Water treatment technologies for removing priority pesticides.

Abstract

The development of technologies to remove pesticides from environmental matrices is an important issue as they may be toxic to the environment and human health. The objective of this review is to understand the treatability of five selected pesticides including the main treatment processes and conditions employed worldwide to remove them. Despite its widespread use in water treatment plants (WTP), conventional technologies alone were only tested for atrazine and resulted in low average removal (up to 50 %). Several studies using advanced oxidation processes have been successful for atrazine, but few experiments have been performed under practical conditions. Regarding reported efficiencies, 80 % of atrazine was degraded when conventional treatment was followed by ozonation using aluminum sulfate and magnafloc LT 22 as coagulants and ozone as disinfectant. For acephate and methamidophos, the use of titanium dioxide was the best treatment, leading to 87.7 % to 100 % removal in laboratory-scale experiments. Anodic Fenton treatment and a combination of Fenton and ultrasound exhibited high (99 and 100 %, respectively) carbofuran removal efficiencies. In terms of time and conditions tested, the membrane anodic Fenton treatment was the best one, but large-scale application needs to be further evaluated. In general, advanced oxidation processes are good complementary technologies. However, understanding the fate and toxicity of the transformation by-products is crucial, as well as its applicability (economic and environmental sustainability) on a large scale.