Simultaneous Carbon Removal Research Articles

Exploring the promoting behavior of weak electric mediation on indole and pyridine biodegradation under anaerobic condition

Indole and pyridine, which are highly produced refractory compounds in the industrial wastewater, exhibit poor degradation capabilities in natural environments. In this study, we developed an anaerobic digestion system coupled with weak electric mediation (ED), and investigated the promoting effect of weak electricity on indole and pyridine biodegradation. The degradation characteristics were systematically explored, and the results showed that the degradation rate and mineralization of indole and pyridine were significantly enhanced, the production of CH4 was increased 1.4-fold, and the optimal voltages were 1.0 V and 0.8 V in the ED, respectively. Moreover, simultaneous removal of carbon and nitrogen was achieved. Gas chromatography–mass spectrometry analysis verified the transformation products, and possible pathways were proposed. Several byproducts of indole and pyridine were identified, with oxindole and glutaric dialdehyde being the main metabolites, respectively. Additionally, density functional theory (DFT) analysis was performed to investigated the radical indices and stabilities of the molecules to further confirm the degradation pathway. Microbial structure analysis demonstrated that the electrically mediated enhanced metabolism and activity of functional microbes, led to the promotion of indole and pyridine mineralization. Moreover, such species as degrading bacteria (Alicycliphilus, Shinella) and electroactive bacteria (Achromobacter), anaerobic ammonia-oxidizing bacteria (SM1A02), and denitrifying bacteria (Thiobacillus) coexisted. This study demonstrates that weak electric mediation is a promising methodology for enhancing the removal of indole and pyridine from wastewater under anaerobic conditions.

Aerobic granulation and resource production under continuous and intermittent saline stress

Three sequential batch reactors (SBR) were operated to evaluate salt addition's impact on granulation, performance, and biopolymer production in aerobic granular sludge (AGS) systems. System R1 was fed without adding salt (control); system R2 operated with saline pulses, i.e., one cycle with salt (2.5 g NaCl/L) addition followed by another without salt; and R3 received continuous supplementation of 2.5 g NaCl/L. The results indicated that the reactors supplemented with salt presented higher concentrations of mixed liquor volatile suspended solids (MLVSS) and better settleability than R1, showing that osmotic pressure contributed to biomass growth, accelerated granulation, and improved physical characteristics. The faster granulation occurred in R2, thus proving the beneficial effects of intermittent salt addition through alternating pulses. Salt addition did not impair the simultaneous removal of carbon, nitrogen, and phosphorus. In fact, R2 showed better carbon removals. In conclusion, continuous or intermittent (pulsed) supplementation of 2.5 g NaCl/L did not lead to increased production of extracellular polymeric substances (EPS) and alginate-like exopolymers (ALE). This outcome could be attributed to the low saline concentration employed, a higher food-to-microorganism (F/M) ratio observed in R1, and possibly greater endogenous consumption of biopolymers in the famine period in R2 and R3 due to the greater solids retention time (SRT). Therefore, this study brings important results that contribute to a better understanding of the effect of salt in continuous dosing or in pulses as a selection pressure strategy to accelerate granulation, as well as the behavior of the AGS systems for saline effluents.

New insights into microbial community for simultaneous removal of carbon and nitrogen via heterotrophic nitrification aerobic denitrification process

Heterotrophic nitrification aerobic denitrification (HNAD) process is considered to be a promising strategy for efficient removal of nitrogen and refractory organic pollutants from aquatic environments. However, isolated single strains or microbial communities of HNAD in most studies suffer from severe inadaptability in the face of complex aquatic environments. Therefore, the existence of fundamental microbial communities that is able to adapt to contaminants through shaping its structure and then remove the pollutants is a promising solution to this deficiency. Herein, we introduced three aromatic compounds (ACs) (2,4,6-Trinitrotoluene, Aniline, and Phenanthrene), and established HNAD microcosms containing the different ACs and nitrogen through aeration. Impressively, the removal efficiencies of aerobic microcosms were nearly 94.5%, 99.4% and 100% for 2,4,6-Trinitrotoluene, Aniline and Phenanthrene, respectively, and above 90% for total nitrogen (TN), demonstrating superior ACs and nitrogen elimination capabilities. Meanwhile, analysis of microbial community structure and symbiont networks exhibited that there are eight commonly dominant genera in different microcosms, namely Arthrobacter, Bacillus, Sphingobium, Massilia, Novosphingobium, Noviherbaspinrillum, Lysobacter and Azohydromonas. Notably, these core bacteria changed only in relative abundance with the microcosms, and had been proven that they all have laudable carbon and nitrogen conversion capabilities. This finding confirmed the existence of basic microbial communities whose dominant species coordinate with each other to adapt to different water environments for the purpose of water purification. Finally, the mechanism of nitrogen transformation at both gene and enzyme levels was revealed by KEGG enrichment analysis. Summarily, this study will provide valuable references for future development of water treatment technologies.

