Comparative analysis of residual organic pollutants from bleached and unbleached paper mill wastewater and their toxicity on Phaseolus aureus and Tubifex tubifex

The paper industry wastewater even after bio-treatment at industrial scale is a major source of aquatic and soil pollution due to various unknown compounds. Hence, the study has focused on the detection of residual organic pollutants from the bleached and unbleached paper mill wastewater and both sources showed endocrine-disrupting compounds. The toxicity test with Phaseolus aureus seed germination showed inhibition of seed germination and alpha-amylase activity >25% in bleached and unbleached paper mill wastewater. The LC50 of Tubifex tubifex was noted of >50% after 48 hours incubation test. This revealed that the wastewater discharged from bleached paper mill is more toxic than unbleached paper mill waste this might be due to the use of more chemicals during bleaching and pulping process. This study has revealed that there is need to treat both paper mill wastewaters adequately prior to discharge.