Effects of different quaternary ammonium compounds on intracellular and extracellular resistance genes in nitrification systems under the pre-contamination of benzalkyl dimethylammonium compounds.

As the harm of benzalkyl dimethylammonium compounds (BACs) on human health and environment was discovered, alkyltrimethyl ammonium compound (ATMAC) and dialkyldimethyl ammonium compound (DADMAC), which belong to quaternary ammonium compounds (QACs), were likely to replace BACs as the main disinfectants. This study simulated the iterative use of QACs to explore their impact on resistance genes (RGs) in nitrification systems pre-contaminated by BACs. ATMAC could initiate and maintain partial nitrification.

Phenacetin enhanced the inorganic nitrogen removal performance of anammox bacteria naturally in-situ enriched system.

Among the earliest synthetic antipyretic drugs, phenacetin (PNCT) could be used as the novel partial nitrification (PN) inhibitor to effectively inhibit nitrite-oxidizing bacteria (NOB). In practical application, the rapidly starting of PN could provide stable source of nitrite for anaerobic ammonium oxidation (anammox) process. However, impact of PNCT on anaerobic ammonia oxidizing bacteria (AnAOB) and its underlying mechanisms were not clear.

Evolution of microbial community and resistance genes in denitrification system under single and combined exposure to benzethonium chloride and methylparaben.

Benzethonium chloride (BZC) and methylparaben (MeP) are commonly added into cosmetics as preservatives, which are frequently detected in wastewater treatment plants. Different response patterns of denitrification system were proposed under single and combined exposure to BZC and MeP (0, 0.5, 5 mg/L) by evaluating system performance, functional genes, extracellular polymeric substance (EPS), cytotoxicity, microbial community structure and resistance genes (RGs).

Genomic synergistic efficient carbon fixation and nitrogen removal induced by excessive inorganic carbon in the anammox-centered coupling system.

Given the significance of HCO for autotrophic anammox bacteria (AnAOB), excessive HCO was always provided in anammox-related systems and engineering applications. However, its impact mechanism on anammox process at genome-level remains unknown. This study firstly established an anammox-centered coupling system that entails heterotrophic partial denitrification (PD) and hydrolytic acidification (A-PDHA) fed mainly with inorganic carbon (high HCO concentration and low C/N ratio).

Enhancing Fenton-like reaction mediating performance of covalent organic frameworks through porosity modification.

Covalent organic framework (COF) catalytic photocatalysts mediating Fenton-like reactions have been applied to the treatment of organic dyes in printing and dyeing wastewater. However, the photocatalytic performance of original COF is often unsatisfactory. This study investigated the impact of porosity modification strategies on the performance of COF photocatalysts in mediating the removal of organic dyes via Fenton-like reaction.

Whatever does not kill them makes them stronger: Using quaternary ammonia antimicrobials to alleviate the inhibition of ammonia oxidation under perfluorooctanoic acid stress.

Perfluorooctanoic acid (PFOA), benzalkyl dimethylammonium compounds (BAC) and antibiotic resistance genes (ARGs) have negative effects on biological sewage treatment. The performance of nitrification systems under stress of PFOA (0.1-5 mg/L) or/and BAC (0.

Natural pyrite and ascorbic acid co-enhance periodate activation for inactivation of antibiotic resistant bacteria and inhibition of resistance genes transmission: A green disinfection process dominated by singlet oxygen.

The transmission of antibiotic resistance genes (ARGs) and the propagation of antibiotic resistant bacteria (ARB) threaten public health security and human health, and greener and more efficient disinfection technologies are expected to be discovered for wastewater treatment. In this study, natural pyrite and ascorbic acid (AA) were proposed as environmental-friendly activator and reductant for periodate (PI) activation to inactivate ARB. The disinfection treatment of PI/pyrite/AA system could inactivate 5.

Effects of polyvinyl chloride microplastics and benzylalkyldimethylethyl compounds on system performance, microbial community and resistance genes in sulfur autotrophic denitrification system.

Benzylalkyldimethylethyl ammonium compounds (BAC) and polyvinyl chloride microplastics (PVC MPs), as the frequently detected pollutants in wastewater treatment plants (WWTPs), have attracted more concerns on their ecosystem risks. Therefore, this study investigated how the sulfur autotrophic denitrification (SAD) system responded to the single and joint stress of PVC MPs (1, 10 and 100 mg/L) and BAC (0.5, 5 and 10 mg/L).

