影响活性污泥产率的环境因素研究

【作者】 李冰；

【导师】 孙英兰；

【作者基本信息】 中国海洋大学 ， 环境工程， 2006， 博士

【摘要】 活性污泥法是城市污水处理厂广泛应用的生物处理技术,是生化法处理废水的基本工艺。但它一直存在一个最大的弊端,那就是在运行过程中会产生大量的剩余污泥。虽然城市污水处理厂中的污泥产量仅为所处理污水量的1～2%,但污泥处理设施的投资往往占到整个污水处理厂总投资的40～50%。由于污泥的最终处置越来越困难,为了防止污泥的二次污染,最有效的措施是通过技术进步和工艺改造等手段减少污泥的产生量。因此我们需要研究活性污泥产率(真实产率和表观产率)都受到哪些环境因素的影响,并分析各影响因素的相对重要性,这样我们就可以通过改变环境影响因素来减少污泥产量。本文先提出一种改进的耗氧速率(OUR)测量装置,以便用于后面实验数据的测量,然后系统研究了不同的环境条件(电子受体、温度、基质、重金属离子和化学解偶联剂等)对表观产率Yobs、真实产率YH以及衰减系数Kd产生的影响。通过上述一系列的实验研究,得出了一些新的认识和结论,主要包括:1.设计了一种测量OUR的新装置,利用该装置测得微生物的产率系数YH和衰减系数Kd都文献报道基本相符,表明这种装置可以比较准确的测定有机废水的耗氧速率。2.发现淀粉、蛋白质和苯酚三种基质的表观污泥产率Yobs和真实污泥产率YH都具有相同规律,即:淀粉>蛋白质>苯酚,这说明易降解基质的污泥产率会更高一些。不过YH都要高于Yobs,这可能是因为YH不受细菌的捕食、死亡和再生等作用的影响。进水中不同类型的基质会引起污泥内微生物菌群的变化,不同菌群的微生物其细胞产率系数和内源代谢系数等都不同,这可能是造成污泥产率差异的根本原因。3.发现温度的变化不影响好氧污泥的YH,原因可能在于代谢相同基质的污泥内的微生物菌群相同,因此其细胞产率也相同,不受温度影响;但是低温Yobs比高温的要大,这可能是因为在温度较高的条件下,内源呼吸作用较强,导致污更多还原

【Abstract】 Activated sludge treatment is the biological treatment extensively applied in city sewage plant, and is the traditional technology for biochemical treatment method for wastewater. But there is a malpractice during the operation, which produce large quantity of residual sludge. The investment in sludge treatment account for 40～50% of total investment of wastewater treatment plant, although the sludge production quantity just 1～2% of the wastewater being treated. As the final disposal for sludge is a hard work, and in order to prevent the secondary pollution produced by the sludge, the most effective measure is to cut down the produced sludge quantity by improving and alteration of the technology. So it is necessary to study the environment effectors to activated sludge production ratio (real yield and observation yield) and analysis the relative significance of each factors in order to lessen the sludge production through adjust the environmental factors.An improved OUR equipment was put forward in this paper, and was used in rest measurement. The effects of different environment conditions (temperature、substrate、heavy metal and uncoupled metabolism) to Yobs, YH and Kd were investigated systemically. According to the series of studies above, a number of main conclusions can be drawn as follows:1. A new device of measuring OUR was designed, and the real yield(YH) and Kd measured with which are match to the YH and Kd reported in some literatures. And this indicated that the OUR of organic wastewater can be measured using this device comparatively exactly.2 For the Yobs and YH to starch、protein and phenol, there are same orderliness of starch > protein > phenol, which showed that there are higher yield for more degradabel medium. And both YH are higher than the corresponded Yobs, these maybe because the YH not susceptible to predatory, death, regeneration and so on. The different type of medium in influent can result in the change of microorganism makeup, and result in different cell yield and ,which is the ultimate reason for更多还原