垃圾渗滤液中有机物分子量的分布及在MBR系统中的变化

利用凝胶层析方法分析了垃圾渗滤液中有机物分子量的分布情况,并考察了利用膜生物反应器(MBR)处理垃圾渗滤液系统中有机污染物分子量的分布以及水溶性腐殖质(AHS)含量的变化．研究发现,垃圾渗滤液中的有机物主要由两部分组成,即分子量大于6000的大分子物质和分子量小于1500的小分子物质．大分子物质主要是水溶性腐殖质,而小分子物质主要由挥发性有机酸及水溶性腐殖质组成．大分子的AHS难以被微生物降解,但能被微滤膜截留．大部分小分子的AHS既难以被微生物降解,又不能被膜截留,是构成MBR处理出水COD的主要成分．     

垃圾渗滤液组合工艺处理技术

针对垃圾渗滤液氨氮浓度高、COD浓度高、难降解物质含量高的特点,研究了MAP脱氮-生物处理-混凝组合工艺,考察了不同单元的作用及影响处理效果的因素。试验结果表明,高浓度的垃圾渗滤液经该优化组合工艺处理,污染物的去除率为COD97.5%、BOD599.2%、NH4-N87.2%、E26075.3%。除NH4-N外,其余指标均达到了生活垃圾填埋污染控制标准中规定的二级排放标准值。     

垃圾渗滤液的Fenton氧化预处理研究

采用Fenton氧化法对垃圾渗滤液进行预处理,考察了渗滤液初始pH值、H2O2和FeSO4.7H2O投加量、H2O2/Fe2＋投加的物质的量比及氧化反应时间等对Fenton氧化处理效果的影响,获得Fenton氧化处理垃圾渗滤液的最佳工艺条件：初始pH=3.0,H2O2投加量为5.0 mL.L-1,FeSO4.7H2O投加量为3.48 g.L-1,H2O2/Fe2＋物质的量比为4-1,反应时间为1.5 h。最佳条件下处理后垃圾渗滤液COD为5 220 mg.L-1,COD去除率达57.8%。凝胶渗透色谱和三维荧光光谱分析结果表明,垃圾渗滤液中主要含有腐殖酸类大分子物质,经Fenton氧化后降解变成小分子化合物。     

pH值对AOA-SBR处理污水过程中COD三维荧光法表征的影响

为探究在AOA-SBR工艺处理城市污水过程中不同pH值对COD快速表征的影响,利用三维荧光光谱技术研究溶解性有机物(DOM)的荧光强度与COD浓度的相关性,并进一步研究不同pH值对其相关性的影响。根据三维荧光光谱及相关性分析得知,污水处理过程中DOM主要有低激发波长色氨酸、高激发波长色氨酸和类腐殖酸3种物质,且2种色氨酸及两者之和的荧光强度与COD有很强的正相关关系,R2分别为0.982 3、0.977 4和0.980 9。当pH值为4时,低激发波长色氨酸、高激发波长色氨酸及色氨酸荧光强度之和与COD的R2为0.871 1、0.856 7和0.873 3;当6≤pH值≤8时,相关性呈平稳变化趋势,R2波动范围分别为0.926 2~0.983 4、0.969 3~0.982 7和0.952 1~0.988 8;当pH值8时,相关性随pH值增大呈下降趋势,R2波动范围分别为0.845 7~0.749 0、0.900 8~0.869 9和0.889 5~0.837 6。认为当pH值为6~8时DOM与COD的相关性较好。     

滤层厚度对慢滤池深度处理污水的性能影响

将慢滤池用于污水二级出水的深度处理,并利用小试装置研究了滤层厚度对慢滤池性能的影响。选取浊度、COD和色度三个指标,在滤层不同深度处多次取样,分析各指标沿滤层厚度的变化。结果表明,采用粒径为0．4～0．6mm,滤层厚度为800mm的石英砂做滤床时,慢滤池对二级出水具有较好的净化效果：当进水浊度、COD和色度分别为1.3～6．9NTU、30．4～70．0mg·L^-1和20．6°～57．6°时,平均去除率分别达到86．5％、45．0％和46．3％。从试验结果可以看出,慢滤池类似一个微缩的污水二级处理系统,滤层表面的粘性滤膜起到类似初沉池的作用,可以对各指标实现较好的去除,58．6％的浊度、52．7％的COD和45．7％的色度是在滤层上部去除的;慢滤池中部起到类似曝气池的作用,下部起到类似二沉池的作用,对水质指标也能实现一定的去除。     

