改性煤气化灰渣协同超声波调理污泥脱水性能研究

发布时间：2019-03-08 13:58

【摘要】：活性污泥法在城市污水处理中应用广泛,当前污水处理行业正处于高速发展阶段,随之带来的是污水处理过程中产生的大量剩余污泥,这些污泥含水率高、体积庞大,处理难度大,污泥处置已成为不容忽视的环境问题。在污泥处理处置及资源化过程中,污泥脱水是必不可少的前处理环节。本文通过改性煤气化灰渣协同超声波调理污泥,改善污泥脱水性能。选取合肥市经济开发区污水处理厂剩余污泥作为研究对象,采用经氢氟酸改性的煤气化灰渣和超声波对剩余污泥进行调理,以污泥比阻(SRF),毛细吸水时间(CST)作为污泥脱水性能主要评价指标,并结合污泥滤液中可溶性有机物含量、Zeta电位以及污泥粒径变化情况探讨调理机制。实验主要研究内容及研究成果如下:(1)单独改性煤气化灰渣调理污泥,研究改性煤气化灰渣在不同投加量下对污泥脱水性能的影响,实验结果表明,随着投加量的增加,改性煤气化灰渣对污泥脱水性能产生了显著影响,污泥脱水性能呈现先下降后升高的趋势。在投加量为20%(基于污泥干重),污泥脱水性能表现最好,污泥比阻、毛细吸水时间分别为5.11×10~(11)m/kg、55s。与原污泥相比分别降低了49.9%、29.5%。改性煤气化灰渣的构架骨架作用及吸附作用,改善了污泥脱水性能。(2)单独超声波调理污泥,研究了超声波功率、作用时间对污泥脱水性能影响,实验结果表明,适宜的超声波能量能显著改善污泥脱水性能,但能量过高,污泥脱水性能会恶化。超声波作用参数为:功率60W,作用时间20s,此时污泥脱水达到最好,污泥比阻、毛细吸水时间分别为7.2×10~(11)m/kg、66s。与原污泥相比分别降低了29.4%、15.4%。超声波能够破坏污泥絮体结构释放间隙水,破解污泥细胞结构释放胞内水,改善污泥脱水性能。(3)改性煤气化灰渣与超声波协同调理污泥,经正交试验(超声波功率、作用时间、投加量)确定最佳效果时两者的操作参数。在超声波功率为60W、超声波作用时间30s,改性煤气化灰渣投加量为30%(基于污泥干重)时脱水效果达到最佳,污泥比阻、毛细吸水时间分别为3.7×10~(11)m/kg、45s。与原污泥相比分别降低了63.7%、42.3%。超声波破坏污泥絮体,破解细胞结构造成胞内物质溶出,改性煤气化灰渣能吸附溶出物质,且起构建骨架作用,显著提高污泥脱水性能。
[Abstract]:Activated sludge process is widely used in municipal sewage treatment. At present, the sewage treatment industry is in a high-speed development stage, resulting in a large number of surplus sludge produced in the process of sewage treatment. These sludge have high moisture content and huge volume. It is difficult to deal with sludge, and sludge disposal has become an environmental problem that can not be ignored. Sludge dewatering is an essential pre-treatment process in sludge disposal and resource recovery. In this paper, the sludge dewatering performance was improved by using modified coal gasification ash and ultrasonic wave to improve sludge dewatering performance. The residual sludge in the sewage treatment plant of Hefei Economic Development Zone was selected as the research object. The residual sludge was adjusted with hydrofluoric acid modified coal gasification ash and ultrasonic wave, and the sludge specific resistance (SRF),) was used. Capillary water absorption time (CST) was used as the main evaluation index of sludge dewatering performance, and the conditioning mechanism was discussed in combination with the content of soluble organic matter in sludge filtrate, the Zeta potential and the change of sludge particle size. The main contents and achievements of the experiment are as follows: (1) the effects of modified coal gasification ash slag on sludge dewatering performance under different dosages are studied, and the experimental results show that, with the increase of the dosage, the modified coal gasification ash slag affects the sludge dewatering performance, and the experimental results show that: (1) the modified coal gasification ash slag can improve sludge dewatering performance. The modified coal gasification ash had a significant effect on sludge dewatering performance, and the sludge dewatering performance decreased first and then increased. When the dosage is 20% (based on the dry weight of sludge), the sludge dewatering performance is the best, sludge specific resistance and capillary water absorption time are 5.11 脳 10 ~ (11) mg 路kg ~ (- 1) and 55s. Compared with the original sludge, it decreased by 49.9% and 29.5% respectively. The framework skeleton and adsorption of modified coal gasification ash can improve the dewatering performance of sludge. (2) the effects of ultrasonic power and action time on sludge dewatering performance are studied, the experimental results show that: The appropriate ultrasonic energy can significantly improve the sludge dewatering performance, but the sludge dewatering performance will worsen when the energy is too high. The parameters of ultrasonic wave are: power 60W, action time 20s, sludge dewatering best, sludge specific resistance, capillary water absorption time 7.2 脳 10 ~ (11) mg 路kg ~ (- 1), 66s. Compared with the original sludge, it was reduced by 29.4% and 15.4% respectively. Ultrasound can destroy the release of interstitial water from the floc structure of sludge, decipher the cellular structure of sludge and release intracellular water, and improve the dewatering performance of sludge. (3) modified coal gasification ash and ultrasonic wave can co-regulate sludge, and the orthogonal test (ultrasonic power, ultrasonic power) is used to improve sludge dewatering performance. Action time, dosage) to determine the optimal effect of the two operating parameters. When the ultrasonic power is 60W, the ultrasonic action time is 30s and the dosage of modified coal gasification ash is 30% (based on the dry weight of sludge), the optimum dewatering effect is achieved. The specific resistance of sludge and the capillary water absorption time are 3.7 脳 10 ~ (11) mg 路kg ~ (- 1) and 45s respectively. Compared with the original sludge, it decreased by 63.7% and 42.3% respectively. Ultrasonic wave destroys sludge flocs, breaks down cell structure and causes intracellular material dissolution. Modified coal gasification ash can adsorb dissolved substances, and play a role in constructing skeleton, which can significantly improve sludge dewatering performance.
【学位授予单位】：安徽建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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