Achieving simultaneous removal of carbon and nitrogen by an integrated process of anaerobic membrane bioreactor and flow-through biofilm reactor

In this study, a combined system consisting of an anaerobic membrane bioreactor (AnMBR) and flow-through biofilm reactor/CANON (FTBR/CANON) was developed to simultaneously remove carbon and nitrogen from synthetic livestock wastewater. The average removal efficiencies of total nitrogen (TN) were 64.2 and 76.4% with influent ammonium (NH4+-N) concentrations of approximately 200 and 500 mg/L, respectively. The COD removal efficiencies were higher than 98.0% during the entire operation. Mass balance analysis showed that COD and TN were mainly removed by the AnMBR and FTBR/CANON, respectively. The anammox process was the main nitrogen removal pathway in the combined system, with a contribution of over 80%. High functional bacterial activity was observed in the combined system. Particularly, an increase in the NH4+-N concentration considerably improved the anammox activity of the biofilm in the FTBR/CANON. 16S rRNA high-throughput sequencing revealed that Methanosaeta, Candidatus Methanofastidiosum, and Methanobacterium were the dominant methanogens in the AnMBR granular sludge. In the CANON biofilm, Nitrosomonas and Candidatus Kuenenia were identified as aerobic and anaerobic ammonium-oxidizing bacteria, respectively. In summary, this study proposes a combined AnMBR and FTBR/CANON process targeting COD and nitrogen removal, and provides a potential alternative for treating high-strength wastewater.

Unraveling microbial characteristics of simultaneous nitrification, denitrification and phosphorus removal in a membrane-aerated biofilm reactor

This study describes the simultaneous removal of carbon, ammonium, and phosphate from domestic wastewater by a membrane-aerated biofilm reactor (MABR) which was operated for 360 days. During the operation, the maximum removal efficiencies of chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) reached 93.1%, 83.98%, and 96.41%, respectively. Statistical analysis showed that the MABR could potentially treat wastewater with a high ammonium concentration and a relatively low C/N ratio. Dissolved oxygen and multiple pollutants, including ammonium, carbon, phosphate, and sulfate, shaped the structure of the microbial community in the MABR. High throughput sequencing uncovered the crucial microbiome in ammonium transformation in MABR. Phylogenetic analysis of the ammonia monooxygenase (amoA) genes revealed an important role for comammox Nitrospira in the nitrification process. Diverse novel phosphate-accumulating organisms (Thauera, Bacillus, and Pseudomonas) and sulfur-oxidizing bacteria (Thiobacillus, Thiothrix and Sulfurimonas) were potentially involved in denitrification in MABR. The results from this study suggested that MABR could be a feasible system for the simultaneous removal of nitrogen, carbon, phosphorus, and sulfur from sewage water.

Coupling Iron Sludge Addition and Intermittent Aeration for Achieving Simultaneous Methanogenesis, Feammox, and Denitrification in a Single Reactor Treating Fish Sludge.

An integrated anaerobic digestion system for the simultaneous removal of carbon and nitrogen from fish sludge was developed by coupling iron sludge supplementation with intermittent aeration. In terms of nitrogen removal, Fe(III) in iron sludge could trigger Feammox reactions and intermittent aeration could drive the Fe(II)/Fe(III) cycle to sustain continuous ammonia removal. Mass balance analysis suggested that nitrate was the main product of Feammox, which was subsequently removed through heterotrophic denitrification. In terms of carbon removal, the Fe(III)-induced dissimilatory iron reduction (DIR) process significantly promoted fish sludge hydrolysis and provided more simple organics for methanogens and denitrifiers, but aeration showed a negative impact on methanogenesis. To promote nitrogen removal and avoid serious methanogenesis inhibition, different aeration intensities were studied. Results showed that compared with the control without aeration or iron sludge addition, aeration for 5 min every 3 days (150 mL/min) contributed to a 29.0% lower NH4+-N concentration and a 12.1% lower total chemical oxygen demand level on day 28, and the decline in methane yield was acceptable (only 13.5% lower). Simultaneous methanogenesis, Feammox, and denitrification in a single reactor treating fish sludge were achieved, which provides a simple and low-cost strategy for the treatment of organic wastewater.

