Enhanced anaerobic degradation of quinoline, pyriding, and indole with polyurethane (PU), Fe3O4@PU, powdered activated carbon (PAC), Fe(OH)3@PAC, biochar, and Fe(OH)3@biochar and analysis of microbial succession in different reactors

The enrichment characterisation of Nitrospira under high DO conditions

Nitrite-oxidizing bacteria (NOB) are crucial to nitrification and nitrogen elimination in wastewater treatment. Mass reports exist on the links between NOB and other microorganisms, for instance, ammonia-oxidizing bacteria (AOB). However, a few studies exist on the enrichment characterisation of NOB under high dissolved oxygen (DO) conditions. In this study, NOB was designed to be enriched individually under high DO conditions in a continuous aeration sequencing batch reactor (SBR), and the kinetic characterisation of NOB was evaluated. The analysis revealed that the average NO2--N removal rate was steady above 98%, with DO and NO2--N being 3-5 mg L-1 and 50-450 mg L-1, respectively. The NO2--N removal efficiency of the system was significantly enhanced and better than in other studies. The high-throughput sequencing suggested that Parcubacteria_ genera_incertae_sedis was the first dominant genus (21.99%), which often appeared in the NOB biological community with Nitrospira. However, the dominant genus NOB was Nitrospira rather than Nitrobacter (8.49%). This result suggested that Nitrospira was capable of higher NO2--N removal. But lower relative abundance indicated that excessive NO2--N had an adverse effect on the enrichment and activity of Nitrospira. In addition, the nitrite half-saturation constant (KNO2) and the oxygen half-saturation constant (KO) were 1.71 ± 0.19 mg L-1 and 0.95 ± 0.10 mg L-1, respectively. These results showed that the enriched Nitrospira bacteria had different characteristics at the strain level, which can be used as a theoretical basis for wastewater treatment plant design and optimisation.

Overview of enhancing biological treatment of coal chemical wastewater: New strategies and future directions

Coal chemical wastewater (CCW) is a type of refractory industrial wastewater, and its treatment has become the main bottleneck restricting the sustainable development of novel coal chemical industry. Biological treatment is considered as an economical, effective and environmentally friendly technology for CCW treatment. However, conventional biological process is difficult to achieve the efficient removal of refractory organics because of CCW with the characteristics of composition complexity and high toxicity. Therefore, seeking the novel enhancement strategy appears to be a favorable solution for enhancing biological treatment efficiency of CCW. This review focuses on presenting a comprehensive picture about the exogenous enhancement strategies for CCW biological treatment. The performance and potential application of exogenous enhancement strategies, including co-metabolic substrate enhancement, biofilm filler enhancement, adsorption material enhancement and conductive mediator enhancement, were expounded. Meanwhile, the enhancing mechanisms of different strategies were comprehensively discussed from a biological perspective. Furthermore, the prospects of enhancement strategies based on the engineering performance, economic cost and environmental impact (3E) evaluation were introduced. And novel enhancement strategy based on "low carbon emissions", "resource recycling" and "water environment security" in the context of carbon neutrality was proposed. Taken together, this review provides technical reference and new direction to facilitate the regulation and optimization of typical industrial wastewater biological treatment.

Evaluating the stability and performance of a novel core-shell ZVI@C-montmorillonite particle for anaerobic treatment of chloramphenicol wastewater

ZVI@C-MP is a novel composite particle consisting of zero-valent iron (ZVI) enclosed within a carbon shell. The purpose of this composite material is to enhance the anaerobic treatment of wastewater containing chloramphenicol (CAP). This approach aims to address the initial challenge of excessive corrosion experienced by ZVI, followed by its subsequent passivation and inactivation. ZVI@C-MP was synthesized through a hydrothermal process and calcination, with montmorillonite as binder, it exhibits stability, iron-carbon microelectrolysis (ICME) properties, and strong adsorption for CAP. Its ICME actions include releasing iron ions (0.70 mg/L) and COD (11.3 mg/L), generating hydrogen (3.82%), and raising the pH from 6.30 to 7.71. With minimal structural changes, it achieved release equilibrium. ZVI@C-MP boasts high removal efficiency of CAP (98.96%) by adsorption, attributed to surface characteristics (surface area: 167.985 m2/g; pore volume: 0.248 cm3/g). The addition of ZVI@C-MP increases COD removal (10.16%), methane production (72.86%), and reduces extracellular polymeric substances (EPS) from 70.58 to 52.72 mg/g MLVSS. It reduces microbial by-products and toxic effects, enhancing CAP biodegradation and microbial metabolic activity. ZVI@C-MP's electrical conductivity and biocompatibility bolster functional flora for interspecies electron transfer. It's a novel approach to antibiotic wastewater treatment.

