Applicability of intI1 as an indicator gene for securing the removal efficiency of extracellular antimicrobial resistance genes in full-scale wastewater treatment plants.

Mitigating the release of extracellular antimicrobial resistance genes (exARGs) from wastewater treatment plants (WWTPs) is crucial for preventing the spread of antimicrobial resistance from human domains into the environment. This study aimed to evaluate the applicability of intI1 as a performance indicator for securing the removal of exARGs at WWTPs. We investigated the reduction of exARGs and intI1 in a full-scale WWTP, where identical wastewater was treated using conventional activated sludge (CAS) and membrane bioreactor (MBR) systems.

Important properties of anion exchange resins for efficient removal of PFOS and PFOA from groundwater.

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) present in various water sources have raised a serious concern on their health risk worldwide. Anion exchange is known to be one of the effective treatment methods but the resin properties suitable for theses contaminants have not been fully understood. We examined four commercially available anion exchange resins with different properties (DIAION™ PA312, HPA25M, UBA120, and WA30) and one polymer-based adsorbent (HP20), for their PFOA and PFOS removal in the batch experiment.

Reduction of SARS-CoV-2 by biological nutrient removal and disinfection processes in full-scale wastewater treatment plants.

Detection of SARS-CoV-2 RNA in wastewater poses people's concerns regarding the potential risk in water bodies receiving wastewater treatment effluent, despite the infectious risk of SARS-CoV-2 in wastewater being speculated to be low. Unlike well-studied nonenveloped viruses, SARS-CoV-2 in wastewater is present abundantly in both solid and liquid fractions of wastewater. Reduction of SARS-CoV-2 in past studies were likely underestimated, as SARS-CoV-2 in influent wastewater were quantified in either solid or liquid fraction only.

Biological treatment of perfluorooctanesulfonic acid (PFOS) using microbial capsules of a polysulfone membrane.

Perfluorooctanesulfonic acid (PFOS) is a persistent organic substance that has been extensively applied in many industries and causes severe, widespread adverse health impacts on humans and the environment. The development of an effective PFOS treatment method with affordable operational costs has been expected. This study proposes the biological treatment of PFOS using microbial capsules enclosing a PFOS-reducing microbial consortium.

Ammonia tolerance and microbial community in thermophilic co-digestion of sewage sludge initiated with lignocellulosic biomass.

Rice straw is a useful lignocellulosic biomass for controlling ammonia inhibition in the thermophilic anaerobic digestion of sewage sludge. However, it is challenging to procure rice straw throughout the year because of its seasonal production. This study investigated methane production in a laboratory-scale digester by gradually decreasing rice straw addition to solid thermophilic sewage sludge digestion.

Removal performance of SARS-CoV-2 in wastewater treatment by membrane bioreactor, anaerobic-anoxic-oxic, and conventional activated sludge processes.

The potential risk of SARS-CoV-2 in treated effluent from a wastewater treatment plant (WWTP) is concerned since SARS-CoV-2 is contained in wastewater during the COVID-19 outbreak. However, the removal of SARS-CoV-2 in WWTP has not been well investigated. The objectives of this study were (i) to clarify the removal performance of SARS-CoV-2 during wastewater treatment, (ii) to compare the removal performance of different secondary treatment processes, and (iii) to evaluate applicability of pepper mild mottle of virus (PMMoV) as a performance indicator for the reduction of SARS-CoV-2 RNA in wastewater treatment.

Selection of surrogate viruses for process control in detection of SARS-CoV-2 in wastewater.

Since SARS-CoV-2 RNA in wastewater is often present at low concentration or under detection limit, ensuring the reliability of detection processes using appropriate process controls is essential. The objective of this study was to evaluate applicability and limitations of candidate surrogate viruses as process controls under combinations of different virus concentration and RNA extraction methods. Detection efficiency of SARS-CoV-2 spiked in wastewater was compared with those of candidate surrogate viruses of bacteriophage ϕ6, pepper mild mottle virus (PMMoV), F-specific coliphage (F-phage), and murine norovirus (MNV).

Initial behaviors and removal of extracellular plasmid gene in membrane bioreactor.

Extracellular antibiotic resistance genes (eARG) are considered to play an important role in spread of antimicrobial resistance (AMR) in wastewater treatment and water environment. Membrane bioreactor (MBR) reportedly has better removal of ARGs in wastewater than conventional activated sludge process. However, removal of eARG is possibly limited because eARG is small to pass through microfiltration (MF) membranes.

