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787600.8611Sulfamethoxazole impact on pollutant removal and microbial community of aerobic granular sludge with filamentous bacteria. In this study, sulfamethoxazole (SMX) was employed to investigate its impact on the process of aerobic granule sludge with filamentous bacteria (FAGS). FAGS has shown great tolerance ability. FAGS in a continuous flow reactor (CFR) could keep stable with 2 μg/L of SMX addition during long-term operation. The NH(4)(+), chemical oxygen demand (COD), and SMX removal efficiencies kept higher than 80%, 85%, and 80%, respectively. Both adsorption and biodegradation play important roles in SMX removal for FAGS. The extracellular polymeric substances (EPS) might play important role in SMX removal and FAGS tolerance to SMX. The EPS content increased from 157.84 mg/g VSS to 328.22 mg/g VSS with SMX addition. SMX has slightly affected on microorganism community. A high abundance of Rhodobacter, Gemmobacter, and Sphaerotilus of FAGS may positively correlate to SMX. The SMX addition has led to the increase in the abundance of the four sulfonamide resistance genes in FAGS.202336871701
720310.8601Removal of cephalexin and erythromycin antibiotics, and their resistance genes, by microalgae-bacteria consortium from wastewater treatment plant secondary effluents. Antibiotics have become a concern in the aquatic environments owing to the potential development of bacterial resistances. Thus, this study evaluated the removal of cephalexin (CEP) and erythromycin (ERY) from a local wastewater treatment plant (WWTP) effluent, mediated by microalgae-bacteria consortium. Likewise, the removal of correlated antibiotics resistance genes bla(TEM) and ermB was also assessed. The incubation results showed that the added concentrations of selected antibiotics did not restrain the consortium growth. Moreover, CEP and ERY were almost completely removed after the cultivation period, reaching total removals of 96.54% and 92.38%, respectively. The symbiotic interaction between microalgae and bacteria plays a role in the kinetics removal of CEP and ERY. The abundance of bla(TEM) and ermB was reduced by 0.56 and 1.75 logs, respectively. Lastly, our results suggest that technology based on natural microalgae-bacteria consortium could be a potential alternative to improve the quality of WWTP effluents.202134268682
810920.8599The fate of antibiotic resistance genes and their influential factors in swine manure composting with sepiolite as additive. Manures are storages for antibiotic resistance genes (ARGs) entering the environment. This study investigated the effects of adding sepiolite at 0%, 2.5%, 5%, and 7.5% (CK, T1, T2, and T3, respectively) on the fates of ARGs during composting. The relative abundances (RAs) of the total ARGs in CK and T3 decreased by 0.23 and 0.46 logs, respectively, after composting. The RAs of 10/11 ARGs decreased in CK, whereas they all decreased in T3. The reduction in the RA of the total mobile genetic elements (MGEs) was 1.26 times higher in T3 compared with CK after composting. The bacterial community accounted for 47.93% of the variation in the abundances of ARGs. Network analysis indicated that ARGs and MGEs shared potential host bacteria (PHB), and T3 controlled the transmission of ARGs by reducing the abundances of PHB. Composting with 7.5% sepiolite is an effective strategy for reducing the risk of ARGs proliferating.202235063626
775530.8598Anthropogenic impacts on sulfonamide residues and sulfonamide resistant bacteria and genes in Larut and Sangga Besar River, Perak. The environmental reservoirs of sulfonamide (SA) resistome are still poorly understood. We investigated the potential sources and reservoir of SA resistance (SR) in Larut River and Sangga Besar River by measuring the SA residues, sulfamethoxazole resistant (SMX(r)) in bacteria and their resistance genes (SRGs). The SA residues measured ranged from lower than quantification limits (LOQ) to 33.13 ng L(-1) with sulfadiazine (SDZ), sulfadimethoxine (SDM) and SMX as most detected. Hospital wastewater effluent was detected with the highest SA residues concentration followed by the slaughterhouse and zoo wastewater effluents. The wastewater effluents also harbored the highest abundance of SMX(r)-bacteria (10(7) CFU mL(-1)) and SRGs (10(-1)/16S copies mL(-1)). Pearson correlation showed only positive correlation between the PO(4) and SMX(r)-bacteria. In conclusion, wastewater effluents from the zoo, hospital and slaughterhouse could serve as important sources of SA residues that could lead to the consequent emergence of SMX(r)-bacteria and SRGs in the river.201931726563
