印染污泥调质与深度脱水研究

发布时间：2018-01-14 19:20

本文关键词：印染污泥调质与深度脱水研究　出处：《天津大学》2015年硕士论文　论文类型：学位论文

【摘要】：我国作为纺织大国每年在处理印染废水的过程中产生大量印染污泥。印染污泥因其成分复杂、颗粒粒径小、含水量高,给脱水处理带来极大困难,其处理过程中脱水工段的成本占整个印染污泥处理成本的大部分,最具有挑战性。因此开发一种经济高效的印染污泥深度脱水技术尤为重要。针对印染污泥颗粒粒径小,难于脱水的问题,采用预处理技术对印染污泥进行调质处理,提高其脱水性能。无机高分子絮凝剂作为一种新型絮凝剂,在水处理过程中应用广泛,尤其在脱色、除浊方面表现出了优越的性能,但在污泥脱水中应用较少。本文采用无机高分子絮凝剂聚合氯化铝(PAC)和聚合硫酸铁(PFS)对印染污泥进行调质,以期提高印染污泥的脱水性能。采用PAC和PFS单独调理印染污泥过程中,发现这两种絮凝剂都可以有效提高印染污泥的沉降性能和过滤性能,而这两种性能是表征污泥脱水性能的重要指标。其中,PFS在印染污泥调质过程中表现出更好的效果。通过分析调理前后污泥的pH值、zeta电位、粒度、结合水含量、压缩性系数等,发现无机高分子絮凝剂可以有效的调节污泥悬浮液的pH值,降低污泥zeta电位,使小颗粒团聚成较大的絮体,但是其絮凝架桥作用并不强,主要以电位中和为主。此外,无机高分子絮凝剂还可以有效降低污泥的可压缩性及结合水含量,其中PFS调理后的效果更优。有文献结果表明多种药剂复合调理往往比单一絮凝剂的调理效果更好,本研究将调质效果好的PFS分别与阳离子聚丙烯酰胺(CPAM)、生石灰复配,并通过正交实验获得最佳复配比。实验结果表明,在低压(0.1MPa)下,两种复配方案都可以有效提高印染污泥的过滤性能,但是在高压下进行过滤压榨实验(过滤压力0.6MPa,压榨压力2.0MPa)时,PFS与CPAM复配虽然可以有效降低滤饼比阻,但所得滤饼的含水率反而比PFS单独调理时要高;PFS与生石灰复配则既可以获得更低的滤饼比阻,也可以获得更低的滤饼含水率。最后,采用最佳复配方案(10%PFS+10%生石灰)调理印染污泥,研究连续过滤压榨时不同操作条件对印染污泥脱水效果的影响。结果表明随着过滤压力的提高,过滤效率逐渐提高,但是滤饼含水率并无明显变化;在过滤进入压密期前开始压榨,可以在滤饼含水率基本不变的情况下,有效的提高处理量;适当提高压榨压力可以有效的改善压榨效率,但是压榨压力过高,不仅不能提高过滤效率,反而会使滤饼含水率有所上升。
[Abstract]:As a textile country, China produces a large number of printing and dyeing sludge in the process of treatment of printing and dyeing wastewater every year. Because of its complex composition, small particle size and high water content, printing and dyeing sludge brings great difficulties to dehydration treatment. The cost of dewatering section accounts for most of the treatment cost of printing and dyeing sludge. Therefore, it is very important to develop an economical and efficient deep dewatering technology for printing and dyeing sludge, aiming at the problem of small particle size and difficult dewatering of printing and dyeing sludge. As a new flocculant, inorganic polymer flocculant is widely used in water treatment, especially in decolorization. In this paper, the inorganic polymeric flocculants polyaluminum chloride (PAC) and polyferric sulfate (PFS) were used to regulate the dyeing sludge. In order to improve the dewatering performance of printing and dyeing sludge, it is found that both flocculants can effectively improve the sedimentation performance and filtration performance of printing and dyeing sludge in the process of using PAC and PFS to treat dyeing sludge separately. These two properties are important indexes to characterize sludge dewatering performance. PFS shows better effect in the process of dyeing and printing sludge conditioning. The pH value of sludge before and after conditioning is analyzed and the Zeta potential of sludge is analyzed. Particle size, water content, compressibility coefficient and so on, it is found that inorganic polymer flocculant can effectively adjust the pH value of sludge suspension, reduce the zeta potential of sludge, and make small particles agglomerate into a larger floc. But its flocculation bridging function is not strong, mainly by potential neutralization. In addition, inorganic polymer flocculant can also effectively reduce the compressibility of sludge and binding water content. The results of literature show that the compound conditioning of many kinds of chemicals is better than that of single flocculant. In this study, PFS with good tempering effect was mixed with cationic polyacrylamide (CPAM) and quicklime respectively, and the optimum blending ratio was obtained by orthogonal experiment. Under the condition of low pressure and 0.1 MPA, both schemes can improve the filtration performance of printing and dyeing sludge effectively, but the filtration press experiment (filtration pressure 0.6 MPA) is carried out at high pressure. The mixture of CPAM and PFS can effectively reduce the specific resistance of filter cake, but the moisture content of filter cake is higher than that of PFS alone. The combination of PFS and quicklime can not only obtain lower specific resistance of filter cake but also get lower moisture content of filter cake. Finally, the best mixing scheme (10 PFS 10% lime) is used to treat the dyeing sludge. The effect of different operating conditions on the dewatering effect of printing and dyeing sludge was studied. The results showed that the filtration efficiency increased gradually with the increase of filtration pressure, but the moisture content of filter cake did not change obviously. In the filtration into the compaction period before the press, can be in the filter cake moisture content basically unchanged, the treatment capacity can be effectively increased; Properly increasing the press pressure can effectively improve the press efficiency, but the press pressure is too high, not only can not improve the filtration efficiency, but will increase the moisture content of filter cake.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X791

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