Swine Wastewater Treatment Research Articles

The Performance and Spatial Distribution of Membrane Fouling in a Sequencing Batch Ceramic Membrane Bioreactor: A Pilot Study for Swine Wastewater Treatment.

The extensive application of ceramic membranes in wastewater treatment draws increasing attention due to their ultra-long service life. A cost-effective treatment for high-strength swine wastewater is an urgent and current need that is a worldwide challenge. A pilot-scale sequencing batch flat-sheet ceramic membrane bioreactor (ScMBR) coupled with a short-cut biological nitrogen removal (SBNR) process was developed to treat high-strength swine wastewater. The ScMBR achieved stable and excellent removal of COD (95.3%), NH4+-N (98.3%), and TN (92.7%), though temperature went down from 20 °C, to 15 °C, to 10 °C stepwise along three operational phases. The COD and NH4+-N concentrations in the effluent met with the discharge standards (GB18596-2001). Microbial community diversity was high, and the genera Pseudomonas and Comamonas were dominant in denitritation, and Nitrosomonas was dominant in nitritation. Ceramic membrane modules of this pilot-scale reactor were separated into six layers (A, B, C, D, E, F) from top to bottom. The total filtration resistance of both the top and bottom membrane modules was relatively low, and the resistance of the middle ones was high. These results indicate that the spatial distribution of the membrane fouling degree was different, related to different aeration scour intensities demonstrated by computational fluid dynamics (CFD). The results prove that the membrane fouling mechanism can be attributed to the cake layer formation of the middle modules and pore blocking of the top and bottom modules, which mainly consist of protein and carbohydrates. Therefore, different cleaning measures should be adopted for membrane modules in different positions. In this study, the efficient treatment of swine wastewater shows that the ScMBR system could be applied to high-strength wastewater. Furthermore, the spatial distribution characteristics of membrane fouling contribute to cleaning strategy formulation for further full-scale MBR applications.

Removal efficiency and abundance of nitrogen cycling microorganism in three bio-matrix materials to treat swine wastewater.

A bio-matrix material (BMM) system is used to pretreat swine wastewater and reduce the nitrogen (N) concentration to the tolerance range of plants in constructed wetlands. In this study, rice straw (RS), wheat straw (WS), and corn stalk (CS) were applied to treat pollutants from swine wastewater, respectively. This one year-long field experiment make up for the lack of long-term experiments and mechanistic investigations of BMM. The pollutant removal efficiency, degradation process of crop straw, and the abundance of nitrogen cycling genes were determined in different BMM systems. The results showed that the removal efficiency of COD, TN, NH4+, and NO3- was the best in the initial 6months. Furthermore, RS and WS exhibited favorable annual removal efficiency of TN and NH4+, which were 32.81% and 32.99%, 35.3% and 34.97%, respectively. Moreover, the removal efficiency of COD was 30.81% in three BMM systems. Meanwhile, it was found that the dry matter (DM) degradation of crop straws was fast in the first 4-5months. The degradation rates of cellulose, hemicellulose, and lignin were 94.19%, 94.36%, and 87.32%, respectively, in 1year. The abundance of nitrogen cycling genes significantly increased by adding BMM, compared with CK (P < 0.05). This showed the abundance of the hzsB gene in RS was the highest, while nirK, nirS, AOA, and AOB were the highest in WS. The addition of RS and WS was better than that of CS in promoting the abundance of nitrogen cycling microorganisms. The results indicated that adding BMM could enhance the anaerobic ammonia oxidation, nitrification, and denitrification. This study not only extends our comprehension of BMM mechanisms in swine wastewater treatment but also serves as a guiding light for numerous farms in similar climate regions.

Effect of Pretreatment of Anaerobic Acid Fermentation Sludge from Mixed Swine Wastewater and Food Waste Leachate on Biohydrogen Generation

