The Extractive of APMP Effluent and it Influence on Biological Treatment

China's booming paper industry has results in a strong growth in the Alkaline peroxide Mechanicla Pulping (APMP) sector, largely due to the fact that China has limited forest resource, and the APMP process can deliver a high pulp yield and good pulp properties for various paper grades. The loads of COD and BOD of the effluent from the APMP process are higher than those from the conventional mechanical pulping, but lower than those from the chemical pulping processes. The MTBE extractives were 147.2mg/L which consist mainly of resin and fatty acids that are generally regarded as the main toxicity contributors in pulping effluents. GC analysis indicates that there were about 30 kinds of compounds in the extractives. The antibacterial effects were tested by inhibition zone experiment, S13 fermentation experiment and activated sludge system. At 147.2 mg/L wood extractives, the COD removal efficiency of S13 fermentation was about 50%, When the concentration of wood extractives was increased by three times to 441.6mg/L, the COD removal efficiency decreased only about 20% (from 50% down to 40%). At the activated sludge system, the concentration of wood extractives was tripled to 441.6mg/L, resulting in 60% decrease in COD removal efficiency (from 50% down to 20%). All those studies indicated that the extractives of APMP effluent contain some toxic organic compounds. © 2011 IEEE.