二氧化氯深度处理垃圾渗滤液研究

利用二氧化氯对生物处理后的垃圾渗滤液进行深度处理，根据废水中有效氯浓度、COD、氨氮及细菌数等参数的分析，初步探讨了不同浓度的二氧化氯在不同处理时间内对垃圾渗滤液的处理效果。结果表明，对于COD初始浓度为450 mg/L左右的水样，二氧化氯的投加浓度达100 mg/L（有效氯），反应时间在50 min时，处理水样可达到同类废水的国家二级排放标准；对于同样条件下的水样，当加入约25 mg/L的二氧化氯时可以杀灭水样中的大肠杆菌，加入浓度达到90 mg/L的二氧化氯时，可以杀灭水样中几乎所有的细菌。     

Mammalian cell line-based bioassays for toxicological evaluation of landfill leachate treated by Pseudomonas sp. ISTDF1

Landfill leachate has become a serious environmental concern because of the presence of many hazardous compounds which even at trace levels are a threat to human health and environment. Therefore, it is important to assess the toxicity of leachate generated and discharge it conforming to the safety standards. The present work examined the efficiency of an earlier reported Pseudomonas sp. strain ISTDF1 for detoxification of leachate collected from Okhla landfill site (New Delhi, India). GC-MS analysis performed after treatment showed the removal of compounds like alpha-limonene diepoxide, brominated dioxin-2-one, Bisphenol A, nitromusk, phthalate derivative, and nitrobenzene originally found in untreated leachate. ICP-AES analysis for heavy metals also showed reduction in concentrations of Zn, Cd, Cr, Fe, Ni, and Pb bringing them within the limit of safety discharge. Methyl tetrazolium (MTT) assay for cytotoxicity, alkaline comet assay for genotoxicity, and 7-ethoxyresorufin-O-deethylase (EROD) assay for dioxin-like behavior were carried out in human hepato-carcinoma cell line HepG2 to evaluate the toxic potential of treated and untreated leachates. The bacterium reduced toxicity as shown by 2.5-fold reduction of MTT EC₅₀ value, 7-fold reduction in Olive Tail Moment, and 2.8-fold reduction in EROD induction after 240 h of bacterial treatment.     

Effects of landfill leachate effluent and bisphenol A on glutathione and glutathione-related enzymes in the gills and digestive glands of the freshwater snail Bellamya purificata

Environmental contaminants with estrogenic activity have recently attracted attention due to their potential detrimental effects on the reproduction of human and wildlife. The aim of this study was to evaluate the use of endogenous glutathione and glutathione-related enzymes as biomarkers of exposure to landfill leachate effluent and bisphenol A (BPA) in the freshwater snail, Bellamya purificata. Following exposure to 1%, 5% and 10% landfill leachate effluent and 1, 10, 50 and 100mugl(-1) BPA for 0, 2, 7 and 15d, activities of glutathione S-transferase (GST), selenium-dependent glutathione peroxidase (SeGPx) and glutathione reductase (GR) and levels of total glutathione were measured in the gills and digestive glands of the snails. GST and total glutathione were the most sensitive parameters in both exposure scenarios. GST activities increased by about 80%, while total glutathione decreased to 70% and 80% in the gills and digestive glands, respectively. In contrast, SeGPx and GR activities remained at the same levels in all the treatment groups compared with those of controls. The results indicated that among glutathione and glutathione-related enzymes, GST activity and total glutathione level, which showed dose-dependent dynamics, could be used as biomarkers of aquatic ecosystems contaminated with landfill leachate.     

Detection of environmental clastogens and aneugens in human fibroblasts by cytokinesis-blocked micronucleus assay associated with immunofluorescent staining of CENP-A in micronuclei

The cytokinesis-blocked micronucleus (CBMN) assay, in combination with fluorescent in situ hybridization (FISH) of human pan-centromeric DNA probes, or with CREST antibodies that specifically stain kinetochore proteins, is widely used on several cell types. It distinguishes micronuclei containing one or several whole chromosomes, which are positively labeled (centromere positive micronucleus, C+MN, due to aneugenic effect), or acentric chromosome fragments, which are unlabeled due to the absence of centromere (centromere negative micronucleus, C−MN, due to clastogenic effect). However, the very slight level of the centromeric signals obtained with the FISH technique on primary human fibroblasts, a cell type commonly used in environmental genetic toxicology, leads to great difficulties in distinguishing C+MN and C−MN. Furthermore, the CREST technique may lead to inappropriate results particularly with regards to variations in antibody composition between patient sera. Our results show that the in vitro CBMN, in combination with immunofluorescence staining of CENP-A (centromere protein A), efficiently screens genotoxicants for their ability to induce clastogenic and/or aneugenic effects. We propose the in vitro CBMN assay in combination with immunofluorescence staining of CENP-A as a suitable tool in environmental genotoxicity testing of primary human fibroblasts.     