垃圾渗滤液对蚕豆根尖细胞微核效应的研究

利用蚕豆根尖细胞微核测定技术对垃圾渗滤液的微核效应进行了监测．结果表明,填埋场垃圾的微核率为１２．７０×１０－３ ,渗滤液的微核率为（１６ ．７６ ～２９．５）×１０ －３ ．垃圾场底部０～１０ ｃｍ 处的土层已被污染,微核率为１５．３８ ×１０－３ ,与ＣＫ有显著性差异;而３０ ～４０ ｃｍ 处土层的微核率为７ ．６５ ×１０－３ ,与ＣＫ无显著性差异,提示该处土层对垃圾渗滤液中污染物向下迁移有拦截、净化作用．经过处理后的渗滤液的微核率明显降低．蚕豆根尖微核检测结果与化学分析结果相吻合,认为此法可用于对垃圾渗滤液污染状况进行生物监测．     

温度对填埋垃圾渗滤液特征的影响

温度对填埋场有机垃圾的厌氧降解具有十分重要的影响,因而对填埋场渗滤液特征也产生重要的影响。文章通过在常温及29~45℃范围内设置的6个不同温度下的模拟垃圾柱降解对照试验,分析研究了温度对填埋有机垃圾渗滤液特征的影响。结果表明,在垃圾降解适宜的温度范围(29~45℃)内,较高的温度对渗滤液COD衰减具有较大的促进作用,而保持恒定的温度比升高温度对渗滤液COD衰减的影响更加显著,但温度对垃圾降解渗滤液中氨氮影响并不明显。     

垃圾渗滤液中典型内分泌干扰物质(EDCs)细胞毒性分析

垃圾渗滤液的人类健康风险评估日益受到人们重视,也成为研究热点。本文采用一种新型高级氧化技术UV-Fenton处理渗滤液,并用人体乳腺癌细胞(MCF-7)评估处理过程中渗滤液原液以及渗滤液中典型内分泌干扰物质(EDCs)的细胞毒性,对垃圾渗滤液中EDCs的细胞毒性和变化规律进行了研究。结果表明渗滤液中的邻苯二甲酸二丁酯(DBP)、双酚A(BPA)、壬基酚(NP)是产生细胞毒性的主要物质,其毒性大小为DBPBPANP。在同样的氧化降解过程中显示出不同毒性变化规律,通过GC-MS分析,结果显示UV-Fenton过程中产生了大量的中间产物,这也是引起毒性变化的主要原因。实验结果也说明垃圾渗滤液细胞毒性可以通过UV-Fenton过程有效去除。     

微波催化氧化法处理垃圾渗滤液的正交试验

在微波辐射条件下,采用活性炭与Fenton试剂处理垃圾渗滤液,并通过正交试验考察了微波辐射时间、pH、活性炭用量、硫酸亚铁用量和H2O2用量对处理效果的影响.结果表明:pH对处理效果的影响最大,其次为活性炭用量、微波辐射时间、硫酸亚铁用量和H2O2用量;在100 mL水样中,最佳处理条件为活性炭2 g、H2O20.2 mL、硫酸亚铁0.834 g、pH 6、微波辐射时间10 min,垃圾渗滤液中的COD去除率达到75.36%.     

渗滤液难降解物质物化性质研究

渗滤液是生活垃圾处理过程的必然产物,经过近15年的研究,其产生机理和处理方法获得了一定进展,但随着<生活垃圾填埋场污染控制标准GB16889-2008>标准的实施,现有处理技术出水大都不能达标,特别是老龄渗滤液或经一定处理后的渗滤液尾水,其处理极限COD大约在300 mg·L-1以上.渗滤液难降解物质的表征可能是解决渗...     

Algal purification of pretreated landfill Leachate

The efficiency of microalgae in removing various pollutants in landfill leachate after pretreatment by free stripping or air stripping was tested by a laboratory batch system. The results showed that Chlorella pyrenoidosa and Scenedesmus sp. had similar removal efficiencies with regard to ammoniacal‐nitrogen, oxidized‐nitrogen, orthophosphate and chemical oxygen demand (COD). The COD removal by algal treatment was better in Junk Bay (JB) leachate than in Gin Drinkers’ Bay (GDB) leachate (14–21% and 0.4–7% respectively). No significant difference (P > 0.05) was found in removing other nutrients including ammoniacal‐nitrogen, oxidized‐nitrogen and orthophosphate between leachate from the two landfills, regardless of the pretreatment used. The removal efficiencies of ammoniacal‐nitrogen and phosphorus were found to be higher in air‐stripped leachate than in free‐stripped one. Removal of ammoniacal‐nitrogen and phosphorus in air‐stripped leachate was 30% and 87% respectively. Poor removal of ammoniacal‐nitrogen was probably due to a deficiency in phosphorus (high N : P ratio) for algal growth in leachate. The two‐stage leachate treatment (ammonia stripping followed by algal purification) resulted in overall reduction of COD (38–51%), ammoniacal‐nitrogen (72–96%) and orthophosphate (79–96%).     

