Antibiotics removal and antimicrobial resistance control by ozone/peroxymonosulfate-biological activated carbon: A novel treatment process.

Biological activated carbon (BAC) is one of the important treatment processes in wastewater and advanced water treatment. However, the BAC process has been reported to have antimicrobial resistance (AMR) risks. In this study, a new BAC-related treatment process was developed to reduce AMR caused by BAC treatment: ozone/peroxymonosulfate-BAC (O/PMS-BAC).

Effect of DNA sizes and reactive oxygen species on degradation of sulphonamide resistance sul1 genes by combined UV/free chlorine processes.

Nowadays, antibiotic resistance genes (ARGs) have been characterized as an emerging environmental contaminant, as the spread of ARGs may increase the difficulty of bacterial infection treatments. This study evaluates the combination of ultraviolet (UV) irradiation and chlorination, the two most commonly applied disinfection methods, on the degradation of sulphonamide resistance sul1 genes. The results revealed that although both of individual UV and chlorination processes were relatively less effective, two of the four combined processes, namely UV followed by chlorination (UV-Cl) and simultaneous combination of UV and chlorination (UV/Cl), delivered a better removal rate (up to 1.

Assessment of the extent of bacterial growth in reverse osmosis system for improving drinking water quality.

This study was carried out to assess reverse osmosis (RO) treatment efficacy of drinking water in terms of biological stability in the distribution system. Two flat-sheet RO membranes were used in this study. Experiments were designed to investigate the growth of biofilm and bulk phase bacteria for the RO-treated water flowing through a model distribution system under controlled conditions without disinfectants.

[Behaviors and environmental risk assessment of estrogenic endocrine disruptors in anaerobic domestic wastewater treatment].

Solid phase extraction-LC/MS/MS detection method was applied to study the concentrations and sludge adsorptions of nine estrogenic endocrine disruptors (EEDs) in an upflow anaerobic sludge blanket (UASB) and an anaerobic filter (AF). Nonylphenol equivalent quantity (NEQ) was calculated to evaluate the environmental risk of the EEDs. The results show anaerobic sludge adsorption has positive correlation with IgK(ow) and molecular length of EEDs.

Ozone-biological activated carbon as a pretreatment process for reverse osmosis brine treatment and recovery.

Ozonation was used in this study to improve biodegradability of RO brine from water reclamation facilities. An ozone dosage ranging from 3 to 10 mg O(3)/L and contact times of 10 and 20 min in batch studies were found to increase the biodegradability (BOD(5)/TOC ratio) of the RO brine by 1.8-3.

Alternative immunofluorescent labeling of Cryptosporidium parvum in water samples using semiconductor quantum dots.

The application of immunofluorescent labeling using quantum dots for detection of inactivated Cryptosporidium parvum oocysts in spiked water samples (reservoir water, treated wastewater effluent, permeate of a membrane bioreactor, and tap water) provided more consistent results compared with the organic fluorophores label. The varying degree of particles present in the different water samples (with turbidity ranging from 0.2 to 6.

Effect of formaldehyde on biofilm activity and morphology in an ultracompact biofilm reactor for carbonaceous wastewater treatment.

The effects of formaldehyde on biofilm morphology and biomass activity were investigated in an ultracompact biofilm reactor (UCBR) for carbonaceous wastewater treatment. The wastewater contained a fixed amount of glucose (with a chemical oxygen demand concentration of 600 mg/L) and an increasing concentration of formaldehyde (ranging from 21.4 to 271.

Quorum quenching enzyme activity is widely conserved in the sera of mammalian species.

Acyl-homoserine lactone (AHL) quorum sensing signals play a key role in synchronizing virulence gene expression in Pseudomonas aeruginosa, which could cause fatal bloodstream infections. We showed that AHL inactivation activity, albeit with variable efficiency, was conserved in the serum samples of all the 6 tested mammalian animals. High-performance liquid chromatography and mass spectrometry analyses revealed that mammalian sera had a lactonase-like enzyme(s), which hydrolyzed the lactone ring of AHL to produce acyl homoserine, with enzyme properties reminiscent of paraoxonases (PONs).

Use of semiconductor quantum dots for photostable immunofluorescence labeling of Cryptosporidium parvum.

Cryptosporidium parvum is a waterborne pathogen that poses potential risk to drinking water consumers. The detection of Cryptosporidium oocysts, its transmissive stage, is used in the latest U.S.

Microbial diversity and prevalence of virulent pathogens in biofilms developed in a water reclamation system.

Bacterial biofilm is a common phenomenon in both natural and engineered systems which often becomes a source of contamination and microbially influenced corrosion. It is thought that formation of biofilm in the monoculture of several bacterial species is regulated by acylhomoserine lactone (AHL) quorum-sensing signals. In this study, we investigated the microbial diversity and existence of AHL-producing and AHL-degrading bacterial species in the biofilm samples from a water reclamation system located in a tropical environment.

A study on arsenic removal from household drinking water.

Arsenic removal from household drinking water has been receiving considerable attention in the field of water supply engineering. To develop the optimal coagulation protocol, the effectiveness of several operation options such as coagulants, coagulant aids and additives, as well as flocs separation systems were investigated in this study through the use of orthogonal array experiment based on Taguchi method. Arsenic removal mechanism during household coagulation (via manual mixing) was also discussed.

Effect of particles on the recovery of cryptosporidium oocysts from source water samples of various turbidities.

Cryptosporidium parvum can be found in both source and drinking water and has been reported to cause serious waterborne outbreaks which threaten public health safety. The U.S.

Arsenic removal from household drinking water by adsorption.

Geogenic inorganic arsenic contamination in drinking water has been raising public health concern especially in developing countries. Cost-effective and stopgap arsenic removal method for household use (cooking and drinking) is very urgent. Several iron treated natural materials such as Fe-treated activated carbon (FeAC), Fe-treated gel beads (FeGB) and iron oxide-coated sand (IOCS), were investigated in this study for arsenic removal from dispersed household drinking water supply (scattered wells in the endemic arsenic poisoning areas).