【作者】 王燕妮；

【导师】 张景成；

【作者基本信息】 哈尔滨工业大学 ， 市政工程， 2007， 硕士

【摘要】 我国东北地区冬季气候寒冷,城市污水水温最低可达4～7℃,寒冷的气候条件对污水的生物处理极为不利。目前,这些地区虽然采取了一定的措施来保证低温污水处理达标排放,但这些措施不仅会增加工程投资和运行费用,而且污水处理效果也很难得到保证。为了保证低温污水出水效果更好,本试验采用低温菌种利用曝气生物滤池工艺处理低温生活污水。通过中试试验,研究了低温菌种曝气生物滤池的挂膜启动、对污染物的去除效能及影响因素,最终确定了工艺运行的最佳控制参数和反应动力学模型;比较了低温菌挂膜和自然挂膜曝气生物滤池处理低温污水的效果,研究了反应器内生物膜的生态结构和微生物的种群组成及分布。试验结果表明:水温13℃左右时曝气生物滤池利用低温菌悬液挂膜,18天左右就可以完成。挂膜过程中当CODcr的去除率达到77%左右,NH4+-N的去除率达到31%左右并且呈直线增长时挂膜就已完成。当进水水温为9～13℃、水力负荷为1.6 m3/(m2·h)、气水比为5:1时,反应器出水中各污染物的浓度均优于国家规定的排放标准。通过试验确定了水力负荷应控制在1.6 m3/(m2·h)左右,有机负荷应在3.71～15kgCODcr/(m3·d)范围内,NH4+-N负荷应保持在0.61～0.70 kgNH4+-N/(m3·d)范围内较为合适。研究了利用低温菌种曝气生物滤池工艺处理大庆市生活污水的反应动力学模型可表示为:。进水水力负荷不同时,反应器沿程污染物去除规律不同。当水力负荷为2.4 m3/(m2·h)时,反应器对CODcr和NH4+-N的去除率均与滤层高度呈正相关;当水力负荷为1.6 m3/(m2·h)时, CODcr的去除率仅与滤池下部滤层高度呈正相关性,且大部分的CODcr在这高度被去除;而NH4+-N的去除率与滤层高度无一致的相关性。在所有水力负荷下SS的去除率均与填料高度无相关性,70%～80%以上的SS均被900mm以下的滤料所截留。曝气生物滤池采用气水联合反冲洗,试验确定了反冲洗条件。通过比较低温菌种挂膜和自然挂膜两种方式处理大庆市生活污水表明:两种方式反应器出水中污染物的浓度差别不大。试验研究了反应器中的生物膜形态结构特征和微生物的种群组成及分布。稳态运行时,曝气生物滤池中生物膜沿水流方向厚度减小,表面粗糙和伸展起伏程度下降,颜色逐渐变浅。反应器内的微生物有细菌类、真菌类、原生动物、后生动物、寡毛类等微生物,并且微生物种群有沿反应器高度变化的趋势。本文以处理水量为10000m3/d的生活污水为例进行经济分析表明:曝气生物滤池工艺工程总投资和运行成本均优于生物接触氧化工艺。更多还原

【Abstract】 It’s cold in winter of northeast in our country and sometimes the lowest temperature of sewage can reach to 4～7℃. It’s disadvantage for biological treatment of sewage. At present, we have taken some measures to make low- temperature sewage conform to the discharging standards, but the measures increased project investments. Moreover, the processing effect of sewage could’t conform to the discharging standards.We adopted cold-adapted microorganisms and sued biological aerated filter to treat the low-temperature sewage. The experiment investigated many problems such as start-up of biological aerated filter by cold-adapted microorganisms, the treatment efficiency for pollutants and some effect factors. At last, the study found the best controlling parameters and the dynamics model. The experiment also made the comparision between cold-adapted microorganisms and natural microorganisms, and investigated biofilm pattern and characteristics of microorganism population in BAF.The experiment demonstrated that it took about 18 days to complete the start-up under the condition of about 13℃with the cold-adapted microorganisms as seed. When the removal efficiency of CODcr and NH4+-N respectively reached to about 77% and 31%, and the removal efficiency of NH4+- N growing with Linear, the start-up of BAF have been completed. The concentration of pollutants in effluent completely excelled the requirement of discharging standards, under the condition that the influent temperature varied between 9～13℃, the hydraulic load was 1.6 m3/(m2·h), the proportion of aerated intensity and sewage intensity was 5:1. The experiment demonstrated that it was suitable that the hydraulic load was about 1.6 m3/(m2·h), the organic load was at the scope of 3.71～15kgCODcr/(m3·d)and the NH4+-N load varied between 0.61～0.70 kgNH4+-N/(m3·d).And we found the dynamics model equation of BAF that treated domestic sewage by using cold-adapted microorganisms, which expressed ln. The removal rules of pollutants varied following the water flow direction in BAF, under different hydraulic load conditions. The removal efficiency of CODcr and NH4+-N have positive correlation with the height of filter, for hydraulic load being 2.4 m3/(m2·h).When hydraulic load was 1.6 m3/(m2·h), the removal efficiency of CODcr only have positive correlation with the height of lower section in filter and the great mass of CODcr were removed at this section. However, the removal efficiency of NH4+-N have no correlation with the height of filter. Under all hydraulic load operated during the experiment, removal efficiency of SS have no correlation with the height of filter, and up to 70%～80% of SS was captured in the first 900mm. BAF adopted air-water backwash, the backwashing parameters had been decided during the experiment.The experiment demonstrated that the concentration of pollutants in effluent was similar in the two filters. The experiment studied biofilm pattern and the characteristics of microorganism population in BAF. The thickness of biofilm in BAF is thiner, the surface of biofilm is smoother, the extension and fluctuation of biofilm becomes smaller and the colour of biofilm changes shallower following the water flow direction, when the reactor was at the state of stable operating. There were many kinds of microorganism in BAF, such as bacterium, fungi, protozoan, metazoan, and oligochaetes. And the characteristics of microorganism population changed gradually along reactor height.With the example of 10000m3/d sewage treatment project, the results of the economic analysis showed that the total investments and the operating cost of BAF was excelled the biological oxidation.更多还原