Chlorination enhances the phthalates release and increases the cytotoxicity and bacterial functions related to human disease of drinking water in plastic pipes.

The interaction between water and pipe surfaces can deteriorate drinking water quality, thus threatening public health. However, uncertainties remain in the release mechanism of phthalates acid esters (PAEs) from plastic pipes and their effects on drinking water quality. Our study indicated that PAEs released from polyvinyl chloride (PVC) pipes was higher than polyethylene (PE) pipes.

Synergistic effects of ozonation pretreatment and trace phosphate on water quality health risk and microbial stability in simulated drinking water distribution systems.

The proliferation and chlorine resistance of pathogenic bacteria in drinking water distribution systems (DWDSs) pose a serious threat to human health. In this study, the synergistic effects of ozonation pretreatment and trace phosphate on water quality health risk and microbial stability were investigated in the small-scale DWDSs simulated by biofilms annular reactors with cast iron coupons. The results indicated that ozonation of drinking water containing trace phosphate was equivalent to increasing microbial carbon and phosphorus sources, further leading to the rapid proliferation of opportunistic pathogens (OPs) in subsequent DWDSs.

Comprehensive comparison of water quality risk and microbial ecology between new and old cast iron pipe distribution systems.

The effects of cast iron pipe corrosion on water quality risk and microbial ecology in drinking water distribution systems (DWDSs) were investigated. It was found that trihalomethane (THMs) concentration and antibiotic resistance genes (ARGs) increased sharply in the old DWDSs. Under the same residual chlorine concentration conditions, the adenosine triphosphate concentration in the effluent of old DWDSs (Eff-old) was significantly higher than that in the effluent of new DWDSs.

Synergistic effects of trace sulfadiazine and corrosion scales on disinfection by-product formation in bulk water of cast iron pipe.

The effects of trace sulfadiazine (SDZ) and cast-iron corrosion scales on the disinfection by-product (DBP) formation in drinking water distribution systems (DWDSs) were investigated. The results show that under the synergistic effect of trace SDZ (10 μg/L) and magnetite (FeO), higher DBP concentration occurred in the bulk water with the transmission and distribution of the drinking water. Microbial metabolism-related substances, one of the important DBP precursors, increased under the SDZ/FeO condition.

Effect of micropollutants on disinfection byproducts and antibiotic resistance genes in drinking water in the process of biological activated carbon treatment.

The biofilm stress response of biological activated carbon (BAC) was investigated under prolonged exposure to sulfadiazine and 2,4-Dichlorophenoxyacetic acid, simulating complex emerging organic contaminants (EOCs) that are mainly involved in the formation of nitrogenous disinfection byproducts (N-DBPs) and antibiotic resistance genes (ARGs). Under trace complex EOCs condition (2 µg/L), N-DBP precursors and abundance of ARGs increased significantly in BAC effluent. The total formation potential of haloacetonitriles (HANs) and halonitromethanes (HNMs) was 751.

Synergetic effects of catalyst-surface dual-electric centers and microbes for efficient removal of ciprofloxacin in water.

Antibiotics and antibiotic resistance genes (ARGs) are still a problem in biological treatment. Herein, we propose a synergetic strategy between microbes and dual-electric centers catalysts (CCN/Cu-AlO/ceramsite) for Ciprofloxacin (CIP)-contained (5 mg/L) water treatment in an up-flow biological filter. CIP was cleaved into small molecules by the catalyst, bringing a 57.

Self-purification of actual wastewater via microbial-synergy driving of catalyst-surface microelectronic field: A pilot-scale study.

High energy consumption is impedimental for eliminating refractory organics in wastewater by current technologies. Herein, we develop an efficient self-purification process for actual non-biodegradable dyeing wastewater at pilot scale, using N-doped graphene-like (CN) complexed Cu-AlO supported AlO ceramics (HCLL-S8-M) fixed-bed reactor without additional input. About 36% chemical oxygen demand removal was achieved within 20 min empty bed retention time and maintained stability for almost one year.

Trace Iron as single-electron shuttle for interdependent activation of peroxydisulfate and HSO/O enables accelerated generation of radicals.

The generation of reactive oxygen species generally requires initiators in various environmental remediation processes, which necessitates high dosage of activators and downstream treatment for eliminating the accumulation of deactivated catalysts. Herein, a coupled process was constructed using trace iron for simultaneously activating HSO/O system and peroxydisulfate (PDS) oxidation system, where the iron ions (2 mg/L) transferred single-electron from the former system to the latter due to the moderate redox potential (Fe/Fe, +0.77 V) between the potentials of SO/HSO (+0.

[Synergistic Control of Nitrogenous Disinfection By-products and Opportunistic Pathogens in Drinking Water by Iron-Modified Quartz Sand Filtration].

