Impacts of disinfection methods in a granular activated carbon (GAC) treatment system on disinfected drinking water toxicity.

The efficacy of implementing granular activated carbon (GAC) treatment in combination with pre- or post-chlorination for mitigating disinfection byproducts (DBPs) in drinking water has been promising, yet its impact on water toxicity remains unclear, necessitating cost-effective and informative effect-based toxicity assessment. This study, using recently developed yeast toxicogenomic and human cell RT-qPCR assays targeting DNA and oxidative stress, compares the toxicity level and nature of water treated through a pilot-scale GAC system with post-chlorination (GAC/Cl) or pre-chlorination upstream of GAC (Cl/GAC/Cl), with water treated by chloramination (Cl/NHCl). Experiments were conducted at environmentally relevant bromide and iodide levels across three GAC beds.

Cytotoxicity Comparison between Drinking Water Treated by Chlorination with Postchloramination versus Granular Activated Carbon (GAC) with Postchlorination.

Granular activated carbon treatment with postchlorination (GAC/Cl) and chlorination followed by chloramination (Cl/NHCl) represent two options for utilities to reduce DBP formation in drinking water. To compare the total cytotoxicity of waters treated by a pilot-scale GAC treatment system with postchlorination (and in some instances with prechlorination upstream of GAC (i.e.

Biodistribution and toxicity of antimicrobial ionic silver (Ag) and silver nanoparticle (AgNP) species after oral exposure, in Sprague-Dawley rats.

Although antimicrobial nanosilver finds numerous applications in the health and food industries, the in vivo toxicity of positively charged silver nanoparticles (AgNPs) and relevant controls are largely unexplored. This study investigates the relationship between the biodistribution and toxicity of the well-known cetyltrimethylammonium bromide (CTAB)-capped AgNPs in 6-weeks old female Sprague-Dawley rats, at sublethal doses. Amounts comparative to those leaked from food products or considered for animal feed were administered through daily water intake, for an 18-day period: AgNPs (40 μg mL), Ag (40 μg mL), antimicrobial CTAB (24 μg mL) and tap water.

Ecogenomics reveals community interactions in a long-term methanogenic bioreactor and a rapid switch to sulfate-reducing conditions.

The anaerobic digestion of wastes is globally important in the production of methane (CH4) as a biofuel. When sulfate is present, sulfate-reducing bacteria (SRB) are stimulated, competing with methanogens for common substrates, which decreases CH4 production and results in the formation of corrosive, odorous hydrogen sulfide gas (H2S). Here, we show that a population of SRB within a methanogenic bioreactor fed only butyrate for years immediately (within hours) responded to sulfate availability and shifted the microbial community dynamics within the bioreactor.

Micromechanical Response of Crystalline Phases in Alternate Cementitious Materials using 3-Dimensional X-ray Techniques.

Cementitious materials are complex composites that exhibit significant spatial heterogeneity in their chemical composition and micromechanical response. Modern 3-dimensional characterization techniques using X-rays from synchrotron light sources, such as micro-computed tomography (μCT) and far-field high-energy diffraction microscopy (ff-HEDM), are now capable of probing this micromechanical heterogeneity. In this work, the above mentioned techniques are used to understand the varying micromechanical response of crystalline phases (cubic iron oxide and α-quartz) inherently present within an alkali-activated fly ash (AAF) during in-situ confined compression.

The fate of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in water from Poyang Lake, the largest freshwater lake in China.

The fate of polycyclic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in the water columns from Poyang Lake was studied. The total concentrations of OCPs and PAHs were 19.10-111.