Performance evaluation of polyacrylonitrile-based polymeric composites as dual-function sorbents for some pollutants of interest to nuclear activities

Abstract

The increasing concern towards protection of the environment and optimization of a wide range of activities in nuclear field imposes the need for the development of advanced separation processes in particular for treatment of liquid wastes. But, applying the traditional treatment processes is challenged by the coexistence of cationic and anionic (radio)toxicants in liquid wastes, where multi-treatment processes and/or multi-steps are required to treat such wastes. Accordingly, the time and cost of the treatment process are increased. A one-step treatment process is therefore necessary to avoid such drawbacks. The work presented in this thesis addressed the above objective through synthesizing two novel polyacrylonitrile (PAN)-based polymeric adsorbents and evaluating their adsorbability towards two adsorbate systems (134Cs+ cations/HCrO4- anions and 60Co2+ cations/MnO4- anions). The thesis comprises four chapters which are summarized below.

CHAPTER I: Introduction The aim of this first chapter is to give an overview of: (i) The conventional treatment technologies: basic concepts, advantages and disadvantages, (ii) Adsorption: definitions and terminology, adsorption steps, adsorption operation modes, categorization of adsorbents, categories of adsorption isotherms, surface-complexes, adsorbent materials and adsorbent selection, (iii) Polyacrylonitrile: synthesis, properties and activation methods (functionalization, nitrile conversion, copolymerization and composite formation),