Catalytic dechlorination of 1,2-DCA in nano Cu-borohydride system: effects of Cu/Cu ratio, surface poisoning, and regeneration of Cu sites.

Aqueous-phase catalyzed reduction of organic contaminants via zerovalent copper nanoparticles (nCu), coupled with borohydride (hydrogen donor), has shown promising results. So far, the research on nCu as a remedial treatment has focused mainly on contaminant removal efficiencies and degradation mechanisms. Our study has examined the effects of Cu/Cu ratio, surface poisoning (presence of chloride, sulfides, humic acid (HA)), and regeneration of Cu sites on catalytic dechlorination of aqueous-phase 1,2-dichloroethane (1,2-DCA) via nCu-borohydride.

The journey of toluene to complete mineralization via heat-activated peroxydisulfate in water: intermediates analyses, CO monitoring, and carbon mass balance.

Our study has thoroughly investigated the complete mineralization of toluene in water via heat-activated peroxydisulfate (PDS) by: (1) monitoring concentrations/peak areas of various intermediates and CO throughout the reaction period and (2) identifying water-soluble and methanol-soluble intermediates, including trimers, dimers, and organo-sulfur compounds, via non-target screening using high-resolution mass spectrometry. Increased temperature and PDS dosage enhanced toluene removal/mineralization kinetics and increased the rate/extent of benzaldehyde formation and its further transformation. Artificial groundwater and phosphate buffer minimally impacted toluene removal but significantly decreased benzaldehyde formation, indicating a shift in transformation pathways.

A high-throughput and cost-effective microplate reader method for measuring persulfates (peroxydisulfate and peroxymonosulfate).

Frequent use of persulfates as oxidants, for in situ chemical oxidation and advanced oxidation processes, warrants the need for developing a fast and efficient method for measuring persulfate concentrations in aqueous samples in the lab and on site. Here, we propose a modified method, based on Liang et al.'s (2008) spectrophotometric method, for measuring both peroxydisulfate (PDS) and peroxymonosulfate (PMS) in the aqueous samples.

Effect of low permeability zone location on remediation of Cr(VI)-contaminated media by electrokinetics combined with a modified-zeolite barrier.

Research on electrokinetics-permeable reactive barrier (EK-PRB) remediation to date has mainly focused on homogeneous soils or soils with micro-scale heterogeneities. The potential impact of macro-scale physical heterogeneities, such as stratified layers or lenses, on EK-PRB remediation has not received much attention. This study investigates the effect of a low permeability stratum on EK-PRB remediation of hexavalent chromium (Cr(VI)).

Sulfidated nano zerovalent iron (S-nZVI) for in situ treatment of chlorinated solvents: A field study.

Sulfidated nano zerovalent iron (S-nZVI), stabilized with carboxymethyl cellulose (CMC), was successfully synthesized on site and injected into the subsurface at a site contaminated with a broad range of chlorinated volatile organic compounds (cVOCs). Transport of CMC-S-nZVI to the monitoring wells, both downgradient and upgradient, resulted in a significant decrease in concentrations of aqueous-phase cVOCs. Short-term (0-17 days) total boron and chloride measurements indicated dilution and displacement in these wells.