811340.8595Fate of antibiotic resistance genes in mesophilic and thermophilic anaerobic digestion of chemically enhanced primary treatment (CEPT) sludge. Anaerobic digestion (AD) of chemically enhanced primary treatment (CEPT) sludge and non-CEPT (conventional sedimentation) sludge were comparatively operated under mesophilic and thermophilic conditions. The highest methane yield (692.46±0.46mL CH(4)/g VS(removed) in CEPT sludge) was observed in mesophilic AD of CEPT sludge. Meanwhile, thermophilic conditions were more favorable for the removal of total antibiotic resistance genes (ARGs). In this study, no measurable difference in the fates and removal of ARGs and class 1 integrin-integrase gene (intI1) was observed between treated non-CEPT and CEPT sludge. However, redundancy analysis indicated that shifts in bacterial community were primarily accountable for the variations in ARGs and intI1. Network analysis further revealed potential host bacteria for ARGs and intI1.201728797965
805050.8586Effects of antibiotics on corncob supported solid-phase denitrification: Denitrification and antibiotics removal performance, mechanism, and antibiotic resistance genes. Solid-phase denitrification (SPD) has been used in wastewater treatment plant effluent to enhance nitrate removal, and antibiotics co-existing in the effluent is a common environmental problem. In this study, it was systematically investigated the effect of single trace sulfamethoxazole (SMX)/trimethoprim (TMP) and their mixture on microbial denitrification performance, the antibiotics removal, and antibiotics resistance genes (ARGs) in corncob supported SPD system. The average denitrification rate was improved by 46.90% or 61.09% with single 50 µg/L SMX or TMP, while there was no significant inhibition with mixed SMX and TMP. The abundance of dominant denitrifiers (Comamonadaceae family and Azospia) and fermentation bacteria (Ancalomicrobium) were consistent with the denitrification performance of different antibiotics groups. Single SMX and TMP achieved relatively higher denitrification gene and enzyme abundance. Mixed SMX and TMP improved the denitrification gene copies, but they reduced the key denitrification enzymes except for EC 1.7.7.2. Additionally, the removal efficiency of TMP (56.70% ± 3.18%) was higher than that of SMX (25.44% ± 2.62%) in single antibiotic group, and the existence of other antibiotics (i.e. SMX or TMP) had no significant impact on the TMP or SMX removal performance. Biodegradation was the main removal mechanism of SMX and TMP, while sludge and corncob adsorption contributed a little to their removal. SMX had the risk of sulfanilamide resistance genes (SRGs) dissemination. Furthermore, network analysis indicated that Niveibacterium and Bradyrhizobium were the potential hosts of SRGs, which promoted the horizontal transmission of ARGs.202337032040
774460.8582Dynamics and removal mechanisms of antibiotic and antibiotic resistance genes during the fermentation process of spectinomycin mycelial dregs: An integrated meta-omics study. Antibiotic mycelial dregs (AMDs) have been listed as industrial hazardous wastes. With the aim of reducing the environmental risk, the integrated-omics and qPCR approaches were used to reveal the dynamics and removal mechanisms of antibiotic and antibiotic resistance genes (ARGs) during the fermentation of different spectinomycin mycelial dregs (SMDs). The results showed that the removal efficiency of antibiotic in the fermentation of high moisture SMDs reached up to 98%. The high abundance of aadA1 gene encoded by