. The highest levels of removal efficiencies—for chemical oxygen demand, 85%, for phenols, 80%, and for dissolved organic carbon, 94%—were achieved using a TiO2-GO catalyst with a concentration in the wastewater of 1.5 g/L.

Filtration characteristics of garnet media before and after modification

Abstract High-temperature calcination was used to modify garnet media. Brunauer–Emmett–Teller (BET) measurements, X-ray diffractometer (XRD), scanning electron microscopy (SEM), zeta potential analysis, and a static adsorption experiment on humic acid removal were carried out to compare unmodified garnet and traditional quartz sand. Fitting adsorption isotherm of the media before and after modification was conducted to determine the adsorption type, and a dynamic filtration experiment was performed to treat micro-polluted water. Results of the characterization analysis and the static adsorption experiment revealed that, compared with the smooth surface of unmodified garnet, the surface of modified garnet media was covered with Fe2O3, which showed a rough concave-convex structure with a specific area that was 2.44 times larger than that of unmodified garnet. The removal efficiency of organic matter after modification increased from 2.5–4.5% to 51.7–63.1%, and the adsorption capacity increased 11–24 times. The adsorption type of the modified garnet media belongs to the Langmuir and Freundlich adsorption mode, while that of the original media belongs to the Freundlich adsorption mode. Results of the dynamic filtration experiment revealed that the effect of modified garnet media on turbidity, CODMn, and UV254 removal was better than that of unmodified garnet and traditional quartz sand.

Diclofenac and carbamazepine removal from domestic wastewater using a Constructed Wetland-Solar Photo-Fenton coupled system

The presence of pharmaceutical compounds in aquatic ecosystems may affect both biota and human health because these micropollutants are capable of altering the metabolism and reproduction capacity of the live organisms of the aquatic ecosystems. The main route of entry of these pollutants into the aquatic environment is through Wastewater Treatment Plants (WWTPs) effluents. Compounds such as diclofenac (DCF) and carbamazepine (CBZ) persist, undergoing little or no degradation during treatment. Coupled systems combining biological treatments and Advanced Oxidation Technologies (AOTs) represent an alternative to reduce the risk of the presence of pharmaceuticals in the environment by achieving high removal efficiency at a low cost. This research evaluated the performance of a coupled system integrated by Horizontal Subsurface Flow Constructed Wetland (CW HSSF) and Solar Photo-Fenton at laboratory scale under America tropical conditions for the removal of DCF and CBZ from domestic wastewater at 15 μg L−1, on average. Three Fe2 +/H2O2 ratios (0.1, 0.3, and 0.8) were tested. Concentrations of DCF, CBZ, organic matter (DOC), Total Nitrogen (TN), and in situ variables were measured throughout the experiment.Removal efficiencies up to 92% and 86% were achieved for DCF and CBZ, respectively, using the Fe2+/H2O2 ratio of 0.1. There were no significant differences between the Fe2+/H2O2 ratios used (p < .05), but significantly greater efficiencies were achieved when CW was coupled with solar Photo-Fenton (40% only CW and 92% coupled system). Additionally, the coupled system showed a removal efficiency of organic matter (DOC) and total nitrogen (TN) greater than 61%. The concentration of DOC and TN, pH, solar UV radiation, and peroxide consumption had no significant effect on the removal efficiency of DCF and CBZ.

Performance of Cyperus papyrus in constructed wetland mesocosms under different levels of salinity

