Economic feasibility analysis of low cost adsorbents for the removal of Cr(VI) from wastewater

Population growth, coupled with industrialization and urbanization, has resulted in an increasing demand for water thus leading to water crisis and serious consequences on the environment. The effluent stream released from the industries mainly comprises of hazardous chemicals and heavy metal ions. Chromium is abundant in nature and has a dominant presence in most of the effluent streams as compared to other heavy metal ions. The present work comprises of a solution for the treatment of effluent streams containing Cr(VI). Adsorption process which is a cost effective and versatile method for the removal of Cr(VI) is selected in the present study. Low cost adsorbents such as activated tamarind seeds, activated neem leaves, sawdust, and activated flyash are developed from the naturally and abundantly available biodegradable materials to make the adsorption process economically feasible. The performance of above adsorbents is compared with the commercially available activated carbon which is a well known adsorbent used for the removal of Cr(VI) from wastewater by carrying out the batch experiments. The maximum adsorption capacity is obtained as 62.9 mg/g for activated neem leaves among various developed adsorbents, while the maximum adsorption capacity for commercially available activated carbon is found to be 71.7 mg/g. Cost analysis is carried out for the developed and commercial adsorbent shows that sawdust is the most economically viable option for Cr(VI) removal from wastewater. The social and environmental benefits obtained by industrial organization using low cost adsorbents are also discussed.