城市污水处理厂污泥固化及制备陶粒初探

发布时间：2018-05-19 10:48

  本文选题：污泥 + 固化　； 参考：《北京工业大学》2015年硕士论文

【摘要】：本文针对北京市檀州污水处理厂的剩余污泥采用一种固化/稳定化方法,可以在短期内实现污泥的安全处理。同时利用其烧制污泥陶粒,在减量化、无害化的基础上尝试开辟一条新的污泥利用途径。研究采用安徽某厂家的固化剂MC4对脱水污泥进行固化处理,研究发现随着固化剂添加量、养护龄期的增加,固化块的含水率显著降低,养护7天后含水率最低至50%以下。而固化块的pH值则普遍升高,稳定在11左右。加入硫酸铝可以显著改善污泥固化体的pH值,但其对污泥脱水性能影响不大。固化作用虽然可以有效降低污泥的有机质含量,但固化后的污泥低位热值高于2500 kJ/kg,具有一定的燃料利用价值。养护7天后固化体抗压强度达到395.8 KPa,能够满足《城镇污水处理厂污泥处置——混合填埋用泥质》(GB/T 23485-2009)的标准。利用扫描电镜对固化体的表面形貌观察后发现固化剂的添加使固化块颗粒密实性提高,骨架作用提高了固化块的力学性能,并有利于防止重金属浸出。研究采用水泥和MgO为主要骨架,以膨润土、三乙醇胺、硫酸铝作为添加剂对檀州污水处理厂剩余污泥进行自主固化试验。结果表明,随着水泥和MgO掺入量的增加,固化体的增容比和力学强度大幅提高,单独掺入MgO的固化体强度显著提高,增容比保持在1.5以下,远远小于水泥固化体的增容比。当水泥和MgO协同作用时,可以大大降低水泥的用量,有效提高固化体的力学强度的同时减少固化体占地面积,使得污泥处理处置成本下降。研究通过污泥陶粒原料配比试验,优选出污泥烧制陶粒的最佳方案为污泥35%,白土30%,炉渣25%,玻璃粉10%。并确定了制备污泥陶粒的最优工艺参数为预热温度450℃,预热时间15 min,烧结温度1125℃,烧结时间30 min。在最优烧制条件下进行陶粒抗压强度最高达到4.2 MPa,1 h吸水率14.4%,表观密度1.46 g/cm3,堆积密度0.39 g/cm3。试验通过考察工艺参数及污泥掺入量对污泥陶粒性能的影响,揭示了污泥制备烧胀陶粒的作用机理。利用SEM分析陶粒表面形貌及内部气孔结构表明:烧结温度过高,使陶粒表面气孔多且互为联通,导致陶粒结构松散,陶粒吸水率变高;污泥掺入量增加,陶粒表面气孔较少且不能形成玻璃相包裹在陶粒表面,导致陶粒吸水率增加,抗压强度降低。
[Abstract]:In this paper, a solidification / stabilization method is adopted for the excess sludge of Danzhou sewage treatment Plant in Beijing, which can realize the safe treatment of sludge in a short period of time. At the same time, it was used to produce sludge ceramsite, and a new way of sludge utilization was tried on the basis of reduction and innocuity. The curing treatment of dewatered sludge was carried out by using the curing agent MC4 from a certain factory in Anhui province. It was found that the moisture content of the solidified sludge decreased significantly with the increase of curing age and the water content of the solidified sludge decreased significantly after 7 days of curing. The moisture content of the solidified sludge decreased to less than 50% after 7 days of curing. However, the pH value of the solidified block generally increased and stabilized at about 11. The pH value of sludge solidified sludge was significantly improved by adding aluminum sulfate, but it had little effect on sludge dewatering performance. Although the solidification effect can effectively reduce the organic matter content of sludge, the low calorific value of the solidified sludge is higher than 2500 kJ / kg, which has certain value of fuel utilization. After 7 days of curing, the compressive strength of the solidified body reaches 395.8 KPA, which can meet the standard of sludge disposal for municipal wastewater treatment plant-mixed landfill mud > GBT / 23485-2009). Scanning electron microscope (SEM) was used to observe the surface morphology of the solidified body. It was found that the addition of curing agent improved the compactness of solidified block, the skeleton effect improved the mechanical properties of the solidified block, and was beneficial to the prevention of heavy metal leaching. Cement and MgO were used as the main framework, bentonite, triethanolamine and aluminum sulfate were used as additives to self-solidify the excess sludge of Danzhou sewage treatment plant. The results show that with the increase of cement and MgO content, the compatibilization ratio and mechanical strength of solidified body increase greatly, and the strength of solidified body with MgO alone increases significantly, and the compatibilization ratio is kept below 1.5, which is far less than the compatibilization ratio of cement solidified body. When the cement and MgO act together, the amount of cement can be greatly reduced, and the mechanical strength of the solidified body can be improved and the area of the solidified body can be reduced, which will reduce the cost of sludge treatment and disposal. According to the experiment of raw material proportion of sludge ceramsite, the optimum scheme of sludge sintering is as follows: sludge 35, clay 30, slag 25, glass powder 10. The optimum process parameters for the preparation of sludge ceramsite were determined as follows: preheating temperature 450 鈩，

本文编号：1909809