Constructed wetlands (CWs) are consolidated technologies used for removing organic matter (OM) and nutrients (nitrogen (N) and phosphorus (P)) from wastewater. Recently, these systems have been implemented for treating wastewater under saline conditions. In this context, the aim of this study was to evaluate the effect of wastewater with different levels of salinity, expressed as electrical conductivity (EC), on the removal efficiencies of OM and on the growth of vegetation planted in CW mesocosms. For this, five horizontal subsurface flow constructed wetlands (HSSFs) planted with Cyperus papyrus were operated under different salinity levels: 1 (CW-C), 2.5 (CW-2.5), 5 (CW-5), 7.5 (CW-7.5) and 10 mS/cm (CW-10) using CW-C as a control system. To analyze the effects of different salinity levels, the removal efficiencies of chemical oxygen demand (COD) and biological oxygen demand (BOD5) were evaluated. Moreover, the growth characteristics of Cyperus papyrus were compared in the different CWs through the determination of chlorophyll concentration and nutrient contents in different plant tissues. The results of this study showed that the removal efficiencies of OM were above 50%. Regarding the effect of salinity on the removal of contaminants, the COD and BOD5 removals decreased 18% and 31%, respectively, from CW-C to CW-10 (p < .05). The sodium (Na+) concentration in Cyperus papyrus increased 82% when the salinity increased from 1 (CW-C) to 10 mS/cm (CW-10). In contrast, the chlorophyll concentration decreased 17% with increasing salinity (from 1 to 10 mS/cm). Finally, the vegetation presented mechanisms of salt tolerance, mainly Na+ accumulation in plant tissues. Despite these results, the technology of CWs could be a feasible alternative for the treatment of saline wastewater improving the plant selection.

Rheological measurements as indicators for hydrolysis rate, organic matter removal, and dewaterability of digestate in anaerobic digesters

The relationship between rheological properties and the hydrolysis rate in anaerobic digestion (AD) is poorly understood. This study investigated AD of waste-activated sludge (WAS) in batch digesters of 2.10%, 3.40%, 4.10%, and 5.02%TS digester media (WAS mixed with inoculum). The digesters operated below ammonia inhibition levels and at the same food to inoculum (F/I) ratios, temperature, and mixing. The results indicated that a decrease in the hydrolysis rate was associated with an increase in yield stress, the flow consistency index, and viscoelastic moduli. In addition, the statistical analysis revealed the linear relationships between changes in the flow consistency index and hydrolysis rate as well as the efficiency of organic matter removal, regardless of the types and origin of sludge, the F/I ratio, and the seasons when sampling occurred. A linear relationship between yield stress and dewaterability was also revealed. These findings indicate that the flow consistency index measurement could be a reliable method for monitoring the hydrolysis stage and organic matter removal in anaerobic digesters.

Influence of cosubstrates for linear anionic sulfonated alkylbenzene degradation and methane production in anaerobic batch reactors

This study evaluated the influence of cosubstrates, acetate, formate, and fumarate on the anionic surfactant degradation (linear alkylbenzene sulfonated - LAS), using anaerobic batch reactors at 30 °C, 50 rpm at 25.8 ± 0.2 mgLAS/L. Cosubstrates were tested separately for LAS degradation and methane production. Organic matter removal efficiency were 23 ± 1.2 %, 65 ± 2.8 %, 60 ± 5.6 %, 59 ± 0.8 % and 75 ± 2.7 %, for control without LAS (67 ± 11.9 mg/L), control with LAS (129 ± 27.2 mg/L), reactors with acetate (172 ± 19.8 mg/L), formate (126 ± 13.7 mg/L) and fumarate (332 ± 16.3 mg/L). Methane production for the experimental series was 0.072 ± 0.002 μmol, 0.6 ± 0.07 μmol, 1.69 ± 0.11 μmol, 1.51 ± 0.15 μmol and 2.18 ± 0.24 μmol in control reactors in the absence and presence of LAS and with the acetate, formate and fumarate, respectively. Under the nutritional conditions with cosubstrates, there was a higher LAS degradation in both dissolved and adsorbed fraction in anaerobic biomass. These cosubstrates can directly assist the metabolic pathways of microorganisms for energy generation and toxic removal. Among the cosubstrates tested, fumarate favored greater LAS degradation reaching a removal efficiency of 98.3 ± 0.8 % for 26 ± 1.13 mg/L of surfactant and also provided higher methane production in anaerobic batch systems.