Objectives:This study aims to investigate the effects of heat shock and 2-bromoethanesulfonate (2-BES) injection on hydrogen production and methanogens inhibition in anaerobic acid fermenter sludge and methane fermenter sludge using mixed swine wastewater and food waste leachate as substrates. Additionally, the analysis of biogas, fermentation products such as volatile fatty acids (VFAs) and alcohols, and microbial community changes were conducted to derive efficient pretreatment conditions for anaerobic hydrogen generation.Methods:Sludge samples were collected from two-phase anaerobic digesters treating swine wastewater and food waste leachate. Heat shock (90°C, 15 min) and 2-BES injection (1, 5, 10, 50, and 100 mmol/L) pretreatments were applied to the each sludge, along with control reactor without pretreatment before anaerobic digestion. Batch experiments were conducted at 30°C to assess biogas, organic compounds (COD, VS, VFAs, and alcohols), and microbial community composition.Results and Discussion:In methanogenic sludge, hydrogen gas was not produced under all conditions, but heat shock method inhibited methane production more effectively than 2-BES injection method. As the concentration of 2-BES increased, methane production decreased. Conversely, hydrogen was produced from the all acid fermentation sludges, mainly attributed to the butyric acid production by dominant Clostridium spp., but the pattern of biogas production varied over time. In the experimental group injected with 2-BES, even at a low concentration of 1 mmol/L, methane gas did not produce due to the inhibition of methanogens. However, in the control group, produced hydrogen was entirely converted to methane by hydrogenotrophic methanogens such as Methanobrevibacter and Methanosphaera. The heat shock group showed delayed hydrogen production due to prolonged lag phase of hydrogen-producing bacteria, with hydrogenotrophic methanogen metabolism starting after 12 days. Heat shock and 2-BES injection reduced bacterial diversity in the acid fermentation process compared to the initial stage.Conclusion:For efficient anaerobic hydrogen production from swine wastewater and food waste leachate, 2-BES injection into the acid fermentation sludge was found to be a preferable method over heat shock, considering hydrogen production efficiency and sustained methanogen inhibition. Further research is needed to find more economical and efficient pretreatment methods and operational strategies considering subsequent methane production processes for practical application in the field.

Regulatory mechanisms of biochar alleviating ammonia inhibition to methanogenesis during long-term operation of anaerobic membrane bioreactor treating swine wastewater

Anaerobic Membrane Bioreactor (AnMBR) is regarded as an advanced technology for the anaerobic digestion (AD) of swine wastewater. However, the high ammonia level in swine wastewater is a crucial issue to inhibit methane production. This study aimed to establish a biochar-assisted AnMBR (BC) to mitigate ammonia inhibition during AD of swine wastewater. As the gradual ammonia loading rate (ALR) increased from 3.0 g/L to 6.0 g/L, BC maintained methane yields ranging from 74.9 % to 48.1 %, which were 9.1 % to 33.3 % higher than those of a regular AnMBR (CT). Moreover, the COD removal efficiency steadily surpassed 80 %. Although the increase in ALR had negative effects on both BC and CT, the presence of biochar enhanced the methanogenic activity of bulk sludge, specifically accelerating processes involved in syntrophic acetate oxidation and CO2-reducing methanogenesis under high ALR conditions. Integrated characterizations using PARAFAC-based EPS analysis, INT-ETS, and WO3 probe-based extracellular electron transfer (EET) activities indicated that biochar stimulated the secretion of humic-like and aromatic protein-like compounds in the TB-EPS, which likely established a redox-active matrix with biochar between VFA oxidation bacteria and CO2-reducing methanogens to facilitate EET. This potentially made the syntrophic VFA oxidation with favorably thermodynamic kinetics under high ammonia stress. Furthermore, the analysis of microbial community coupling prediction of functional genes associated with methanogenic pathways revealed that as ALR increased, the presence of biochar re-shaped the microbial communities by enriching electro-active Syntrophomonas and Methanosarcina/Methanospirillum, which mainly triggering EET-based syntrophic methanogenesis by accelerating the intracellular enzymatic transformation from Formylmethanofuran to 5,10-Methylenetetrahydromethanopterin process. We expect the major findings of this study provide new insights to understand the mechanisms of biochar alleviating ammonia inhibition during long-term operation of AnMBR.

Sustainable Treatment of Swine Wastewater: Optimizing the Culture Conditions of Tetradesmus cf. obliquus to Improve Treatment Efficiency

Sustainable Treatment of Swine Wastewater: Optimizing the Culture Conditions of Tetradesmus cf. obliquus to Improve Treatment Efficiency

Carbon flow, energy metabolic intensity and metagenomic characteristics of a Fe (III)-enhanced anerobic digestion system during treating swine wastewater

