Study of electrochemical process effect on detergent removal from polluted water and fish bioassay test of the effluent

Abstract

Aims: Linear alkylbenzene sulfonate (LAS) is an anionic surfactant which is widely used in household and industrial detergents usage, and after use, it usually finds a way to the wastewater treatment systems. Conventional treatment is not recognized as an efficient method due to the long residence time and enlarged cost. Hence, advanced oxidation processes including electrochemical techniques are important. In this paper, electrochemical degradation of a synthetic solution of LAS with initial concentration 200 ppm has been investigated. Methods: The experiment was performed using eight stainless steel electrodes as cathode and anode with a monopolar arrangement. The effects of current intensity and density were studied as operational parameters on detergent removal efficiency. Results: The maximum removal efficiency 94% was achieved at current intensity equal to 300 mA and current density 6 mA/cm2. The energy consumption was calculated 2.7 ± 0.1 WH/g. The bioassay test showed that only under optimum conditions, 80% of fish was survived until 4 days since the end of the process and the rest were died immediately. All ten fish leaved in unpolluted were survived until 4 days monitoring. Conclusion: The results showed that, by reducing the current density, removal efficiency increases it was true for all current intensities.

Keywords

• Bioassay
• detergent
• surfactant
• water pollutants