Publications by authors named "Ruya Chen"

Plasmid-borne conjugation transfer of antibiotic resistance genes (ARGs) triggered by non-antibiotic stresses has attracted widespread attention, known to motivate conjugation through well-recognized reactive oxygen species and SOS response. However, a notable knowledge gap remains on the potential risks of reductive compounds, such as synthetic phenolic antioxidants (SPAs), in facilitating horizontal gene transfer by the other mechanisms beyond intracellular ROS. Therefore, intragenus and wastewater indigenous microbiota conjugation models were established to examine conjugative transfer frequency of RP4 plasmid under exposure of four extensively detected SPAs.

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p-Phenylenediamines (PPDs) are widely used as antioxidants in numerous rubber products to prevent or delay oxidation and corrosion. However, their derived quinones (PPD-Qs), generated through reactions with ozone, are ubiquitous in the environment and raise significant health and toxicity concerns. This review summarizes the current state of knowledge on environmental distribution and fate, human exposure, and biological toxicity of PPDs and PPD-Qs, and makes recommendations for future research directions.

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Determining the occurrence of disinfection byproducts (DBPs) in drinking water distribution system (DWDS) remains challenging. Predicting DBPs using readily available water quality parameters can help to understand DBPs associated risks and capture the complex interrelationships between water quality and DBP occurrence. In this study, we collected drinking water samples from a distribution network throughout a year and measured the related water quality parameters (WQPs) and haloacetic acids (HAAs).

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This paper aims to develop a flow-through electrochemical system with a series of graphene nanoparticles loaded PbO reactive electrochemical membrane electrodes (GNPs-PbO REMs) on porous Ti substrates with pore sizes of 100, 150, 300 and 600 μm, and apply them to treat antibiotic wastewater. Among them, the GNPs-PbO with Ti substrate of 150 μm (Ti-150/GNPs-PbO) had superior electrochemical degradation performance over the REMs with other pore sizes due to its smaller crystal size, larger electrochemical active specific area, lower charge-transfer impedance and larger oxygen evolution potential. Under the relatively optimized conditions of initial pH of 5, current density of 15 mA cm, and membrane flux of 4.

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In recent years, increasing demand for inland river water quality precision management has heightened the necessity for real-time, rapid, and continuous monitoring of water conditions. By analyzing the optical properties of water bodies remotely, unmanned aerial vehicle (UAV) hyperspectral imaging technology can assess water quality without direct contact, presenting a novel method for monitoring river conditions. However, there are currently some challenges to this technology that limit the promotion application of this technology, such as underdeveloped sensor calibration, atmospheric correction algorithms, and limitations in modeling non-water color parameters.

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Per- and polyfluoroalkyl substances (PFASs) have raised significant concerns within the realm of drinking water due to their widespread presence in various water sources. This prevalence poses potential risks to human health, ecosystems, and the safety of drinking water. However, there is currently a lack of comprehensive reviews that systematically categorize the distribution characteristics and transformation mechanisms of PFASs in drinking water sources.

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Interactions between dissolved organic matter (DOM) and surrounding environments are highly complex. Understanding DOM at the molecular level can contribute to the management of soil pollution and safeguarding agricultural fields. Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) has enabled a molecular-level understanding of DOM.

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Groundwater contamination has become increasingly prominent, therefore, the development of efficient remediation technology is crucial for improving groundwater quality. Bioremediation is cost-effective and environmentally friendly, while coexisting pollutant stress can affect microbial processes, and the heterogeneous character of groundwater medium can induce bioavailability limitations and electron donor/acceptor imbalances. Electroactive microorganisms (EAMs) are advantageous in contaminated groundwater because of their unique bidirectional electron transfer mechanism, which allows them to use solid electrodes as electron donors/acceptors.

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Remediation of environmental toxic pollutants has attracted extensive attention in recent years. Microbial bioremediation has been an important technology for removing toxic pollutants. However, microbial activity is also susceptible to toxicity stress in the process of intracellular detoxification, which significantly reduces microbial activity.

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The adverse health effects of phthalate esters (PAEs) and perfluoroalkyl substances (PFAS) in drinking water have attracted considerable attention. Our study investigated the effects of PAEs and PFAS on the bacterial community and the growth of potential human pathogenic bacteria in rural drinking water distribution systems. Our results showed that the total concentration of PAEs and PFAS ranged from 1.

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Granular activated carbon (GAC) adsorption is one of the best available technologies for removing perfluoroalkyl substances (PFASs) from drinking water. However, GAC processes in full-scale drinking water treatment plants frequently encounter unstable, even negative removal efficiency on PFASs due to the lack of understanding between the GAC characteristics and the PFASs polluted water quality conditions. In this study, the scenarios of raw water pre-chlorination and emergency contamination by multiple PFASs were simulated to evaluate the PFASs control performance by in-service GAC with different properties and ages.

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Residual manganese(II) in finished water undergoes further oxidation and deposition in drinking water distribution systems (DWDS), and Mn deposits can function as sites for accumulating organic and inorganic pollutants. This study aims to explore how Mn transformation and deposition affect the formation of disinfection byproducts (DBPs) in chlorinated DWDS, and trihalomethanes (THMs) was selected as a representative DBP. In a 100 μg/L Mn system, regulated THMs (chlorinated/bromated-THMs) increased by over 20% higher than Mn-free system after 150-day operation; when 50 μg/L iodide (I) entered pipe systems after 150 days, iodinated THMs (I-THMs) in 100 μg/L Mn system increased by over 30% compared with Mn-free system.