Deep treatment and bioenergy recovery of swine wastewater (SW) are beneficial for constructing a low-carbon footprint and resource-recycling society. In this study, Fe (III) addition from 0 to 600 mg/L significantly increased the methane (CH4) content of the recovered biogas from 61.4 ± 2.0 to 89.3 ± 2.0 % during SW treatment in an anaerobic membrane digestion system. The specific methane yields (SMY) also increased significantly from 0.20 ± 0.05 to 0.29 ± 0.02 L/g COD. Fe (III) and its bio-transformed products which participated in establishing direct interspecific electron transfer (DIET), upregulated the abundance of e-pili and Nicotinamide adenine dinucleotide (NADH), enriched electroactive bacteria. The increase in cellular adenosine triphosphate (cATP) from 6583 to 14,518 ng/gVSS and electron transport system (ETS) from 1468 to 1968 mg/(g·h) promoted the intensity of energy flow and electron flow during anaerobic digestion of SW. Moreover, Fe (III) promoted the hydrolysis and acidification of organic matters, and strengthened the acetoacetic methanogenesis pathway. This study established an approach for harvesting high quality bioenergy from SW and revealed the effects and mechanisms from the view of carbon flow, energy metabolic intensity and metagenomics.

Evaluation of the optimum conditions of an anaerobic Down-flow Stationary Fixed Film reactor for swine wastewater treatment

The Down-flow Stationary Fixed Film (DSFF) reactor is a downstream anaerobic reactor combined with a fixed layer of adhesive media that is capable of handling large organic loads, has cheap investment costs, and has a shorter treatment time than other conventional anaerobic technologies. In this study, the DSFF reactor was used to investigate its potential to remove contaminants from swine wastewater. The optimal operating conditions of the DSFF reactor including hydraulic retention time (HRT), organic concentration, and nutrient ratio were investigated. The obtained results showed that the COD removal efficiency increased from 50% to 79.721% when the influent COD enhanced from 500 to 3000 mg/L. The COD removal efficiency was 85.66%, 61.71% and 50.81% at three different nutritional ratios of C/N/P:250/1.5/1, C/N/P:250/7.5/1, and C/N/P:250/7.5/0.2, respectively. The overall results revealed that the optimal HRT is 12 hours, the optimal COD concentration is between 2000 mg/L and 3000 mg/L, and the optimal nutrient ratio is C/N/P:250/1.5/1. The DSFF reactor effectively manages BOD and phosphorus removal while handling a range of contamination levels in swine wastewater. Furthermore, there is no significant sludge loss and the operation mode is simple. This reactor is potentially appropriate for implementation in pig farming households.

Removal of RNA viruses from swine wastewater using anaerobic membrane bioreactor: Performance and mechanisms

The effective removal of viruses from swine wastewater using anaerobic membrane bioreactor (AnMBR) is vital to ecological safety. However, most studies have focused only on disinfectants, whereas the capabilities of the treatment process have not been investigated. In this study, the performance and mechanism of an AnMBR in the removal of porcine hepatitis E virus (HEV), porcine kobuvirus (PKoV), porcine epidemic diarrhea virus (PEDV), and transmissible gastroenteritis coronavirus (TGEV) are systematically investigated. The results show that the AnMBR effectively removes the four viruses, with average removal efficiencies of 1.62, 3.05, 2.41, and 1.34 log for HEV, PKoV, PEDV and TGEV, respectively. Biomass adsorption contributes primarily to the total virus removal in the initial stage of reactor operation, with contributions to HEV and PKoV removal exceeding 71.7 % and 68.2 %, respectively. When the membrane is fouled, membrane rejection dominated virus removal. The membrane rejection contribution test shows the significant contribution of membrane pore foulants (23–76 %). Correlation analysis shows that the surface characteristics and size differences of the four viruses contribute primarily to their different effects on biomass adsorption and membrane rejection. This study provides technical guidance for viral removal during the treatment of high-concentration swine wastewater using an AnMBR.

Removal of antibiotics by four microalgae-based systems for swine wastewater treatment under different phytohormone treatment

This study examined the removal of typical antibiotics from simulated swine wastewater. Microalgae-bacteria/fungi symbioses were constructed using Chlorella ellipsoidea, endophytic bacteria (S395-2), and Clonostachys rosea as biomaterials. The growth, photosynthetic performance, and removal of three types of antibiotics (tetracyclines, sulfonamides, and quinolones) induced by four phytohormones were analyzed in each system. The results showed that all four phytohormones effectively improved the tolerance of symbiotic strains against antibiotic stress; strigolactones (GR24) achieved the best performance. At 10−9 M, GR24 achieved the best removal of antibiotics by C. elliptica + S395-2 + C. rosea symbiosis. The average removals of tetracycline, sulfonamide, and quinolone by this system reached 96.2–99.4 %, 75.2–81.1 %, and 66.8–69.9 %, respectively. The results of this study help to develop appropriate bio enhancement strategies as well as design and operate algal-bacterial-fungal symbiotic processes for the treatment of antibiotics-containing wastewater.

