Removal of Chloroacetanilide Herbicides from Water Using Heterogeneous Photocatalysis with TiO2/UV-A

Abstract

Chloroacetanilide herbicides are widely used in the agricultural sector throughout the world. Because of their poor biodegradability, high water solubility, and long persistence, chloroacetanilide herbicides have a high potential to contaminate water, and conventional water treatment processes do not ensure sufficient removal. Therefore, heterogeneous photocatalysis using TiO2/UV-A was investigated for the degradation of alachlor, acetochlor, and metolachlor from water. Two commercially available TiO2 (P25 and AV-01) were used as photocatalysts. Different experimental setups were also tested. In addition, the toxicity of single herbicides and mixtures of their photocatalytic degradation products to the freshwater alga Chlorella kessleri was investigated via a growth inhibition test. The maximum removal efficiency for alachlor, acetochlor, and metolachlor was 97.5%, 93.1%, and 98.2%, respectively. No significant differences in the removal efficiency of chloroacetanilide herbicides were observed for the photocatalysts used. Although the concentrations of all herbicides during photocatalysis decreased, the toxicity of the resulting mixtures of degradation products increased or remained the same, indicating the formation of toxic degradation products.

Synthesis of CBO (Co3O4-Bi2O3) Heterogeneous Photocatalyst for Degradation of Fipronil and Acetochlor Pesticides in Aqueous Medium

“…A 1000 mL solution of 10 mg/L concentration was used for each pesticide. Furthermore, the toxicity of these pesticides was also investigated using freshwater alga Chlorella kessleri [49]. Wang and co-workers [50] reported the removal of Acetochlor via adsorption and degradation using MnFe 2 O 4 @AC as the adsorbent and catalyst.…”

Towards a Better Understanding of the Back-Side Illumination Mode on Photocatalytic Metal–Organic Chemical Vapour Deposition Coatings Used for Treating Wastewater Polluted by Pesticides

“…In the field of water treatment, emerging contaminants (ECs) are a major concern [1][2][3]. Even at very low concentrations (in the order of less than micrograms per litre), such contaminants and their transformation products (TPs) can have extremely harmful effects on human health and the environment [4].…”