磷石膏渗滤液在不同渗漏运移模式下电阻率分布特征

为评估电阻率法监测磷石膏堆场渗滤液运移过程的有效性,首先采用自制电阻率四极装置测试渗滤液污染土的电性特征,随后针对表层单点渗漏、内部岩溶管道多点渗漏2种模型开展不同时段渗滤液运移监测物理模拟实验,并加入岩溶水进行空白对照实验。结果表明,渗滤液及其污染土电阻率随渗滤液浓度增加呈递减趋势,且低浓度区间变化更为剧烈;在表层单点入渗过程中,渗滤液主要进行横向运移,并逐步形成漏斗状渗漏形态,而管道渗漏模式下渗滤液以四周扩散方式运移;加入岩溶水后,借助电阻率差异能够区分相同含水率下的污染区与未污染区;最后借助一种常用的电阻率法——高密度电法 (ERT) 对贵州省某磷石膏堆场进行实测,得到的低阻体范围与堆场位置存在较好对应关系,验证了前述实验结果。电阻率法可用于监测磷石膏堆场渗滤液在地表及地下管道内的渗漏过程及污染分布。     

微生物菌剂对好氧填埋垃圾稳定过程的影响

为加速好氧填埋场的稳定化进程,提出利用生物强化技术加速好氧填埋垃圾的生物降解,通过模拟实验,研究了微生物菌剂对填埋垃圾稳定过程的影响。结果表明:微生物菌剂降低了好氧填埋场的有机污染负荷,使渗滤液COD下降更加明显,整个填埋周期所产渗滤液的COD总量较对照组少20.20%;加速了含氮物质的生物转化,氨氮峰值出现较对照组提前6 d,经历峰值以后,氨氮快速下降,较对照组提前22 d达到国家生活垃圾填埋场污染控制标准(GB 16889-2008)所规定的渗滤液氨氮排放标准25 mg/L,并使整个填埋周期氨氮总量减少9.15%;微生物菌剂降低了渗滤液的产量,使整个填埋周期渗滤液累计产量减少8.29%;使垃圾中有机质降解加快并使其降解更加彻底,至实验结束时总有机质含量较对照组低8.82%,干重较对照组减少35.95%;沉降性能优于对照组,至填埋结束时较对照组沉降量提高6.35%。     

南京地区简易生活垃圾堆场的污染现状和稳定化评价

针对南京市废弃简易生活垃圾堆场,通过采集和分析渗滤液以及堆体不同深度固体样品,研究其污染现状和稳定化程度。结果表明,渗滤液COD、NH3-N、TN超标倍数分别为4～6倍、7～10倍和4～10倍;固体样品TOC含量在10%左右,含水率在25%左右,均处于基本稳定的水平;固体样品浸出液COD 39～249 mg/L、NH3-N 0.9～14.88 mg/L、TN 8.82～28.14 mg/L。为了评价稳定化程度,确定了3因子:渗滤液、固体样品、浸出液及6个参数:COD,NH3-N,含水率,TOC,COD,TN作为评价指标,评价结果表明堆场处于基本稳定到中度稳定阶段。     

AO-SBR短程硝化反硝化垃圾渗滤液预处理中试应用

针对某垃圾渗滤液处理厂现有氨吹脱预处理工艺存在的脱氮效果不佳、运行费用高、易产生二次污染等问题,开展了基于短程硝化反硝化的AO-SBR垃圾渗滤液预处理中试研究,考察了反应系统的脱氮效能,分析了氮素的迁移转化途径,计算长期稳定时预处理工艺的主要运行成本。在中试实验中,垃圾渗滤液进水氨氮浓度为1 000~2 500 mg·L⁻¹,控制SBR池pH为 6.5~7.5、DO为 1.0~1.5 mg·L⁻¹,投加甲醇调节进水碳氮比为1.4~2.0,通过FNA抑制实现了短程硝化反硝化中试系统的启动和稳定运行。稳定阶段系统中的亚硝化率为90%以上,氨氮去除率为80%以上,总氮去除率为50%左右。典型周期氮元素平衡分析结果表明,通过短程硝化反硝化途径和硝化反硝化途径去除的总氮负荷分别占据总氮去除负荷的74.8%和13.5%。AO-SBR短程硝化反硝化作为垃圾渗滤液预处理工艺可以满足后续工艺流程进水要求,最终出水达到纳管标准,该垃圾渗滤液预处理工艺运行成本比氨吹脱降低约30%。短程硝化反硝化工艺替代氨吹脱工艺进行垃圾渗滤液预处理具有技术及经济可行性。以上研究结果可为垃圾渗滤液处理厂预处理工艺的升级改造提供技术支持。     

