粘土处理垃圾渗滤液的探讨

介绍了粘土处理垃圾渗滤液的作用机理和国内外研究概况。通过粘土作为处理介质,重点考察COD和氨氮的变化情况,对垃圾渗滤液的处理进行试验,并通过物理化学法、生物法、土地法等常规处理方法的比较,提出粘土处理垃圾渗滤液的可行性和应用性。     

Screening and Application of Functional Bacteria in the Advanced Treatment Process of Landfill Leachate

To improve organic pollutant degradability of landfill leachate, culture medium was prepared with landfill leachate and agar.And then three functional bacteria were cultured and screened from sludge in aeration pool of biochemical treatment system by bioaugmentation.Based on 16S rDNA identification, these bacteria were named Mari nobacter (coded Y1), Acinetobacter (coded Y2) and Escherichia (coded Y3).Functional bacteria were scaling up, and then inoculated into biological activated carbon (BAC) reactor by physical circle absorption method.With the control experiment, it was shown that the natural start up BAC had significant degradation capacity to organic pollutants with molecular weight M of 10 ~ 5 kDa.And the inoculums' start up BAC with functional bacteria was kept with was with removal rate of 76.1% for organic pollutants with molecular weight M of 100 ~ 30 kDa, and 80.9% for organic pollutants with molecular weight M exceeding 100 kDa.     

Integrated Flow-based System Displaying an In-line Mini Soil Column to Monitor Iron Species in Soils Leachates

ABSTRACT

Contamination of ground water as a consequence of soil leaching processes is an issue of major concern. In this context, a simulation of the soil leaching process was designed. A sequential injection (SI) method to monitor the soil leaching of iron complexes with in-line rain simulation for leachate production is described. The developed methodology comprises the SI determination of both iron(III) and 3-hydroxy-4-pyridinones iron(III) complexes, coupled to a mini soil column (mSC) for displaying in-line rain simulations. The described SI method enabled iron(III) determination within the range 2.0–35 µmol L^?1, with a detection limit of 0.42 µmol L^?1, and determination of iron(III) complexes in the range 1.0–45 µmol L^?1. It was successfully applied to leachates from laboratory scale soil columns (LSSC), with good precision for both iron(III) and iron complexes determinations: calculated relative standard deviation (RSD) of 5% and 6%, respectively. A step further in automation and miniaturization was attained with the incorporation of a mini soil column for the in-line leachate production. The system enabled the soil leachate production and assessment in less than 5 min, including determinations in triplicate.     

Ca2+对磷酸铵镁沉淀法处理垃圾渗滤液的影响研究

磷酸铵镁沉淀法因其反应时间短，操作简便和原材料容易获得的优势被广泛利用在垃圾渗滤液的处理中。在生活垃圾产生的渗滤液中出存在着大量的Ca2+，而这些Ca2+会对磷酸铵镁沉淀法处理渗滤液产生一定影响。实验通过设置渗滤液中Ca2+的浓度探索Ca2+对磷酸铵镁沉淀法降低COD和氨氮的影响。在实验中，磷酸铵镁沉淀法对氨氮的去除率从65.12%下降至42.52%，同时COD的去除率也从51.90%下降至37.87%。实验证明，垃圾渗滤液中Ca2+的含量会影响Mg2+与PO43-和氨氮结合，降低氨氮和COD去除率。     

一种处理垃圾渗滤液的新型组合工艺

针对垃圾渗滤液水质特点，研发了一套新型组合工艺，经过罗定市垃圾填埋场晚期渗滤液的中试处理试验，并对工艺进行改良和优化，结果表明：垃圾渗滤液能够得到很好的处理，各项出水指标基本达到规定的标准，在实际工程中发挥良好的作用。     

Overland flow systems for treatment of landfill leachates—Potential nitrification and structure of the ammonia-oxidising bacterial community during a growing season

Overland flow systems are useful for treating landfill leachates, because they provide favourable conditions for nitrification and they are easy to maintain. However, little is known about the microbial communities in such systems or the nitrification capacity of those microorganisms. In this study, seasonal variations in potential nitrification and in community composition of nitrifying bacteria were investigated in two overland flow areas receiving leachate from landfills at Korslöt and Hagby, Sweden. Samples were collected in the settling ponds sediment and at two depths in the overland flow areas (the macrophyte litter layer and the rhizosphere) in May, August and November 2003. A short-term incubation method was used to measure potential oxidation of ammonia and nitrite (designated PAO and PNO). The ammonia-oxidising bacterial (AOB) community was investigated using a 16S rRNA gene approach that included PCR amplification and analysis of PCR products by denaturing gradient gel electrophoresis (DGGE), followed by nucleotide sequencing and phylogenetic analysis.PAO was determined in the range 5-2700 (NO₂⁻+NO₃⁻)-N g⁻¹ dw d⁻¹ and PNO in the range 60-2000 μg NO₂⁻-N g⁻¹ dw d⁻¹. At Korslöt, PAO and PNO showed similar temporal variation in the different ecosystems, whereas no such relationship was noticed at Hagby. Considering both sites, there was no obvious change in the composition of the AOB community over the growing season. However, the composition did differ between the ecosystems: Nitrosomonas-like sequences were more common in the ponds, and in the litter layers they were found as often as Nitrosospira-like sequences, whereas Nitrosospira-like sequences were more common in the rhizospheres. Altogether, we found nine different AOB sequences, five Nitrosomonas-like and four Nitrosospira-like, which belonged to clusters 0, 2, 3b, 6a, 6b and 7. There was no apparent relationship between the number of AOB populations and the PAO in different soil layers and sediments.     