Effect of air flow, intermittent aeration time and recirculation ratio in the hydrodynamic behavior of a structured bed reactor

Among the novel system configurations that remove organic matter and nitrogen simultaneously, the structured bed reactor with recirculation and intermittent aeration (SBRRIA) can be mentioned. Studies addressing the SBRRIA have shown high efficiency of organic matter and nitrogen removal, as well as low sludge production. However, operational parameters such as the recirculation rate, intermittent aeration time, and airflow are not fully established. Therefore, this research aimed to evaluate the effect of these three parameters on the mixing characteristics of an SBRRIA adopting established hydrodynamic models, also proposing a new flow model for the reactor. Hydrodynamic tests were performed using sodium chloride as a tracer, and the variables were the recirculation rate, intermittent aeration time, and airflow. Results showed that the reactor presented a plug-flow behavior when the aeration was turned off and behaved as a completely stirred reactor when the aeration was turned on. Traditional models were not sufficient to explain the flow of the SBRRIA, resulting in the development of a simplified programming pseudo-code to adequately represent the flow in the reactor. The tested airflow and recirculation rates did not affect the mixing behavior in the SBRRIA. These observations represent a significant advance in SBRRIA studies as they show that energy consumption could be optimized, making the system even more advantageous by saving electrical energy up to 75% due to pumping.

Post-treatment of stabilized landfill leachate by upflow gravel filtration and granular activated carbon adsorption

ABSTRACT Stabilized leachates from sanitary landfills generally display high levels of recalcitrant organic matter, sometimes requiring a combination of biological and physicochemical treatment processes. This study evaluated the post-treatment by Upflow Gravel Filtration (UGF) followed by Granular Activated Carbon Adsorption (GACA) on a pilot scale of two different landfill leachates previously treated by biological processes. The system design was proven technically feasible for a continuous flow post-treatment in relation to recalcitrant organic matter removal efficiency. The UGF experiments presented 83.9% and 82.0% COD removals for leachates A and B, respectively, with residual values of 107 and 194 mg L−1. The UGF-GACA experiments, in turn, produced effluents with residual COD values of 67 and <60 mg L−1 for leachates A and B, respectively, corresponding to 89.9% and >94.6% efficiencies.

The role of synergistic effects between ozone and coagulants (SOC) in the electro-hybrid ozonation-coagulation process

In order to improve the dissolved organic matter removal efficiency, an electro-hybrid ozonation-coagulation (E-HOC) system was developed in this study, in which the electro-coagulation (EC) and ozonation occurred simultaneously in one integrated unit. Higher removal efficiency was observed for the E-HOC process compared with those of EC, ozonation and pre-ozonation-EC process for the treatment of wastewater treatment plant (WWTP) effluent and ibuprofen (IBP). 58.6% dissolved organic carbon (DOC) removal efficiency was achieved in the E-HOC process for the treatment of WWTP effluent at optimal operational condition (current density 15 mA/cm2, initial pH 5 and ozone dosage 1.5 mg O3/mg DOC). Based on the reactive oxygen species (ROS) detection and reactions on the electrodes, the synergistic effects between ozone and coagulants (SOC) were found to be involved in the E-HOC process. According to pseudo-first-order rate constant analyses, the contribution of five possible organic removal pathways was quantified. It was revealed that the peroxone and SOC effects exhibited almost equal contribution to IBP removal at initial pH 5 under different current densities, both of which played the dominant role in the E-HOC process. However, the contribution of the SOC effects decreased significantly when the initial pH increased to 7 and 9. As an important pathway for organic removal in the E-HOC process at initial pH 5, the mechanism of the SOC effects was analysed at initial pH 5. It was revealed the SOC effects can further improve hydroxyl radicals (•OH) generation, and the surface hydroxyl groups of the hydrolysed Al species generated from anode electrolysis were determined to be the active sites to generate ROS in the SOC effects.