Streptomyces, Lactobacillus, and Pseudomonas was associated with the efficient degradation of spectinomycin, and the inactivating enzymes secreted by degradative bacteria were identified. Furthermore, the dominant microbiota was impacted by moisture content significantly under high temperature environments. In the fermentation of low moisture SMDs, Saccharopolyspora was the dominant microbiota which secreted S8 endopeptidase, M14, M15, S10, S13 carboxypeptidases, M1, M28, S15 aminopeptidases, and antioxidant enzymes, while in the fermentation of high moisture SMDs, Bacillus and Cerasibacillus were dominant genera which mainly secreted S8 endopeptidase and antioxidant enzymes. The abundance of ARGs and mobile genetic elements decreased significantly at thermophilic phase, with maximum drops of 93.7% and 99.9%, respectively. Maintaining moisture content below 30% at the end phase could prevent the transmission of ARGs effectively.202234396972
810570.8581Refluxing mature compost to replace bulking agents: A low-cost solution for suppressing antibiotic resistance genes rebound in sewage sludge composting. Antibiotic resistance genes (ARGs) rebounding during composting cooling phase is a critical bottleneck in composting technology that increased ARGs dissemination and application risk of compost products. In this study, mature compost (MR) was used as a substitute for rice husk (RH) to mitigate the rebound of ARGs and mobile genetic elements (MGEs) during the cooling phase of sewage sludge composting, and the relationship among ARGs, MGEs, bacterial community and environmental factors was investigated to explore the key factor influencing ARGs rebound. The results showed that aadD, blaCTX-M02, ermF, ermB, tetX and vanHB significantly increased 4.76-32.41 times, and the MGEs rebounded by 38.60% in the cooling phase of RH composting. Conversely, MR reduced aadD, tetM, ermF and ermB concentrations by 59.49-98.58%, and reduced the total abundance of ARGs in the compost product by 49.32% compared to RH, which significantly restrained ARGs rebound. MR promoted secondary high temperature inactivation of potential host bacteria, including Ornithinibacter, Rhizobiales and Caldicoprobacter, which could harbor aadE, blaCTX-M02, and blaVEB. It also reduced the abundance of lignocellulose degrading bacteria of Firmicutes, which were potential hosts of aadD, tetX, ermF and vanHB. Moreover, MR reduced moisture and increased oxidation reduction potential (ORP) that promoted aadE, tetQ, tetW abatement. Furthermore, MR reduced 97.36% of total MGEs including Tn916/1545, IS613, Tp614 and intI3, which alleviated ARGs horizontal transfer. Overall finding proposed mature compost reflux as bulking agent was a simple method to suppress ARGs rebound and horizontal transfer, improve ARGs removal and reduce composting plant cost.202539798649
613280.8578Molecular characterization of copper resistance genes from Xanthomonas citri subsp. citri and Xanthomonas alfalfae subsp. citrumelonis. Copper sprays have been widely used for control of endemic citrus canker caused by Xanthomonas citri subsp. citri in citrus-growing areas for more than 2 decades. Xanthomonas alfalfae subsp. citrumelonis populations were also exposed to frequent sprays of copper for several years as a protective measure against citrus bacterial spot (CBS) in Florida citrus nurseries. Long-term use of these bactericides has led to the development of copper-resistant (Cu(r)) strains in both X. citri subsp. citri and X. alfalfae subsp. citrumelonis, resulting in a reduction of disease control. The objectives of this study were to characterize for the first time the genetics of copper resistance in X. citri subsp. citri and X. alfalfae subsp. citrumelonis and to compare these organisms to other Cu(r) bacteria. Copper resistance determinants from X. citri subsp. citri strain A44(pXccCu2) from Argentina and X. alfalfae subsp. citrumelonis strain 1381(pXacCu2) from Florida were cloned and sequenced. Open reading frames (ORFs) related to the genes copL, copA, copB, copM, copG, copC, copD, and copF were identified in X. citri subsp. citri A44. The same ORFs, except copC and copD, were also present in X. alfalfae subsp. citrumelonis 1381. Transposon mutagenesis of the cloned copper resistance determinants in pXccCu2 revealed that copper resistance in X. citri subsp. citri strain A44 is mostly due to copL, copA, and copB, which are the genes in the cloned cluster with the highest nucleotide homology (≥ 92%) among different Cu(r) bacteria.201121515725
