Removal of alachlor from water by catalyzed ozonation on Cu/Al2O3honeycomb

Abstract

BackgroundThe herbicide alachlor (2-chloro-2′6′-diethyl-N-methoxymethylacetanilide) has been known as a probable human carcinogen, and the MCL (minimum contamination level) for drinking water has been set at 2 μg L-1. Therefore, the advanced methods for effectively removing it from water are a matter of interest. Catalyzed ozonation is a promising method for refractory organics degradation. Cu/Al2O3 catalyzed ozonation for degrading an endocrine disruptor (alachlor) in water was investigated.ResultsExperimental results showed that the ozonation of alachlor can be effectively catalyzed and enhanced by Cu/Al2O3-honeycomb. The main intermediate products formed (aliphatic carboxylic acids) were mineralized to a large extent in the catalytic process.ConclusionsThis study has shown that Cu/Al2O3-honeycomb is a feasible and efficient catalyst in the ozonation of alachlor in water. Less intermediate oxidation product was produced in the catalytic process than in the uncatalytic one. Furthermore, the mineralization of alachlor could be enhanced by increasing the pH of the reaction solution.

Catalytic ozonation for the removal of organic contaminants in water on alumina

“…4b, e). Such a phenomenon could be attributed to desportion of contaminants leading to a slight increase of pH followed by formation of acidic by-products, which then led to the decrease of pH [24] but further research is needed to verify this hypothesis. Fig.…”

Advanced Oxidation Processes for Activated Carbon Regeneration: From Fundamental to Application

“…Similarly, in persulfate-based regeneration, a lower pH enhances the degradation efficiency when PDS is activated by Fe 2+ . Additionally, a higher pH could facilitate the formation of • OH in ozonation processes, ultimately enhancing the degradation of anionic organic contaminants. , Therefore, pH adjustment is critical to effectively managing the trade-offs between enhancing desorption and optimizing ROS-mediated degradation.…”

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

“…In addition to photocatalytic oxidation, other AOPs and their combination have been studied for the removal of chloroacetanilide herbicides from water, with alachlor again receiving the most attention. The application of different ozone-based AOPs [40][41][42], photo-Fenton oxidation [35,43], and electro-oxidation processes [18,44], as well as relatively new plasma-based AOPs, has been reported for the elimination of alachlor in water [45,46]. Metolachlor and acetochlor have been removed by direct ozonation and catalytic ozonation [11,[47][48][49], and the photo-Fenton process [50,51].…”