Natural purification capacity of tidal flats for organic matters and nutrients: A mesocosm study

The regulating services by natural tidal flats to purify organic pollutants are increasingly recognized, but a quantitative assessment is very limited. We developed a mesocosm system to determine removal efficiency of organic matters and nutrients by simulating a natural tidal condition. The tidal flat sediments significantly removed waterborne organic pollutants to background levels in ~2 and 6–7 days for COD and TP, respectively. This rapid removal of organic matters by natural sediments could be attributed to the microbe community degrading the corresponding pollutants. Temporal trend and degree of removal rates for COD and TP were similar between the bare tidal flat and the salt marsh. Meantime, the salt marsh environment removed waterborne DIP much quickly and also efficiently, implying a high affinity of halophytes on dissolved organic matters. Of note, sedimentary organic sink prevailed in defaunated condition under the smaller bioturbation effect. A mini-review on the purification capacity of natural and/or constructed coastal wetlands generally supported a high efficiency of vegetation to remove various sources of organic matters.

Effect of Using a Ceramic Separator on the Performance of Hydroponic Constructed Wetland-Microbial Fuel Cell

Lack of proper physical separation between the anodic and cathodic zones of a constructed wetland-microbial fuel cell (CW-MFC) causes higher oxygen diffusion into the anodic zone, which leads to nonproductive electron losses. In this investigation, performance of two upflow hydroponic CW-MFCs with a low-cost ceramic separator (R1) and without a separator (R2) was evaluated with Canna indica at the cathodic side. The chemical oxygen demand removal efficiencies of R1 and R2 were found to be 86.2 ± 8.1% and 91.5 ± 4.9%, respectively. However, from the polarization plots, internal resistance of R1 (240 Ω) was found to be 2.6 times lower than that of R2 (626 Ω). In addition, it was revealed that R1 (258.78 mW·m−3) exhibited almost three times higher power density than R2 (91.02 mW·m−3). The normalized energy recovery of the CW-MFC with a ceramic separator was also 2.7 times higher than that without a separator. The presence of a separator thus facilitated better anaerobicity to support substrate utilization by electrogenesis in the anodic zone of R1 and prevented oxygen diffusion, which resulted in higher energy recovery while only marginally compromising the efficiency of organic matter removal.

A hydroponic green roof system for rainwater collection and greywater treatment

A hydroponic green roof system (HGRS) was developed to reduce urban storm water runoff and to meet the demand of collecting, treating, and reusing grey- and rainwater onsite in green buildings. This system works by treating greywater separately during periods without precipitation and by simultaneous rainwater collection and greywater treatment during rainy periods. Therefore, we first studied the performance of this system when greywater was treated separately under the three hydraulic retention times (HRTs) of 4, 6, and 8 days. Thereafter, we studied this system as it simultaneously collected rainwater and treated greywater under an HRT of 8 days. The results show that, at this HRT, the removal efficiency of organic matter and anionic surfactants, as well as a decrease in turbidity, were quite significant in this system. The average reduction in chemical oxygen demand (COD), five-day biochemical oxygen demand (BOD5), anionic surfactants, and decrease in turbidity reached 81%, 97%, 88%, and 75%, respectively. Microbial sequencing showed the presence of organisms (i.e., Phenylobacterium) in the system that were capable of degrading anionic surfactants. The relative abundance of Phenylobacterium was closely related to the changes in the anionic surfactant concentration, while the microbial species richness gradually increased with extended treatment time. When this system collected rainwater and treated greywater simultaneously, the COD, BOD5, and anionic surfactant concentration in the effluent were lower than when greywater was treated alone, resulting in superior water quality.