Hormesis and synergistic effects of disinfectants chloroxylenol and benzethonium chloride on highly efficient heterotrophic nitrification-aerobic denitrification functional strain: From performance to mechanism.

The heterotrophic nitrification-aerobic denitrification (HNAD) strain Exiguobacterium H1 (H1) was isolated in this study. The changes in nitrogen metabolism functions of H1 strain were discussed in presence of disinfectants chloroxylenol (PCMX) and benzethonium chloride (BEC) alone and combined pollution (PCMX+BEC). The H1 strain could use NH-N, NO-N and NO-N as nitrogen sources and had good nitrogen removal performance under conditions of C/N ratio 25, pH 5-8, 25-35 C and sodium acetate as carbon.

Exposure to zinc and dialkyldimethyl ammonium compound alters bacterial community structure and resistance gene levels in partial sulfur autotrophic denitrification coupled with the Anammox process.

Dialkyldimethyl ammonium compound (DADMAC) is widely used in daily life as a typical disinfectant and often co-exists with the heavy metal zinc in sewage environments. This study investigated the effects of co-exposure to zinc (1 mg/L) and DADMAC (0.2-5 mg/L) on the performance, bacterial community, and resistance genes (RGs) in a partial sulfur autotrophic denitrification coupled with anaerobic ammonium oxidation (PSAD-Anammox) system in a sequencing batch moving bed biofilm reactor for 150 days.

Phenacetin promoted the rapid start-up and stable maintenance of partial nitrification: Responses of nitrifiers and antibiotic resistance genes.

Phenacetin (PNCT) belongs to one of the earliest synthetic antipyretics. However, impact of PNCT on nitrifying microorganisms in wastewater treatment plants and its potential microbial mechanism was still unclear. In this study, PN could be initiated within six days by PNCT anaerobic soaking treatment (8 mg/L).

The combination of ciprofloxacin and dialkyldimethyl ammonium compound synergistically proliferated intracellular resistance genes in nitrifying system.

Antibiotics and quaternary ammonium compounds (QACs) usually co-exist in wastewater treatment plants. Hence, three sequencing batch reactors were established and named as R1, R2 and R3, to investigate the effects of individual and combined exposure of different concentrations of ciprofloxacin (CIP) (0.2, 1.

Mechanisms on the removal of gram-negative/positive antibiotic resistant bacteria and inhibition of horizontal gene transfer by ferrate coupled with peroxydisulfate or peroxymonosulfate.

The existence of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) has been a global public environment and health issue. Due to the different cell structures, gram-positive/negative ARB exhibit various inactivation mechanisms in water disinfection. In this study, a gram-negative ARB Escherichia coli DH5α (E.

The synergistic effect of periodate/ferrate (VI) system on disinfection of antibiotic resistant bacteria and removal of antibiotic resistant genes: The dominance of Fe (IV)/Fe (V).

The proliferation of antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB) caused by antibiotic abuse has raised concerns about the global infectious-disease crisis. This study employed periodate (PI)/ferrate (VI) (Fe (VI)) system to disinfect Gram-negative ARB (Escherichia coli DH5α) and Gram-positive bacteria (Bacillus subtilis ATCC6633). The PI/Fe (VI) system could inactivate 1 × 10 CFU/mL of Gram-negative ARB and Gram-positive bacteria by 4.

Efficient peroxymonosulfate activation by nanoscale zerovalent iron for removal of sulfadiazine and sulfadiazine resistance bacteria: Sulfidated modification or not.

Whether it's necessary to extra chemical synthesis steps to modify nZVI in peroxymonosulfate (PMS) activation process are worth to further investigation. The 56 mg/L nZVI/153.65 mg/L PMS and 56 mg/L sulfidated nZVI (S-nZVI) (S/Fe molar ratio = 1:5)/153.

NH-MIL-101(Fe)-mediated photo-Fenton reaction enhanced simultaneous removal of nitrogen and refractory organics in anammox process through interfacial electron transfer.