准好氧矿化垃圾反应床＋超声／芬顿联用技术处理垃圾渗滤液

针对垃圾渗滤液污染物浓度高、可生化性差等特点，采用准好氧矿化垃圾反应床＋超声／芬顿联用技术对垃圾渗滤液进行预处理。准好氧矿化垃圾床处理后渗滤液中COD、氨氮、总磷、色度的去除率分别为80％、85％、92％和85％。通过单因素实验和正交实验，确定了超声／Fenton法最佳工艺条件。经该组合工艺后，渗滤液中COD、氨氮、总磷和色度的最高去除率分别可达96％、86％、94％和95％，且出水无臭，颜色为淡黄色，BOD5／COD从0．16增至0．35左右，可生化性基本满足后续生物处理需要，且COD、总磷这2个指标达到《生活垃圾填埋场污染控制标准》（GB16889—2008）规定的排放标准。     

Polyfluoroalkyl compounds in landfill leachates

Polyfluoroalkyl compounds (PFCs) are widely used in industry and consumer products. These products could end up finally in landfills where their leachates are a potential source for PFCs into the aqueous environment. In this study, samples of untreated and treated leachate from 22 landfill sites in Germany were analysed for 43 PFCs. ΣPFC concentrations ranged from 31 to 12,819 ng/L in untreated leachate and 4-8060 ng/L in treated leachate. The dominating compounds in untreated leachate were perfluorobutanoic acid (PFBA) (mean contribution 27%) and perfluorobutane sulfonate (PFBS) (24%). The discharge of PFCs into the aqueous environment depended on the cleaning treatment systems. Membrane treatments (reverse osmosis and nanofiltrations) and activated carbon released lower concentrations of PFCs into the environment than cleaning systems using wet air oxidation or only biological treatment. The mass flows of ∑PFCs into the aqueous environment ranged between 0.08 and 956 mg/day.     

臭氧预氧化-BAF工艺深度处理垃圾渗滤液

以广东省江门市垃圾填埋场垃圾渗滤液为研究对象，对经SBR生化处理和聚合硫酸铁混凝后的垃圾渗滤液，采用臭氧-BAF(曝气生物滤池)工艺进行深度处理。该工艺优点在于：臭氧高级氧化技术使大分子有机污染物降解成二氧化碳和水，或者小分子有机污染物，有利于后继BAF的生化处理，且臭氧处理过后废水的色度明显降低，是废水处理的有效方法之一。而后采用曝气生物滤池对垃圾渗滤液进行进一步处理，对COD进一步去除。结果表明，当臭氧的加入量为150 mg/L，BAF停留时间＞4 h，出水COD低于85 mg/L，稳定达到国家GB 16889-1997《生活垃圾填埋污染控制标准》一级排放标准，臭氧氧化法处理每吨垃圾渗滤液的费用为4.8元。     

浓缩液回灌出水电导率与离子浓度的灰色关联度研究

研究渗滤液浓缩液回灌出水电导率与离子浓度的关系对完善渗滤液浓缩液回灌体系具有重要的意义。采用成都某垃圾填埋场的渗滤液浓缩液,在实验室矿化垃圾填埋柱中开展了回灌实验,分别得到了回灌出水中电导率和8种离子浓度的变化规律。基于灰色关联模型,对电导率与离子浓度的灰色关联度进行了分析,结果表明,电导率与K+的关联系数最大,其次是NO-3、Na+和Cl-。因此在回灌出水中这4种离子与电导率的关联性较大、可将其作为回灌体系中优先控制的离子。     