The construction of a microalgal-bacterial biofilm reactor for enhanced swine wastewater treatment

Traditional biological wastewater treatment methods face challenges in treating swine wastewater with a low carbon-to‑nitrogen ratio. Microalgae show great potential in low-cost swine wastewater treatment for nutrient recovery. This study investigated the effects of altering the carbon/nitrogen/phosphorus (C:N:P) ratio in swine wastewater and immobilizing microalgae for enhancing treatment using Desmodesmus sp. A C:N:P proportion of 106:16:1 was determined to be optimal for treatment. The implementation of an inclined plate bioreactor facilitated microalgal adherence, forming a biofilm that improved treatment efficiency. The biofilm exhibited removal rates of 92 % for ammonia nitrogen (NH4+-N), 98 % for total phosphorus (TP), and 99 % for chemical oxygen demand (COD). The harvested biomass from the biofilm was 7.6 times higher than that from the suspended system with a high content (63 %) of fatty acids (C16:0, C18:0, C18:1n9c and C18:2n6c) suitable for biodiesel production. Proteobacteria were dominant in the biofilm, while Firmicutes and Bacteroidetes contributed to effective organic matter and nitrogen removal. These findings present a promising technology for cost-effective swine wastewater treatment and resource recovery.

Mechanisms of copper and zinc bioremoval by microalgae and bacteria grown in nutrient rich wastewaters

Swine farming produces large quantities of nutrient-rich wastewater, which often contains metals such as Cu and Zn, used as feed additives for pigs. These metals must be removed from the wastewater before discharge but their retention in the biomass can limit its subsequent utilization. Photobioreactors are a very promising alternative for swine wastewater treatment, as the consortium of microalgae and bacteria growing symbiotically in these reactors allows high nutrient and metal removal efficiency at moderate costs. This work studies the mechanisms of removal of Cu(II) and Zn(II) by the two types of microorganisms growing in these photobioreactors. A microalga commonly used in wastewater treatment (Scenedesmus almeriensis) and an activated sludge were kept in contact with synthetic wastewater containing 100 mg/L of Cu and Zn. After 72 h, Scenedesmus almeriensis removed 43% of Cu and 45% of Zn, while activated sludge removed 78% of Cu and 96% of Zn. Single and sequential extractions of the biomasses using different extracting reagents revealed that biosorption on protonable groups is the dominant removal mechanisms. Mild reagents solubilized 69% of Cu and 94% of Zn from the microalgae and 76% of Cu and 93% of Zn from the activated sludge. Low metal concentrations in the oxidizable and residual fractions evidenced minimal bioaccumulation inside the cells. FTIR and ESEM-EDX analysis confirmed biosorption by ion exchange and complexation as the main metal remediation mechanisms. The weak bonds of the biosorbed Cu and Zn ions are beneficial for the valorization of biomass and the obtaining of safe bioproducts.

Valorization of treated swine wastewater and generated biomass by microalgae: Their effects and salt tolerance mechanisms on wheat seedling growth

The extensive use of mineral fertilizers has a negative impact on the environment, whereas wastewater and microalgal biomass can provide crops with nutrients such as nitrogen, phosphorus, and potassium, and have the potential to be used as a source of fertilizers in circular agriculture. In this study, a step-by-step resource utilization study of algae-containing wastewater generated from microalgae treatment of swine wastewater was carried out. When wheat seedlings were cultivated in the effluent after microalgae separation, the root fresh weight, seedling fresh weight, and total seedling length were increased by 3.44%, 14.45%, and 13.64%, respectively, compared with that of the algae-containing wastewater, and there was no significant difference in seedling fresh weight, total seedling length, maximum quantum yields of PSII photochemistry (Fv/Fm), and performance index (PIABS) from that of the Hogland solution group, which has the potential to be an alternative liquid fertilizer. Under salt stress, microalgae extract increased the contents of GA3, IAA, ABA, and SA in wheat seedlings, antioxidant enzymes maintained high activity, and the PIABS value increased. Low-dose microalgae extract (1 mL/L) increased the root fresh weight, seedling fresh weight, longest seedling length, and total seedling length by 30.73%, 31.28%, 16.43%, and 28.85%, respectively. Algae extract can act as a plant biostimulant to regulate phytohormone levels to attenuate the damage of salt stress and promote growth.

