电絮凝预处理垃圾渗滤液的可行性研究

本研究采用电絮凝技术预处理垃圾渗滤液,在以铁为阳极、不锈钢为阴极,极板距离1·5cm,电流密度50mA/cm2,不外加电解质的情况下,电解90min,渗滤液的CODCr去除率达到57·6%,NH4+去除率达40·1%,BOD5/CODCr比值由0·15提高到0·32,达到了较好的预处理效果。     

上海老港填埋垃圾场渗滤液COD与UVA的相互关系

本实验研究对象为上海老港填埋场1991年填埋单元渗滤液和各处理工艺出水渗滤液,水样经过不同孔径膜微滤和超滤后,比较了各自COD值和UVA值之间的相关性．结果表明,水样COD浓度愈低,与其对应的UVA相关性愈好．由于有机物的组成不同,对应的特征吸收范围存在差别,因此,不同渗滤液的UVA与COD的关系也不同．渗滤液中的胶体物质对COD值有贡献,微滤和超滤系统使渗滤液中的胶体物质被截留,COD值减小,测定得到对应的UVA值也相应减小．     

垃圾渗滤液SND生物脱氮的工程实践

介绍了同时硝化 反硝化 (SND)生物脱氮技术在江苏省吴江市垃圾卫生填埋场渗滤液处理中的实验和应用情况。研究结果表明 :同时好氧硝化 反硝化技术可以实现硝化耗碱和反硝化产碱互补 ,使得反应pH控制变得简单经济 ;在第一曝气池中的溶解氧浓度在 1～ 2mg L、第二曝气池中溶解氧浓度维持在 3～ 4mg L时 ,出水氨氮浓度可以保持在 <5mg L的水平 ,去除率达 99%     

生物流化床厌氧氨氧化脱氮处理垃圾渗滤液的研究

采用厌氧流化床反应器 (AFB)作为厌氧氨氧化反应器 ,对垃圾渗滤液脱氮进行了研究。以模拟废水完成了反应器的启动 ,然后加入一定比例的垃圾渗滤液 ,对垃圾渗滤液厌氧氨氧化脱氮的影响因素进行了研究 ,取得了较好的脱氮效果。实验表明 ,厌氧氨氧化脱氮对高氨氮浓度的垃圾渗滤液的处理具有较大的潜力。     

Characterization of the Leachate in an Urban Landfill by Physicochemical Analysis and Solid Phase Microextraction-GC/MS

The aim of this study is to evaluate extensively the characterization and identification of major pollutant parameters by paying attention to the organic chemical pollution for unregulated dumping site leachate in Eskişehir/Turkey. The study that is first and only one research has been very important data related with before new sanitary landfill site in Eskişehir city. For this purpose, in this study leachate samples were collected in-situ at monthly interval for a period of 8 months. Firstly, thirty three physicochemical parameters were monitored. Secondly, SPME technique was used for identification of organic pollutants. Meteorological data were also recorded for the same sampling period to correlate meteorological data and physicochemical parameters. Mean values are used in the correlation analysis. Correlation is shown only for the relationship between air temperature and NO₃ ⁻. No correlation has been found between rain and leachate quality parameters since the amount of rain was very low during the sampling period. However, analysis results were generally decreased in winter season when each parameter and each sampling point are examined separately. According to correlation between every parameter, especially solid content and dissolved oxygen concentration of leachate is affecting to other parameters. Also, sodium and potassium are changing proportionally with same parameters (suspended solids, fixed solids, dissolved oxygen) and high correlation between chloride and heavy metal concentration is showing. The results were statistically evaluated by use of SPSS 10.0 program. Second part of the study, the leachate was extracted by Solid Phase Microextraction (SPME) technique and then analyzed. Of the methodologies tested in this study, the best one selected was based on 100 μ m polydimethylsiloxane coated fiber (PDMS), headspace with heating (Δ HS) sampling mode and an extraction time of 15 min. at a temperature of 50 ^o C. Thirty three organic compounds in leachate were identified by GC/MS.     

垃圾渗滤混合液启动ANAMMOX反应器研究

试验研究了采用垃圾渗滤混合液启动厌氧氨氧化反应器的可行性.试验结果表明,采用高负荷培养法可在161天内成功启动厌氧氨氧化生物反应器.随着厌氧氨氧化生物反应器的启动进程的推进,硝态氮和氨氮去除量的比值逐渐缩小,且趋于稳定.在厌氧氨氧化活性稳定阶段,硝态氮和氨氮去除量的平均比值为1.19,进出水碱度和pH值趋向一致.厌氧氨氧化生物反应器启动过程中,硝态氮和氨氮去除量的比值和反应器内碱度、pH值的变化可指示厌氧氨氧化生物反应器的启动状况.     