Heavy metal binding capacity (HMBC) of municipal solid waste landfill leachates

This research describes the use of a toxicity assay for the identification of metal toxicity, bioavailability and heavy metal binding capacity (HMBC) of municipal solid waste (MSW) landfill leachates. MetPLATE, an assay specific for heavy metal toxicity, was used to determine the HMBC of MSW leachates collected from 14 sites in Florida, with a wide range of chemical and physical characteristics. The leachates displayed a low toxicity which was attributed to the site-specific parameters, including, high concentrations of both organic and inorganic ligands. The HMBC test was undertaken to measure the effect of these site-specific parameters on metal toxicity. The potential for MSW leachate to bind and, thus, detoxify heavy metals was investigated with copper, zinc, and mercury. The HMBC values obtained ranged from 3 to 115, 5 to 93 and 4 to 101 for HMBC-Cu+2, HMBC-Zn+2, and HMBC-Hg+2, respectively. Additionally, the high strength leachates displayed the highest binding capacities, although the landfills sampled represented a wide range of characteristics. For comparison, the HMBC values reported with local lake water, Lake Alice and Lake Beverly, and a wastewater treatment plant effluent were all below 3. A partial fractionation of MSW leachate samples from sites 1, 5 and 8, was conducted to further investigate the influence of selected site-specific physico-chemical parameters on metal binding. The fractionation revealed that the HMBC of the leachate samples was heavily influenced by the concentration of solids, organics and hardness.     

Effect of landfill leachate irrigation on red maple (Acer rubrum L.) and sugar maple (Acer saccharum Marsh.) seedling growth and on foliar nutrient concentrations

Greenhouse experiments were conducted to investigate the nature and severity of stresses imposed on northern hardwood tree species (red maple (Acer rubrum L.) and sugar maple (Acer saccharum Marsh.)) by the application of municipal landfill leachate. Red maple seedlings received applications of untreated and pretreated (lime, activated carbon) leachate, to both leaves and soil, at irrigation rates consistent with evapotranspirational demands. Plant height measurements indicated no significant growth effects arising from leachate application over a 7-week period. Stem diameter, however, was positively affected by applications of both untreated and lime-treated leachate diluted to 75% with deionized water. Iron foliar concentrations were significantly higher in seedlings irrigated with untreated leachate applied to leaves and soil, but not in seedlings where leachate was applied to soil only. Nitrogen foliar concentrations were substantially higher in seedlings receiving undiluted and untreated leachate applied to the soil only. The Cu concentration of the red maple foliage decreased appreciably in plants receiving moderate applications of leachate. Foliar Ca concentrations decreased notably in seedlings irrigated with untreated leachate applied to the soil and with diluted, carbon-treated leachate. The Cu concentration of the red maple foliage decreased appreciably in plants receiving applications of undiluted and 50% water-diluted lime-treated leachate while Mn levels were consistently high across all treatments. Leachate application did not cause any discernable changes in foliar concentrations of P, K, Mg, B or Zn. In an ancillary experiment, sugar maple seedlings were subjected to saturation/ drainage treatment cycles with undiluted and untreated leachate. Severe visible symptoms of vegetative stress were apparent within 24 h and 100% seedling mortality occurred after five such waterlogging cycles. Fe assimilation was apparent in both leachate treatments relative to the 24 h water treatment. Despite the short-term nature of the experiments, the results indicate how quickly forest vegetation may respond to altered chemical environments. This underscores the need for correct installation and control of leachate irrigation systems.     

厌氧陈腐垃圾模拟柱对渗滤液COD和NH_3-N的处理特性

通过实地钻取阿苏卫填埋场陈腐垃圾,真实模拟填埋场压实工艺,制作2种不同压实密度的陈腐垃圾模拟柱,对比研究其对渗滤液COD、NH3-N处理效果。结果表明,当模拟柱压实密度为1.09 t/m3时,渗滤液垂直运动明显;回灌此模拟柱水力负荷分别为18.6、28、37.2和46.5 L/t时,COD去除效果稳定,平均去除率达82.4%,最高去除率可达90.1%;出水NH3-N浓度均值为549.3 mg/L,且介于415～700 mg/L间变化。自循环回灌COD去除率最高仅为11.5%,NH3-N去除率最高仅为11.8%,两者去除效果不明显。因此,北方平原型填埋场进一步完善填埋工艺,使填埋场垂直方向渗透系数分布均匀,充分利用陈腐垃圾堆体的自降解能力,才是处理渗滤液污染的关键。     

Treatment of landfill leachate by electrochemical oxidation and anaerobic process.

