滤材的表面改性对淤泥脱水过程中渗透性能的影响

Effects of modified filter cloth on permeability of dredged sludge in dewatering process

滤布是淤泥脱水过程中重要的过滤材料,实验选用5种滤布(3927、621、758、750A、750B)作为淤泥脱水过程中的过滤材料,探究了滤布种类对淤泥脱水过程中渗透性能的影响,并通过扫面电镜观察淤泥在不同滤布表面的附着情况,基于最佳滤布,引入织物平滑剂、毛毯柔软剂及氟表面活性剂等3种表面活性剂并采用自然干燥和烘箱烘干等2种不同干燥方式改性滤布,通过测定表面接触角表征改性后滤布表面亲疏水性能,并探究了不同表面活性剂种类及干燥方式所得改性滤布对淤泥脱水过程中渗透性能的影响,最后通过扫描电镜对比改性前后750B滤布负载过滤后淤泥颗粒附着情况。结果表明,滤布750B作为过滤材料时淤泥渗透性能最佳。对比6种改性方式所得改性750B滤布,采用氟表面活性剂改性并在烘箱中105℃烘2 h所得改性滤布在负载过滤实验中所得渗透系数及渗水量最大,渗透性能大幅提升。

Five kinds of filter cloth（3927,621,758,750 A and 750B） as filter materials were used for sludge dewatering experiments,which played an important role in dewatering process. The influence of filter cloth on the permeability of dredged sludge was investigated,and the residues in the surface of filter cloth was observed through the scanning electron microscope. Based on the optimum filter cloth,three kinds of surfactants including smoothing agent,blankets softener and fluorine surfactant were applied to modify the surface properties of filter cloth by in natural drying and heating drying. The influences of surfactant varieties and drying methods on the permeability of dredged sludge for modified filter cloth were investigated,which was tested the surface contact angle to characterize the hydrophobicity and hydrophilicity of modified filter cloth. The graph of microscope were obtained after filtering in 750 B filter cloth before and after modified. Based on the test results,the permeability of filter cloth 750 B was optimal. Compared with 6 kinds of modification ways,the permeability of sludge increased significantly after filter cloth 750 B modified by fluorine surfactant and baked in an oven for 2 h at 105℃,at the same time,the permeability and the seepage volume were largest,the permeability of dredged sludge was improved significantly.