Characterization and assessment of paper mill effluent for physico-chemical and biological properties and assessment for the suitability as a source of irrigation

The present investigation was carried out during 2009-2010 to characterize and assess the treated paper mill effluent from The Tamilnadu Newsprint and Papers Limited (TNPL) for physico-chemical and biological properties. Treated paper mill effluent samples were collected from TNPL, Kagithapuram, Karur District of Tamil Nadu and were analyzed in the Department of Environmental Sciences, Tamil Nadu Agricultural University, Coimbatore. The paper mill effluent collected from TNPL, Karur was light brown in colour. The effluent was found to be neutral in reaction with a pH of 7.61. It recorded an EC of 1.68 dS m and organic carbon content of 0.48 per cent. The effluent had considerable amount of cations like calcium (236 mg L), magnesium (32.5 mg L), sodium (302 mg L) and potassium (19.0.0 mg L) along with anions like chloride (357.0 mg L), bicarbonate (135.5 mg L) and sulphate (85.2 mg L), respectively.The BOD and COD values of treated effluent were 26.0 and 235 mg L, respectively.The paper mill effluent supported a considerable amount of microbial population. In general, the major quality parameters analyzed viz., pH, EC, TDS, BOD, COD, chloride and sulphate values of treated effluent were observed to be well within the permissible limits as prescribed by the TNSPCB (Tamil Nadu State Pollution Control Board) norms. From the present study, it is concluded that the treated TNPL effluent complies with TNSPCB norms and could be used for irrigation in light textured dry land soils with adequate drainage facilities.