The removal performance of typical refractory organic compounds in landfill leachate was investigated during the electrochemical (EC) oxidation and anaerobic process combined treatment system in this paper. The results indicated that the treatment of landfill leachate by the combined system was highly effective. The toxicity of leachate was notably decreased after the electrochemical oxidation process and the biodegradability was improved. The concentration of the organic acid with low molecular weight in the leachate increased from 28% to 90% based on the biodegradability assays after the EC oxidation process. The anaerobic digestion could further remove the residual organic compounds. At a hydraulic retention time (HRT) of 16 hours and an organic loading rate (OLR) of 8 kg COD/m3 d, the concentration of COD, SS, ALK, VA, N-TKN, N-NH4+ and P-PO4(3)- [corrected] in UASB effluent were 532, 12, 6744, 400, 540, 455 and 11.6 mg/L, respectively, with approximately 90% removal efficiency of COD. The organic compounds in the landfill leachate revealed different degradation characteristics in the combined system. p-chloroaniline, bisphenol A, 6-methyl-2-phenyl-quinoline, dimethylnaphthaline and N'-(2-methyl-4-chlorophenyl)-N-cyclohexyformamidine, classified into the first group in this paper, were completely removed by the EC oxidation and did not reappear in the effluent of the UASB reactor. Phenylacetic acid, 3-methyl-indole and N-cyclohexyl-acetamide, called the second group, were completely removed, but reappeared in the UASB reactor. 4-methyl-phenol, 3,4-dihydroisoquinoline, 2(3H)-benzothiazolone, exo-2-hydroxycineole and benzothiazole, the third group, were degraded little in the EC oxidation process, but extensively removed by the anaerobic process. Benzoic acid, benzenepropanoic acid and 2-cyano-3,5-dimethyl-1-hydroxypyrrole, the fourth group, concentration obviously increased in the EC process, but was completely removed in the UASB reactor. The content of volatile fatty acids (VFAs) markedly increased from 0.68% in the leachate to 16.18% in the effluent from the electrochemical oxidation process (EC(effl)). In addition, the degradation rate of organic compounds from the landfill leachate was different in the EC oxidation and anaerobic process.     

垃圾填埋场渗滤液生物处理尾水的性质研究

采用多种先进测试分析仪器对不同月份的垃圾填埋场渗滤液生物处理尾水(简称渗滤液尾水)进行了全面的分析.结果表明,经生物处理后的渗滤液尾水难以进一步生物降解,仍然有很强的污染性,COD和NH3-N仍分别高达419～622、12.4～174.0 mg/L,未达到国家排放标准,且仍含有多种环境优先控制污染物.除有机物外,渗滤液尾水中还有部分无机类物质贡献COD,TN主要由无机氮构成.渗滤液生物处理的效果与温度关系密切,6、9月的处理效果明显好于3、12月.     

夏季潮滩对上海老港垃圾填埋场渗滤液氮、磷净化效果研究

垃圾填埋产生的渗滤液造成的环境污染问题El益严重。采用自然湿地对垃圾渗滤液净化有诸多优点,而相关的研究较少。根据渗滤液的不同浓度和不同滞留时间的净化效果不同,采用实验室模拟和培养的方法来研究老港垃圾填埋场附近潮滩对垃圾渗滤液营养盐N、P的净化效果。研究发现：夏季老港中、低潮滩在较短滞留时间（6h）内对各浓度渗滤液中N、P的净化效果不明显,而在较长滞留时间内（96h）中、低潮滩对各浓度渗滤液净化效果明显,净化后污水中N、P含量可达到排放标准;垃圾渗滤液质量分数为5％时,潮滩对N、P的净化效果最为明显。     

The biological treatment of landfill leachate using a simultaneous aerobic and anaerobic (SAA) bio-reactor system

A set of simultaneous aerobic and anaerobic (SAA) bio-reactor system was used for the removal of organic pollutants and ammonia in the landfill leachate generated from Datian Shan Landfill in Guangzhou, China. The influent concentrations of COD and NH(4)(+)-N were 1000-3300 and 80-230 mg L(-1), respectively. The average effluent concentrations of COD and NH(4)(+)-N were 131 and 7 mg L(-1), respectively. The concentrations of COD and NH(4)(+)-N had reached the Chinese second grade effluent standard (COD<300 mg L(-1), NH(4)(+)-N<25 mg L(-1)) for this kind of wastewater. Gas chromatogram-mass spectrum (GC/MS) analysis was used to measure the organic pollutants in the landfill leachate. About 87 organics were detected in this landfill leachate, and 16 of them belong to the list of environmental priority pollutants established by the US Environmental Protection Agency. About 31 of the 87 organic pollutants were completely removed by the SAA bio-reactor, the concentrations of further 14 organic pollutants were reduced by more than 80%, and the removal efficiencies of the other 25 organic pollutants were over 50%.     

