Reuse of Treated Tannery Wastewater for Irrigation by a Combined Electrocoagulation/ Electrodialysis Process

Abstract

Most of countries have plentiful water resources and they all provide priority to the protection of water quality. In this work, a laboratory scale a combined electrocoagulation (EC)/ Electrodialysis (ED) process was applied to treat the tannery wastewater in order to bring the quality up to the international wastewater reuse standards. The effects of operational variables on performance were examined. The electrocoagulation current density, operating time and pH are the most important variables. In wide ranges, conductivity has no remarkable effects on pollutant removal but constitutes a good way for minimizing operating costs. Thus, it was found that that removing of 1 Kg of COD produces 0.35 Kg of organic sludge. In contrast, we concluded that 1 Kg of chromium produces regarding 6.5 Kg of inorganic sludge. However, combined process was sufficient to reuse treated tannery wastewater for irrigation. The quality of treated tannery wastewater was compared with various international standards/guidelines for wastewater reuse. It was found that the studied parameters such as, pH, COD, NH ₃-N, Cr and color were within allowable limits. In addition, electrical conductivity and TDS are important to determine the suitability of wastewater for safe irrigation. Their values are within safe range. Ultimately, it can be confirmed that the study may help to conserve tannery wastewater and alleviate the water shortage problem in the study area.

Keywords: Combined process; irrigation; guidelines; tannery; reuse

DOI: 10.7176/JNSR/11-24-04

Publication date: December 31^st 2020