The main function of quartz sand in drinking water treatment has been to remove turbidity, while the microbial effect of its solid-liquid interface has been ignored. In order to solve the limitations of control of the disinfection by-products (DBPs) and opportunistic pathogens (OPs) in common quartz sand, the common quartz sand was modified to iron sand. The maximum DBPs formation potential of typical nitrogenous disinfection by-products (N-DBPs) and carbonaceous disinfection by-products was determined using gas chromatography-ECD.

Effects of cast iron pipe corrosion on nitrogenous disinfection by-products formation in drinking water distribution systems via interaction among iron particles, biofilms, and chlorine.

The effects of cast iron pipe corrosion on nitrogenous disinfection by-products formation (N-DBPs) in drinking water distribution systems (DWDSs) were investigated. The results verified that in the effluent of corroded DWDSs simulated by annular reactors with corroded cast iron coupons, typical N-DBPs, including haloacetamides, halonitromethanes, and haloacetonitriles, increased significantly compared with the influent of DWDSs. In addition, more dissolved organic carbon, adenosine triphosphate, and iron particles were simultaneously detected in the bulk water of corroded DWDSs, thereby indicating that abundant iron particles acted as a "protective umbrella" for microorganisms.

Contribution of extracellular polymeric substances and microbial community on the safety of drinking water quality: By mean of Cu/activated carbon biofiltration.

Change in water quality was investigated with laboratory-scale ozone-biological activated carbon filters using copper-modified granular activated carbon (Cu/GAC) and unmodified granular activated carbon (GAC). In the first seven days of the experimental period, Cu/GAC removed organic matter more efficiently owing to its enhanced adsorption capacity. As the running time increased, the amount of disinfection by-products (DBPs), dissolved organic carbon, and extracellular polymeric substances (EPS) increased sharply in the effluent of the Cu/GAC filter (CCW).

Destruction of microbial stability in drinking water distribution systems by trace phosphorus polluted water source.

The effects of trace phosphate concentrations (0, 0.3 and 0.6 mg/L) in water source were investigated on microbial stability of the drinking water distribution systems (DWDSs).

Enhancing inhibition of disinfection byproducts formation and opportunistic pathogens growth during drinking water distribution by FeO/Coconut shell activated carbon.

The effects of biological activated carbon treatment using FeO modified coconut shell-based activated carbon (Fe/CAC) were investigated on the occurrence of opportunistic pathogens (OPs) and formation of disinfection by-products (DBPs) in simulated drinking water distribution systems (DWDSs) with unmodified CAC as a reference. In the effluent of annular reactor (AR) with Fe/CAC, the OPs growth and DBPs formation were inhibited greatly. Based on the differential pulse voltammetry and dehydrogenase activity tests, it was verified that extracellular electron transfer was enhanced in the attached biofilms of Fe/CAC, hence improving the microbial metabolic activity and biological removal of organic matter especially DBPs precursors.

Efficient removal of disinfection by-products precursors and inhibition of bacterial detachment by strong interaction of EPS with coconut shell activated carbon in ozone/biofiltration.

The change of water quality was investigated in pilot-scale ozone-biological activated carbon (O-BAC) filters using an emerging coconut shell-based granular activated carbon (CAC) or traditional granular activated carbon (GAC), respectively. More dissolved organic carbon (DOC) and disinfection by-products (DBPs) precursors were removed, meanwhile, less microbes, less metabolites and smaller microbial clusters were detected in the effluent of CAC compared with GAC. Sequentially, lower DBPs formation and higher disinfection efficiency were achieved in drinking water distribution systems (DWDSs).

Effect of sequential UV/free chlorine disinfection on opportunistic pathogens and microbial community structure in simulated drinking water distribution systems.

Drinking water distribution systems (DWDS) may be a "Trojan Horse" for some waterborne diseases caused by opportunistic pathogens (OPs). In this study, two simulated DWDS inoculated with groundwater were treated with chlorine (Cl) and ultraviolet/chlorine (UV/Cl) respectively to compare their effects on the OPs distributed in four different phases (bulk water, biofilms, corrosion products, and loose deposits) of DWDS. 16S rRNA genes sequencing and qPCR were used to profile microbial community and quantify target genes of OPs, respectively.

One-year survey of opportunistic premise plumbing pathogens and free-living amoebae in the tap-water of one northern city of China.

In this study, qPCR was used to quantify opportunistic premise plumbing pathogens (OPPPs) and free-living amoebae in 11 tap water samples collected over four seasons from a city in northern China. Results demonstrated that the average numbers of gene copies of Legionella spp. and Mycobacterium spp.

O-BAC-Cl: A multi-barrier process controlling the regrowth of opportunistic waterborne pathogens in drinking water distribution systems.

