Abstract
Pressurized biochemical process is a kind of innovative water treatment technology, which is derived from traditional activated sludge process. The major advantage of this method is that oxygen transfer barrier is overcome by increasing dissolved oxygen level. In this paper, high concentration pesticide wastewater treatment by pressurized activated sludge process was experimentally investigated. All results were compared with that by the bioreactor operating at atmospheric pressure. It was found that the removal of chemical oxygen demand(COD) increased steadily with the increase of operating pressure, aeration time and sludge concentration within the range of pressure (0-0.3MPa). 85.0-92.5% COD removal (the effluent COD of 230-370mg/L) was achieved under the operation condition of influent COD 2500-5000mg/L, operating pressure 0.2MPa, and the aeration time of 6 hours. The COD volumetric loading of the equipment is 5.8-7.6kgCOD/m3.d while the COD volumetric loading is 2-2.8kgCOD/m3.d at atmospheric pressure. The COD removal can be described by modified Monod model, with the biochemical kinetics parameters, Sn=122mg/L, Vmax=2.31d-1, KS=487mg/L.