Efficient elimination of nonylphenol and 4-tert-octylphenol by weak electrical stimulated anaerobic microbial processes

The investigation into the degradation of alkylphenol pollutants (APs) has become a hotspot due to their harmful effects on the environment and human health. In this study, microbial electrolysis cells (MECs) were used to degrade nonylphenol (NP) and 4-tert-octylphenol (4-tert-OP). The study found that the degradation rates of NP and 4-tert-OP for a 6-day period were 83.6% and 96.3%, respectively, which were 30.53% and 26.7% higher than those of the group without applied voltage. The double layer area in the degradation of 4-tert-OP was larger than that of NP, and the resistance exhibited by 4-tert-OP (87.47 Ω) in MEC was lower than that of NP (99.42 Ω). Meanwhile, NP had a greater effect on the bioenzyme activity than 4-tert-OP. GC-MS analysis showed that the degradation pathways of both pollutants mainly included oxidation and hydroxylation reactions. Furthermore, the microbial community analysis indicated that the main functional bacteria in NP degradation were Citrobacter, Desulfovibrio and Advenella, and those in 4-tert-OP degradation were Stenotrophomonas, Chryseobacterium, Dokdonella, and the key microbiomes underlying the cooperative relationship. The biotoxicity test indicated that the toxicity of residual substances was significantly reduced. Therefore, the MEC system is efficient and environmentally friendly and has broad application prospects in phenol refractory organics.

Role of cycle duration on the formation of quinoline-degraded aerobic granules in the aspect of sludge characteristics, extracellular polymeric substances and microbial communities

This study investigated the culture and characteristics of quinoline-degraded aerobic granular sludge (AGS) under 8-h and 12-h cycle duration. According to results, the cultivation of an 8-h cycle duration enhanced the growth of quinoline-degraded AGS, as well as the settleability of sludge and the retention of biomass. Quinoline can be removed from mature AGS at a rate of more than 90%, but it is removed at a rate slightly higher when the AGS are cultured for 12-h. Compared to 12-h cycle duration, 8-h cycle duration result in a greater increase in the production of extracellular polymeric substances, particularly extracellular proteins. In these two systems, Acidovorax and Paracoccus dominated the quinoline degrading bacteria. In addition, analysis by non-metric multidimensional scaling (based on Bray-curtis distance) showed significant differences of community structure between the two reactors. Clostridia and Acidaminobacter are different bacteria with an 8-h cycle duration compared to 12 h. Relative abundance of nitrogen metabolism genes based on PICRUSt2 prediction, which explain the better total nitrogen removal for an 8-h cycle duration compared to a 12-h cycle duration. Finally, the KEGG pathway was analyzed in order to confirm the results of the microbial analysis.

Iron Compounds in Anaerobic Degradation of Petroleum Hydrocarbons: A Review

Waste and wastewater containing hydrocarbons are produced worldwide by various oil-based industries, whose activities also contribute to the occurrence of oil spills throughout the globe, causing severe environmental contamination. Anaerobic microorganisms with the ability to biodegrade petroleum hydrocarbons are important in the treatment of contaminated matrices, both in situ in deep subsurfaces, or ex situ in bioreactors. In the latter, part of the energetic value of these compounds can be recovered in the form of biogas. Anaerobic degradation of petroleum hydrocarbons can be improved by various iron compounds, but different iron species exert distinct effects. For example, Fe(III) can be used as an electron acceptor in microbial hydrocarbon degradation, zero-valent iron can donate electrons for enhanced methanogenesis, and conductive iron oxides may facilitate electron transfers in methanogenic processes. Iron compounds can also act as hydrocarbon adsorbents, or be involved in secondary abiotic reactions, overall promoting hydrocarbon biodegradation. These multiple roles of iron are comprehensively reviewed in this paper and linked to key functional microorganisms involved in these processes, to the underlying mechanisms, and to the main influential factors. Recent research progress, future perspectives, and remaining challenges on the application of iron-assisted anaerobic hydrocarbon degradation are highlighted.