Degradation of refractory organics in concentrated leachate by the Fenton process: Central composite design for process optimization

• 90% total COD, 95.3% inert COD and 97.2% UV₂₅₄ were removed. • High R² values (over 95%) for all responses were obtained with CCD. • Operational cost was calculated to be 0.238 €/g COD_removed for total COD removal. • Fenton oxidation was highly-efficient method for inert COD removal. • BOD₅/COD ratio of leachate concentrate raised from 0.04 to 0.4. The primary aim of this study is inert COD removal from leachate nanofiltration concentrate because of its high concentration of resistant organic pollutants. Within this framework, this study focuses on the treatability of leachate nanofiltration concentrate through Fenton oxidation and optimization of process parameters to reach the maximum pollutant removal by using response surface methodology (RSM). Initial pH, Fe²⁺ concentration, H₂O₂/Fe²⁺ molar ratio and oxidation time are selected as the independent variables, whereas total COD, color, inert COD and UV₂₅₄ removal are selected as the responses. According to the ANOVA results, the R² values of all responses are found to be over 95%. Under the optimum conditions determined by the model (pH: 3.99, Fe²⁺: 150 mmol/L, H₂O₂/Fe²⁺: 3.27 and oxidation time: 84.8 min), the maximum COD removal efficiency is determined as 91.4% by the model. The color, inert COD and UV₂₅₄ removal efficiencies are determined to be 99.9%, 97.2% and 99.5%, respectively, by the model, whereas the total COD, color, inert COD and UV₂₅₄ removal efficiencies are found respectively to be 90%, 96.5%, 95.3% and 97.2%, experimentally under the optimum operating conditions. The Fenton process improves the biodegradability of the leachate NF concentrate, increasing the BOD₅/COD ratio from the value of 0.04 to the value of 0.4. The operational cost of the process is calculated to be 0.238 €/g COD_removed. The results indicate that the Fenton oxidation process is an efficient and economical technology in improvement of the biological degradability of leachate nanofiltration concentrate and in removal of resistant organic pollutants.     

利用矿化垃圾层预防和控制渗滤液导排系统堵塞

在卫生填埋场中,垃圾渗滤液导排系统堵塞普遍存在,悬浮固体形成的物理堵塞、有机物降解和金属离子沉淀导致的生物-化学堵塞是引起导排系统堵塞的关键因素.本文构建了"矿化垃圾+砾石层导排"的渗滤液下渗装置,通过矿化垃圾预处理渗滤液中悬浮固体和有机物以控制导排系统发生的物理和生物-化学堵塞.结果表明,在矿化垃圾层,渗滤液中化学需氧量(COD)和悬浮固体(SS)去除较多,去除率分别达到了85%和87%,并且Ca²⁺浓度也出现了波动较大的现象;然而,渗滤液在砾石层下渗过程中,其COD、SS和Ca²⁺浓度保持稳定.并且,砾石层可排水孔隙率在长期运行的过程中没有明显变化,表明渗滤液在砾石导排层没有形成明显的沉淀.与此同时,在没有添加矿化垃圾的对照组发现,砾石层可排水孔隙率减少最多的区段是渗滤液的进水点位(可排水孔隙率减少达到了53%),即渗滤液有机负荷最大处的饱和砾石层堵塞最为严重,其无机堵塞物主要是碳酸钙等.因此,在渗滤液流入砾石层前,采用矿化垃圾层部分饱和的方式对渗滤液中有机物和悬浮固体进行预处理,可以预防和控制渗滤液在砾石层形成沉淀堵塞.研究为填埋场的运行管理渗滤液导排系统堵塞提供了新的思路和方法.     

活性污泥在渗滤液循环处理中的作用

渗滤液是垃圾填埋场产生的一种含有高浓度污染物的废水，它对环境造成的污染已经引起了人们的关注。渗滤液的处理方法很多，其中渗滤液循环法以其投资小、运行费用低、能加速填埋场稳定化进程等特点而倍受关注。利用活性污泥引入微生物，是在渗滤液循环基础上提出的一种新的设想，通过实验研究结果显示：加入干污泥循环可使渗滤液的COD由最高值2275mg／L降为67lmg／L．加入湿污泥循环可使渗滤液COD由最高值2075mg／L降为82lmg／L；而单纯进行渗滤液循环只使渗滤液的COD由最高值23llmg／L下降到l386mg／L。     

