Application of electron beam treatment for degradation of pollutants in real textile wastewater

Abstract

Textile wastewater contains numerous nondegradable contaminants such as dyes, pigments, detergents, and other auxiliaries, which make the conventional Effluent treatment plant (ETP) processes (viz coagulation-flocculation followed by biodegradation process) ineffective. Advanced oxidation processes (AOPs) are one of the alternatives by which non-degradable contaminants or pollutants can be converted to less toxic or non-toxic degradable by-products with the use of highly reactive oxidative species. Electron beam treatment is one of the AOPs that uses accelerated electrons to form highly reactive species when applied to water without using any other chemical. The present work aims to study the effectiveness of electron beam treatment in the degradation of pollutants in wastewater produced by the textile industry. Accordingly, two process house samples (Separate Dyeing and Printing process) and each section of ETP samples were collected from the textile industry and applied by electron beam treatment. The e-beam treatment was carried out at the Electron Beam Center (EBC), Kharghar, Navi Mumbai, with the beam energy 10 MeV RF Accelerator. Initially, a 10 kGy e-beam dose was applied over all collected samples and analyzed for changes in visual color, pH, and COD. Irradiation with 10 kGy alone was found to be effective for the removal of color from dyeing effluent and incoming effluent to ETP, however, no significant reduction was observed in COD values. Thereafter a variable dose (0–100 kGy) of e-beam treatment was conducted over equalization tank effluent at variable pH to study its effect on the impact of e-beam treatment. These results indicate that e-beam treatment's impact is more favorable in alkaline conditions in reducing COD. Furthermore, biodegradability enhancement towards industrial effluent sample was examined by applying low doses of e-beam treatment in terms of BOD/COD ratio and by experiment e-beam followed by biodegradation through activated sludge process. It suggests that the 2 kGy e-beam dose followed by the biodegradation process results in a faster reduction in COD than the biological treatment alone.