Chlorella vulgaris on the cathode promoted the performance of sediment microbial fuel cells for electrogenesis and pollutant removal

The lack of electron acceptors in cathode has limited the widespread application of sediment microbial fuel cells (SMFCs). In this study, Chlorella vulgaris (C. vulgaris) was added to the cathode to produce oxygen as an electron acceptor. The synergistic effects between C. vulgaris and electrogenic microorganisms in SMFCs were investigated, and were shown to enhance biodegradation of organic matter in sediments and convert chemical energy into electrical energy. Results showed that the addition of C. vulgaris on the cathode of SMFCs significantly reduced their internal resistance. The low algae concentration SMFC group reduced the initial internal resistance by 67.4% under illumination and produced a maximum power density of 5.17 W/m3, which was 6 times higher than that of SMFCs without addition of C. vulgaris. We also obtained organic matter removal efficiencies 37.2% higher after 16 days, which accelerated the startup time for three times. It was demonstrated that IEF-N and OP, respectively, were forms of nitrogen and phosphorus removed by SMFCs. Additionally, high-throughput sequencing of microbial communities indicated that C. vulgaris increased the abundance of electrogenic bacteria (Geobacter and Desulfobulbaceae) in the anode and types of photosynthetic bacteria that support oxygen production in the cathode. The combined application of microalgae- and SMFC-based technologies offer a promising remediation approach for organically-contaminated sediments.

Characteristics of refractory organics in industrial wastewater treated using a Fenton-coagulation process

ABSTRACT It is a challenging environmental issue to develop a cost-efficient approach for the removal of low-concentration refractory organics in industrial wastewater. In this study, the Fenton-coagulation process was utilised to remove the organics from the industrial effluent. The operational conditions of the Fenton-coagulation process were optimised, and then, the molecular weight (MW) and resin fraction distribution of dissolved organic matter (DOM) were investigated before and after the Fenton-coagulation process. The results showed that the efficiency of organic matter removal was affected by the Fe2+/H2O2 molar ratio, pH, and reaction time. The removal rate of chemical oxygen demand (COD) by Fenton-coagulation process reached 37.8% under the following conditions: pH = 4.0 − 5.0, H2O2 concentration = 34 mg/L, Fe2+/H2O2 molar ratio = 1.5, and reaction time = 120 min. The resin fraction distribution results showed that hydrophobic bases (HoB) were almost completely removed, and the removal rate of hydrophobic acids (HoA) reached 58%, while hydrophilic matter (HiM) became the dominant form in the final effluent after the Fenton-coagulation process due to the appearance of hydrophilic charged fractions (HiC). The results were explained by a two-step mechanism (Fenton oxidation and Fe3+ coagulation). According to the molecular weight (MW), 35.7% removal of the main fractions of organic matter with MW < 1 kDa was achieved. Furthermore, a pilot test proved that the final effluent quality after the Fenton-coagulation process conformed to the first class of the A discharge standard of pollutants for municipal wastewater treatment plants in Tianjin.

Effects of carbon to nitrogen ratio on the performance and stability of aerobic granular sludge

The purpose of this study was to assess the nutrient salts removal efficiency and stability of the aerobic granular sludge (AGS) by change in C/N (carbon to nitrogen) ratio. The laboratory-scale experiments were performed to analyze the removal efficiencies for organic matter and contents of nitrogen, MLSS, sludge volume index, and extracellular polymeric substances (EPS) under C/N ratio conditions of 5.0, 10.0, 15.0, and 20.0. The microorganisms were observed using optical microscope and the microbial communities were analyzed using pyrosequencing. The increase in C/N ratio from 5.0 to 20.0 increased the organic matter and nitrogen removal efficiency to 95.9 and 79.1%, respectively. For the EPS contents, an influencing factor of granule stability, the polysaccharides to protein (PS/PN) ratio increased from 0.55 to 0.79. For the microbial community, the &lt;i&gt;Thauera&lt;/i&gt; was the most common genus in ending phase occupying 63.7%. This microorganism is regarded as one contributing to organic matter degradation and improved production of EPS including AGS of microorganism, thus, may be an explanation of the results of this study such as increase in organic material in AGS and improvement of denitrification efficiency and contents of EPS with increase in C/N ratio.

