Simultaneous Coagulation-Adsorption Process Optimization for the Treatment of Real Wastewater of Complex Dyes Manufacturing Plant

Abstract

This research study was carried out for the optimization of treatment efficiency of industrial dyes wastewater. Hybrid process of coagulation-adsorption was utilized for an effective reduction of wastewater pollutants concentration with the use of commercial coagulants namely Ferric chloride (FeCl3), Ferrous Sulfate (FeSO4) and Alum [Al2(SO4)3] and bottom based coal ash (BBCA) as an adsorbent. An effective adsorbent was prepared from coal power plant ash waste by physico-chemical treatment in order to enhance its physical properties. The removal efficiencies of pollutants for each individual and combined process were determined keeping contact time, agitation rate, equilibrium conditions similar in each case except for the dosages of chemicals added to suit the pollutants removal rates. Adsorptive capacity and adsorption (%) of BBCA adsorbent was determined for adsorption of organic pollutants along with dosage effects. Adsorption isotherm models such as Langmuir and Freundlich were applied for the determination of adsorption suitability and their mechanism. Both processes reduced the concentration of Chemical oxygen demand (COD), coloring matter, turbidity and total suspended solids (TSS) in the range of 60-70%, whereas, hybrid process of coagulation and adsorption optimized the treatment efficiency up to 80%. The overall treatment efficiency with FeCl3-BBCA, FeSO4-BBCA and Alum-BBCA was observed as 80%, 78% and 73%, respectively.