804990.8575Microalgae simultaneously promote antibiotic removal and antibiotic resistance genes/bacteria attenuation in algal-bacterial granular sludge system. This study investigated the effects of microalgae growth on antibiotic removal and the attenuation of antibiotic resistance genes (ARGs)/ARGs host bacteria in algal-bacterial granular sludge (ABGS) system. In the presence of tetracycline (TC) and sulfadiazine (SDZ) mixture (2-4 mg/L), microalgae could grow on bacterial granular sludge (BGS) to form ABGS, with a chlorophyll-a content of 7.68-8.13 mg/g-VSS being achieved. The removal efficiencies of TC and SDZ by ABGS were as high as 79.0 % and 94.0 %, which were 4.3-5.0 % higher than those by BGS. Metagenomic analysis indicated that the relative abundances of TC/SDZ- related ARGs and mobile genetic elements (MGEs) in BGS were 56.1 % and 22.1 % higher than those in ABGS. A total of 26 ARGs were detected from the granules, and they were identified to associate with 46 host bacteria. 13 out of 26 ARGs and 13 out of 46 hosts were shared ARGs and hosts, respectively. The total relative abundance of host bacteria in BGS was 30.8 % higher than that in ABGS. Scenedesmus and Chlorella were the dominant microalgae that may reduce the diversity of ARGs hosts. Overall, ABGS is a promising biotechnology for antibiotic-containing wastewater treatment.202235777142
8108100.8570Insights into the beneficial effects of woody peat for reducing abundances of antibiotic resistance genes during composting. Antibiotic resistance genes (ARGs) in manure endangered human health, while heavy metals in manure will pose selective pressure on ARGs. This study explored the effects on ARGs of adding woody peat during composting at different ratios (0 (CK), 5% (T1), and 15% (T2)). After composting, the relative abundances of 8/11 ARGs were 6.97-38.09% and 10.73-54.31% lower in T1 and T2, respectively, than CK. The bioavailable Cu content was 1.40% and 18.40% lower in T1 and T2, respectively, than CK. Network analysis showed that ARGs, mobile genetic elements (MGEs), and metal resistance genes possessed common potential host bacteria, such as Streptococcus, Dietzia, and Corynebacterium_1. Environmental factors, especially bioavailable Cu, and MGEs accounted for 80.75% of the changes in the abundances of ARGs. In conclusion, 15% Woody peat is beneficial to decrease the bioavailable Cu content and weaken horizontal gene transfer for controlling the spread of ARGs during composting.202134534940
8058110.8570Effects of biochars on the fate of antibiotics and their resistance genes during vermicomposting of dewatered sludge. It is currently still difficult to decrease the high contents of antibiotics and their corresponding antibiotic resistance genes (ARGs) in sludge vermicompost. To decrease the environmental risk of vermicompost as a bio-fertilizer, this study investigated the feasibility of biochar addition to decrease the levels of antibiotics and ARGs during vermicomposting of dewatered sludge. To achieve this, 1.25% and 5% of corncob and rice husk biochars, respectively, were added to sludge, which was then vermicomposted by Eisenia fetida for 60 days. The sludge blended with corncob biochar showed increased decomposition and humification of organic matter. Higher biochar concentration promoted both the number and diversity of bacteria, and differed dominant genera. The level of antibiotics significantly decreased as a result of biochar addition (P < 0.05), and tetracycline was completely removed. Relative to the control without addition of biochars, ermF and tetX genes significantly decreased with corncob biochar treatment (P < 0.05). Rice husk biochar (5%) could effectively decrease sul-1 and sul-2 genes in vermicompost (P < 0.05). However, the abundance of the intI-1 gene increased with biochar concentration. This study suggests that biochar addition can lessen the antibiotic and ARG pollution in sludge vermicompost, depending on the type and concentration of biochars.202032388093