Continuous Heterogeneous Fenton for Swine Wastewater Treatment: Converting an Industry Waste into a Wastewater Treatment Material

Continuous Heterogeneous Fenton for Swine Wastewater Treatment: Converting an Industry Waste into a Wastewater Treatment Material

Research Advancements in Swine Wastewater Treatment and Resource-Based Safe Utilization Management Technology Model Construction

Swine wastewater contains large amounts of organic matter, nutrients, toxic metal elements, and antibiotics. If it is directly discharged or not properly treated, it poses a significant threat to the environment and human health. Currently, the management of swine wastewater has become a focus of social attention, and it adopts a dual-track parallel model of standard discharge supplemented by resource utilization. If treated properly, it can achieve the recycling of water resources and promote the effective recovery of resources. Based on the pollution characteristics of swine wastewater, this paper analyzes its impact on the environment, society, and the economy in detail and expounds on the research progress of swine wastewater treatment technology. From the perspective of resource utilization and recycling of anaerobic digestion liquid (biogas slurry) from swine wastewater and the carrying capacity of the soil environment and cumulative ecological environmental risks, this study explores new development trends and application prospects for swine wastewater treatment technology.

Biotreatment of swine wastewater by mixotrophic Galdieria sulphuraria

Biotreatment of swine wastewater via microalgae is an environmentally sustainable and economical efficient strategy capable to transform nitrogen, phosphorous, and organic/inorganic carbons into value added products as lipids, carbohydrates, and proteins, while high ammonium tolerant microalgal species with efficient COD and ammonium removal efficiency is lacking, limiting its practical application. Thermophilic and acidophilic Galdieria sulphuraria (G. sulphuraria) are reported to have high ammonium removal efficiency, while its application in ammonium rich swine wastewater treatment without dilution is rarely reported. Accordingly, mixotrophic cultivation of G. sulphuraria has been tested for biotreatment of swine wastewater. The results indicate that G. sulphuraria can grow well in swine wastewater with maximum growth rate of 0.72 g/(L.d) when 15 g/L of glucose is added. Simultaneously, a maximum COD removal efficiency of 94.8% and ammonium removal rate of 550.5 mg/(L.d) are observed. The addition of glucose leads to decreases of lipid, protein and ash contents, and simultaneous increase of carbohydrates owing to the varied C/N ratios. The final microalgal biomass has relatively lower carbon content of 48.5% with 20 g/L glucose than 49.3% of control, consequently leads to a relatively lower HHV value of 20.64 MJ.kg−1. Above all, mixotrophic cultivation of G. sulphuraria are promising strategy for swine wastewater treatment with high energy recovery, potentially providing an economical strategy for swine wastewater treatment.

Preparation of a coagulant of polysilicate aluminum ferric from foundry dust and its coagulation performance in treatment of swine wastewater

Polysilicate aluminum ferric (FD-PSAF) was prepared from foundry dust under polymerization temperature of 50 °C, polymerization time of 2 h and pH 2, to produce its amorphous Si–Al–Fe polymer. Removal efficiency of chemical oxygen demand (COD), color, turbidity and phosphate from swine wastewater reached 50.4%, 95.7%, 97.1% and 99.7% after addition of 10 mL/L of the prepared FD-PSAF, which were higher than those obtained when using polysilicate aluminum ferric (PSAF), polyaluminum chloride (PAC) and polymerized ferrous sulfate (PFS). The percentage content of Feb for PFS, PSAF and the prepared FD-PSAF was 7%, 11% and 24%, respectively. The mean particle size in the swine wastewater increased from 39 nm to 84 nm, 1003 nm, 1198 nm and 2138 nm respectively after the addition of PSAF, PAC, PFS and prepared FD-PSAF into the swine wastewater. The prepared FD-PSAF with the higher coagulation performance could be related to its higher percentage content of Feb and greater particle aggregation ability. The removal efficiency of color, turbidity and phosphate from swine wastewater by FD-PSAF did not obviously change with storage time from 1 d to 32 d, indicating that FD-PSAF had good stability performance. The FD-PSAF is an efficient coagulant that could be used to treat swine wastewater.

