THE REMEDIATION OF LIGNITE-DERIVED WATER PRODUCED FROM HOT PRESS UPGRADING BY A~2/O TREATMENT

摘要

Hot Press Upgrading (HPU) is a process that is being developed to improve the quality of lignite. A large amount of lignite-derived water is created during the HPU process. This lignite-derived water's parameters such as turbidity, BOD_5, COD_(Cr), Mn, NH_3-N are higher than those allowed for re-use as circulating cooling water in a power plant. Treated by anaerobic-anoxic-oxic (A~2/O) process, the quality of lignite-derived water met the standard for re-use as circulating cooling water in power plants in China. The water reflux ratio from the oxic reactor to the anoxic reactor was set at 3:1 and the sludge reflux ratio from the secondary sedimentation tank to the anaerobic reactor was set at 50%, the denitrification and nitrification dynamic kinetic equations were derived. The NO_3~--N concentration of the effluent of the anoxic unit and the NH_3-N concentration of the effluent of the oxic unit were simulated in this paper.