珠江口广州海域COD与DO的分布特征及影响因素

于2003-2007年2月(冬季)、5月(春季)、8月(夏季)、10月(秋季)调查了广州海域16个站位的COD、DO以及其它理化因子的时空分布特征.调查期间,COD质量浓度范围为0.76～9.12 mg·L~(-1),平均值为2.83 mg·L~(-1);溶解氧质量浓度范围为1.98～9.79 mg·L~(-1),平均值为5.27 mg·L~(-1).结果表明,COD与DO的时空分布特征主要受生活污水排放,陆源排污,降雨量以及水动力状况等因素的影响.COD质量浓度在冬季和秋季较高,春季和夏季较低,而DO质量浓度则是冬季和春季高于秋季和夏季.空间分布上,COD质量浓度从湾内向湾外逐步递减,而DO变化趋势则相反,湾内站位在夏季出现缺氧区.相关性分析中,COD质最浓度与氮营养盐及Chl-a显著正相关,而DO则与COD、Chl-a、Ph以及石油烃显著负相关.COD与DO分布特征对于河口地区的赤潮及碳循环研究有一定研究价值.     

光化学方法处理垃圾填埋场渗沥液的研究

实验研究了光化学方法处理垃圾填埋场渗沥液的效果和相关的影响因素 ,结果表明 ,光化学方法受pH值 ,光照时间 ,催化剂等的影响 ,在pH =3、混凝后渗沥液光照 4h可取得 64 %的COD去除率     

Decolorization of remazol yellow RR gran by white rot fungus Phanerochaete chrysosporium

In this study, the removal of color, chemical oxygen demand (COD) and aromatic group from one of the azo dyes, Remazol Yellow RR Gran, had been carried out by using one of the white rot fungi, Phanerochaete chrysosporium. Experimental studies were performed in growth media containing different amounts of dye and glucose. Color measurements were done at 436nm wavelength using spectrophotometer while aromatic group measurements were done at 280 nm wavelength using UV/Visible spectrophotometer. As a result of this study the values of the removable color concentration were determined as 10 mgl(-1) and lower. The optimum medium glucose concentration was determined to be 2 gl(-1) during color removal processes, aromatic group measurements were done in samples in the UV region at 280 nm wavelength. As a result of the measurements, it was shown that certain amount of aromatic group remained in the model wastewater at the end of the process.     

序批式膜反应器处理高氨氮渗滤液同步硝化反硝化特性

应用序批式生物膜反应器(SBBR)处理实际垃圾渗滤液,在DO浓度分别为0.45mg.l-1和1.19mg.l-1条件下,研究了系统的有机物,氨氮和总氮去除特性以及游离氨(FA),DO对系统同步硝化反硝化(SND)类型的影响.250d试验研究表明:SBRR系统能够稳定高效地同步去除渗滤液内高浓度有机物和高浓度氨氮.在初始COD浓度为122—2385 mg.l-1的情况下,出水COD浓度为23—929 mg.l-1,有机物最大去除速率25.6 kgCOD.m-2载体.d-1.在初始NH4+-N浓度为40—396.5 mg.l-1的情况下,出水NH4+-N浓度为0—41.2 mg.l-1,最大硝化速率2.87 kgN.m-2载体.d-1.SBBR系统内发生了明显的同步硝化反硝化(SND)现象,TN平均去除率分别为73.8%(DO=0.45 mg.l-1)和30%(DO=1.19 mg.l-1)左右.当FA浓度在1.5—11.6 mg.l-1范围内时,系统中共存硝酸型SND和亚硝酸性SND.当FA从18.6 mg.l-1增加到56 mg.l-1,系统中形成稳定的亚硝酸SND.因此,FA是影响系统SND类型的主要因素,DO可促进亚硝酸性SND向硝酸型SND转化.     

Anaerobic degradation of coconut husk leachate using UASB-reactor

Reffing of coconut husk, the majorprocess in quality coir fibre extraction, causes serious pollution with brackish water lagoons of Kerala. An attempt is made to treat the coconut husk leachate by using a laboratory scale UASB-reactor The experiment was conducted with loading of leachate from 1 kg of fresh coconut husk. The anaerobic treatment was done continuously The parameters like VFA, pH, COD and polyphenols were analysed regularly during the evaluation of the reactor performance. The polyphenol, VFA and COD were diminished gradually with time. The pH of the reactor during the study was found to be in the range of 6-8. The biogas production was increased with loading and about 82% of the total COD/kg husk could be converted to biogas. The maximum polyphenol loading in the reactor was reached to about 298.51 mg/l of husk.     

Landfill leachate treatment methods: A review

Landfilling of municipal waste is still a major issue of the waste management system in Europe. The generated leachate must be appropriately treated before being discharged into the environment. Technologies meant for leachate treatment can be classified as follows (i) biological methods, (ii) chemical and physical methods. Here we review briefly the main processes currently used for the landfill leachates treatments.