Treatment of paper and pulp industry wastewater by Electro coagulation Technique

Abstract

The paper industry accounts for 1.6% of the world s production of paper and paperboard. newlinePaper and paperboard have become the essential requirement of daily life. The current Global newlinepaper and paperboard demand is 402 million tons per annum and there are more than 7745 mills newlineproducing 192 million tons of pulp. The paper demands have mostly doubled in 20 years from newline242.79 million tons during 1990 to 402 million tons by 2011, by 2021 paper production has newlinereached 521 million tons per annum. Asia produces nearly 177 million tons (44%) while; rest of newlinethe world produces 225 million tons (56%), the demand for paper is strongly linked to GDP newlinegrowth. Forest produce sector is estimated to contribute about 1.2% of world s GDP and 3% of newlineinternational merchandise trade. newlineThe paper-making is a water-intensive process, Waste generated by the pulp and paper newlineindustries carries high Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand newline(COD),Toxic substances, recalcitrant organics, pH, turbidity, high temperature, intense color, newlinehigh organic matter, and suspended solids. Biochemical methods are not so efficient for the newlinetreatment of pulp and paper industry wastewater. Further the popular conventional techniques newlinesuch as adsorption, chemical oxidation and chemical coagulation along with requiring external newlinechemical addition will also lead to the production of secondary pollutants Indian paper newlineindustries largely adopt two-step methods of effluent treatment at their treatment plants such as newlineprimary treatment (sedimentation, floatation) and secondary treatment (activated sludge, newlineanaerobic or aerobic process). These methods hardly succeed in meeting the requirements of newlinecomplete degradation of bio-refractory compounds, COD and color. They also have the added newlinedrawbacks like high treatment cost and generation of high volume of sludge, consequently newlinedemanding secondary treatment which undone would otherwise lead to secondary pollution. newlineHence, there is an urgent need not only to stop the formation of secondary pollutants but also to newlineimpose suita