7757120.8569Removal of antibiotics and antibiotic resistance genes from domestic sewage by constructed wetlands: Effect of flow configuration and plant species. This study aims to investigate the removal of antibiotics and antibiotic resistance genes (ARGs) in raw domestic wastewater by various mesocosm-scale constructed wetlands (CWs) with different flow configurations or plant species including the constructed wetland with or without plant. Six mesocosm-scale CWs with three flow types (surface flow, horizontal subsurface flow and vertical subsurface flow) and two plant species (Thaliadealbata Fraser and Iris tectorum Maxim) were set up in the outdoor. 8 antibiotics including erythromycin-H2O (ETM-H2O), monensin (MON), clarithromycin (CTM), leucomycin (LCM), sulfamethoxazole (SMX), trimethoprim (TMP), sulfamethazine (SMZ) and sulfapyridine (SPD) and 12 genes including three sulfonamide resistance genes (sul1, sul2 and sul3), four tetracycline resistance genes (tetG, tetM, tetO and tetX), two macrolide resistance genes (ermB and ermC), two chloramphenicol resistance genes (cmlA and floR) and 16S rRNA (bacteria) were determined in different matrices (water, particle, substrate and plant phases) from the mesocosm-scale systems. The aqueous removal efficiencies of total antibiotics ranged from 75.8 to 98.6%, while those of total ARGs varied between 63.9 and 84.0% by the mesocosm-scale CWs. The presence of plants was beneficial to the removal of pollutants, and the subsurface flow CWs had higher pollutant removal than the surface flow CWs, especially for antibiotics. According to the mass balance analysis, the masses of all detected antibiotics during the operation period were 247,000, 4920-10,600, 0.05-0.41 and 3500-60,000μg in influent, substrate, plant and effluent of the mesocosm-scale CWs. In the CWs, biodegradation, substrate adsorption and plant uptake all played certain roles in reducing the loadings of nutrients, antibiotics and ARGs, but biodegradation was the most important process in the removal of these pollutants.201627443461
7746130.8567Phosphate-modified calamus-based biochar filler enhanced constructed wetland mitigating antibiotic resistance risks: insight from metagenomics. In this study, an innovative phosphate-modified calamus-biochar (PBC) filler with high antibiotic adsorption capacity was developed to enhance constructed wetlands (CWs) wastewater treatment. Results showed that the erythromycin (ERY) and sulfamethoxazole (SMX) removal efficiency of PBC-CW was 86.5 % and 84.0 %, which was 2-fold higher than those of the blank group. Metagenomic analysis found that the ERY and SMX would significantly promote the increase in abundance of antibiotic resistance genes (ARGs), mobile genetic elements (MGEs) and virulence factor genes (VFGs). Compared to blank group, the abundances of ARGs, MGEs and VFGs were reduced by 67.2 %, 33.3 % and 11.1 % in PBC-CW. Among them, the abundance of sulfonamide and MLS, which were key genes to resistance to SMX and ERY, respectively, were reduced by 71.8 % and 63.1 % in PBC-CW. Moreover, these persistent ARG subtypes, detected simultaneously in all the samples, reduced the total abundance by 44.8 %. In addition, microbial community analysis found that the sum abundance of Arenimonas, Chryseobacterium and Hydrogenophaga, which were suggested as potential antibiotic-resistant bacteria (ARB) via correlation analysis, were significantly decreased from 1.54 % in blank group to 0.23 % in PBC group. Moreover, Chryseobacterium and Hydrogenophaga were positively correlated with VFGs, they could be pathogens with resistance genes. Therefore, PBC-CW could effectively reduce the abundance of ARGs and pathogenic microorganisms, thereby improving water security.202540845656
