文献名： Effect of tannic acid on the dewaterability of dredged sediment and the conditioning mechanism

作者 ： Qunshan Wei ^ab ， Xiaojing Liu ^ab ， Yanxia Zhang ^ab ， Kai Zhang ^ab ， Zheng Li ^ab ， Zhemin Shen ^c ， Christopher W.K.Chow ^d

^a College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China

^b State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China

^c School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China

^d Scarce Resources and Circular Economy (ScaRCE), UniSA STEM, University of South Australia, Mawson Lakes, SA 5095, Australia

摘要： Protein, the main component of extracellular polymeric substances, plays a vital role in sediment dewatering. Tannic acid (TA) can bind with protein, so was used as a new conditioner for sediment dewatering. The benefit of using TA as a conditioner for sediment dewatering and its mechanism were explored in this study. A series of laboratory-based experiments were conducted and the water content (Wc) of sediment cakes, specific resistance to filtration (SRF) and the filterable dehydration rate were used to evaluate the sediment dewaterability. The results showed that at the optimal dosage of 0.20 mmol/gTS (total solid), TA reduced Wc of sediment cakes by 12.3% and SRF by 70.6%, and increased the filterable dehydration rate by 9%. These results indicated TA effectively improved the dewatering performance of sediment. The conditioning mechanism study of TA supported that the protein content was reduced by combining with TA, and the bound water was gradually converted into free water. When TA was added in sufficient amount, the particle size gradually increased, large and dense aggregates were formed which enhanced the dewatering performance of the sediment. These results confirm the feasibility  of using TA as an effective option for rapid dewatering of sediment and provide a reference for selecting the appropriate conditioner for sediment dewatering.

关键词： Sediment Dewaterability ； Chemical conditioning ； Extracellular polymeric substances ； Protein