基于硫自养反硝化的深度除磷脱氮研究

发布时间：2017-12-28 02:06

本文关键词：基于硫自养反硝化的深度除磷脱氮研究　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来国家逐步提高污水处理厂出水水质要求,地表IV类水标准成为污水厂排水标准的一种趋势。因此,近年来对污水厂的出水采取进一步的深度处理成为研究的热点。本课题在考察异养反硝化深度脱氮的基础上,重点研究了硫自养反硝化的脱氮效能,并进行了成本分析,并探索了在硫自养反应器中加入单质铁的强化除磷效果。异养反硝化填充床能够进行深度脱氮并达到地表水IV类水。以乙酸钠为外加碳源,进水NO_3~--N浓度为12.5 mg/L,在碳氮比(COD/NO_3~--N)=4.4,水力停留时间为0.5 h时,NO_3~--N和NO_2~--N的出水浓度均小于0.20 mg/L。但在COD/NO_3~--N=2.86(当量比)的条件,随着HRT的延长达到4 h,出水NO_3~--N浓度基本不变,为3.50 mg/L。若要达到深度脱氮的效果,则需投加额外COD,使C/N达到4.4,很容易导致出水COD超标。硫自养反硝化能够进行深度脱氮并达到地表水IV类水。当进水NO_3~--N浓度为12.5 mg/L,水力停留时间为1 h时,出水NO_3~--N和NO_2~--N浓度均小于0.20 mg/L,硝氮的去除负荷与进水硝氮负荷基本相等。在硫自养反硝化填充床的前30 cm处,硝氮的出水浓度为1.2 mg/L,去除率达到91%,硫自养反硝化具有脱氮快,效果好的优点。硫自养反硝化同时具有去除少量TP和NH4+-N的效果。在硫自养反硝化系统中投加适量有机物有助于强化脱氮。出水硫酸盐含量约为100 mg/L,低于国家规定值250 mg/L。假设二级生化出水NO_3~--N含量为12.5 mg/L左右,分别以异养反硝化和硫自养反硝化进行深度脱氮达到地表水IV类水。异养反硝化(以乙酸钠为例)的成本为0.1458元/t,硫自养反硝化的成本为0.046元/t。在硫自养反硝化系统中掺加铁单质后,能达到强化除磷的效果。在进水NO_3~--N浓度为12.5 mg/L,TP为1 mg/L,水力停留时间为1 h时,加入单质铁之后,系统的出水TP平均值为0.10 mg/L。在硫自养反硝化系统中加入铁单质后脱氮效果有促进作用,掺加铁单质前后的半级反应速率常数分别为6.56和10.03 mg1/2/(L1/2·h),能够强化硝氮向亚硝氮的转化过程。
[Abstract]:In recent years, the country has gradually improved the water quality requirements of the sewage treatment plant, and the surface IV water standard of the surface has become a trend in the drainage standard of the sewage plant. Therefore, in recent years, the further treatment of effluent from the sewage plant has become a hot spot of research. On the basis of investigating the deep denitrification of heterotrophic denitrification, this study focused on the denitrification efficiency of sulfur autotrophic denitrification, and analyzed its cost, and explored the effect of enhanced phosphorus removal by adding elemental iron in sulfur autotrophic reactor. The heterotrophic denitrification packed bed can carry out deep denitrification and reach IV water in surface water. Taking sodium acetate as an external carbon source, when the influent NO_3~--N concentration is 12.5 mg/L, the effluent concentration of NO_3~--N and NO_2~--N is less than 0.20 mg/L when the ratio of carbon COD/NO_3~--N to nitrogen (COD/NO_3~--N) =4.4 and hydraulic retention time is 0.5 h. However, with the condition of COD/NO_3~--N=2.86 (equivalent ratio), with the extension of HRT up to 4 h, the concentration of NO_3~--N in the effluent is basically unchanged, which is 3.50 mg/L. In order to achieve the effect of deep denitrification, additional COD should be added to make C/N 4.4, which is very easy to lead to the exceeding the standard of the effluent COD. Sulphur autotrophic denitrification can carry out deep denitrification and reach IV water in surface water. When the influent NO_3~--N concentration is 12.5 mg/L and the hydraulic retention time is 1 h, the effluent NO_3~--N and NO_2~--N concentrations are all less than 0.20 mg/L, and the nitrate nitrogen removal load is basically equal to the nitrate nitrogen load. At the first 30 cm of the sulfur autotrophic denitrifying packed bed, the effluent concentration of nitrate nitrogen is 1.2 mg/L, and the removal rate is 91%. Sulfur autotrophic denitrification has the advantages of fast denitrification and good effect. Sulfur autotrophic denitrification also has the effect of removing a small amount of TP and NH4+-N. Adding a proper amount of organic matter to the sulfur autotrophic denitrification system helps to strengthen the denitrification. The sulfate content in the effluent is about 100 mg/L, which is lower than the national stipulated value of 250 mg/L. It is assumed that the NO_3~--N content of the two grade biochemical effluent is about 12.5 mg/L, and the depth denitrification by heterotrophic denitrification and autotrophic denitrification can reach IV water in the surface water respectively. The cost of heterotrophic denitrification (as an example of sodium acetate) is 0.1458 yuan /t, and the cost of autotrophic denitrification by sulfur is 0.046 yuan /t. After adding iron to the sulfur autotrophic denitrification system, the effect of enhanced phosphorus removal can be achieved. When the influent NO_3~--N concentration is 12.5 mg/L, TP is 1 mg/L, and the hydraulic retention time is 1 h, the average value of the effluent TP is 0.10 mg/L after adding the iron. The effect of nitrogen removal was promoted after adding iron matrix in sulfur autotrophic denitrification system. The rate constants of the half stage reaction were 6.56 and 10.03 mg1/2/ (L1/2. H), respectively, which could enhance the transformation process of nitrate nitrogen to nitrite.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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