Simulated drinking water distribution system (DWDS) treated with O-BAC-Cl (ozone-biological activated carbon-chlorine) was constructed to study its effects on the regrowth of five typical opportunistic pathogens (OPs). It was found that O-BAC-Cl could significantly reduce the regrowth of target OPs in the effluents of DWDS compared with Cl and O-Cl with the same residual chlorine levels. However, the effect of O-BAC-Cl on the average numbers of target OPs gene markers in the biofilms of DWDS was not apparent, suggesting that OPs in the biofilms of DWDS were tolerant to the upstream disinfection process.

Response of microorganisms in biofilm to sulfadiazine and ciprofloxacin in drinking water distribution systems.

Effects of sulfadiazine and ciprofloxacin on microorganisms in biofilm of drinking water distribution systems (DWDSs) were studied. The results verified that the increases of 16S rRNA for total bacteria and bacterial genus Hyphomicrobium were related to the promotion of antibiotic resistance genes (ARGs) and class 1 integrons (int1) in DWDSs with sulfadiazine and ciprofloxacin. Moreover, the bacteria showed higher enzymatic activities in DWDSs with sulfadiazine and ciprofloxacin, which resulted in more production of extracellular polymeric substances (EPS).

Electronic Structure Modulation of Graphitic Carbon Nitride by Oxygen Doping for Enhanced Catalytic Degradation of Organic Pollutants through Peroxymonosulfate Activation.

Oxygen-doped graphitic carbon nitride (O-CN) was fabricated via a facile thermal polymerization method using urea and oxalic acid dihydrate as the graphitic carbon nitride precursor and oxygen source, respectively. Experimental and theoretical results revealed that oxygen doping preferentially occurred on the two-coordinated nitrogen positions, which create the formation of low and high electron density areas resulting in the electronic structure modulation of O-CN. As a result, the resultant O-CN exhibits enhanced catalytic activity and excellent long-term stability for peroxymonosulfate (PMS) activation toward the degradation of organic pollutants.

A human cell panel for evaluating safe application of nano-ZrO/polymer composite in water remediation.

Nanomaterials, such as ZrO nanoparticles (ZrO NPs), are very effective in water remediation. However, the safety issues related to nanoparticle release and toxicity to humans remain to be resolved. Here we evaluated the cytotoxicity of ZrO NPs and their adducts with pollutants using a human cell panel containing stomach, intestine, liver and kidney cells.

Effects of O/Cl disinfection on corrosion and opportunistic pathogens growth in drinking water distribution systems.

The effects of O/Cl disinfection on corrosion and the growth of opportunistic pathogens in drinking water distribution systems were studied using annular reactors (ARs). The corrosion process and most probable number (MPN) analysis indicated that the higher content of iron-oxidizing bacteria and iron-reducing bacteria in biofilms of the AR treated with O/Cl induced higher FeO formation in corrosion scales. These corrosion scales became more stable than the ones that formed in the AR treated with Cl alone.

Characterization of bacterial community and iron corrosion in drinking water distribution systems with O-biological activated carbon treatment.

Bacterial community structure and iron corrosion were investigated for simulated drinking water distribution systems (DWDSs) composed of annular reactors incorporating three different treatments: ozone, biologically activated carbon and chlorination (O-BAC-Cl); ozone and chlorination (O-Cl); or chlorination alone (Cl). The lowest corrosion rate and iron release, along with more FeO formation, occurred in DWDSs with O-BAC-Cl compared to those without a BAC filter. It was verified that O-BAC influenced the bacterial community greatly to promote the relative advantage of nitrate-reducing bacteria (NRB) in DWDSs.

Effects of phosphate-enhanced ozone/biofiltration on formation of disinfection byproducts and occurrence of opportunistic pathogens in drinking water distribution systems.

The effects of ozone-biologically activated carbon (O-BAC) treatment with various phosphate doses (0, 0.3 or 0.6 mg/L) were investigated on the formation of disinfection by-products (DBPs) and occurrence of opportunistic pathogens (OPs) in drinking water distribution systems (DWDSs) simulated by annular reactors (ARs).

Sulfadiazine/ciprofloxacin promote opportunistic pathogens occurrence in bulk water of drinking water distribution systems.

Effects of sulfadiazine and ciprofloxacin on the occurrence of free-living and particle-associated opportunistic pathogens in bulk water of simulated drinking water distribution systems (DWDSs) were investigated. It was found that sulfadiazine and ciprofloxacin greatly promoted the occurrence of opportunistic pathogens including Pseudomonas aeruginosa, Legionella pneumophila, Mycobacterium avium and its broader genus Mycobacterium spp., as well as the amoebae Acanthamoeba spp.