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Iron oxidation inevitably occurs in drinking water distribution systems (DWDSs) and can cause water quality problems such as increased turbidity and discoloration of tap water. Considering that chlorine disinfection is also widely used in DWDSs, the role of disinfectant and disinfection byproducts (DBPs) in iron oxidation should not be neglected. Interestingly, here the well-known deoxidizer ascorbic acid (VC), which is also a food additive, could induce the formation of FeO besides FeOOH resulting in the color change from yellow to black in the presence of trichloroacetic acid (TCA, one of the most typical DBPs) and NaClO (disinfectant).

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The removal efficiencies of disinfection byproducts formation potentials (DBPFPs) and generated DBPs under pre-chlorination condition (pre-generated DBPs) during different drinking water treatment trains in eight full-scale drinking water treatment plants (WTPs) were investigated through field and laboratory studies. Haloacetic acids (HAAs) and haloacetonitriles (HANs) were identified to be two representative DBPs based on cytotoxicity and genotoxicity assessments. The performances of advanced treatment train for HAAs and HANs were better than that of conventional treatment train.

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Article Synopsis
  • Perfluoroalkyl substances (PFASs) can be found in water sources and often bypass treatment in drinking water plants, posing a risk to consumers.
  • The study examined PFAS transportation across seven water treatment facilities in eastern and northern China, revealing that long-distance water transport can reduce PFAS levels due to deposits but also increases contamination risk from certain channels.
  • Treatment methods showed that ozonation-biological activated carbon (O-BAC) was more effective than granular activated carbon (GAC) alone in removing PFASs, while the design of distribution systems influenced how PFAS mixed and accumulated in finished water.
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Aluminum (Al) release and deposition in drinking water distribution systems (DWDS) are highly detrimental to tap water quality. In this study, five drinking water treatment plant supply areas in two cities of China were examined to understand the transportation stability of Al in the DWDS. The two cities were selected based on the wide disparity reported in pH and turbidity in the finished and tap water qualities, with higher fluctuation of pH (average 8.

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Particulate manganese oxide (MnOx) deposition in drinking water distribution systems (DWDS) gives rise to the risk of water discoloration at the consumers' tap; however, its role in the fate and transport of trace organic pollutants in DWDS is not clear. Perfluorooctanoic acid (PFOA), a persistent organic pollutant frequently detected in natural water, was selected to investigate the potential effect of MnOx on its transportation behavior under DWDS conditions through laboratory batch experiments. The results show that PFOA can be greatly combined with MnOx formed in-situ through a Mn(II) oxidation process by free chlorine.

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In drinking water distribution system (DWDS), disinfection byproducts (DBPs) have a large possibility of participating in iron oxidation by dissolved oxygen (DO), which may induce particle structure transformations and increase unknown risks. In this work, the influence of trichloroacetic acid (TCAA, one of the most typical DBPs) on iron oxidation processes was studied, and the potential effects of the resulting α-FeOOH particles were evaluated through two aspects: (i) influence on the bacterial community and (ii) toxicity to human cells. TCAA promoted iron oxidation process through an Fe-O-C linkage, which led to a sharper surface of the particles (TCAA-mediated Fe oxide particles, TFOP) than that without TCAA (Fe oxide particles, FOP).

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This study profiled the bacterial community variations of water from four water treatment systems, including coagulation, sedimentation, sand filtration, ozonation-biological activated carbon filtration (O-BAC), disinfection, and the tap water after the distribution process in eastern China. The results showed that different water treatment processes affected the bacterial community structure in different ways. The traditional treatment processes, including coagulation, sedimentation and sand filtration, reduced the total bacterial count, while they had little effect on the bacterial community structure in the treated water (before disinfection).

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Although human exposure to perfluoroalkyl acids (PFAAs) through tap water is an ongoing concern, knowledge of the PFAAs occurrence in the tap water and the associated transport behaviors of PFAAs in drinking water distribution systems (DWDSs) are scarce. This investigation profiled the occurrence of 17 kinds of PFAAs in tap water of some Chinese cities, and the transport behaviors of PFAAs in DWDS were observed in eastern China. Tap water samples both along trunk pipelines and at the distal ends were collected to display the PFAAs occurrence scenarios.

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Discoloration events in drinking water distribution systems (DWDSs) are usually considered an aesthetic issue rather than a health concern, and the potential toxicity of the iron-based particles resuspended from deposits in DWDSs has not been a focus. More importantly, it has not been recognized that the iron-based particles may have structural transformation under the complex condition in DWDSs which would further increase their adverse effects. In the present study, iron particle-dominated loose deposits, which were collected from a real DWDSs through pipe flushing, were firstly found to possess obvious toxicity to human liver cells.

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Drinking water discoloration is one of the most common customer complaints. The accumulation of residual manganese (Mn) in drinking water distribution systems (DWDS) accounts for part of the discolored water that reaches household taps. Field studies were conducted at seven full-scale DWDS to investigate the deposition and release behaviors of Mn in different forms and at different concentrations in finished water.

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The occurrence and transformation behaviors of disinfection byproducts (DBPs) were investigated in the finished water and tap water of 14 water treatment plants in rural areas of eastern China. Mammalian cell toxicity data from previous studies were used to evaluate the cytotoxicity of trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), trichloronitromethane (TCNM) and the genotoxicity of HAAs, HANs and TCNM. Correlation analysis was conducted to identify the factors that might influence the variability of DBPs.

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