Impact of Influent Composition and Operating Conditions on Carbon and Nitrogen Removal from Urban Wastewater in a Continuous-Upflow (Micro)Aerobic Granular Sludge Blanket Reactor

Aerobic granular sludge is an interesting alternative to the conventional activated sludge (CAS) system and modified-Ludzack–Ettinger (MLE) process for biological wastewater treatment, as it allows a more cost-effective and simultaneous removal of carbon (C) and nitrogen (N) compounds in a single stage. In this study, (micro)aerobic C and N removal from synthetic urban wastewater was investigated in a continuous-double-column-upflow aerobic granular sludge blanket (UAGSB) system. The UAGSB reactor was operated under different dissolved oxygen (DO) ranges (0.01–6.00 mg∙L−1), feed C/N ratios (4.7–13.6), and hydraulic retention times (HRTs) (6–24 h). At a DO range of 0.01–0.30 mg∙L−1, feed C/N ratio of 13.6, and HRT of 24 h, the UAGSB achieved the highest chemical oxygen demand (COD), N-NH4+, and total inorganic nitrogen (TIN) removal efficiencies of 86, 99, and 84%, respectively. A preliminary assessment of the energy and economic savings associated with the process investigated was also carried out. The impact of capital and operating costs mainly related to the energy consumption of the aeration was taken into account. The assessment reveals that the capital and energy expenses of the UAGSB reactor would result in cost savings of around 14 and 7%, respectively, compared with a MLE system.

Advanced treatment of municipal reverse osmosis concentrate by a hybrid ozone-membrane aerated biofilm reactor system

Municipal reverse osmosis concentrate (mROC) possesses some characteristics, such as complex composition, poor biodegradability and high salinity. If mROC is discharged directly to the environment, it will cause serious damage to the ecological system. In this study, a hybrid ozone-membrane aerated biofilm reactor (O3-MABR) system was designed to treat mROC. This hybrid system combined the high efficiency of ozone to degrade refractory substances with the simultaneous removal of carbon and nitrogen in MABR. The effects of operating conditions including the ozone oxidation time, aeration pressure, hydraulic retention time (HRT) and the content of external carbon source on the system performance were investigated. Under the optimal parameters (ozone oxidation time was 10 s, aeration pressure and HRT of MABR-1 were 0.002 MPa and 28 h, respectively, and aeration pressure, HRT and carbon source addition amount of MABR-2 were 0.01 MPa, 22 h and 125 mg COD/L, respectively.), the average effluent COD and TN concentration of the coupling system were 41.4 mg/L and 12.3 mg/L, respectively, which met the Class A of the Discharge standard of pollutants for wastewater treatment plants (WWTP) (GB18918-2002). Furthermore, it revealed that the main phyla in biofilms of MABR were Proteobacteria and Firmicutes via high-throughput sequencing technology. This work had successfully developed an effective advanced treatment process of mROC, which lays a favorable foundation for subsequent technical promotion and applied research.

Elucidating the elevated salinity effect on removal of carbon and nitrogen in coupling aromatic degradation to anaerobic denitrification

Denitrification-dependent aromatics anaerobic degradation in saline environments have been unsuspected recently. In this study, the elevated salinity inhibition on denitrification-dependent degradation of aromatic compounds was investigated in an up-flow anaerobic fixed bed (UAFB) reactor, microbiota associated with aromatics and nitrogen conversion, and osmoregulation triggered by different salinities were also deciphered. Results showed that increasing salinity from 0% to 3% significantly limited the removal of organics and nitrate, decreasing from 72.47% to 72.20%, 25.14%, and 19.80%, respectively. The gene abundance of nirB decreased from 0.011 to 0.015% to 0.003–0.005%, inhibiting the nitrate reduction process under salt stress. Methane yield also significantly declined from 27.33 to 58.18% to 1.19–2.85%, which was attributed to acetate accumulation and increased ammonia concentration under salt stress. And the enriched genera Pelotomaculum, candidate_division_Zixibacteria, Syntrophus, Mesotoga, and candidate_division_Hyd24-12 under salt stress were involved in the salinity inhibition on methanogenesis. Increasing salinity facilitated the osmoregulation capacity of compatible solutes, and glutamate, and trehalose were dominant at 3% salinity, accompanied by Na+/K+ expulsion. It provided a deeper understanding of the simultaneous removal of carbon and nitrogen under saline stress.

