STUDIES ON FERTILIZING VALUE OF PAPER MILL ETP SLUDGE

Abstract

Sludge produced in paper mill in general and effluent treatment plant in particular being recognized as a valuable source of nutrients and micronutrients which can increase agricultural yield and reduce environmental problems of cities. The present study deals with evaluation of fertilizing characteristic of paper mill sludge from ETP. The sludge was taken from the waste paper based paper mill with a capacity 30 tonnes/day and producing about 45 kg/t of sludge from ETP. Its comparative analysis with sewage sludge shows that paper sludges are lower in nitrogen and potassium content and are valuable source of other macro and micronutrients which are not provided by many commercial fertilizers. Also, from the point of view of most important C:N ratio, sewage sludges are more superior than paper mill ETP sludges. If paper mill sludges are applied than matching nitrogen fertilizer has to be added to bring to its required ratio unlike sewage sludges. It is estimated that paper sludge from the ETP alone provides 2500 Kg nitrogen, 2700 Kg of phosphorus and 1850 kg of potassium per year as fertilizer..