土壤中挥发性有机物的顶空制备方法研究

对土壤中挥发性有机物（VOCs）有效提取的顶空（HS）前处理条件进行了研究。结果表明,在一定的气相色谱条件下,影响顶空装置对挥发性有机物提取水平的主要有顶空平衡时间、平衡温度、基准修正液的加入量等因素,在一定的HS—GC条件下,土壤中挥发性有机物的准确度可达80%。     

重点行业企业用地地下水中挥发性有机物分析方法探究

通过优化顶空条件(氯化钠加入量、顶空平衡温度、顶空平衡时间),对采用顶空-气相色谱-质谱联用法测定地下水中55种挥发性有机物的方法进行探究。结果表明:该方法检出限为0.24~2.30μg/L,相对标准偏差为0.76%~13.2%,实际样品加标回收率为82.7%~119%。该方法具有较高的灵敏度、精密度和准确度,操作简便,可用于企业用地地下水中挥发性有机物的检测。     

顶空气相色谱分析原理与技术

系统讨论了静态顶空气相色谱的原理,包括多次相平衡法、改变相比法和标准加入定量法。测定了挥发性有机物在气液两相间的分配常数及其在水中的含量。提出了通过测定分配常数作为分析准确度的判据。研究了温度、相比、分配常数和无机盐对顶空分析灵敏度的影响。采用顶空色谱测定了河流底泥中的可酸挥发硫化物。     

固体废物中氰化物的浸出特性研究

采用零顶空提取器,对固体废物中氰化物做浸出试验,浸出液用流动注射法测定,并探讨固体废物中影响氰化物浸出的因素。对浸提时间和浸提次数的试验考察可知,冲刷、溶解、吸附、解吸等多种机制作用于浸出的不同阶段。试验表明,当浸提时间为18 h、浸提次数为2次时能将氰化物基本浸提出来;固体废物经稳固化处理后可明显降低氰化物的浸出量,固体废物本身所含的吸附性组分可不同程度地降低氰化物的浸出量。     

硫酸锰废渣的浸出毒性及无害化处理的研究

研究了硫酸锰废渣的主要金属元素组成及浸出毒性,并采用锰渣加石灰混合的方法进行无害化处理。结果表明,硫酸锰废渣浸出液中Mn和Cd含量超标,锰渣加石灰混合的方法能有效降低废渣的浸出毒性,锰渣与石灰的质量比为25∶2效果最佳。     

铬渣制砖的毒性浸出及评价

对铬渣制砖的毒性浸出进行了研究，结果表明铬渣制砖可对六价铬起到封闭作用，但被封闭的六价铬的液体环境中会有浸出，砖样浸出液中六价铬的含量随时间及浸出方法的不同而不同，浸泡20d浸出液中六价铬含量达到稳定，碱性环境有利于六价铬的重新溶出。     

顶空-气相色谱/质谱法测定土壤中挥发性有机物

本方法采用静态顶空进样技术对土壤样品进行处理,利用气相色谱质谱联用对土壤中挥发性有机物(37种)进行了测定分析,通过测定得到最低检出浓度为:0.39～1.76μg/kg;加标回收率为:69.8%～110.2%;RSD为:3.1%～10%。本实验分析时间短,操作简单,灵敏度及测定结果较为满意。     

土壤中挥发性芳香烃的顶空前处理方法研究

本方法针对土壤中挥发性芳香烃顶空前处理条件进行了研究,优化了顶空密封垫的选择、顶空平衡温度、加热平衡时间、进样时间和顶空瓶压力等顶空前处理条件,测定条件科学、准确,完全能够满足土壤中挥发性芳香烃监测分析的灵敏度和准确度相关的技术要求。该方法精密度为1.7%~9.8%,准确度为34.3%~83.7%,检出限为2.0~4.2μg/kg。为制订土壤中挥发性芳香烃监测分析方法提供了技术支持。     

吐鲁番市挥发性有机物排放特征及防治对策

挥发性有机物作为细颗粒物和臭氧的重要前体物,对大气环境影响日益突出。针对吐鲁番市挥发性有机物排放特征进行分析,找出挥发性有机物污染防治存在的问题,并提出防治对策,全面加强挥发性有机物污染防治工作,从源头上实现挥发性有机物排放量的减少。     

顶空-气相色谱-质谱法测定土壤中卤代烃

建立顶空-气相色谱-质谱法同时测定土壤中挥发性及半挥发性卤代烃的方法。实验优化顶空平衡温度、顶空平衡时间及盐度条件,并对优化后方法的线性、检出限、精密度及回收率进行分析。结果表明:29种目标化合物在线性范围内线性良好,相关系数均大于0.997,方法检出限为2.2~5.9μg/kg,样品不同浓度水平加标回收率范围为80.0%~120%,相对标准偏差小于20%。该方法适用于土壤样品中挥发及半挥发性卤代烃的测定。     

