连续在线滤袋式淤泥脱水技术

以太湖淤泥为研究对象，研究了絮凝剂和滤袋性质对淤泥脱水性能的影响，并进行了滤袋脱水中试研究。结果表明，淤泥的含水率为90％时，在PAM和PAC最佳添加量55mg／L和1000mg／L条件下，淤泥比阻从8．7×10^7S2／g降低到2．0×10^7S2／g，Zeta电位从-28．77mV变成-4．68mV，滤袋平均过滤速度提高了137．9％，脱水性能显著提升。不同含水率下的实验得出了淤泥的最佳絮凝剂添加曲线；特殊材料滤袋相比于普通材料滤袋，滤袋的脱水综合能力大幅度提升，平均过滤速度达到0．479m^3／（m^2·h），淤泥回收率为98．7％，泥饼含水率为71．6％；中试实验表明，淤泥经过4h过滤后，淤泥的含水率降到较低的65％，最终回收率可达到98．6％，滤液中污染物浓度满足国家排放标准。与传统技术相比，本技术具有脱水周期短、成本低、操作简单、安全性强等优点。

Continuous on-line operation for silt dewatering by filter bag

Effects of flocculants addition and filter bag from Taihu Lake were investigated and pilot-scale tests were properties on the dewatering performance of the silt carried out. When the moisture content of silt was 90% , the most appropriate dosages of PAM and PAC were 55 and 1 000 mg/L, respectively. The specific resist- ance of silt reduced from 8.7 × 107 to 2.0 × 107 s2/g and Zeta potential shifted from - 28.77 to - 4.68 mV. Meanwhile, the average filtration velocity of filter bag was improved by 137.9% and dewatering ability of slit was also obviously improved. The optimum flocculant dosing curve was obtained by a series of dewatering tests by u- sing silts with different moisture contents. The comprehensive dewatering ability of this special filter bag showed advantages over the ordinary filter bags with the average filtration rate of 0. 479 m3/（m2 · h）, silt recovery rate of 98.7% and sludge cake moisture content of 71.6%. Furthermore, pilot-scale tests showed that the moisture content of silt could be declined to less than 65% after filtered for four hours. The silt recovery rate could reach 98.6% and the quantity of the effluent could meet the national discharging standards. Compared with traditional technologies, this new technology presented the advantages of easy operation, reliable performance, low cost and short-time operation period.