Textile wastewater treatment by application of combined chemical coagulation, electrocoagulation, and adsorption processes

The aim of this work was to study the feasibility of treating real textile wastewater by combined chemical coagulation (using poly aluminum chloride (PAC) as coagulant), electrocoagulation (using aluminum electrodes), and adsorption process (using pistachio nut shell ash) to achieve the required standards. The influence of the critical operating variables such as coagulant dose, electrical potential, reaction time, and adsorbent dose on the removal efficiencies of major pollutants was determined. The results of this study were showed that removal of pollutants increased with increasing doses of PAC and applied voltage. The chemical coagulation process showed 40% of chemical oxygen demand (COD), 34% of biochemical oxygen demand (BOD5), 23.7% TSS, and 44.5% of dye removal efficiency, even though using relatively low PAC concentration (30 mg/L). COD, BOD5, and dye removals of 93.1, 88.8, and 98.6% were achieved by electrocoagulation process (applied voltage 60 V). In addition, COD, BOD5, and dye removals of 98, 94.2, and 99.9% were achieved by overall combined process (chemical coagulation, electrocoagulation, and adsorption processes). The experiments demonstrated the effectiveness of combined processes for the treatment of real textile wastewaters. Consequently, combined processes are inferred to be superior to these processes alone for the removal of both organic and inorganic compounds from textile wastewater.