Removal of Heavy Metal (Zinc) from Electroplating Industry Waste Water by Adsorption Technique
by Mandeep S. Saini
Fastest growing industrialization has resulted in the discharge number of toxic pollutants into the effluent among which the major component is of heavy metals. All the heavy metals pose a considerable risk to human health. Zinc is one of the heavy metal which is used in various industries
like galvanizing, metallurgical, electroplating, mining, paints, pigments, pulp and paper and pharmaceuticals and is generally found in higher concentrations as per the current scenario in Ludhiana city. Ions of zinc metal get accumulated in the living organisms after consumed through food chain, causing several diseases and disorders like failure of kidney, effect on liver. There are some methods those are used to removal of heavy metals in the wastewater such as chemical precipitation, ion exchange, reverse osmosis, electro dialysis, ultra filtration and phyto-remediation. When metals are in high concentration then these methods are either expensive or inefficient for their removal . So this research work dealt with the adsorption technique using the natural coagulants- banana peels and mausambi peels which is an economical and environmental friendly technique for removing zinc metal from the industrial effluents. The research work involved studying the variation of removal efficiencies with pH variation (2-10 pH), contact time variation (1-5 hours) and optimum dosage variation (1-14 g/l) in order to optimize each of them for getting the maximum removal efficiency. The results showed that the highest percentage of removal obtained was at a pH of 6 in case of both banana peel and mausambi peels but the removal was higher in banana peel (50.90 %) as compared to mausambi (citrus limetta) peels (45.72%) at a same initial dose of 2g/litre of both the adsorbents. Further, the final values of contact time for banana peel and mausambi peel was observed to be 3 and 2 hours respectively. The results for adsorbent dosage showed that the highest removal that could be attained was 81.81% in case of banana peels at a dosage of 8 g/l which was higher as compared to 75.87 % in case of mausambi peels at an adsorbent dosage of 10 g/l. The analysis finally showed that the removal efficiency is a function of initial concentration of zinc present in the wastewater sample i.e more the concentration, lesser was the removal observed and also that the banana peels were observed to be a better adsorbent as the removal was at a higher rate.