Toxicity Analysis of Treated Paint Wastewater by Advanced Oxidation Process Using Bacterial Growth Inhibition and Seed Germination Test

Abstract

Advanced oxidation processes (AOPs) are increasingly being adopted for treatment of industrial wastewaters for eliminating organic elements. Although the reduction in chemical oxidation generally reduces toxicity, high efficiency of organic component breakdown does not always result in a drop in toxicity to a tolerable level. Hence, toxicity reduction studies for industrial effluent are required. However, it is difficult to carry out toxicity studies with higher vertebrates due to ethical and logistical constraints. Therefore, proxy tests, such as the use of indicator bacteria, have the potential to provide insights for toxicological studies of (treated) wastewater. Having reviewed various methods and indicators adopted for toxicity analysis of AOP treated wastewater, the toxicity of treated paint wastewater was studied by bacterial growth inhibition test using Bacillus subtilis and seed germination test using mung bean (Vigna radiata) and Bengal gram (Cicer arietinum). The results showed that the treated wastewater is completely toxic free for the growth of indicator bacteria. This indicates that the heterogeneous Fenton’s oxidation using laterite as catalyst is an effective AOP in reducing the toxicity of paint wastewater. The finding reported in this research is significant because it proves laterite soil, which is abundantly available in tropical regions, to be an efficient catalyst for Fenton’s Oxidation treatment of paint wastewater which opens up further scope for treatment of other similar industrial effluents in tropical regions. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.