生活垃圾填埋场渗滤液“三级垃圾填料床+臭氧法+SBR法”组合技术研究

【作者】 安正阳；

【导师】 徐晓军；

【作者基本信息】 昆明理工大学 ， 环境工程， 2014， 博士

【摘要】 我国垃圾渗滤液具有污染物浓度高、水质和水量变化大的特点。如果这些垃圾渗滤液未得到适当的处理,那么将会对周围环境(特别是对水环境)产生重大污染。而且,随着垃圾填埋时间的延长,垃圾渗滤液中所含的难生化降解的有机物逐渐增多,可生化降解性很差(B/C值约等于0.1),如果直接采用生物传统工艺来处理这类废水难以收到预期的效果。本研究的研究对象是昆明东郊垃圾填埋场的收集的垃圾渗滤液,实验中采用的处理工艺为“三级垃圾填料床+臭氧氧化+生物法”工艺；研究过程中不仅研究了各工艺单元的最佳运行参数,而且还探讨了三级垃圾填料床和臭氧氧化的特征表征和污染物的降解机理。研究中使用的垃圾渗滤液具有老龄化(通常是指垃圾的填埋时间超过10年)渗滤液的特征,其水质指标为：COD为5000～1100mg/L; BOD为440～830mg/L; NH3-N为900～1200mg/L; pH:7.4～8.6。对垃圾填料床、臭氧氧化法以及生物法三种工艺单元分别进行研究,得出了各工艺单元的最优运行参数和最佳处理效果。(1)经粉煤灰陶粒优化的三级垃圾填料床处理后,垃圾渗滤液出水中的COD、BOD.NH3jN和色度的去除率分别达到83.9%、99.9%、97%和91.6%。由此可知,三级垃圾填料床能极大地降低高浓度的难降解有机物；垃圾渗滤液的颜色从黑褐色变为浅黄色；原水中BOD5/COD接近于零,这表明垃圾填料床能高效去除率垃圾渗滤液中的污染物；但经垃圾填料床处理后的垃圾渗滤液很难直接再通过生物法处理去除其中的有机污染物。(2)用臭氧法深度处理垃圾填料床处理后垃圾渗滤液的出水,当臭氧浓度为262mg/L时,废液中的COD浓度从318mg/L降至179mg/L；色度从56度降低为3.15度；但是BOD5浓度却从6mg/L升高到84mg/L。与此同时,BOD5/COD值则升至0.47,极大地提高了垃圾渗滤液出水的可生化性；色度的去除也得到了明显的提高。臭氧实验表明,臭氧氧化不仅能有效降低垃圾渗滤液中的COD浓度、色度,并有效提高其BOD浓度,从而在一定程度上提高了其可生化性。(3)当臭氧浓度为235mg/L时,后续生物处理出水COD浓度为92mg/L；当臭氧浓度调节至262mg/L时,生物处理出水中COD浓度则继续降低为75mg/L,完全满足新国标垃圾渗滤液排放标准(GB16889-2008)。(4)采用经处理后的锯末强化的SBR法处理臭氧法处理后的尾水。试验得出如下结果：①实际出水COD浓度比理论计算值COD浓度高,这表明臭氧处理后的垃圾渗滤液中仍存在着能降低生物处理效率的有毒性物质；②当TN/BOD>1,活性污泥的生物硝化过程可能会影响COD的去除；而当NH3-N的浓度大于50mg/L时,生物法去除COD的效果将迅速降低；③当磷的浓度从0mg/L升高至2mg/L时,出水COD浓度变化范围为81±3mg/L。因此,磷源不是影响出水COD浓度的限制性因素。④碳源的增加可有效增强微生物的活性,促使一些非降解物质被微生物吸附而浓度逐渐降低。经生物处理后的垃圾渗滤液中仍含有不能被活性污泥降解、吸附的污染物。上述结果表明：垃圾填料床能有效地降解渗滤液中所含有的难降解有机污染物、NH3-N及色度；而臭氧氧化则在去除COD和色度的同时,提高了BOD浓度,从而在一定程度上提高了渗滤液的可生化性,为后续的SBR法处理创造有利条件；“三级垃圾填料床+臭氧氧化+生物法”组合工艺的最终处理出水水质指标可达到新的国家排放标准GB16889-2008的排放要求。因此,采用组合工艺处理老龄垃圾填埋场渗滤液对实际工程应用具有积极的借鉴意义。更多还原

