The prevailing most widely used and convenient method in India for Wastewater treatment such as primary and secondary treatment by flocculants and coagulants as well as secondary treatment by using micro organisms and color removal by using activated Carbon. However this method is quite expensive. So the present study is about the use of cow dung ash as an adsorbent in the secondary treatment of wastewater to reduce the contaminants. Various different parameters viz. pH, Total Dissolved Solids (TDS), Total Suspended Solids (TSS), Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) for tertiary wastewater will be analyzed before and after the treatment with Cow dung ash to find out the effect on effluent. This natural adsorbent is cheap, easily available and ecofriendly.