Simultaneous removal of carbon, nitrogen, and phosphorus from landfill leachate using an aerobic granular reactor

In this study, aerobic granular reactor (AGR) was used to treat landfill leachate by changing the concentrations of chemical oxygen demand (COD) (668 ± 110-1149 ± 93 mg/L), ammonia (NH 3 –N) (30 ± 3.3-48 ± 1.3 mg/L), and phosphorus (PO 4 –P) (147 ± 18-221 ± 17 mg/L). The average COD removal was gradually reduced from 81 to 75%, increasing COD concentrations from 668 ± 110 to 1149 ± 93 mg/L. In phase I, the maximum removal of COD (94%) and NH 3 –N (85%) were observed at influent concentrations of 668 ± 110 mg/L and 30 ± 3.3 mg/L, respectively. Significant removal of PO 4 –P was observed, resulting in a maximum of up to 87%, further reducing up to 34% due to an increase in influent PO 4 –P concentration. The SVI 30 reduced from 77 mL/g to 24.15 mL/g towards the end of phase III indicates the formation of granular biomass. The stability of AGR was also investigated in extreme conditions like shut-down and shock-loading phases. The treatment of real leachate diluted with wastewater ( ∼ 20:80% v/v) in AGR showed a significant COD, NH 3 –N, and PO 4 –P removal of 62%–65%, 61%–93%, and 56%–64%, respectively. Mass balance analysis indicated that the AGR requires a lower nitrogen percentage for microbial assimilation than the COD and phosphorus. Proteobacteria and Planctomycetes were identified as the predominant (80%) bacterial community in aerobic granules responsible for removing COD, NH 3 –N, and PO 4 –P from leachate using AGR. The maximum biodegradation rate ( r max ) and half-saturation constant ( K s ) of COD in AGR were determined as 123.5 mg/L h and 309 mg/L, respectively. • Aerobic Granular Reactor (AGR) successfully treated landfill leachate. • Carbon, nitrogen, and phosphorus simultaneously removed using AGR. • A decrease in sludge volume index (SVI 30 ) indicates granule formation. • AGR showed better performance at higher shock loading of leachate. • Proteobacteria and Planctomycetes are predominant species in AGR.

Organic matter and nutrient removal in a combined anaerobic–aerobic fixed-bed reactor treating digestate from anaerobic biodigester

Anaerobic digestion has become a possible approach for treating organic fraction of urban solid waste. However, the treatment of the digestate is still a matter for technological development. In this work a single anaerobic–aerobic fixed-bed reactor subjected to recirculation was used to treat the effluent from an anaerobic digester fed with organic food waste. The reactor was operated for 100 days, with hydraulic retention time of 24 h. The organic loading rate applied was 1 kg COD m−3 d−1. The efficiency in removing nitrogen, organic matter, and phosphorus were 73%, 83%, and 23%, respectively. This reactor configuration proved to be quite promising to promote simultaneous removal of carbon, nitrogen, and phosphorus from effluents with high nitrogen and organic matter contents.

Candida tropicalis prompted effectively simultaneous removal of carbon, nitrogen and phosphorus in activated sludge reactor: Microbial community succession and functional characteristics

A new Candida tropicalis that simultaneously remove nitrogen and phosphorus, and degrade organic matters was isolated. Three continuous stirred tank reactors inoculated with C. tropicalis, activated sludge, and their co-existing system in aerobic condition were operated for 150 days. Results demonstrated that the inoculation of C. tropicalis in the co-existing system remarkably improved the carbon, nitrogen, and phosphorus removal efficiencies. The co-existing system had increased carbon, nitrogen, and phosphorus removal efficiencies (92%, 73%, and 63%, respectively); decreased biomass (reduced from 1200 mg/L to 500 mg/L); and C. tropicalis as the dominant strain. The relative abundance of traditional nitrogen- and phosphorus-removing microorganisms, such as Mycobacterium, Flavonifactor, and Devsia, increased in the co-existing system. Metagenomic analysis showed that the presence of the PCYT2, EPT1, and phnPP genes and more complexed metabolism pathways in the co-existing system might be responsible for the more activated metabolism process.

