Butachlor usage is increasing due to the increasing demand for agricultural products. However, it has toxic effects on surface and underground water. The experiment was conducted under visible light and the effects of parameters such as pH, adsorbent quantity, contact time, and the initial concentration of pesticides were investigated on the degradation of different pesticide solutions. The optimum dosing for ZnO and TiO₂ was 0.5 g/L. Degradation by ZnO reached 96.3% and that by TiO₂ reached 98.5%. The degradation effect of pH change was also analyzed and found to be higher in the basic region. The COD value was reduced effectively with TiO₂. The results showed that TiO₂ is more effective for degradation.

Diclofenac sodium (DCF) is a non-steroidal anti-inflammatory drug mainly used as an analgesic, arthritic and anti-rheumatic. This study deals with the degradation of diclofenac by photo catalytic-based advanced oxidation processes. Artificial UV lamp and solar rays have been applied to activate the ZnO catalyst, thereby generating highly oxidizing species. These species initiate the degradation process of the drug, which results in intermediates that finally dissociate into carbon dioxide and water. The solar reactor system is comprised of quartz and borosilicate tubes alternatively for the absorption and transmission of the solar rays to the pollutant sample. The degradation rate has been analyzed by composition analysis using high performance liquid chromatography. TOC and COD tests have also been conducted for degraded samples. ZnO catalyst loading was tested from 0.1 gm/L to 1 gm/L and the degradation rate showed a rising trend up to 0.250 gm/L, but further increase in loading resulted in a drop in degradation. Similarly, degradation is higher in acidic condition as compared to neutral or basic pH. The results showed a higher degradation rate for UV lamp irradiation as compared to the solar system. Moreover, TOC and COD reduction is also found to be higher for UV lamp photo catalysis.