The high water content and large volume of dredging sediment made it uneasy to transport, storage and reutilize. Thus, the volume reduction was very important in dredging sediment treatment. A high-efficiency microbial flocculant-producing strain F22 was screened and cultured in the lad, the optimal culture conditions were obtained as follow: glucose as carbon source, yeast extract and urea as nitrogen source, culture at 32 ℃ for 60 h. The experiment was carried out to use F22 for rapid dehydrate of dredging sediment. The results shown that, when the water content rate of the dredging sediment was 93%, the volume was 100 mL and pH ranged 8-10, optimum dosage of CaCl2 was 4-5 mL, and the optimum dosage of F22 fermentation liquid was 3 mL. After adding the F22 fermentation liquid in dredging sediment, the floe was sedimentated to the bottom in about one minute. The results indicated that the F22 had perfect dewater capacity; saccharide played an important role in the flocculation process of microbial flocculants; the flocculating mechanism was hydrogen bonding.%河道疏浚底泥含水率高、体积庞大,不便于储存、运输和资源化利用.首先需要对其进行减量化,使其快速脱水.通过筛选获得一株高技的微生物絮凝剂产生菌F22,通过试验获得其最佳培养条件:葡萄糖为碳源,酵母膏和尿素为氮源,培养时间为60h,培养温度为32℃.将F22菌株所产絮凝剂应用于底泥脱水,试验结果表明,当底泥泥浆(含水率为93％)体积为100mL时,絮凝体系最佳pH为8～10,助凝剂CaCl2最佳投加量为4～5mL,F22菌株发酵液最佳投加量为3mL;絮体在1min左右大部分沉降至底部,F22菌株所产絮凝剂能够使底泥快速脱水.F22菌株所产絮凝剂在絮凝过程中起作用的是糖类物质,其通过氢键结合力产生絮凝作用.
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