Treatment of polyacrylamide-polluted wastewater using a revolving algae biofilm reactor: Pollutant removal performance and microbial community characterization

Industries such as oil mining face challenges in the treatment of polyacrylamide (PAM)-containing wastewater produced during petroleum extraction. The feasibility of using revolving algae biofilm (RAB) reactors to treat PAM-contaminated wastewater for simultaneous removal of carbon and nitrogen was evaluated. The presence or absence of external nitrogen sources had a significant impact on the treatment effect of the RAB system. With the additional N source, the PAM, COD, TOC, and TN removal rates were 64.1 ± 2.0, 58 ± 1.5, 34.5 ± 1.5, and 85 ± 6.0%, respectively. High-throughput sequencing showed that the biofilms on RAB reactors contained a variety of bacteria, cyanobacteria, and green algae, degrading PAM through various mechanisms. The results of infrared spectroscopy analysis indicate that the product of these processes was carboxylic acid. Based on these results, it was concluded that RAB systems can be effectively applied to the treatment of polymer-containing wastewater.

Candida Tropicalis Prompted Effectively Simultaneous Removal of Carbon, Nitrogen and Phosphorus in Activated Sludge Reactor: Microbial Community Succession and Functional Characteristics

Candida Tropicalis Prompted Effectively Simultaneous Removal of Carbon, Nitrogen and Phosphorus in Activated Sludge Reactor: Microbial Community Succession and Functional Characteristics

Effect of calcium addition to aerobic granular sludge systems under high (conventional SBR) and low (simultaneous fill/draw SBR) selection pressure

This paper investigated the effect of calcium addition on the formation and properties of aerobic granules under high (conventional SBR) and low (simultaneous fill/draw SBR) selection pressure. Additionally, the simultaneous removal of carbon, nitrogen, and phosphorus, and the operational stability were assessed. The conventional SBRs showed earlier granule development (20 days) than the simultaneous fill/draw SBRs. The effect of calcium on granulation was more accentuated in conventional SBRs, forming larger granules in a shorter interval of time due to the higher EPS production. Additionally, higher amounts of calcium were found in the EPS matrix, mainly during the formation of granules. The operation regime and the addition of calcium did not affect the removal of carbon, nitrogen, and phosphorus. However, they both influenced the granulation time, settleability characteristics, size, and granule composition.

Various applications of aerobic granular sludge: A review

Aerobic granular sludge involves microbial community, which allows simultaneous removal of carbon, nitrogen, phosphorus, and other pollutants in a single reactor. The feasibility of aerobic granular sludge has been extensively studied for implementation in wastewater treatment for municipal, domestic and industrial wastewater including palm oil mill effluent, livestock, leachate, dairy, textile and other complex effluents. This article reviews the application of aerobic granular sludge for nutrient, phenolic compound and heavy metals removal from municipal, domestic and industrial wastewater. It discusses the integration of aerobic granular bioflocs with membrane technology, microbial fuel cells and microalgae to enhance the efficiency of wastewater treatment. • Latest research on 2019 for aerobic granulation technology were reviewed. • Biological nutrient removal using aerobic granular bioflocs were covered. • Biosorption of heavy metals by aerobic granular sludge was extensively discussed. • Integration of aerobic granular sludge with membrane technology, microbial fuel cells and microalgae was detailed.

Discovering the Importance of ClO• in a Coupled Electrochemical System for the Simultaneous Removal of Carbon and Nitrogen from Secondary Coking Wastewater Effluent.

Inorganic constituents in real wastewater, such as halides and carbonates/bicarbonates, may have negative effects on the performance of electrochemical systems because of their capability of quenching HO•. However, we discovered that the presence of Cl- and HCO3- in an electrochemical system is conducive to the formation of ClO•, which plays an important role in promoting the simultaneous elimination of biorefractory organics and nitrogen in secondary coking wastewater effluent. The 6-h operation of the coupled electrochemical system (an undivided electrolytic cell with a PbO2/Ti anode and a Cu/Zn cathode) at a current density of 37.5 mA cm-2 allowed the removal of 87.8% of chemical oxygen demand (COD) and 86.5% of total nitrogen. The electron paramagnetic resonance results suggested the formation of ClO• in the system, and the probe experiments confirmed the predominance of ClO•, whose steady-state concentrations (8.08 × 10-13 M) were 16.4, 26.5, and 1609.5 times those of Cl2•- (4.92 × 10-14 M), HO• (3.05 × 10-14 M), and Cl• (5.02 × 10-16 M), respectively. The rate constant of COD removal and the Faradaic efficiency of anodic oxidation obtained with Cl- and HCO3- was linearly proportional to the natural logarithm of the ClO• concentration, and the specific energy consumption was inversely correlated to it, demonstrating the crucial role of ClO• in pollutant removal.