Transcriptomic response of HepG2 cells exposed to three common anti-inflammatory drugs: Ketoprofen, mefenamic acid, and diclofenac in domestic wastewater effluents.

The biological impacts of residual pharmaceuticals in the complex wastewater effluents have not been fully understood. Here, we investigated changes in the transcriptomic responses of hepatobrastoma (HepG2) cells exposed to a single or partially combined three common non-steroidal anti-inflammatory drugs (NSAIDs); ketoprofen (KPF), mefenamic acid (MFA) and diclofenac (DCF), in domestic wastewater effluents. After 48 h sub-lethal exposure to single compounds, the DNA microarray analysis identified 57-184 differently expressed genes (DEGs).

Detection of SARS-CoV-2 in wastewater in Japan during a COVID-19 outbreak.

The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in wastewater samples has been documented in several countries. Wastewater-based epidemiology (WBE) is potentially effective for early warning of a COVID-19 outbreak. In this study, presence of SARS-CoV-2 RNA in wastewater samples was investigated and was compared with the number of the confirmed COVID-19 cases in the study area during COVID-19 outbreak in Japan.

A bioelectrochemical-system-based trickling filter reactor for wastewater treatment.

A bioelectrochemical system (BES)-based trickling filter (TF) reactor was utilized for wastewater treatment. At a COD load of 1.0 g-COD/L/day, effluent chemical oxygen demand (COD) and total nitrogen (TN) were 115 and 108 mg/L, respectively, which were allowed for discharge.

Transcriptomic analysis of HepG2 cells exposed to fractionated wastewater effluents suggested humic substances as potential inducer of whole effluent toxicity.

We performed a transcriptome-based bioassay (TSB assay) using human hepatoma HepG2 cells to evaluate the potential toxicity of whole wastewater effluents from two membrane bioreactors (MBRs) and a conventional activated sludge process (AS). The biologically active agent(s) in the wastewater effluents were characterized based on expression of the marker genes (i.e.

Candidates of quorum sensing bacteria in activated sludge associated with N-acyl homoserine lactones.

This study aimed to explore candidates of microbial groups which is associated with quorum sensing in activated sludge. Activated sludge samples were collected from three wastewater treatment plants (WWTP) to analyze N-acyl homoserine lactone (AHL) by Fourier-transform mass spectrometry (FTMS) and 16S rRNA-based microbial community. Among activated sludge samples taken at 3 WWTPs in different seasons, 2 AHL species of N-3-hydroxyoctanoyl-l-homoserine lactone and N-3-hydroxydecanoyl-l-homoserine lactone were detected in the range of ranged of 0.

Multiple-endpoints gene alteration-based (MEGA) assay: A toxicogenomics approach for water quality assessment of wastewater effluents.

Wastewater effluents contain a significant number of toxic contaminants, which, even at low concentrations, display a wide variety of toxic actions. In this study, we developed a multiple-endpoints gene alteration-based (MEGA) assay, a real-time PCR-based transcriptomic analysis, to assess the water quality of wastewater effluents for human health risk assessment and management. Twenty-one genes from the human hepatoblastoma cell line (HepG2), covering the basic health-relevant stress responses such as response to xenobiotics, genotoxicity, and cytotoxicity, were selected and incorporated into the MEGA assay.

Toxicity assessment of chlorinated wastewater effluents by using transcriptome-based bioassays and Fourier transform mass spectrometry (FT-MS) analysis.

Effects of chlorination on the toxicity of wastewater effluents treated by activated sludge (AS) and submerged membrane bioreactor (S-MBRB) systems to HepG2 human hepatoblastoma cells were investigated. In addition to the cytotoxicity and genotoxicity assays, the DNA microarray-based transcriptome analysis was performed to evaluate the change in types of biological impacts on HepG2 cells of the effluents by chlorination. Effluent organic matter (EfOM) and disinfection by-products (DBPs) were also characterized by using Fourier transform mass spectrometry (FT-MS).

Evaluation of whole wastewater effluent impacts on HepG2 using DNA microarray-based transcriptome analysis.

DNA microarray-based transcriptome analysis with human hepatoma HepG2 cells was applied to evaluate the impacts of whole wastewater effluents from the membrane bioreactors (MBRs) and the activated sludge process (AS). In addition, the conventional bioassays (i.e.