【Abstract】 There are some high concentration pollutants in the landfill leachate. And water quality and quantity are changed frequently. It will cause serious pollution to the surrounding environment if it is not treated properly. Moreover, the landfill leachate easily appears the aged characteristics:refractory organics is more than before, and the biodegradability is very poor (BOD/COD=0.1). It is difficult that this kind of wastewater is efficiently treated with the traditional landfill leachate treatment technology.In this study, Landfill leachate from Kunming Donjiao landfill leachate is experimented by the " three-phase refuse filler bed+ozone oxidation method and activated sludge treatment" process; During the experiment, the treatment effect and the influence factors ofthe each process unit are not only studied, but also the treatment effect and main the influence factors of the combination process are studied.The main results are as follows:There are the aged characteristics(landfill time is more than10years) in the leachate from Shanghai Laogang landfill. The water quality indicators are as follows:COD:5000-110000mg/L, BOD:440-830mg/L, NH3-N:900-1200mg/L, pH:7.4-8.6. The optimum operation parameters and the best effect are studied in the process of the refuse filler bed, ozone oxidation and biological methodand the joint process.(1) The removal rate of COD、BOD5、NH3-N, and E. coli were83.9%、99.9%、97%and91.6%. When the landfill leachate was treated by three level refused filling bed. Through three-phase garbage packed bed, high concentration of refractory organics was greatly reduced; wastewater in the entrance is dark brown, and the effluent are light yellow in color; BOD5/COD is close to zero, which indicates that the packed garbage bed can efficiently remove pollutants; but it is very difficult to directly remove the organic pollutants from landfill leachateby biological treatment once more after the refuse filler bed treament.(2) The effluent was treated by ozone method after the refuse filler bed treatment.when the ozone concentration is262mg/L, The rate of CODwas reduced from318mg/L to179mg/L; chroma was reduced from56degrees to3.15degrees; but the BOD5concentration was increased from the original6mg/L to84mg/L. Therefore, the rate of BOD5/COD is increased to0.5; The biodegradability of the landfill leachate is improved greatly. It is showed that the ozone oxidation can not only decrease the COD concentration and chroma in the landfill leachate greatly, but also improve the BOD concentration.So the biodegradability is improved effectively.(3) When the ozone concentration is235mg/L, the COD concentration of the effluent treated by activated sludge process was92mg/L; when the ozone concentrationwas increased to262mg/L, the COD concentration was75mg/L, coming up the newest emission standard ofthe landfill leachate (GB16889-2008).(4)The effluent was treated by activated sludge process after ozone oxidation. Test results are as follows:①In addition, the COD concentration ofthe effluent is higher than that of theory. It indicates that there are still some toxic substances that reduce the efficiency of biological treatment of leachate after ozone oxidation.②When TN/BOD>1, the nitrification process may have an effect on COD removal; When the NH3-N concentration exceeds50mg/L, the removal rate of the COD decreases rapidly;③The COD concentration of the effluent was81+3mg/L when the phosphorus concentration changed between0to2(mg/L). Therefore, the phosphorus source is not the key factor which affects the COD concentration of the effluent.④The carbon source increased can enhance microbial activity, thereby promoting the microbial adsorption to some non-degradable material. The final effluent still contained some pollutants that could not be degraded or adsorpted by activated sludge.It is showed that: The garbade packed bed can effectively degrade the refractory organic pollutants, NH3-N and chroma; The COD concentration and chroma was reduced and the BOD concentration is improved. So the biodegradability was increased to a certain exten after the wastewater is treated by the ozone oxidation; the final effluent which was treated by the "three refuse filler bed+ozone oxidation method and biological" combined process could meet the newest national discharge standard (GB16889-2008). Therefore, it is significant that landfill leachate is treated by the combined process for practical engineering application.更多还原