Improving the Quality of Pulp & Paper Mill Waste Water Employing Electroflocculation Technology

Pulp and Paper Industry is one of the highest polluting industries. The wastewater from this industry has very high proportion of organic pollutants and significant color loads. Although there is no stringent legislation to the tolerance limits for discharged color in effluents but some state pollution control authorities have imposed tolerance limits for the color in discharged effluents. The present practice of color removal involves precipitation and coagulation of colored substances using aluminium salts. Although such chemical treatment methods are expensive but the industry has perforce adapted these methods to contain the tolerance limits for color discharge. Lot of research has been carried out worldwide on various EOP options for removal of color from pulp & paper mill effluent. One such option is electroflocculation (EF) technology which has been extensively studied by Central Pulp & Paper Research Institute (CPPRI). The present paper highlights the findings of pilot plant trials conducted by CPPRI on electroflocculation technology at a mill site to assess the techno-economic viability of the technology for treating different colored streams for improving the quality of pulp & paper mill waste water.