Electrolyte selection and microbial toxicity for electrochemical oxidative water treatment using a boron-doped diamond anode to support site specific contamination incident response

Abstract

Intentional and unintentional contamination incidents, such as terrorist attacks, natural disasters, and accidental spills, can result in large volumes of contaminated water. These waters may require pre-treatment before disposal and assurances that treated waters will not adversely impact biological processes at wastewater treatment facilities, or receiving waters. Based on recommendations of an industrial workgroup, this study addresses such concerns by studying electrochemical advanced oxidation process (EAOP) pre-treatment for contaminated waters, using a boron-doped diamond (BDD) anode, prior to discharge to wastewater treatment facilities. Reaction conditions were investigated, and microbial toxicity was assessed using the Microtox® toxicity assay and the Nitrification Inhibition test. A range of contaminants were studied including herbicides, pesticides, pharmaceuticals and flame retardants. Resulting toxicities varied with supporting electrolyte from 5%−92%, often increasing, indicating that microbial toxicity, in addition to parent compound degradation, should be monitored during treatment. These toxicity results are particularly novel because they systematically compare the microbial toxicity effects of a variety of supporting electrolytes, indicating some electrolytes may not be appropriate in certain applications. Further, these results are the first known report of the use of the Nitrification Inhibition test for this application. Overall, these results systematically demonstrate that anodic oxidation using the BDD anode is useful for addressing water contaminated with refractory organic contaminants, while minimizing impacts to wastewater plants or receiving waters accepting EAOP-treated effluent. The results of this study indicate nitrate can be a suitable electrolyte for incident response and, more importantly, serve as a baseline for site specific EAOP usage.

Design and Performance of Novel Self-Cleaning g-C3N4/PMMA/PUR Membranes

“…Rapid growth in population and industrialization is the main factor responsible for the increase in chemical and biological contaminants in our environment. In recent decades, many modern methods have been used for the purification of water including ultrafiltration [1][2][3], solvent extraction [4,5], electrochemical treatment [6,7], chemical precipitation [8], membrane technologies and adsorption [9,10]. However, most of these methods suffer from various drawbacks such as the need for large tanks to obtain high effectivity in the case of chemical precipitation processes.…”

Self-powered photo-thermo electrochemical sensor for harvesting of low photo thermal energy

“…These organic pollutants of electrolytes are causing the environmental contaminations (Xia et al 2017). Therefore, the alternate electrolyte materials of least potential toxic effects and economically affordable are introduced to deal with the environmental safety aspects in electrochemical applications (Phillips, James, and Magnuson 2018). Eco-friendly organic dye such as orange dye (OD) as an electrolyte can be the most appropriate substitute of conventional electrolyte in electrochemical sensors.…”

The Dependence of Oxidation Parameters and Dyes’ Molecular Structures on Microstructure of Boron-Doped Diamond in Electrochemical Oxidation Process of Dye Wastewater

“…7 The high efficiency is essentially due to the electrogenerated hydroxyl radical ( • OH) with a quite high standard redox potential (E • = 2.8V/SHE), which is able to oxidize organic substances directly into CO 2 , H 2 O or other inorganic ions. 8,9 Anode material is the key to electrochemical oxidation technology which should have high oxygen evolution potential and electrocatalytic activity, good conductivity, corrosion resistance and stability. In recent years, the anode materials of electrochemical oxidation have developed rapidly from graphite to metal to metal oxide and borondoped diamond (BDD).…”