The present research relates to class of adsorbents obtained by systematic biopolymer modification of cenospheres transfigured from coal fly ash (CFA): an immense waste by-product of coal based thermal power plant, method of preparation thereof and their use in wastewater treatment contaminated by tanneries, distilleries, cosmetics, textiles, plastics, pulp and paper industries, paints, electroplating and food processing industries effluents. Removal percentage of disperse dyes had better correlated with Langmuir isotherm, tested among Freundlich, Temkin and Redlich-Peterson isotherm which indicated saturated monolayer attachment of dye molecules onto the surface of adsorbent with maximum capacity 500.4 and 500.0 mg/g for Disperse Orange 25 (DO) and Disperse Blue 79:1 (DB) dyes, respectively. The uptake rate of dye molecules followed pseudo-second order kinetics in all cases. Recovery of dye molecules was completed best in three cycles with acetic acid for CFA and cenospheres, with Di-chloromethane for CNAC and in four cycles with non-polar solvent (chloroform) for zeolite and CNCH nanocomposite. The used adsorbents could easily be dumped into landfill with in concrete pit liming, or can also be used in brick making to minimize the environmental risk.
Part of the book: Innovation in Global Green Technologies 2020