渗滤液回灌频率对生物反应器填埋场的影响研究

通过模拟实验研究了渗滤液回灌周期为1、2、3和5 d的4个模拟垃圾柱的产甲烷过程和渗滤液水质的变化情况.在用NaOH调节回灌渗滤液pH值的前提下,回灌频率越高,模拟厌氧型生物反应器填埋垃圾柱先开始产甲烷,但当回灌周期低于3 d时,开始产甲烷的时间相差不多.从渗滤液水质看,回灌周期为3 d的垃圾柱渗滤液COD、VFA等有机污染物浓度下降最快.综合考虑启动时间、运行费用和填埋场的稳定进程,在厌氧型生物反应器填埋场中,实施3 d/次的渗滤液回灌频率最为合适.     

磷石膏基胶结材固结磷尾矿性能及浸出特征

以磷石膏基材料代替水泥作为磷尾矿充填胶结材,研究了磷尾矿固结浆体和硬化体性能、浸出液污染特性和固结机理。结果表明,在同样条件下,磷石膏基材料固结磷尾矿浆体比水泥泌水量要小、浆体流动性能更优;磷石膏基材料胶结磷尾矿硬化体除3 d抗压强度略低外,其他龄期的强度是水泥的1.21~1.95倍。3 d之后,磷石膏基材料和水泥胶结尾矿硬化体浸出液总磷含量基本相近,但pH明显远低于水泥,总磷也低于污水综合排放标准限值,对环境危害低。硬化体SEM和XRD分析发现,磷石膏基材料水化生成的水化硅酸钙凝胶、针状钙矾石晶体和磷尾矿中白云石、含磷矿物生成的透钙磷石等,是整个磷尾矿固结硬化体具有较高强度、较低总磷含量和pH值主要原因。该研究表明,磷石膏基材料固化磷尾矿比水泥更有应用前景。     

无污泥持留序批式预处理反应器渗滤液预处理的正交试验研究

以黑石子垃圾填埋场渗滤液强化预处理-生物接触氧化为依托,针对其处理效果的局限性,研究无污泥持留序批式预处理(WSIP)反应器正交试验,旨在优化运行参数,提高低温期间渗滤液处理效果.实验表明,COD、NH 4-N、TN去除率较高,出水可生化性较好;优化碳氮质量比,为后续好氧微生物降解创造条件;曝气时间、HRT、进水磷浓度、序批周期对NH 4-N、TN去除效果影响显著;低温期间,获得较好出水水质的最佳运行参数为曝气时间9h、HRT4d、进水磷质量浓度50mg/L、序批周期6h.     

催化铁与生物法耦合除磷工艺特性

为了研究催化铁与生物耦合后对生物除磷特性的影响,实验采用人工配水用厌氧／好氧间歇流式富集培养聚磷微生物。对比发现,催化铁与生物耦合组中厌氧末段ORP降低了约60mV,pH值小幅度的上升（≤0．3）,整个培养过程中铁离子的浓度开始快速增加,之后趋于稳定（约40mgFe／gMLSS）。对好氧末段污泥SVI值比较发现,耦合工艺污泥沉降性能得到改善。除磷曲线比较发现,耦合组中厌氧末段磷的释放量下降,而好氧阶段磷的吸收速率增加;胞内聚合物提取表明,耦合组厌氧末段聚磷菌细胞内PHA含量有提高,好氧末段糖原含量有下降。磷形态提取分析表明,耦合组好氧末段污泥中无机态PO3 4-- P含量更高。低浓度铁离子可以起到与生物耦合同步除磷的目的,本工艺长期运行未发现耦合体系中催化铁对除磷的抑制作用。     

污泥干燥焚烧工程系统质能平衡分析

通过建立污泥干燥焚烧系统质能平衡模型对污泥干燥焚烧工程进行质能平衡分析,由模型结果可得,系统污泥最佳入炉含水率为65%,此时系统具有最低总能耗和总烟气量,且污泥恰好能够自持燃烧。之后,对污泥干基低位热值和初始含水率波动对系统运行的影响进行了研究。当初始含水率在研究范围内波动时,需保证入炉污泥含水率基本不变,以保证系统最低能耗。而当污泥热值下降（上升）时,需使入炉污泥含水率随之线性下降（上升）以保证系统最低能耗。总之,在运行参数波动过程中,当污泥被干燥至其入炉应用基热值在波动过程中恰好能支撑自持燃烧时,系统总辅助燃料消耗最低。     