顶空-气相色谱-质谱法测定水中痕量丁基黄原酸

建立了顶空-气相色谱-质谱联用测定水中丁基黄原酸的方法。丁基黄原酸在酸性条件下分解成易挥发的二硫化碳,可用顶空-气相色谱分离、质谱定量测定。与传统的分光光度法相比,该法简便、快捷,在0.010～1.00 mg/L范围内线性良好,准确度高,加标回收率为95.1%～100.6%,精密度好,相对标准偏差为3.1%～6.5%,方法检出限为0.002 mg/L,适用于水中丁基黄原酸的监测。     

Study on the law of heavy metal leaching in municipal solid waste landfill

Comparative leaching experiments were carried out using leaching medium with different pH to municipal solid waste in the landfill columns in order to investigate the mobility of heavy metals. The leachate pH and oxidation–reduction potential were measured by oxidation–reduction potential analyzer; the contents of heavy metals were measured by inductively coupled plasma mass spectrometry. It is very different in leaching concentrations of heavy metals; the dynamic leaching of heavy metals decreased with the rise of the leaching amount on the whole. Acid leaching medium had definite influence on the leaching of heavy metals in the early landfill, but it had the obvious inhibition effect on the leaching in the middle and late period of landfill; the neutral and alkaline leaching medium are more beneficial to the leaching of heavy metals. Due to the influence of the environment of landfill, the differences of the results in cumulative leaching amount, leaching rate, and leaching intensity of heavy metals are very big. The calculation results of the release rates of heavy metals prove that the orders of the release rates are not identical under different leaching conditions. Acid rain made heavy metals migrate from municipal solid waste to soil and detain in soil more easily; approached neutral and alkaline leaching mediums are more beneficial to leaching of heavy metals in the municipal solid waste and soil with leachate. The field verification of experimental data showed that the law of heavy metal leaching in municipal solid waste revealed by the experiment has a good consistency with the data obtained by municipal solid waste landfill.     

电镀污泥标准浸出方法的比对

采用3种固体废物浸出毒性标准浸出方法处理电镀污泥,考察浸提剂、样品粒径、液固比、振荡时间、振荡方式等因素对电镀污泥中重金属浸出效果的影响,用电感耦合等离子体原子发射光谱法同时测定浸出液中铜、锌、镍、铬、铅、镉、钡等元素。试验表明:醋酸缓冲溶液体系浸出液中重金属浓度最高;样品粒径越小,浸出毒性越大;翻转振荡比水平振荡更有利于重金属浸出;液固比增大,重金属浸出量增加;虽然液固比和振荡时间对重金属浸出效果均有影响,但很难确定最佳值。     

Test of a Modelling System for Estimating Nitrogen Leaching – A Pilot Study in a Small Agricultural Catchment

Nitrogen leaching is a world-wide concern for the quality of ground- and surfacewater. Measures to abate this is still limited by a lack of understanding mechanisms behind all factors describing the leaching process, time lags between countermeasures and improvement in waterquality and spatial distribution of nitrogen leaching. The purpose of this study was to do an initial test of the SOILNDB model system which is built on the existing mechanistic SOIL and SOILN models and an automatic parameterization procedure for use of simplified input data. The test was done by simulating nitrogen leaching from each of the 150 fields in a small catchment during a three-year study period. The simulated mean root-zone nitrogen leaching rate from all the fields in the catchment was compared to measurements of nitrogen flow in the stream draining the catchment and showed good agreement in between-year dynamics.     

A study of the elemental leachability and retention capability of compost

In this work a comparison is made between the different approaches that can be taken to evaluate the mobility of elements in compost. The practical consequences of the results obtained are also discussed in terms of methods for cleaning up compost and using compost in environmental remediation. The mobility of potentially toxic elements in compost is evaluated by leaching with four selected eluents, i.e. diluted sulfuric acid, oxalate, citrate and EDTA. In contrast to the chelating agents, diluted sulfuric acid was found to generally have a low leaching capability for removal of heavy metals from compost. This implies that the risk of heavy metal leaching caused by natural rainfall is likely to be low. The results obtained in the leaching experiment were compared with previous results obtained from sequential fractionation. This comparison confirmed that both methods gave similar results for predicting the lability of elements in compost. A non-linear regression analysis of the leaching curves was also conducted. The leaching curves for elements with high lability could be fitted with a two components model. The labile components identified by the kinetic model are approximately in accordance with the fractions obtained from the first step of the sequential extraction method. The kinetic speciation method is shown to be a relatively rapid and simple procedure for compost which gives more information about element lability than simple leaching experiments. The leaching reagents used in this work were not effective enough to be used for cleaning up compost with a high metal content. Compost was however shown to have a high affinity for heavy metals, with the order of affinity of metal for the compost being very similar to that seen for humic acid. Compost may therefore prove to be a good remediation material for metal contaminated waste.     

