ADSORPTIVE REMOVAL OF PARA-XYLENE FROM AQUEOUS SOLUTION USING LOW-COST ADSORBENT: EQUILIBRIUM, KINETICS AND THERMODYNAMICS

Abstract

The consequence of the rapid industrialization in developing countries since 20th century has emerged as a major threat to water pollution. Para-xylene is one of the most widely used chemical in chemical processes. It mainly used for preparation of tetrapthalic acid and diethyl tetrapthalate and as an antiknocking reagent in motor gasoline due to its high octane number (116.4). The huge demand of Para-xylene can be estimated from the fact that it is among the top 10 chemicals produced in U.S.A in terms of quantity according to the EPA source. Due to such increasing demand of production of Para-xylene, its adverse effect on environment is now a matter of great concern. Its emission into environment is contributed by various sources such as point sources like chemical and petrochemical manufacture, polyester manufacture, manufacture of paints and dyes and natural sources like petroleum, coal tar, plant emission etc. For the health point of consideration, the adverse effect of Para-xylene on human being is mostly chronical in nature. Although its effect is restricted to irritating of skin, eyes and respiratory tract, but the major concern is its root of exposure that is through inhalation as it evaporates to atmosphere from liquid effluents. It has also high acute toxicity to aquatic life and causes injury to various agricultural and ornamental crops and is expected to moderately bioaccumulate in fish. From the various alternatives available for the removal of Para-xylene from waste water, adsorption process is one, worth to be considered due to its probing track records for the removal of various hydrocarbons and aromatic compounds