CASS反应器内反硝化聚磷菌处理生活污水的性能

以实际生活污水作为处理对象,创造出适宜反硝化聚磷菌富集的条件,研究CASS工艺去除有机物同步反硝化脱氮除磷的性能。经过阶段 I、阶段 II 2种运行模式共计66 d的污泥培养,实现反应器的稳定运行,出水化学需氧量、氨氮、TN、TP的去除率平均值分别为90.47%、95.02%、84.71%和99.09%。通过释/吸磷实验测定稳定运行阶段的污泥,反硝化聚磷菌占聚磷菌的比例达到80.00%,且典型周期内磷的吸收量与硝酸盐的去除量呈线性关系。在此运行模式下,该CASS运行模式可同时高效去除有机物、总氮与总磷,并且对反硝化聚磷菌具有较高的富集效率。     

Concentrations of Synthetic organic chemicals in leachate from a municipal landfill

A study on the concentrations of synthetic organic chemicals in leachate from the municipal landfill of Lake Charles, Louisiana, was conducted from June 1987 through March 1989. The primary objective of this study was to provide information on the concentrations of synthetic organics in leachate from a typical municipal landfill. Leachate analyses yielded the presence of a variety of synthetic organic compounds at wide ranges in concentration. These compounds are potentially dangerous to human health.     

生活垃圾渗滤液处理工艺探讨

分析了国内生活垃圾（以下简称垃圾）渗滤液的特点,探讨了一种比较科学的垃圾渗滤液处理工艺：沉淀-厌氧处理-MBR-纳滤处理,并且分析了各段工艺的原理、特点以及其作用。     

Water flume study of the enhancement of buoyant rise in pairs of merging plumes

When multiple stacks are grouped or ganged together at a site, the effluent plumes are often observed to merge downwind, forming a single buoyant plume whose rate of rise is enhanced relative to the rise of the plumes individually. The magnitude of this rise enhancement depends on many factors, and the few available models for rise enhancement do not always agree with one another. In the present study the rise behaviour of pairs of merging, buoyant plumes was studied by physical modelling in a water flume at 1:500 scale. The experiments were conducted at several stack separation distances and various exit velocity ratios for stack pairs aligned with, or perpendicular to, the ambient flow. Limited experiments were also done with the stacks aligned at other angles to the flow. The stack releases were made buoyant by heating the source water, and the resulting plumes were measured with an array of sensitive temperature probes. From these measurements it was possible to determine the plume structure and rise rates. For small stack separations when the stacks are aligned with the ambient flow, the experimental results show that the enhanced rise is close to, and sometimes above, the maximum theoretical rise enhancement factor of 2^1/3. For the perpendicular orientation there is little or no rise enhancement. The rise enhancement for other stack orientations is somewhere between these two extremes. A plausible physical explanation for the observed behaviour is given, based on initial momentum shielding and line vortex dynamics in the merging plumes.     

生化-调碱后垃圾渗滤液的Fenton深度处理效果

针对上海老港垃圾填埋场经过厌氧-曝气塘处理后的渗滤液难进一步处理的问题,对其采用厌氧滤池-好氧接触法、氧化钙2种方式预处理,在此预处理基础上,考察了Fenton法深度处理的效果,探讨了H2O2/Fe2+投加比、初始pH、H2O2投加量、反应时间和Fenton试剂投加方式对渗滤液COD去除效果的影响。研究发现:经过生物预处理后,渗滤液的COD和TP分别降低了24%和25%;氧化钙调碱可以进一步使COD和TP去除率分别达到42%和96%;后续Fenton深度氧化的最佳条件为:初始pH为2,H2O2投加量为2.4 g/L,H2O2/Fe2+摩尔比为5∶1,Fenton试剂一次投加,反应时间为2 h。在此条件下,渗滤液的COD从1 340 mg/L降到198 mg/L,总COD去除率达到85%。     

Phytotoxicity data safeguard the performance of the recipient plants in leachate irrigation

