Adsorptive interactions of organic micropollutants in aqueous medium with activated carbons made from wastes

Abstract

TITLE: ADSORPTIVE INTERACTIONS OF ORGANIC MICROPOLLUTANTS IN AQUEOUS MEDIUM WITH ACTIVATED CARBONS MADE FROM WASTES The thesis consists of seven chapters and a bibliography. The first chapter introduces carbon adsorbents with respect to their early history, recent history, preparation, activation, surface chemistry and various lab scale or industrial uses. The important role played by the carbons for effective control of the environmental pollutants has been described in respect to some recent literature with special references on removal of persistent organic micropollutants. The second chapter gives a brief description of the objectives of the work and the experimental methodology. The techniques for pretreatment of solid wastes and their conversion to activated carbons have been described in detail. The carbonization was brought about either by pyrolysis or by treating with concentrated sulfuric acid. The prepared carbons were characterized with respect to their ash content, pH of slurry, iodine number, water and acid soluble matter, and surface area. The eight carbons, prepared in this work, were shown to have pll: 6.0-8.9; ash content (%):5.0-45.4; matter soluble in water (%):0.5-2.5; concentrated HCl(%): 4.6-28.3; dilute HCl(%): 1.6-18.8; Iodine number: 90.8-209.8. IR measurements of the carbons yielded appropriate frequencies for the CH3, CH2 and (CH2)n stretching and bending regions. The methodology for the batch adsorption experiments, the calculation procedures for various parameters, the isotherm studies and the evaluation of the thermodynamic parameters were also described. The next four chapters of the thesis describe the results of interaction of the prepared carbons with four micropollutants, viz., two phenolic compounds-phenol and 2-chlorophenol, and two dyes-methylene blue and Congo Red, taken in the form of synthetic effluents. The third chapter describes the experimental results of phenol adsorption on eight carbons-C1, C2, C3, C4, C5, C6, C7 and C8. The adsorption experiments were carried out...