7859140.8561Abatement of antibiotics and resistance genes during catalytic ozonation enhanced sludge dewatering process: Synchronized in volume and hazardousness reduction. Based on the efficiency of the catalytic ozonation techniques (HDWS+O(3) and MnFe(2)O(4) @SBC+O(3)) in enhancing the sludge dewaterability, the effectiveness in synchronized abatement antibiotics and antibiotic resistance genes (ARGs) was conducted to determine. The results revealed that catalytic ozonation conditioning altered the distribution of target antibiotics (tetracycline (TC), oxytetracycline (OTC), norfloxacin (NOR), ofloxacin (OFL)) in the dewatered filtrate, the dewatered sludge cake and the extra-microcolony/cellular polymers (EMPS/ECPS) layers, achieving the redistribution from solid-phase adsorption to liquid-phase dissolution. The total degradation rate was over 90% for TC and OTC, 72-78% for NOR and OFL; the abatement efficiency of eleven ARGs reached 1.47-3.01 log and 1.64-3.59 log, respectively, and more than four eARGs were eliminated. The effective abatement of the absolute abundance of Mobile genetic elements (MGEs) (0.91-1.89 log) demonstrated that catalytic ozonation conditioning could also significantly inhibit horizontal gene transfer (HGT). The abundance of resistant bacteria was greatly reduced and the signal transduction of the typical ARGs host bacteria was inhibited. The highly reactive oxidation species (ROS) generated were responsible for the abatement of antibiotics and ARGs. These findings provided new insights into the sludge conditioning for ideal and synchronized reduction in volume and hazardousness by catalytic ozonation processes in sludge treatment.202437944236
7756150.8561Mitigation of antibiotic resistance: the efficiency of a hybrid subsurface flow constructed wetland in the removal of resistant bacteria in wastewater. This research investigates the effectiveness of a lab-scale hybrid subsurface flow constructed wetland (HSSFCW) for removing wastewater contaminants, including antibiotic-resistant bacteria (ARB), genes (ARGs) and antibiotics. The results suggested that HSSFCW demonstrated a high removal efficiency for COD (89%) and BOD (88.9%), while lower efficiencies were observed for salts, TDS, EC, and TKN. Further, various bacteria such as Enterobacter cloacae, Serratia liquefaciens and Serratia odorifera were detected in the plant rhizosphere, while Acinetobacter baumanii and Staphylococcus spp. were identified as biofilm formers on the wetland media. The mean removal efficiency of 70.44, 65.99, 70.66 and 51.49% was observed for total heterotrophic bacteria; Cefixime (Cef)-, Ciprofloxacin (Cip)-, and Linezolid (Lzd)-resistant bacteria. Upon chlorination of effluent samples, Cef-, Cip- and Lzd-resistant bacteria were effectively inactivated at 30, 15 and 7.5 mg Cl(2) min/L, respectively. The wetland achieved a removal efficiency of 83.85% for Cip and 100% for Lzd at week 12 with p = 0.040 and p < 0.001, respectively. Further, a log reduction of 0.66 for 16S, 0.82 for blaTEM, 0.61 for blaCTX, and 0.48 for blaOXA was observed. Thus, HSSFCW was observed to be efficient in removing organic contaminants, ARBs, ARGs and antibiotics from domestic wastewater and can be upgraded under natural environments.202540536145
7747160.8561Hydrothermal pre-treatment followed by anaerobic digestion for the removal of tylosin and antibiotic resistance agents from poultry litter. Hydrothermal pretreatment (HPT) followed by anaerobic digestion (AD) is an alternative for harvesting energy and removing organic contaminants from sewage sludge and animal manure. This study investigated the use, in an energetically sustainable way, of HPT and AD, alone or combined, to produce methane and remove tylosin and antimicrobial resistance genes (ARG) from poultry litter (PL). The results showed that HPT at 80 °C (HPT80), followed by single-stage AD (AD-1S), led to the production of 517.9 ± 4.7 NL CH(4) kg VS(-1), resulting in 0.11 kWh kg PL(-1) of electrical energy and 0.75 MJ kg PL(-1) of thermal energy, thus supplying 33.6% of the energy spent on burning firewood at a typical farm. In this best-case scenario, the use of HPT alone reduced tylosin concentration from PL by 23.6%, while the process involving HPT followed by AD-1S led to the removal of 91.6% of such antibiotic. The combined process (HPT80 + AD-1S), in addition to contributing to reduce the absolute and relative abundances of ARG ermB (2.13 logs), intI1 (0.39 logs), sul1 (0.63 logs), and tetA (0.74 logs), led to a significant removal in the relative abundance of tylosin-resistant bacteria present in the poultry litter.202336648713