活性污泥法在工业废水处理中的应用进展

根据国外众多学者的研究成果，本文介绍了活性污泥法对食品加工、造纸、含金属、含酚、煤炭加工业、垃圾渗滤、化工、农药等废水的处理能力，应用范围及其在运行管理中应注意的有关事项。     

粉煤灰的改性及其在垃圾渗滤液深度处理中的应用研究

实验采用物理方法和化学方法对粉煤灰进行改性,并用改性粉煤灰深度处理垃圾渗滤液。通过扫描电镜和X-射线衍射对改性前后粉煤灰的表面结构和主要晶相组成进行分析,同时考察其在垃圾渗滤液深度处理中的吸附效果。结果表明,改性后粉煤灰的比表面积和孔隙度增大,吸附能力增强。通过比较,吸附能力最强的改性粉煤灰是将引发剂A与粉煤灰以质量比为1∶9的比例混合,在800℃下恒温焙烧2 h所制得的改性粉煤灰,该改性粉煤灰对垃圾渗滤液中COD和色度的去除率可达到67.3%和87.3%,相对于改性前去除率提高了96.0%和57.8%。     

Combination of in vitro bioassays for the determination of cytotoxic and genotoxic potential of wastewater, surface water and drinking water samples

In this study we evaluated genotoxicity and cytotoxicity of native samples of wastewaters (15 samples), surface waters (28 samples) and potable waters (8 samples) with the SOS/umuC assay with Salmonella typhimurium TA1535/pSK1002 and MTT assay with human hepatoma HepG2 cells. The genotoxicity of selected samples was confirmed with the comet assay with HepG2 cells. In the SOS/umuC assay 13 out of the 51 samples were genotoxic: two effluent samples from chemical industry; one sample of wastewater treatment plant effluent; two hospital wastewater samples; three river water samples and four lake water samples. Six samples were cytotoxic for HepG2 cells: both effluent samples of chemical industry, two wastewater treatment plant effluent samples, and two river water samples, however, only the chemical industry effluent samples were genotoxic and cytotoxic, indicating that different contaminants are responsible for genotoxic and toxic effects. Comparing genotoxicity of river and lake water samples with the chemical analytical data of the presence of the residues of pharmaceutical and personal care products (non-steroidal anti-inflammatory drugs, UV filters and disinfectants) in these samples, indicated that the presence of UV filters might be linked to the genotoxicity of these samples. The results showed that the application of the bacterial SOS/umuC assay and mammalian cell assays (MTT and comet assay) with HepG2 cells was suitably sensitive combination of assays to monitor genotoxicity and cytotoxicity of native samples of wastewaters and surface waters. With this study we also confirmed that the toxicity/genotoxicity bioassays should be an integral tool in the evaluation of toxicity of complex wastewaters before the release into environment, as well as for the monitoring of surface water quality, providing data useful in risk assessment.     

垃圾渗滤液处理工艺运行参数优化与技术比较

垃圾渗滤液是公认的一种成分复杂且难以处理的高浓度有机废水,笔者在北京市海淀区六里屯垃圾填埋场通过2007—2010年垃圾渗滤液处理的工程实践,以COD和氨氮的去除率为指标,研究了不同的垃圾渗滤液处理工艺组合,以及不同运行参数条件下对垃圾渗滤液的处理效果。结果表明,在中温UASB和A/O的平均水力停留时间(HRT)缩短1/3的情况下,通过改进A/O段曝气方式,优化系统的pH、DO等运行参数,用MBR替代絮凝工艺,使整个组合工艺对COD的年平均去除率达到了94.3%,氨氮的去除率维持在99.5%以上,出水氨氮稳定在10 mg/L以内,而改造前的COD与氨氮的年平均去除率仅为82.2%与55.3%。与改造前的UASB+A/O+絮凝工艺组合相比,改造后的UASB+A/O+MBR工艺组合具有更高的污染物去除能力、更好的抗缓冲性和稳定性。     

污泥活性炭强化SBR法处理垃圾渗滤液的实验研究

为了进一步处理垃圾渗滤液，试验采用污泥活性炭强化序批式间歇反应器（SBR）法进行处理，通过对比普通SBR法试验，得出投加污泥活性炭强化SBR法处理垃圾渗滤液的效果要远远高于普通SBR法。当污泥活性炭的投加量为1.2 g/L，容积负荷为0.5～1.5 kg BOD₅/(m³·d)时，进水1 h，曝气10 h，沉淀1.5 h，闲置1.5 h，处理效果最好，COD的去除率达到了85%，NH³-N的去除率达到了90%。