9ZENG D F, WU J J, KENNEDY J F. Application of a chitosan flocculant to water treatment [ J ]. Carbohydrate Polymers, 2008, 71 ( 1 ) : 135-139.
10TONG K, ZHANG Y H, LIU G H, et al. Treatment of heavy oil wastewater using a conventional activated sludge process coupled with an immobilized biological filter [ J ]. International Biodeterioration & Biodegradation, 2013, 84(6) :65-71.