Impact of sample acidification and extract storage on hormone receptor-mediated and oxidative stress activities in wastewater.

An underemphasized aspect of sampling strategies in effect-based in vitro testing is to determine suitable collection and preparation techniques. In the current study, the impact of sample acidification on bioactivities was assessed using in vitro bioassays for hormone receptor-mediated effects (estrogen receptor [ER] and androgen receptor [AR]) and the oxidative stress response (Nrf2 activity). Sampling was conducted at a recently upgraded Swedish wastewater treatment plant.

Artificial infiltration in drinking water production: Addressing chemical hazards using effect-based methods.

Artificial infiltration is an established managed aquifer recharge method that is commonly incorporated into drinking water processes. However, groundwater sourced from this type of purification method is prone to contamination with chemical hazards. Such an instance was previously shown at a Swedish DWTP where the river water was contaminated by hazardous chemicals during artificial infiltration.

Innovative drinking water treatment techniques reduce the disinfection-induced oxidative stress and genotoxic activity.

Disinfection of drinking water using chlorine can lead to the formation of genotoxic by-products when chlorine reacts with natural organic matter (NOM). A vast number of such disinfection by-products (DBPs) have been identified, making it almost impossible to routinely monitor all DBPs with chemical analysis. In this study, a bioanalytical approach was used, measuring oxidative stress (Nrf2 activity), genotoxicity (micronucleus test), and aryl hydrocarbon receptor (AhR) activation to evaluate an innovative water treatment process, including suspended ion exchange, ozonation, in-line coagulation, ceramic microfiltration, and granular activated carbon.

Integrity breaches in a hollow fiber nanofilter - Effects on natural organic matter and virus-like particle removal.

Ultrafiltration and nanofiltration have become common methods to treat surface water for drinking water purposes. Common aims of a membrane step are removal of natural organic matter (NOM), softening or adding an extra microbiological or chemical barrier. In most cases, the membrane is considered a good disinfection step; commonly the viral removal is at least 4-log.

Upgrading coagulation with hollow-fibre nanofiltration for improved organic matter removal during surface water treatment.

Rising organic matter concentrations in surface waters in many Nordic countries require current drinking water treatment processes to be adapted. Accordingly, the use of a novel nanofiltration (NF) membrane was studied during a nine month period in pilot scale at a large drinking water treatment plant in Stockholm, Sweden. A chemically resistant hollow-fibre NF membrane was fed with full scale process water from a rapid sand filter after aluminum sulfate coagulation.

Selective chlorination of natural organic matter: identification of previously unknown disinfection byproducts.

Natural organic matter (NOM) serve as precursors for disinfection byproducts (DBPs) in drinking water production making NOM removal essential in predisinfection treatment processes. We identified molecular formulas of chlorinated DBPs after chlorination and chloramination in four Swedish surface water treatment plants (WTPs) using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Chlorine-containing formulas were detected before and after disinfection and were therefore classified to identify DBPs.