Progress and prospects of applying carbon-based materials (and nanomaterials) to accelerate anaerobic bioprocesses for the removal of micropollutants

Carbon‐based materials (CBM), including activated carbon (AC), activated fibres (ACF), biochar (BC), nanotubes (CNT), carbon xenogels (CX) and graphene nanosheets (GNS), possess unique properties such as high surface area, sorption and catalytic characteristics, making them very versatile for many applications in environmental remediation. They are powerful redox mediators (RM) in anaerobic processes, accelerating the rates and extending the level of the reduction of pollutants and, consequently, affecting positively the global efficiency of their partial or total removal. The extraordinary conductive properties of CBM, and the possibility of tailoring their surface to address specific pollutants, make them promising as catalysts in the treatment of effluents containing diverse pollutants. CBM can be combined with magnetic nanoparticles (MNM) assembling catalytic and magnetic properties in a single composite (C@MNM), allowing their recovery and reuse after the treatment process. Furthermore, these composites have demonstrated extraordinary catalytic properties. Evaluation of the toxicological and environmental impact of direct and indirect exposure to nanomaterials is an important issue that must be considered when nanomaterials are applied. Though the chemical composition, size and physical characteristics may contribute to toxicological effects, the potential toxic impact of using CBM is not completely clear and is not always assessed. This review gives an overview of the current research on the application of CBM and C@MNM in bioremediation and on the possible environmental impact and toxicity.

Synergy between pyridine anaerobic mineralization and vanadium (V) oxyanion bio-reduction for aquifer remediation

The co-occurrence of toxic pyridine (Pyr) and vanadium (V) oxyanion [V(V)] in aquifer has been of emerging concern. However, interactions between their biogeochemical fates remain poorly characterized, with absence of efficient route to decontamination of this combined pollution. In this work, microbial-driven Pyr degradation coupled to V(V) reduction was demonstrated for the first time. Removal efficiencies of Pyr and V(V) reached 94.8 ± 1.55% and 51.2 ± 0.20% in 72 h operation. The supplementation of co-substrate (glucose) deteriorated Pyr degradation slightly, but significantly promoted V(V) reduction efficiency to 84.5 ± 0.635%. Pyr was mineralized with NH₄⁺-N accumulation, while insoluble vanadium (IV) was the major product from V(V) bio-reduction. It was observed that Bacillus and Pseudomonas realized synchronous Pyr and V(V) removals independently. Interspecific synergy between Pyr degraders and V(V) reducers also functioned with addition of co-substrate. V(V) was bio-reduced through alternative electron acceptor pathway conducted by gene nirS encoded nitrite reductase, which was evidenced by gene abundance and enzyme activity. Cytochrome c, nicotinamide adenine dinucleotide and extracellular polymeric substances also contributed to the coupled bioprocess. This work provides new insights into biogeochemical activities of Pyr and V(V), and proposes novel strategy for remediation of their co-contaminated aquifer.

A novel inhibition mechanism of aniline on nitrification: Aniline degradation competes dissolved oxygen with nitrification

Aniline is a toxic aromatic amine and an inhibitor of nitrification. This study explored the inhibition effect and underlying mechanism. After sludge acclimation, 540 mg/L aniline was removed in 24 h and almost all ammonia released from aniline was oxidized to nitrate. However, nitrification never started until no aniline left. The cellular adenosine triphosphate (cATP) concentration of acclimated sludge reduced only by 2% after aniline exposure. Neither transmembrane transport of ammonia nor ammonia monooxygenase (AMO) activity was affected by aniline. Growing initial aniline concentration did not deteriorate the specific nitrification rate (NR). These all revealed that the toxicity of aniline only play a minor role in inhibition. Competition for dissolved oxygen (DO) was proposed to be another possible inhibition mechanism. The oxygen affinity constant (Ks) of aniline degraders and ammonia-oxidizing bacteria (AOB) was calculated to be 0.894 mg/L and 1.274 mg/L respectively, suggesting the former possessed much stronger oxygen affinity (P < 0.01). With aniline and ammonium as initial substrates, increasing aeration intensity advanced nitrification and increased the NR. Max NR of 0.63 mgN/(gMLSS·h) was achieved at the highest aeration intensity of 1000 mL/min. This study brings one step closer to better removal of aniline and derived nitrogen pollutants.