Thermodynamic and environmental analysis of an integrated multi-effect evaporation and organic wastewater supercritical water gasification system for hydrogen production

Organic wastewater poses significant environmental and human health risks. Supercritical water gasification (SCWG) presents a promising approach for converting organic waste into hydrogen-rich mixed gases. Nevertheless, the high moisture content present in organic wastewater hampers the energy efficiency of the SCWG process. To tackle this challenge, we have designed and developed an organic wastewater SCWG hydrogen production system incorporating a multi-effect evaporator. The developed system demonstrates the ability to achieve autothermal conditions for the treatment of swine wastewater with a solids concentration of 4.3%. Notably, this system exhibits impressive energy efficiency, reaching a maximum value of 44.88%, along with an exergy efficiency of 33.90% when processing 7% swine wastewater. Exergy analysis further reveals that the incorporation of a multi-effect evaporator leads to a reduction in exergy destruction within the gasification unit, oxidation unit, and heat exchanger. These improvements highlight the positive impact of the multi-effect evaporator on the overall performance of the supercritical water gasification system. Sensitivity analysis indicated that suitable concentrated concentration and an appropriate amount of preheated water can improve hydrogen production. The system minimum GWP reaches 5.27 kgCO2-eq/kgH2 after adding the CCUS. This work expands the range of applicable feedstocks for the autothermal SCWG process.

Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Feces and Wastewater Treatment System in Swine Farms, Thailand

The antimicrobial resistance (AMR) problem is one that demands urgent interventions to minimize the rapid spread in humans, animals and the environment. Extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) could spread from livestock farms to environment or circulate in farms via wastewater. This study aimed to quantify and characterize ESBL-Ec in swine feces and wastewater samples collected from 2 conventional swine farms with wastewater treatment systems. Microbiological analysis was performed on fecal and wastewater samples, and the concentration of cefotaxime (CTX)-resistant bacteria, indicative of ESBL-Ec, was determined across different stages of wastewater treatment. Additionally, ESBL-Ec was isolated and identified from fresh feces, swine house wastewater, and treated wastewater from covered lagoons and photosynthetic ponds. Results indicated a higher concentration of CTX-resistant bacteria in the wastewater in the early process of wastewater treatment. However, CTX-resistant bacteria were not detected in the final photosynthetic pond in one of the 2 farms. ESBL-Ec was identified in fresh feces from swine houses and wastewater treatment plants in both farms. Further antimicrobial susceptibility testing revealed diverse resistance patterns among the ESBL-Ec isolates, with tetracycline and gentamicin demonstrated the highest resistance rates. The ESBL genes identified belonged to the CTX-M-14, CTX-M-17 and CTX-M-55. This study demonstrated the presence of ESBL-Ec in swine feces and wastewater, emphasizing the importance of effective wastewater treatment before discharging to limit the spread of AMR bacteria. HIGHLIGHTS ESBL producers was isolated from fecal and wastewater samples from swine farms The wastewater treatment system could reduce cefotaxime-resistant bacteria CTX-M-14, CTX-M-17 and CTX-M-55 genes were detected in swine farms, Thailand GRAPHICAL ABSTRACT

Resource and Energy Utilization of Swine Wastewater Treatment: Recent Progress and Future Directions

Resource and Energy Utilization of Swine Wastewater Treatment: Recent Progress and Future Directions

New insights into antibiotic stimulation of methane production during anaerobic digestion

Residual antibiotics in swine wastewater pose a critical challenge for stable anaerobic digestion (AD). This study offers fresh insights into the anaerobic treatment of swine wastewater. The results showed that the presence of three typical antibiotics (sulfamethoxazole (SMX), oxytetracycline (OTC) and ciprofloxacin (CIP)) in swine wastewater could promote methane production by stimulating the production and conversion of ethanol. Among them, SMX exhibited the strongest methane promotion effect, with the cumulative methane production increasing from 138.47 to 2204.19 mL/g VS. According to the microbial community structure, antibiotics could promote the growth of Corynebacterium, Lutispora and hydrogenotrophic methanogens (Methanosassiliicoccus, Methanobrevibacter, and Methanobacterium), but inhibit the enrichment of acetoclastic methanogen (Methanosaeta). The relative abundance of Methanosaeta decreased from 2.93–19.80% to 0.52–2.58% under antibiotic stress. Furthermore, there were significant differences in the influence of different antibiotic types on methanogenic pathways. Specifically, OTC and CIP promoted the acetoclastic and hydrogenotrophic pathways, respectively, to enhance methane production. However, SMX could promote both acetoclastic and hydrogenotrophic pathways.