【作者】 刘爽；

【导师】 袁林江；

【作者基本信息】 西安建筑科技大学 ， 环境工程， 2009， 硕士

【摘要】 随着城市化进程的加快,城市生活污水处理规模日益增大,产生的剩余污泥量也越来越多,剩余污泥的处理与处置费是废水处理成本的主要构成之一。实际上剩余污泥和活性污泥一样具有较强的吸附能力,若借助剩余污泥对有机物、氮磷的吸附作用,将污染物转移到污泥中,既可实现污水净化的目的,又可以处理相当一部分剩余污泥。泥水分离后,再将吸附的污染物从污泥中释放出来并加以回收利用,即实现污水中有机物、氮、磷的资源化。围绕污染物的生物吸附分离—释放回收,如何提高污泥的吸附能力,控制吸附污染物质的再释放以及污泥活性的保持等问题和关键技术,有待研究解决。本论文通过在吸附了污染物的剩余污泥中接种厌氧污泥,调控污泥的水解酸化环境(即控制停留时间、污泥量、pH及预处理条件),研究了厌氧污泥对污泥的水解酸化程度,揭示污染物C、N、P的释出规律和环境调控对污泥释放能力的影响;通过好氧曝气预处理释放污泥和剩余污泥,研究了活化对污泥再吸附能力恢复的影响,揭示了活化后污泥对污水中有机物、氮和磷的吸附特性。试验结果表明:1.在接种厌氧污泥厌氧发酵24 h后就可以将剩余污泥中吸附了的污染物质大量释出,释出的污染物质相当于原污水中SCOD、氨氮和正磷酸盐分别被浓缩了2.30倍、7.16倍和12.79倍。2.在厌氧发酵时间一定条件下,污染物释出量与污泥质量成正比;吸附污泥相对质量越高,释磷量越大。3.污泥厌氧发酵时,有机物和正磷酸盐的释出量均为碱性条件优于酸性条件,加碱调节发酵体系的pH有利于氨氮的释出。4.温度升高到30℃以上有利于污染物质的大量释出;连续搅拌也可促进污染物的大量释出。5.对吸附污泥进行短时热处理和超声波预处理可以有效缩短厌氧条件下污泥中污染物的释出时间;热处理试验适宜的释出条件为60℃预处理1 h,厌氧发酵6 h;超声波预处理试验中,超声时间10 min,超声功率150 W,厌氧发酵时间6 h较利于释出。6.剩余污泥经好氧曝气活化后其吸附能力得到有效的提升,可作为吸附材料重新吸附污水中的污染物质,适宜的活化条件为好氧曝气30 min。7.在连续试验中,延长运行时间可以有效促进污染物的稳定释出。更多还原

【Abstract】 The scale of municipal wastewater treatment enlarges increasingly, and the productions of excess sludge become more and more. The cost of excess sludge treatment is the most expensive part of wastewater treatment. Actually, excess sludge has the ability of adsorption like activated sludge. With the aid of organism adsorption ability, it is possible to transfer pollutant from waste water to activated sludge. After sedimentation, the pollutants are made to release from the sludge and recovered. Basing on the consideration of pollutants adsorbing-separating-releasing, the problems of how to improve the ability of adsorbing, how to control the condition of releasing pollutant and retain the activity of activated sludge remain to be solved. In this paper, anaerobic sludge was inoculated into the reactor containing the sludge that adsorbed those pollutants from wastewater. The effect on promoting release of the pollutant via hydrolysis-acidification was investigated under different retention time, sludge mass, pH and pretreatment, to understand the disciplinarian and effect of environmental conditioning for pollutant release. The released sludge and excess sludge were activated under aerobic activation treatment, to understand the effect on sludge adsorption ability and the sludge adsorption characteristic after activation. The experimental results showed that:1. The pollutants were released out in a great deal after 24 h treatment, which was equal to that the organic substance, ammonium and phosphate from original wastewater were concentrated 2.30 times, 7.16 times, 12.79 times.2. On the condition of 24 h fermentation, the quantity of pollutant released was in direct proportion to the sludge mass fed. The more the excess sludge fed, the more the quantity of phosphorus released.3. Organic substance and phosphate released under alkaline condition were more than that under acidic condition. Adding alkali to increase pH could promote the release of ammonium.4. When the temperature was higher than 30°C, the pollutants were released out in a great deal via hydrolysis-acidification. The pollutants were also released out in a great deal with continuous mixing.5. Heating and ultrasonic pretreatment of excess sludge could benefit the release with shorter retention time. The suitable conditions are that heating pretreatment for 1 h under 60℃, then fermentation for 6 h; ultrasonic pretreatment for 10 min under 150 W of ultrasonic power, then fermentation for 6 h.6. Adsorption ability of excess sludge was improved after aerobic treatment. It could adsorb a lot of pollutants from wastewater again after activation as adsorption material. Aeration for 30 min was enough for activating sludge.7. The pollutants were released out stably by prolonging the operation time in the continuous experiment.更多还原