Performance improvement of an integrated anaerobic-aerobic hybrid reactor for the treatment of swine wastewater

In this study, performance of a lab-scale anaerobic-aerobic hybrid reactor, treating swine wastewater was evaluated under three different organic loading rates (OLR). The operating of integral hybrid system consisted of two experimental sections: first, an UASB section, and second, a UASB section + aerobic packed-bed with polyethylene rings. During the reactor operation, three assays of SMA were carried out and according to these results (0.26, 0.32 and 0.81 kg COD-CH4/kg VSS·d), the OLR was gradually step increased from 3.26 to 4.02 and finally 10.14 kg COD/m3·d. With this strategy, the removal efficiency of organic matter during the last operational condition increased 34.3% compared to the initial, using the SMA as a control tool. In addition, the nitrogen accumulated that could not be removed in the UASB section was treated by the aerobic packed bed, by nitrification-denitrification simultaneous achieving almost a total removal. This removal was attributed 55 ± 11% to nitrification process, 30% to denitrification and stripping were 11 ± 1%. Therefore, this anaerobic-aerobic hybrid reactor is an integral unit that allowed greater operating efficiencies than other hybrid systems that operate in two or more units, and is capable of complying with current regulations for discharge to water bodies.

Recirculating aquaculture system with three phase fluidized bed reactor: Carbon and nitrogen removal

The core objective of the study was to evaluate the organic matter and nitrogen removal efficiency in a recirculating aquaculture system for the intensive laboratory-bred rainbow trout. The treatment system consisted of an upflow reactor which operated at a hydraulic retention time (HRT) of 18 and 36 min, a pre-filtration unit with HRT of 4.9 and 9.8 min, a three-phase airlift fluidized bed reactor operated at HRT between 5 and 11 min, a granular unit for the upflow and the fluidized bed reactors effluents filtration with 5.8 and 11.6 min as HRT, and an ultraviolet (UV) unit for the final effluent disinfection. A plastic material was used as support media in the upflow reactor, and granular zeolite with an effective size of 1.30 mm in an 80 g/L constant concentration was used as a carrier for the fluidized bed reactor. Average removal efficiencies of biochemical oxygen demand (BOD) chemical oxygen demand (COD), ammonium, nitrite, nitrate, and total nitrogen were 94.4, 91.7, 52.5, 13.4, 1.3 and 6.0% respectively. In the rainbow trout rearing tanks, there was a water volume of 125 L and water exchange rates of 125 and 250 L/h, there were no registered mortalities; the calculated daily weight gains were 1.55 and 1.51 g/day and the final stocking densities were respectively 20.87 and 20.58 kg/m3. The results suggested that the system had the capability to develop a nitrification process for maintaining water quality characteristics within the recommended values for rainbow trout farming, but total nitrogen was not effectively removed due to the weak denitrification process, since there were modest values of nitrite and overall nitrogen removal.

Anoxic-biocathode microbial desalination cell as a new approach for wastewater remediation and clean water production.

Bioelectrochemical systems are emerging as a promising and friendly alternative to convert the energy stored in wastewater directly into electricity by microorganisms and utilize it in situ to drive desalination. To better understand such processes, we propose the development of an anoxic biocathode microbial desalination Cell for the conversion of carbon- and nitrogen-rich wastewaters into bioenergy and to perform salt removal. Our results demonstrate a power output of 0.425 W m-3 with desalination, organic matter removal and nitrate conversion efficiencies of 43.69, 99.85 and 92.11% respectively. Microbiological analysis revealed Proteobacteria as the dominant phylum in the anode (88.45%) and biocathode (97.13%). While a relatively higher bacterial abundance was developed in the anode chamber, the biocathode showed a greater variety of microorganisms, with a predominance of Paracoccus (73.2%), which are related to the denitrification process. These findings are promising and provide new opportunities for the development and application of this technology in the field of wastewater treatment to produce cleaner water and conserve natural resources.