微电解处理垃圾渗沥液的试验研究

根据微电解的特点,采用微电解技术对垃圾渗沥液经生化处理后出水进行深度处理.微电解处理的效果随着进水pH值的升高越来越差.对微电解出水经中和、过滤后的CODCr浓度进行了分析,结果表明微电解产生的Fe(OH)3絮状物通过吸附捕集作用效果明显.出水投加1～2g/L粉末活性炭,CODCr排放浓度可以达到GB16889-1997《生活垃圾填埋污染控制标准》二级排放标准.     

紫外光催化氧化-原子吸收分光光度法测定垃圾渗滤液中重金属的研究

本文采用二氧化钛为催化剂,通过使用光催化氧化的消解方法对垃圾渗滤液样品进行前处理,再用原子吸收分光光度法测定垃圾渗滤液中的重金属,并与常用消解方法进行对比,探讨了紫外光照射时间、紫外灯功率、H2O2的用量等因素对消解效果所产生的影响,选取了消解垃圾渗滤液的最佳条件,讨论了方法的准确度与精密度。     

Evaluation of groundwater flow patterns around a dual-screened groundwater circulation well

Dual-screened groundwater circulation wells (GCWs) can be used to remove contaminant mass and to mix reagents in situ. GCWs are so named because they force water in a circular pattern between injection and extraction screens. The radial extent, flux and direction of the effective flow of this circulation cell are difficult to measure or predict. The objective of this study is to develop a robust protocol for assessing GCW performance. To accomplish this, groundwater flow patterns surrounding a GCW are assessed using a suite of tools and data, including: hydraulic head, in situ flow velocity, measured hydraulic conductivity data from core samples, chemical tracer tests, contaminant distribution data, and numerical flow and transport models. The hydraulic head data show patterns that are consistent with pumping on a dual-screened well, however, many of the observed changes are smaller than expected. In situ thermal perturbation flow sensors successfully measured horizontal flow, but vertical flow could not be determined with sufficient accuracy to be useful in mapping flow patterns. Two types of chemical tracer tests were utilized at the site and showed that much of the flow occurs within a few meters of the GCW. Flow patterns were also assessed based on changes in contaminant (trichloroethylene, TCE) concentrations over time. The TCE data clearly showed treated water moving away from the GCW at shallow and intermediate depths, but the circulation of that water back to the well, except very close to the well, was less clear. Detailed vertical and horizontal hydraulic conductivities were measured on 0.3 m-long sections from a continuous core from the GCW installation borehole. The measured vertical and horizontal hydraulic conductivity data were used to construct numerical flow and transport models, the results of which were compared to the head, velocity and concentration data. Taken together, the field data and modeling present a fairly consistent picture of flow and transport around the GCW. However, the time and expense associated with conducting all of those tests would be prohibitive for most sites. As a consequence, a sequential protocol for GCW characterization is presented here in which the number of tools used can be adjusted to meet the needs of individual sites. While not perfect, we believe that this approach represents the most efficient means for evaluating GCW performance.     

Repeated use of MAP decomposition residues for the removal of high ammonium concentration from landfill leachate

The residues of magnesium ammonium phosphate (MAP) decomposed by heating under alkali conditions were repeatedly used as the sources of phosphate and magnesium for the removal of high ammonium concentration from landfill leachate. Up to 96% of ammonium in MAP powder could be released under the following conditions: NH4(+):OH- molar ratio, 1:1; temperature, 90 degrees C; heating time, 2 h. Fourier transform infrared spectra and X-ray diffraction analysis of MAP before and after heating demonstrated that MAP was mainly transformed to amorphous magnesium sodium phosphate (MgNaPO4), which makes it possible for the NH4(+) to replace Na+ in MgNaPO4 to form more stable struvite. Successful ammonium removal was achieved by using the MAP decomposition residues as the sole phosphate and magnesium sources. The ammonium removal decreased gradually following the increase of MAP reuse cycles, and in the 6th cycle, ammonium removals of 84% and 62% were achieved for synthetic wastewater and landfill leachate, respectively. Analysis of the surfaces of MAP powders acquired at different reuse cycles using scanning electron microscopy with energy dispersive X-ray suggested that the existence of calcium, kalium and aluminum ions in landfill leachate might have inhibited the formation of MAP through competition with ammonium ions for phosphate ions. It is estimated that reuse of MAP for 3 cycles could save about 44% chemical costs.