PHOTOCATALYTIC DEGRADATION OF INDUSTRIAL PULP BLEACHING WASTEWATER FROM BAGASSE-BASED PAPER MILL IN TIO_2 SUSPENSION

摘要

Wastewater from pulp bleaching process has been received increasing attention because these polychlorinated organic compounds are carcinogenic, mutagenic and difficultly degradable. In this paper photocatalytic technology was used to degrade the industrial wastewater from pulp bleaching process of bagasse-based paper mill in the TiO_2 suspension under UV illumination. Results show that COD of wastewater can be effectively removed, optimum TiO_2 addition is 1.5g.l~(-1), and below or above this addition will results in decrease of photocatalytic efficiency. Air aeration will benefit the photocatalytic degradation of wastewater due to formation of electron acceptor O_2~-. COD values of waste water decrease linearly with prolongation of illumination time, and COD values can be lowered from 1200 to 30mg.l~(-1) when illumination is up to 240min, 97% COD is removed.