524170.8558Sulfamethoxazole degradation by Pseudomonas silesiensis F6a isolated from bioelectrochemical technology-integrated constructed wetlands. The antibiotic-degrading ability and mechanism of the bacteria in the novel and ecological bioelectrochemical technology-integrated constructed wetlands (BICW) remain unknown. In this study, the sulfamethoxazole (SMX) degrading strain Pseudomonas silesiensis F6a (F6a), which had high degradation efficiency, was firstly isolated from a substrate sample in BICW. The SMX degradation process of F6a follows pseudo first order kinetics. Four metabolic pathways and twelve degradation products were identified. Based on genomics and proteomics analysis, six key SMX-degrading genes, Gene4641 deoC, Gene0552 narI, Gene0546 luxS, Gene1753 nuoH, Gene0655 and Gene4650, were identified, which were mainly participated in C-S cleavage, S-N hydrolysis and isoxazole ring cleavage. Interestingly, we found the corresponding sulfonamides resistance genes were not detected in F6a, which may provide an evidence for low abundance of the sulfonamides resistance genes in BICW system. These findings would contribute to a better understanding of biotransformation of antibiotic in the BICW.202235636241
8112180.8558Fate of antibiotic resistance bacteria and genes during enhanced anaerobic digestion of sewage sludge by microwave pretreatment. The fate of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) were investigated during the sludge anaerobic digestion (AD) with microwave-acid (MW-H), microwave (MW) and microwave-H2O2-alkaline (MW-H2O2) pretreatments. Results showed that combined MW pretreatment especially for the MW-H pretreatment could efficiently reduce the ARB concentration, and most ARG concentrations tended to attenuate during the pretreatment. The subsequent AD showed evident removal of the ARB, but most ARGs were enriched after AD. Only the concentration of tetX kept continuous declination during the whole sludge treatment. The total ARGs concentration showed significant correlation with 16S rRNA during the pretreatment and AD. Compared with unpretreated sludge, the AD of MW and MW-H2O2 pretreated sludge presented slightly better ARB and ARGs reduction efficiency.201626970692
8000190.8556Fate of antibiotic resistance genes in reclaimed water reuse system with integrated membrane process. The fate of antibiotic resistance genes (ARGs) in reclaimed water reuse system with integrated membrane process (IMR) was firstly investigated. Results indicated that ARGs, class 1 integrons (intI1) and 16S rRNA gene could be reduced efficiently in the IMR system. The absolute abundance of all detected ARGs in the reuse water after reverse osmosis (RO) filtration of the IMR system was 4.03 × 10(4) copies/mL, which was about 2-3 orders of magnitude lower than that in the raw influent of the wastewater treatment plants (WWTPs). Maximum removal efficiency of the detected genes was up to 3.8 log removal values. Daily flux of the summation of all selected ARGs in the IMR system decreased sharply to (1.02 ± 1.37) ×10(14) copies/day, which was 1-3 orders of magnitude lower than that in the activated sludge system (CAS) system. The strong clustering based on ordination analysis separated the reuse water from other water samples in the WWTPs. Network analysis revealed the existence of potential multi-antibiotic resistant bacteria. The potential multi-antibiotic resistant bacteria, including Clostridium and Defluviicoccus, could be removed effectively by microfiltration and RO filtration. These findings suggested that the IMR system was efficient to remove ARGs and potential multi-antibiotic resistant bacteria in the wastewater reclamation system.202031446351