剩余活性污泥对重金属铅、镉的吸附特性研究

发布时间：2018-01-08 02:10

本文关键词：剩余活性污泥对重金属铅、镉的吸附特性研究　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着我国城市的飞速发展和污水处理厂的建设,生活污水以及工业污水的处理排放很大程度上解决了水污染问题,但随之而来的是污水处理厂处理污水所产生的大量的剩余活性污泥,而对剩余活性污泥的处置往往需要耗费大量的资金,若处置不当,很有可能造成二次污染,利用剩余活性污泥吸附重金属废水,以废治废,既对污泥进行了资源化利用,又提高了经济效益。本论文主要研究了剩余活性污泥对典型重金属离子铅、镉的吸附,探讨了污泥吸附铅、镉的影响因素,比较污泥对铅、镉的吸附能力差异,研究了污泥吸附铅、镉热力学及动力学特性,并计算了污泥吸附铅、镉的热力学参数及动力学参数。在污泥吸附重金属的基础上初步研究了污泥中重金属的去除。研究发现,剩余活性污泥对重金属铅、镉的去吸附都较高,且对铅的亲和力大于镉;吸附量受吸附时间、污泥投加量、吸附体系的初始pH值的影响较大,温度的影响很小。铅镉共存吸附体系中,铅镉吸附相互抑制,且铅的竞争吸附对镉的抑制作用更强。活性污泥吸附铅、镉的吸附更符合Langmuir吸附模型,污泥对铅、镉的吸附过程都是吸热过程,且吸附都是自发进行的,其中对铅的吸附自发趋势比镉强。活性污泥对铅、镉的吸附动力学规律更符合用准二级动力学方程来描述。盐酸、柠檬酸和EDTA对铅、镉的去除效果差异较大,柠檬酸的解吸效果最好,认为可采用柠檬酸对高重金属含量的污泥进行解吸,来提高污泥的资源化利用率。
[Abstract]:With the rapid development of cities and the construction of sewage treatment plants in China, the treatment and discharge of domestic sewage and industrial sewage to a large extent solve the problem of water pollution. However, there is a large amount of surplus activated sludge produced by sewage treatment plant, and the disposal of surplus activated sludge often costs a lot of money. If the disposal is not proper, it may cause secondary pollution. The utilization of excess activated sludge to adsorb heavy metal waste water and treat it with waste water not only reused the sludge but also improved the economic benefit. This paper mainly studied the effect of excess activated sludge on the typical heavy metal ion lead. The adsorption of lead and cadmium by sludge was studied. The adsorption capacity of lead and cadmium by sludge was compared. The thermodynamic and kinetic characteristics of adsorption of lead and cadmium by sludge were studied and the adsorption of lead by sludge was calculated. The removal of heavy metals from sludge was studied on the basis of adsorption of heavy metals by sludge. It was found that the removal of lead and cadmium from excess activated sludge was higher than that of activated sludge. And the affinity to lead is higher than that of cadmium. The adsorption capacity was influenced by adsorption time, sludge dosage, initial pH value of adsorption system, and little effect of temperature. In the system of co-adsorption of lead and cadmium, the adsorption of lead and cadmium inhibited each other. The adsorption of lead by activated sludge is more consistent with the Langmuir adsorption model. The adsorption of lead and cadmium by sludge is an endothermic process. The adsorption of lead was more spontaneous than that of cadmium. The kinetics of adsorption of lead and cadmium in activated sludge was more consistent with the quasi-second-order kinetic equation. Hydrochloric acid. The removal efficiency of lead and cadmium by citric acid and EDTA was different, and the desorption efficiency of citric acid was the best. It was suggested that citric acid could be used to desorb sludge with high heavy metal content in order to improve the utilization ratio of sludge.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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