An innovative jet loop-airlift bioreactor for simultaneous removal of carbon and nitrogen from soft drink industrial wastewater: Process performance and kinetic evaluation

Abstract Creating different redox conditions in different regions can be effective for nutrient removal in a single bioreactor. Jet loop-airlift bioreactors are presented as an innovative system that can provide regions with different oxidation–reduction potentials (ORP). In the present study, the performance of a novel jet loop-airlift bioreactor for the simultaneous removal of nutrients from soft drink wastewater (SDW) (COD:N:P of 100:16:1) was investigated. The anoxic and aerobic zones with settling tank could successfully be integrated in a compact high rate bioreactor under continuous aeration and feeding. Two independent variables, hydraulic retention time (HRT) (6–14 h) and air flow rate (2.5-4.5 l/min), were chosen at three levels for modeling, optimization, and trend analysis. According to experimental data, optimum conditions were achieved at HRT of 11 h and air flow rate of 4 l/min with TCOD and TN removal of 98% and 83.6%, respectively. Also, kinetic analysis of the soft drink wastewater treatment process in the jet loop-airlift bioreactor was performed and Y, K d , K s , K and μ max were found to be 0.2425 gVSS/gCOD, 0.038 d−1, 0.00786 g/l, 0.6321 d−1 and 0.165 d−1, respectively. In conclusion, the jet loop-airlift system can be described as an effective low-cost bioreactor for treating wastewater with high carbon and nitrogen.

Heterotrophic growth of Aphanothece microscopica Nägeli in calcium alginate beads from BG11 medium and vinasse

A aplicação de microalgas e cianobactérias imobilizadas no tratamento de efluentes tem sido objeto de diversas pesquisas nos últimos anos, visando principalmente a remoção de carbono e nitrogênio simultaneamente, além de outros nutrientes como fósforo. Quanto aos métodos de imobilização de microalgas, o sistema de encapsulação em matrizes de macromoléculas como o alginato tem despertado interesse devido às suas características de biodegradabilidade, biocompatibilidade e não toxicidade. Neste contexto, o objetivo da pesquisa foi o desenvolvimento de esferas de alginato para a imobilização da cianobactéria Aphanothece microscopica Nägeli, bem como a avaliação do crescimento e capacidade de remoção de glicose, como exemplo de composto orgânico, da fase líquida “bulk”. Os resultados indicaram elevadas velocidades específicas de crescimento para Aphanothece microscopica Nägeli imobilizada em alginato de cálcio tanto para o meio BG11 e vinhaça de cana-de-açúcar, sugerindo a viabilidade do processo, com perspectivas de remoção contínua de matéria orgânica de efluentes a partir deste sistema de cultivo microalgal

Enhanced Simultaneous Nitrogen and Phosphorus Removal in A Denitrifying Biological Filter Using Waterworks Sludge Ceramsite Coupled with Iron-Carbon.

In this study, waterworks sludge ceramsite (WSC) was combined with 3% iron-carbon matrix in a denitrifying biological filter (ICWSC-DNBF) to enhance the simultaneous removal of carbon, nitrogen and phosphorus in secondary effluent of wastewater treatment plant (SE-WTP). The chemical oxygen demand (COD) and nitrogen removal, as well as phosphorus removal and the adsorbed forms of phosphorus were measured and the removal mechanism of these pollutants by the ICWSC-DNBF system for treating SE-WTP were investigated. The results showed that the ICWSC-DNBF achieved good removals of COD, NH4+-N, NO3−-N, total N and total P; effluent concentrations were 17.23 mg/L, 3.72 mg/L, 14.32 mg/L, 17.38 mg/L and 0.82 mg/L, respectively. WSC enhanced the P removal due to its high specific surface area and the high number of adsorption sites. Fe-P and Al-P were the main forms of P adsorbed by WSC, accounting for 78.53% of the total adsorbed P. WSC coupled with Fe and C improved the biodegradability of SE-WTP and promoted the removal of organic matter. The removal of N was attributed to the abundant denitrifying microorganisms in the system and the electrochemical effect produced by the internal electrolysis of Fe and C.