Minimization of Pollution Load of Spent Liquor through Additive Pulping

The pulp and paper industry has been recognized as one of the highly polluting industrial sectors in the country. In the present paper attempt had to be made to show the effectiveness of chemical additive (Phthalic Anhydride) in reduction of COD and BOD which was used during pulping process. COD and BOD values of control spent liquor samples (without additive) were on slightly higher side in comparison to the spent liquor samples, where chemical additive phthalic anhydride was added with pulping chemicals. The reduction in BOD was due to stabilization of carbohydrates against degradation; as a result less amount of hemicellulose comes in spent liquor after pulping, which decreases the BOD values. Hemicellulose is a main constituent, which is responsible for increasing the BOD values; because lignin is refractive material and it does not take part in BOD.