In this study, HO (0.1 ‰) and NH-MIL-101(Fe)-driven (150 mg/L) photo-Fenton-coupled anammox were proposed to simultaneously improve the removal efficiency of nitrogen and humic acid. Long-term experiments showed that the total nitrogen removal efficiency was increased by the photo-Fenton reaction to 91.

Fates of extracellular and intracellular antibiotic resistance genes in activated sludge and plastisphere under sulfadiazine pressure.

Microplastics, antibiotics, and antibiotic resistance genes (ARGs) represent prominent emerging contaminants that can potentially hinder the efficacy of biological wastewater treatment and pose health risks. Plastisphere as a distinct ecological niche for microorganisms, acts as a repository for ARGs and potential pathogenic bacteria. Nonetheless, the spread pattern of extracellular ARGs (eARGs) and intracellular ARGs (iARGs) in plastisphere under antibiotic exposure was not yet known.

Successive exposure to traditional disinfectants and quaternary ammonium compounds enhances resistance genes expression and co-selection in biofilm-based partial nitrification-anammox systems.

Quaternary ammonium compounds (QACs) are recommended disinfectants with surfactant properties, surpassing triclosan (TCS) and chloroxylenol (PCMX). Given the transition from traditional disinfectants, it is essential to investigate their impacts on biological nitrogen removal systems and the fate of resistance genes (RGs). In this study, three biofilm-based partial nitrification-anammox (PN/A) systems were established.

Different fates of extracellular and intracellular antibiotic resistance genes in flocs, granular and biofilm nitrification systems under the stress of acetaminophen.

The spread of antibiotic resistance genes (ARGs), including intracellular ARGs (i-ARGs) and extracellular ARGs (e-ARGs), has become a global problem that cannot be ignored. This study clarified the fates of e-ARGs and i-ARGs in floc sludge reactor (FS), granular sludge reactor (GS) and biofilm reactor (BF) under the stress of acetaminophen (APAP). The results showed that the risk of ARGs transmission, especially for e-ARGs, in FS and BF could increase with the increasing times of APAP treatment, except for that in GS.

The effects of didodecyl dimethyl ammonium chloride on microbial communities and resistance genes in floc, granular and biofilm denitrification sludge.

As a type of quaternary ammonium compounds, didodecyl dimethyl ammonium chloride (DADMAC C12) was frequently detected in wastewater treatment plants. Here, floc-based sequencing batch reactor (FSBR), granule-based SBR (GSBR) and biofilm SBR (BSBR) were fed with 0.5, 5 and 10 mg/L of DADMAC C12 for 120 d.

The knock-on effects of different wastewater feeding modes: Change in microbial communities versus resistance genes in pilot-scale aerobic sludge granulation reactors.

To explore the effects of wastewater feeding modes on the formation of aerobic granular sludge (AGS) and the complex relationships between resistance genes and bacteria, two pilot-scale sequencing batch reactors (SBRs) were established. The SBR with influent wastewater introduced uniformly through pipes at bottom was designated as BSBR, and the SBR with inlet wastewater flowing directly from top was TSBR. BSBR formed dense AGS due to uniform wastewater feeding at bottom, while TSBR failed to cultivate AGS.

Deciphering the interaction impacts between antiseptic benzethonium chloride and biofilm nitrification system: Performance, resistance mechanisms and biodegradation.

Benzethonium chloride (BEC) is one of emerging bacteriostatic agents. BEC-bearing wastewater generated during sanitary applications in food and medication is easily combined with other wastewater streams to flow into wastewater treatment plants. This study focused on the long-term (231 days) impacts of BEC on the sequencing moving bed biofilm nitrification system.

The responses of microbial metabolic activity, bacterial community and resistance genes under the coexistence of nanoplastics and quaternary ammonium compounds in the sewage environment.

Nanoplastics (NPs) and quaternary ammonium compounds (QACs) are frequently detected in sewage. However, little is known about the risks of coexistence of NPs and QACs. In this study, the responses of microbial metabolic activity, bacterial community and resistance genes (RGs) to the exposure of polyethylene (PE), polylactic acid (PLA), silicon dioxide (SiO) and dodecyl dimethyl benzyl ammonium chloride (DDBAC) were focused on 2nd and 30th day of incubation in sewer environment.