Bisphenol A alters volatile fatty acids accumulation during sludge anaerobic fermentation by affecting amino acid metabolism, material transport and carbohydrate-active enzymes

Bisphenol A (BPA), a typical persistent organic pollutant in waste activated sludge, was chosen to explore its influence on the accumulation of volatile fatty acids (VFAs), which is an important raw material, during anaerobic fermentation. BPA in the range of 0-200 mg/kg dry sludge was beneficial to VFAs production, from 1564 mg chemical oxygen demand (COD)/L in the control to 2095 mg COD/L with 50 mg/kg BPA; the acetic acid yield was 563 and 1010 mg COD/L with 0 and 50 mg/kg BPA, respectively. The abundance of microorganisms that can consume VFAs was reduced and those responsible for producing VFAs was increased by BPA. Homologous genes of related enzymes in the pathways for amino acid metabolism, fatty acid biosynthesis, ABC transporters and quorum sensing were enhanced in the presence of BPA. The abundance of carbohydrate-active enzymes increased with BPA when compared with the control, benefitting VFAs production.

Organic matter stabilized Fe in drinking water treatment residue with implications for environmental remediation

Fe-based materials used to adsorb P are commonly considered to be limited by the increased Fe lability, while Fe in drinking water treatment residue (DWTR) shows stable P adsorption abilities. Accordingly, this study aimed to gain insight into Fe lability in DWTR as compared to FeCl₃ and Fe₂(SO₄)₃ using Fe fractionation, EXAFS, and high-throughput sequencing technologies. The results showed that compared to Fe₂(SO₄)₃ and FeCl₃, Fe was relatively stable in the DWTR under the effects of organic matter, sulfides, and anaerobic conditions. Typically, the addition of FeCl₃ and Fe₂(SO₄)₃ enhanced Fe mobility in sediment and overlying water, promoting the formation of Fe-humin acid and ferrous sulfides (FeS and FeS₂). However, the addition of DWTR, even at relatively high doses of Fe, has limited impact on Fe mobility. The addition remarkably increased oxidizable Fe in sediment (by approximately 63%), causing Fe to be dominated by oxidizable and residual fractions (like those in raw DWTR); EXAFS analysis also suggested that Fe-humin acid increased substantially with the addition of DWTR, becoming the main Fe species in sediment (with a relative abundance of 50.1%). Importantly, the Fe distributions were stable in sediment with DWTR added, which demonstrated that organic matter stabilized the Fe in the DWTR. Further analysis indicated that all materials promoted the enrichment of bacterial genera potentially related to Fe metabolism (e.g., Bacteroides, Dok59, and Methanosarcina). Fe₂O₃ in the FeCl₃ and Fe₂(SO₄)₃ groups and Fe-HA in the DWTR group were the key species affecting the microbial communities. Overall, the stabilizing effect of organic matter on Fe in DWTR could be used to develop Fe-based materials to enhance Fe stability for environmental remediation.

Microbial community and function evaluation in the start-up period of bioaugmented SBR fed with aniline wastewater

An enhanced sequencing batch reactor (SBR) system was developed to treat synthetic wastewater rich in 600 mg/L aniline. The aniline degradation efficiency was almost 100%, and the total nitrogen (TN) removal rate was more than 50%. Metagenomics technology revealed the community structure, functional genes and metabolic mechanism during the start-up of the enhanced reactor. Sequencing results showed that Proteobacteria, Bacteroidetes, Chloroflexi and Actinobacteria were dominant phylum. The proportion of degradation of aromatic compounds function increased gradually, but the proportion of nitrogen metabolism function changed little. Functional genes involved in aniline degradation including benA-xylX and dmpB/xylE were detected. The functional genes of nitrogen metabolism were involved in complete nitrification, traditional denitrification, assimilation nitrate reduction and dissimilation nitrate reduction. The functional contribution analysis and network analysis showed that the cooperation and competition of Thauera, Delftia, Diaphorobacter, Micavibrio and Azoarcus ensured the effective removal of aniline and nitrogen.

A state-of-the-art review of quinoline degradation and technical bottlenecks

Quinoline is a critical raw material for the dye, metallurgy, pharmaceutical, rubber, and agrochemical industries, and its use poses a serious threat to human health and the ecological environment. Quinoline has carcinogenic, teratogenic and mutagenic effects on the human body through food accumulation. However, due to the steric hindrance of its bicyclic fused structure and its long photooxidation half-life, quinoline is too difficult to decompose naturally. To date, numerous technologies have been used to degrade quinoline, whereas only a few have been reviewed. Therefore, this paper is focused on offering a comprehensive overview of the state of quinoline degradation in an effort to improve its degradation efficiency and fully utilize the carbon and nitrogen within quinoline without causing any damage to the environment. Accordingly, the strains, research progress and mechanisms of various methods for degrading quinoline are explored and elucidated in detail, especially quinoline biodegradation and the combination of these technologies for efficient removal. The state-of-the-art processes and new findings of our team on the biofortification of quinoline degradation are also presented. Finally, research bottlenecks and gaps for future research were identified along with the prospects and resource utilization of quinoline. These discussions facilitate the realization of the zero discharge of quinoline.