Leachates from an operating and a closed landfill were examined for their phytotoxicity by seed germination/root elongation tests using seeds of Brassica chinensis and Lolium perenne. Their EC50s ranged from 3% to 46% v/v, which varied remarkably with the operating status of the landfills. Seedlings of twelve tree species were grown in pots, which were irrigated with landfill leachate at the EC50 levels, with tap water as control. No tree mortality or growth inhibition was observed after 90 days of leachate application. Chlorophyll fluorescence measurement also showed that plants receiving leachate did not suffer from a decline in photosynthetic efficiency. Litsea glutinosa and Hibiscus tiliaceus had remarkable growth, and other non-N-fixers were not inferior to the N-fixing Acacia auriculiformis. Leachate irrigation improved soil N content, though P deficiency is still a problem. The seed bioassay provided a conservative estimate of the phytotoxicity of landfill leachate. Plants irrigated can be protected from growth inhibition when the leachate irrigation plan is designed with reference to phytotoxicity data.     

垃圾填埋场水分迁移模型的应用研究

以渗滤液回灌为核心的填埋场生化反应器是当今国际固体废物研究的新方向 ,其具有减少渗滤液处理难度和加速填埋场稳定化的作用 ,其中控制填埋场水分是关键。本文通过对填埋场水分运移特征的分析 ,建立了渗滤液回灌条件下 ,生化反应器填埋场水分迁移的饱和 -非饱和三维非稳定数学模型 ,并求其有限单元数值解 ,定量模拟和预报不同回灌条件下填埋场水分的时空分布规律并进行实用研究。针对重庆市长生桥卫生填埋场设计情况和实际条件 ,运移模拟模型分析了水平沟和竖式井回灌条件下填埋场内水分的分布规律 ,证明了协同回灌方式的有效性     

Influence of kinetic sorption and diffusion on pesticide movement through aggregated soils

Laboratory studies were carried out to investigate solute leaching at different times from application in relation to temperature and initial soil moisture. Aggregates of a heavy clay soil were treated with a non-interactive solute (bromide) and the herbicides chlorotoluron, isoproturon and triasulfuron. The soil was incubated at 90% field capacity and either 5 or 15 degrees C. The influence of application to initially dry and initially wet aggregates on the behaviour of isoproturon was also investigated. At intervals, samples were either leached in small columns, centrifuged to characterise the fraction of chemical available in pore water under natural moisture conditions or extracted with organic solvents to assess total residues in soil. Bromide concentrations in leachate and in pore water extracted by centrifugation were constant with time. In contrast, availability for leaching and concentration in pore water of the herbicides decreased with increasing time from application in soil incubated at 15 degrees C. The effect of residence time was much smaller at 5 than at 15 degrees C. At the higher temperature, pesticide concentrations in leachate and pore water declined faster than would be expected from degradation alone, probably due to slow diffusion of the pesticides into soil aggregates where they are less available for leaching and/or slow sorption-desorption. The faster decline in availability for leaching at 15 than at 5 degrees C was attributed to faster degradation of the readily available fraction. There was no significant influence of initial soil moisture on either the leaching behaviour of isoproturon or its availability in soil water.     

1H-NMR-based profiling of organic components in leachate from animal carcasses disposal site with time

Leachate, generated by the decomposition of animal carcasses, presents many environmental, sanitary, and food safety hazards. However, research on the characteristics of leachate is lacking. In this study, we performed biochemical profiling of leachate from two animal species (pig and cattle) in two soil types (sandy loam and sandy soil) using ¹H-NMR-based profiling, followed by multivariate data analysis. The leachate was collected from a well-controlled artificial burial site over a 31-week period. Principal components analysis (PCA) of the NMR data showed similar patterns between species and soil types. Organic components, including organic acids and phenols, predominated, and their levels increased with time. The methylamine level in leachate from pig carcasses 18 weeks following burial was significantly higher than that from cattle carcasses; leachate from cattle carcasses in sandy soil 1 week after burial contained unique components (specifically ethanol, formate, alanine, N-methylation, and taurine), in contrast with those from sandy loam soil. This study suggests that a NMR-based profiling approach is useful to characterize the organic components in leachate from animal carcasses over time.     

冬季垃圾填埋场渗滤液回灌水量平衡的实验研究

渗滤液回灌的水量平衡是垃圾填埋场渗滤液回灌处理法工程应用的关键问题之一。着重研究了冬季渗滤水回灌的水量平衡状况。结果表明,冬季回灌水量仍可通过土壤蒸发得到大量削减,径流量、土壤渗出 水与下渗水的比值大于春夏秋三季,平均蒸发量小于些三季。回灌条件下,土壤湿润度提高,蒸发量增大。     

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.