Application of Commercial and Non-Commercial Materials for Decontamination of Selected Environmental Pollutants: An Adsorption, Equilibrium and Kinetic Study

Environment is continuously intersected with pollution as an integral part with growing industrialization and urbanization resulting in discharge of effluents and waste loaded with pollutants. Not only a single metal but a combination of metals originating from one or several sources caused serious soil and water pollution. Chemical contaminants are difficult to be removed effectively and economically by classical methods. Since adsorption phenomenon are operative in most natural physical, chemical and biological environmental systems, use of potential adsorbents as alternative low cost materials has been emphasized recently for the removal of pollutants. The present study offers economical and potential candidates for the decontamination of selected elements (Zn, Se, Br and Hg) as representative of hazardous and toxic substances. For this purpose, commercial (alumina) and non-commercial novel substances (characterized clay 40% & brick powder brown & potash alum) are applied through batch adsorption. Concentration of Bromide ions, Selenium, mercury and Zinc was determined spectrophotometrically at 590nm, 546nm, 490nm and 620nm, respectively. The results indicate removal efficiency increases with increase in contact time. An initial rapid uptake is followed by a gradual removal till equilibrium. Contact of 45 minutes remove 96% Se (IV), 95% Br(I), 94% Zn(II) and 93% Hg(II) . A respective increase of 11%, 23%, 10% and 11% in removal is noted for the four elements in moving from dose of 5g to 15g. pH is important parameter to determines adsorption tendency of substrate. It is found that each adsorbent worked optimally at pH5 as compared to pH9. The study concludes that each adsorbent has a good tendency to remove the elemental pollutants following sequence of alumina> clay 40% > potash alum. Whereas, elements are removed in decreasing order of Br(I)>Se(IV)>Zn(II)>Hg(II). Langmuir isotherm is in good agreement with the experimental adsorption data.