Effects of Chemical and Solar Soil-Disinfection Methods on Soil Bacterial Communities

The actctivated carbon + solar radiation membrane is an eco-friendly soil disinfestations method for managing soil-borne plant pathogens. However, little was known the impact of Activated carbon + solar radiation membrane on bacterial community structure in strawberry production systems under field conditions. A comprehensive evaluation of the impacts of different soil disinfection methods on the bacterial community structure is fundamental to understand the role of disinfection in maintaining soil health. The changes in the soil bacterial diversity and community composition were detected using realtime fluorescence quantitative PCR (RTFQ PCR) and next-generation sequencing techniques to better understand the effect of soil disinfection. The bacterial community composition was monitored after disinfection using dazomet (DZ), chloropicrin (CP), 100 kg/ha activated carbon + solar radiation membrane (AC1), 200 kg/ha activated carbon + solar radiation membrane (AC2), and 300 kg/ha activated carbon + solar radiation membrane (AC3) and compared with the control (CT). The results indicated that the different dosages of activated carbon (AC1, AC2, and AC3) did not affect the bacterial community structure. On the other hand, DZ and CP considerably reduced the soil biomass and abundance of bacterial species. Chemical fumigants influenced the bacterial community structure, with DZ treatment leading to the dominance of the phylum Firmicutes, accounting for approximately 54%. After fumigation with CP, Proteobacteria and Acidobacteria were the dominant phyla. Beta diversity analysis and principal coordinate analysis revealed that the bacterial communities in the soil treated with DZ and CP formed clusters. Redundancy analysis indicated that soil pH, available potassium, and available phosphorus were the key factors influencing microbial metabolic functional diversity. Thus, it was verified that the damage caused by activated carbon + solar radiation membrane—a potential alternative for chemical fumigant—to the soil bacterial community was less than that caused by chemicals DZ and CP.

Microbial interspecific interaction and nitrogen metabolism pathway for the treatment of municipal wastewater by iron carbon based constructed wetland

In order to explore the pollutant removal performance and interspecific interaction in constructed wetland (CW) with Fe₀-C filler, constructed wetland with Fe₀-C filler (CW-Fe) and with ceramsite filler (CW-C) were set up. Besides, the nutrients removal and interspecific interaction were analyzed, and the results showed that total nitrogen (TN) removal efficiency of CW-Fe system without carbon source was lower than that in CW-C system though CW-Fe system could convert macro-molecular organic matter into micro-molecular organic matter. However, ammonia nitrogen (NH₄⁺-N) increase was observed in CW-Fe system with better total phosphorus (TP) removal performance. High-throughput sequencing showed that the microbial richness and abundance of Bacteroides, Firmicutes, Chlorofeli and Actinobacteria in the CW with Fe₀-C filler was significantly higher than with ceramsite filler. The interaction between two CWs was significantly different, and the functional enzymes abundance of nitrate nitrogen (NO₃^--N) to NH₄⁺-N transformation in CW-Fe system significantly increased.

Performance, mechanism and stability of nitrogen-doped sewage sludge based activated carbon supported magnetite in anaerobic degradation of coal gasification wastewater

In current study, the UASB reactor was enhanced by nitrogen-doped sewage sludge based activated carbon supported Fe₃O₄ (Fe₃O₄/N-SBAC) for coal gasification wastewater treatment. The results showed that COD removal efficiency was increased to 64.4% with Fe₃O₄/N-SBAC assistance and the corresponding methane production rate achieved up to 1093.6 mL/d. Fe₃O₄/N-SBAC promoted microbial growth and enzymatic activity, leading to high extracellular polymeric substances and coenzyme F₄₂₀ concentrations. Fe₃O₄/N-SBAC also facilitated the sludge granulation process with high particle size, substantial interspecific signal molecules and low diffusible signal factor. Microbial community analysis revealed that Fe₃O₄/N-SBAC might support direct interspecies electron transfer process, in which the enriched Geobacter was likely to communicate with Methanothrix via electrical connection, improving anaerobic degradation of coal gasification wastewater. Total phenols shock and pH impact revealed that reactor stability was enhanced in the Fe₃O₄/N-SBAC-supplemented system.

