PRESENCE OF PHTHALATES, BISPHENOL A, AND NONYLPHENOL IN PAPER MILL WASTEWATERS IN SLOVENIA AND EFFICIENCY OF AEROBIC AND COMBINED AEROBIC-ANAEROBIC BIOLOGICAL WASTEWATER TREATMENT PLANTS FOR THEIR REMOVAL

摘要

Paper mills generate varieties of pollutants depending upon the type of the production process. Raw and biologically treated effluents from two paper mills with different production processes and different biological treatment plants were analysed by COD, BOD5, AOX as well as by phthalates, bisphenol A, and nonylphenol which are potential endocrine disrupting compounds. Removal efficiency of aerobic and combined aerobic/anaerobic wastewater treatment plants were studied for investigated compounds. The results indicated that dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di(2-ethylhexyl) phthalate, benzyl butyl phthalate, bisphenol A, and nonylphenol were present in raw and biologically treated paper mill effluents. The removal efficiencies of aerobic and combined aerobic-anaerobic biological wastewater treatment plants were 87% and 87% for dimethyl phthalate, 79% and 91% for diethyl phthalate, 73% and 88% for dibutyl phthalate, 84% and 78% for di(2-ethylhexyl) phthalate, 86% and 76% for benzyl butyl phthalate, 74% and 79% for bisphenol A, and 71% and 81% for nonylphenol, respectively. Despite relative high removal efficiency of biological wastewater treatment plants for investigated compounds, the concentrations of nonylphenol in treated paper mill effluents exceeded limits of 0.3 ng/L according to Directive (2008/105/EC).