Responses of methane oxidation to temperature and water content in cover soil of a boreal landfill

Methane oxidation in a cover soil of a landfill located in a boreal climate was studied at temperatures ranging from 1-19 °C and with water content of 7-34% of dry weight (dw), corresponding to 17-81% of water-holding capacity (WHC) in order to better understand the factors regulating CH₄ oxidation at low temperatures. CH₄ consumption was detected at all the temperatures studied (1-19 °C) and an increase in CH₄ consumption rate in consecutive incubations was obtained even at 1 °C, indicating activation or increase in enzymes and/or microorganisms responsible for CH₄ oxidation. CH₄ consumption was reduced with low water content (17%WHC) at all temperatures. The response of CH₄ consumption to temperature was high with Q₁₀ values from 6.5 to 8.4 and dependent on water content: at 33%WHC or more an increase in water content was accompanied by a decrease in Q₁₀ values. The responses of CH₄ consumption to water content varied at different temperatures so that at 1-6 °C, CH₄ consumption increased along with water content (33-67%WHC) while at 12-19 °C the response was curvilinear, peaking at 50%WHC. CH₄ consumption was less tolerant (higher Q₁₀ values; 6.5-8.4) of low temperatures compared to basal respiration (Q₁₀ values for CO₂ production and O₂ consumption 3.2-4.0). Overall, the present results demonstrate the presence of CH₄-oxidizing microorganisms, which are able to consume CH₄ and to be activated or grow at low temperatures, suggesting that CH₄ oxidation can reduce atmospheric CH₄ emissions from methanogenic environments even in cold climates.     

两级SBR-PAC吸附混凝法处理垃圾渗滤液的研究

垃圾渗滤液的处理一直是近几年污水处理领域的热点和难点问题.本文以杭州市某垃圾填埋场渗滤液(CODCr1500～4500 mg/L,NH4+-N 795～1550 mg/L,pH8.0～9.0)作为研究对象,利用串联运行的回流式两级SBR+活性炭吸附混凝工艺进行了实验研究,出水COD Cr<300 mg/L、氨氮<20 mg/L、色度<20倍.     

微波-活性炭去除垃圾渗滤液中CODcr的研究

采用微波-活性炭联合作用去除垃圾渗滤液中CODcr.通过正交设计,探讨活性炭用量、pH值、水样初始CODcr值、微波功率、辐照时间、搅拌时间6个因素对CODcr去除率的影响.结果表明在PAC用量5g,pH值为9,水样稀释1倍,微波强度为420W,辐照时间为4min,搅拌时间为45min时处理的效果最好,此时CODcr去除率可这83.12%.微波辐照能改变活性炭的结构,并正在表面产生一些高温"热点",这些"热点"是导致有机污染物降解的根本原因.     

Polyethersulfone Membrane Filters for Sampling Soil Water from In Situ Soils and Intact Soil Columns for Phosphate Analysis

Abstract

Porous plates or cups are commonly used to collect soil solution samples in field studies or from intact soil columns. Some commonly used materials for porous plates may adsorb soil solution constituents such as phosphorus (P). An alternative to using a porous plate is to use a membrane filter with a known pore size and bubble point. The objective of this study was to evaluate the utility of polyethersulfone membranes (pore size 0.45 µm and bubble point >200 kPa) to extract soil solution from in situ soils and intact soil columns for phosphate analysis. In situ soil solution samplers were constructed from modified reusable polysulfone membrane filter holders equipped with polyethersulfone membranes (47 mm diameter). A ?10 kPa vacuum was maintained in the samplers, which enabled soil solution collection at soil water potentials of 0 to ?4 kPa in loamy sand, 0 to ?10 kPa in sandy loam, and 0 to ?12 kPa in sandy clay loam soils. In a laboratory study, soil solution samplers continued to hold a vacuum to ?77 kPa soil water potential. Soil solution samplers were further evaluated in a field study at 45‐, 90‐, and 135‐cm depths in two soils. Samplers operated with relatively few difficulties for the first 12 months of field evaluation. Membranes apparently dried during periods of low soil water potential but increases in soil moisture were sufficient to rewet the membrane. Sampler failures in the field increased during 13–18 months because aged vacuum tubing and root interferences with samplers at 45 cm. Improvements in sampler design may improve the durability for implementation in long‐term field experiments. Membrane filters worked near flawlessly to maintain unsaturated conditions in intact soil columns. The filter units facilitated easy collection of soil water from the intact soil columns without altering the chemical composition of the percolate.