A review on facilitating bio-wastes degradation and energy recovery efficiencies in anaerobic digestion systems with biochar amendment

In this review, progress in the potential mechanisms of biochar amendment for AD performance promotion was summarized. As adsorbents, biochar was beneficial for alleviating microbial toxicity, accelerating refractory substances degradation, and upgrading biogas quality. The buffering capacity of biochar balanced pH decreasing caused by volatile fatty acids accumulation. Moreover, biochar regulated microbial metabolism by boosting activities, mediating electron transfer between syntrophic partners, and enriching functional microbes. Recent studies also suggested biochar as potential useful additives for membrane fouling alleviation in anaerobic membrane bioreactors (AnMBR). By analyzing the reported performances based on different operation models or substrate types, debatable issues and associated research gaps of understanding the real role of biochar in AD were critically discussed. Accordingly, Future perspectives of developing biochar-amended AD technology for real-world applications were elucidated. Lastly, with biochar-amended AD as a core process, a novel integrated scheme was proposed towards high-efficient energy-resource recovery from various bio-wastes.

Substrate strategy optimization for polyhydroxyalkanoates producing culture enrichment from crude glycerol

Crude glycerol is by-product produced from biodiesel industry and can be converted directly by mixed microbial culture (MMC) into polyhydroxyalkanoates (PHAs). This study investigated the effects of the reverse (SBR_A) and positive (SBR_B) glycerol gradient substrate strategy on PHA-accumulating culture enrichment and the maximum PHA accumulating stability under substrates with different glycerol and volatile fatty acid (VFA) proportion. The results showed that crude glycerol was mainly used for PHA production rather than biomass growth in SBR_A. The maximum q_PHA was 0.65 g COD/g X^-1·h^-1 under sole crude glycerol condition in SBR_A, which was 2.41 times higher than that of SBR_B. Moreover, the PHA accumulating ability of the biomass from SBR_A was more stable than SBR_B. Saccharibacteria_genera_incertae_sedis was for the first time found to be the dominant genus using crude glycerol for PHA production. This research provides an insight into enrichment strategy to effectively enrich PHA-accumulating culture from crude glycerol.

Enhanced degradation of quinoline by coupling microbial electrolysis cell with anaerobic digestion simultaneous

In this study, the feasibility of quinoline-wastewater treatment was investigated in a coupled microbial electrolysis cell and anaerobic digestion system (MEC-AD). Improved degradation and enhanced mineralization of quinoline were obtained, and the optimal voltage was determined to be 1.0 V. Effective removal of quinoline at relative high concentration, and a 1.5-fold increase in methane production were achieved. The results indicated that the MEC-AD could simultaneously remove carbon and nitrogen from quinoline. Gas chromatography-mass spectrometry analysis identified 2-hydroxyquinoline and 8-hydroxycoumarin as the intermediates of quinoline. The formation and degradation of metabolites were rapid, and they did not accumulate in the MEC-AD. The results of microbial community structure analysis demonstrated that the functional species were enriched and coexisted, and that the dominant bacterial genera were SM1A02, Comamonas, Desulfovibrio, Geobacter, and Actinomarinales_norank; the dominant archaeal genera were Methanocorpusculum and Nitrosoarchaeum. Furthermore, the applied current played a selective role in the enrichment of microorganisms.

DNA-based stable isotope probing identifies triclosan degraders in nitrification systems under different surfactants

Three widely-used surfactants, rhamnolipid (RL), sophorolipid (SL) and sodium dodecyl benzene sulfonate (SDBS), were chosen to investigate their effects on the nitrification systems treating step-wised triclosan (TCS). Surfactants had little effects on nitrification. Surfactants could promote the desorption of TCS and enhance the TCS biodegradation in nitrification systems. And TCS biodegradation efficiencies obtained with RL, SL and SDBS were 1.25, 1.23 and 1.14 times higher than the control with 9.0 mg/L TCS, respectively. Illumina MiSeq sequencing showed that Amaricoccus could be resistant to TCS. And Amaricoccus, detected with RL, SL and SDBS, were more abundant than the control. DNA-based stable isotope probing assays revealed Amaricoccus was the major TCS degrader. And the addition of surfactants could obviously increase the diversity of active TCS degraders, especially for biosurfactants. It seems that the addition of surfactants showed positive effects for the nitrification systems treating TCS wastewater.