响应面法优化测定水体中微囊藻毒素

针对水体中低浓度微囊藻毒素(MC-RR和MC-LR)的富集、淋洗、洗脱等前处理环节,采用单因素响应面优化法探讨微囊藻毒素前处理的最佳条件。结果表明:采用体积分数为25%的甲醇水溶液能够取得最佳淋洗效果,由One Factor设计优化得到体积分数为75%的甲醇水溶液作洗脱剂,MC-RR和MC-LR最佳回收率为89.4%和90.7%。方法在0.100 mg/L~5.00 mg/L范围内线性良好,MC-RR和MC-LR的检出限分别为0.07μg/L和0.04μg/L,实际水样加标回收率分别为80.6%和84.9%,平行测定结果的RSD分别为1.6%和2.4%。     

某碱渣堆放场对岩溶地下水的影响分析

结合某碱渣堆放场的水文地质状况,通过模拟试验,探讨了碱渣堆放场对岩溶地下水的影响。结果表明,碱渣场在冲灰水和大气降水的浸泡、淋滤作用下,其中的氯化物和钙镁盐类大量析出并随碱渣废液一起下渗,石灰岩碎石对氯化物有一定的吸附作用,但能力微弱。据试验数据分析认为,该渣场是焦作市北中部岩溶地下水中氯化物浓度和总硬度持续升高的主要原因。     

危险废物浸出毒性试验方法的研究

在分析各国危险废物浸出毒性试验方法的基础上,综合考虑我国气候状况(降雨量、酸雨现状)及工业固体废物处理处置现状,提出我国危险废物浸出毒性研究的技术路线为:通过模拟工业固体废物填埋场在不规范填埋处置且受酸雨影响条件下,有毒物质浸出向地下渗滤造成对地下水的污染,确定浸出毒性的浸取方法.浸出毒性保护目标为地下水,同时还介绍了主要技术参数液固比、浸取剂pH值和类型的确定方法.     

A method for assessing generalised nitrogen leaching estimates for agricultural land

The purpose of this study was to develop a method for assessing generalised N leaching estimates from large areas of agricultural land. The system developed was based on calculating a number of N leaching estimates for different typical cropping situations. The estimates were normalised with respect to varying weather conditions and crop production. The different cropping situations were described by setting up a matrix consisting of crucial factors influencing leaching such as soils, crops and climate. Nitrogen leaching was then estimated for a number of combinations of these factors. Calculations were made for three different regions where all the major crops were cultivated on soils with seven different textures and four different organic-N classes and two fertilisation regimes. The three regions are representative of climates and agricultural practices in some of the major agricultural areas in Sweden. The model used was the SOILN model. Leaching of nitrogen from the root zone showed large variations. The range was from 1 to 50 kg ha⁻¹ for different soils and crops when only fertiliser N was applied. Leaching varied both due to different climates and differences in cultivation practices between the regions. Leaching decreased in a south-north gradient. Leaching increased as a result of greater mineralisation when the organic matter content in the soils was increased, leaching was less from soils with a high clay content and was very small for the heavy clay soil. This revised version was published online in July 2006 with corrections to the Cover Date.     

Release of arsenic (As) and lead (Pb) from quicklime-sulfate stabilized/solidified soils under diffusion-controlled conditions

A quicklime-sulfate-based stabilization/ solidification (S/S) process for arsenic (As) and lead (Pb) immobilization was evaluated under “semi-dynamic” leaching conditions. In order to simulate aggressive leaching conditions the semi-dynamic leaching tests was modified by using 0.014 N of acetic solution instead of distilled water. Kaolinite-sand and montmorillonite-sand soil samples were artificially contaminated with As and Pb, compacted and cured for 28 days. The semi-dynamic leaching tests were then conducted for 90 days. The effectiveness of the S/S treatment was evaluated by assessing the cumulative release of As and Pb as well as by determining the diffusion coefficients (D _eff) and leachability indices (LX). The release of As and Pb was greatly reduced by quicklime-sulfate treatment as compared to untreated samples. Moreover, the quicklime-sulfate treatment was more effective than the quicklime-only treatment in reducing both As and Pb release. The controlling leaching mechanisms were determined using a diffusion theory model. Upon S/S treatment, As and Pb release was diffusion controlled. The LX of all the treated samples were greater than nine, suggesting that S/S treated samples were suitable for “controlled utilization”.