An integrated system combining electrochemical oxidation and filtration processes to remove chlorine from pharmaceutical industry wastewater

Abstract

This research devised an efficient method to treat wastewater generated from heparin production at a local Taiwanese company. The approach combined electrochemical techniques with filtration processes to manage the wastewater, which exhibited high levels of total dissolved solids (TDS), chemical oxygen demand (COD), organic matter, and chlorine concentration, requiring treatment before disposal or potential reuse. A specialized electrochemical oxidation (EO) system was customized for processing 500 mL of solution at a 2A current, working in tandem with an activated carbon filter chamber. Various experiments were conducted, altering potential and adsorption times, to understand their correlation in eliminating the identified pollutants in pharmaceutical wastewater. Notably, sample 4 (S4), following an electrolysis process at 2A-12 V in 5 h and subsequent adsorption by 10 g of activated carbon for 60 min, exhibited remarkable efficacy Specifically, this treatment regime facilitated the removal of over 90 % (from 14,750 to 1422 mg/L) of chlorine concentration, 91 % (from 1.12 to 0.09 a.u.) of turbidity, and 88 % (from 22,676 to 2786 mg/L) of COD from the effluent stream. These favorable outcomes were attributed to the conversion of chlorine ions into hypochlorous acid, renowned for its potent antibacterial properties in eliminating organic compounds, as well as the robust adsorption capabilities of activated carbon. This study underscores the viability of employing surface adsorption and electrochemical processes in tandem, utilizing low input currents and brief treatment durations, to treat pharmaceutical wastewater effectively.