无机调理剂复配硅酸钠用于市政污泥二次脱水的研究

发布时间：2018-07-09 23:30

本文选题：污泥二次脱水 + 无机调理剂　；参考：《山东大学》2017年硕士论文

【摘要】：污水处理厂剩余污泥经Polyacrylamide或Cationic Polyacrylamide调理后,虽然容易实现固液分离,但是由于聚丙烯酰胺类药剂较强的架桥作用使得污泥内部生成了稳定的网状结构,限制了内部水分,难以实现污泥再进一步地脱水。为了大幅度降低污泥含水率,本文采用污泥深度脱水技术,先后用FeCl_3和AlCl_3,Na_2SiO_3以及聚硅铝铁镁盐(PSAFM)作为调理剂对含水率在83%左右的脱水污泥进行调理,再用高压压滤法对其进行二次脱水并对原理进行探究。结论如下:(1)为了探究FeCl_3和AlCl_3对脱水污泥的调理效果,污泥添加两种调理剂后,再进行二次脱水实验。实验结果表明两种调理剂都能降低污泥含水率,其中FeCl_3的处理效果更好。当FeCl_3为污泥干重的16.7%时,在2Mpa的压力下,污泥水分去除率可达30%。为了探索污泥脱水的原理,对污泥内部性质进行了检测,结果证明阳离子使污泥颗粒表面负电荷被中和,使得颗粒间的排斥力减小并脱稳聚集,最终原污泥中存在的网状结构被破坏,污泥颗粒聚集成更大更密实的絮体,释放了更多的水分。同时,阳离子水解作用产生的沉淀物能够当做骨架结构巩固污泥内部结构,使得排水孔道不易变形,内部水分更易排出。(2)为了进一步提高污泥含固率,Na_2SiO_3和FeCl_3被用作调理剂用于脱水污泥的二次脱水。脱水结果证明Na_2SiO_3在FeCl_3的作用下能进一步改善并提高脱水污泥的脱水性能。当Na_2SiO_3为污泥干重的6.7%,FeCl_3为污泥干重的13.3%时,脱水污泥的含固率可从2O%升至48%左右。对污泥的表面电荷和内部结构进行观察后发现脱水污泥在FeCl_3的电中和作用和Na_2SiO_3的聚合架桥作用下,内部原本由阳离子聚丙烯酰胺产生的网状结构被破坏并产生了新的网状结构,而这种新的网状结构能使污泥絮体更加密实从而减小污泥的可压缩性,最终提高了污泥二次脱水效果。(3)为了进一步提高污泥的脱水效果,将共聚法合成得到的聚硅铝铁镁盐(PSAFM)作为一种新的调理剂用于污泥二次脱水,对调理剂的内部性质和污泥的内部结构进行表征和观测后得出:PSAFM不仅有电中和作用,还有架桥作用和凝结固化作用。脱水污泥经PSAFM调理后,本身的过滤性能和可压缩性得到了大幅度改善。当调理剂为污泥干重的13.3%时,脱水污泥的含固率能够升至50%左右。以上实验结果表明PSAFM是一种适合污泥二次脱水的高效调理剂。
[Abstract]:After being treated with polyacrylamide or Cationic polyacrylamide, it is easy to realize solid-liquid separation, but because of the bridging effect of polyacrylamide, the sludge has a stable network structure, which limits the internal moisture. It is difficult to dewatering sludge further. In order to greatly reduce the water content of sludge, the technology of deep dewatering of sludge was adopted in this paper. FeCl3 and ALCL _ 3 / S _ 2SiO _ 3 and PSAFM were used as conditioning agents to regulate the dewatered sludge with moisture content of about 83%. The secondary dehydration was carried out by high pressure filtration and the principle was explored. The conclusions are as follows: (1) in order to investigate the effect of FeClS3 and ALCL _ 3 on dewatering sludge, the secondary dewatering experiment was carried out after adding two kinds of conditioning agents to sludge. The experimental results show that both kinds of conditioning agents can reduce the moisture content of sludge, and FeCl _ 3 has better treatment effect. When FeCl3 is 16.7% of the dry weight of sludge, the sludge moisture removal rate can reach 30% under the pressure of 2Mpa. In order to explore the principle of sludge dewatering, the internal properties of sludge were tested. The results show that cations neutralize the negative charge on the surface of sludge particles, reduce the repulsive force between the particles and destabilize the aggregation. Finally, the network structure in the original sludge was destroyed, and the sludge granule was accumulated into a larger and more dense floc, which released more water. At the same time, the sediment produced by the cationic hydrolysis can be used as a skeleton structure to consolidate the internal structure of the sludge, making the drainage channels difficult to deform. (2) in order to further increase the solid content of sludge, Na _ 2SiO _ 3 and FeCl _ 3 are used as conditioning agents for secondary dewatering of dewatered sludge. The results of dewatering show that Na2SiO _ 3 can further improve and improve the dewatering performance of dewatered sludge under the action of FeCl _ 3. The solid content of dewatered sludge can be increased from 2% to 48%, when the titer Na2SiO3 is 6.7FeCl3 of the dry weight of sludge and FeCl3 is 13.3wt% of the dry weight of sludge, and the solid content of the dewatered sludge can be increased from 20% to 48%. After observing the surface charge and internal structure of the sludge, it was found that under the effect of the electric neutralization of FeClS3 and the polymerization and bridge of Na2SiO3, the network structure originally produced by cationic polyacrylamide was destroyed and a new network structure was produced. But this new network structure can make the sludge floc more compact, reduce the sludge compressibility, and finally improve the sludge secondary dewatering effect. (3) in order to further improve the sludge dewatering effect, The polysilicon aluminum ferric magnesium salt (PSAFM) synthesized by copolymerization was used as a new conditioning agent for secondary dewatering of sludge. The internal properties of the modifier and the internal structure of sludge were characterized and observed. There is also bridging and solidification. After treated with PSAFM, the filtration performance and compressibility of the dewatered sludge were greatly improved. The solid content of dewatered sludge can increase to about 50% when the conditioning agent is 13.3% of the dry weight of sludge. The experimental results show that PSAFM is an efficient conditioning agent for secondary dewatering of sludge.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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