Determination of the efficiency of electrolyzed water devices for the removal of pesticides in aqueous solutions and the characteristics of the pesticide residues and their transformation products

Abstract

The effect of electrolyzed water treatment on the degradation of pesticide residues (malathion, fenitrothion, p,p′-DDT, and 2-hydroxybiphenyl) in tap water was investigated. Electrolyzed water was generated by electrolysis in commercially available kitchen devices. Three devices with different parameters were tested. The transformation products of pesticides, which are formed after the electrolysis process, were also investigated. Results show that the reduction percentage for electrolyzed water was from 6.2 to 99.7 % for 2-hydroxyphenyl, from 75.5 to approx. 100 % for fenitrothion, from 79.7 to approx. 100 % for malathion, and from 52.1 to 78 % for p,p′-DDT. It was also shown that the obtained transformation products of selected pesticides are more toxic than the parent compounds. Extending the electrolysis time in water electrolysis devices results in more effective degradation of pesticides and transformation products. Our research has shown that electrolyzed water devices can effectively remove pesticide residues, but they can also be a source of other toxic transformation products that may have a synergistic effect.