Electrochemical removal of organic pollutants from process water

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22310%2F19%3A43918233" target="_blank" >RIV/60461373:22310/19:43918233 - isvavai.cz</a>

Result on the web

—

DOI - Digital Object Identifier

—

Result language

angličtina

Original language name

Electrochemical removal of organic pollutants from process water

Original language description

Persistent organic pollutants, which can be found in process water from industrial or agricultural sources, are often difficult to remove by usual water treatment. Furthermore, the pollutants can be toxic for bacteria used in water treatment and they can stay in the environment. Usual ways of dealing with persistent pollutants are: (i) physical methods (adsorption on activated carbon and subsequent burning) or (ii) chemical procedures. The latter relate to oxidation caused by chemical agents, i.e. chlorine or potassium permanganate. Chemical procedures utilizing OH∙ radicals are more advanced in comparison with previously mentioned and are thus called advanced oxidation processes (AOP). The OH∙ radical has high standard reduction potential (2.8 V vs. SHE, in acidic conditions) and is capable of mineralizing even persistent pollutants. Electrochemical AOP (EAOP) offer a highly flexible way of removing organic pollutants from waste-water by generating the OH∙ radical electrochemically. EAOPs usually do not require addition of other chemicals into the processed water but sometimes they require increase in conductivity or acidification. This is an advantage in comparison with i.e. treating water with chlorine because it can cause chlorination of organic components which is undesirable. Using electrodes with high overpotential for oxygen evolution reaction resolves in two possibilities. With low current loads, organic pollutants are oxidized directly on the surface of the electrode by the adsorbed OH∙ radical. With high current loads, apart from direct oxidation, an oxidizing agent such as O3 (ozone) or S2O8(2-) (peroxydisulfate) is generated and reacts with the organic species in the bulk of the solution. Boron doped diamond (BDD) electrode and activated titanium anodes (ATA) based on SnO2 doped by Sb were utilized for removing a model pollutant (acid orange 7) and a real industrial liquid waste. Concentrations of the pollutants were evaluated by UV-Vis spectrophotometry. BDD electrode showed excellent results in terms of organic pollutants removal and stability. ATA electrodes show good removal capabilities but suffer from deactivation with higher current densities.

Czech name

—

Czech description

—

Type

O - Miscellaneous

CEP classification

—

OECD FORD branch

10405 - Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)

Project

<a href="/en/project/TJ02000116" target="_blank" >TJ02000116: Electrochemical treatment of waste concentrates from membrane separation processes</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů