立式磨和袋式除尘器在矿渣粉磨系统中的应用

阐述了矿渣微粉的应用、粉磨工艺和设备现状,并对立式磨生产工艺、立式磨结构和工作原理、袋式除尘器结构和工作原理等进行了重点介绍,分析了工程应用实例,认为国产立式磨和袋式除尘器可为矿渣粉磨的节能减排提供可靠的技术和设备保障。     

污染场地不同深度土壤有机-矿质复合体中有机氯农药的分布

采用物理方法将某农药厂土壤分成4种粒径的有机-矿质复合体组分,粘粒、粉粒、细砂和粗砂,研究有机氯农药在土壤不同有机-矿质复合体组分中的分布特征及有机质含量对污染物质赋存分布的影响。结果表明,粉粒组分中污染物质六六六含量较高,粘粒组分中滴滴涕含量较高。粘粒和粉粒组分中污染物质的含量与相应的有机质含量间呈现显著相关关系,而在细砂和粗砂中这种相关性不显著。lgKoc值与污染物质含量的相关性分析结果与有机质的相关性分析结果相似。有机质可能是影响场地土壤有机氯农药分布的重要因素之一。本研究的结果可为污染场地的风险控制和环境修复提供基础依据。     

面向矿山废弃地复垦的炉渣污泥人工土壤的理化特性

通过添加不同比例的燃煤电厂粉煤灰和炉渣对城市污泥进行钝化,配制成不同灰渣比例的人工土壤,对人工土壤的pH、电导率、养分含量、重金属含量以及持水、渗水性能进行了研究。结果表明,污泥人工土壤pH介于7.5～8.0之间,属于弱碱性土壤;电导率变化范围为2.93～3.71 mS/cm,表明盐分含量较高。污泥人工土壤中有效态养分含量随炉渣比例提高而增加,所有配比人工土壤有机质和有效磷、速效钾的含量达到高肥力水平。人工土壤中Cd、Ni、Pb、Cu、Zn含量均明显低于国家农用标准(GB 4284-84、GB 8173-87)。粉煤灰渣对污泥中有效态Cd、Ni、Pb和Cu有钝化作用,使其向无效态转化,对Zn则有活化作用。炉渣对Cd、Ni的钝化作用要优于粉煤灰,而粉煤灰对Pb、Cu的钝化作用要优于炉渣。添加炉渣提高了污泥人工土壤水分的蒸发量,减弱了人工土壤的持水能力,但加入炉渣使人工土壤的渗透系数显著增加,提高了其渗水性能。     

水相和泥浆系统中地下水成分对高锰酸钾氧化TCE的影响

三氯乙烯（TCE）是污染土壤和地下水中检出率较高的氯代有机物。以TCE为研究对象,考察了地下水无机成分和腐殖酸对高锰酸钾氧化TCE的影响,研究了不同离子强度下的MnO,颗粒行为,并测定了泥浆系统中TCE的氧化效果,结果表明：当TCE初始浓度为20mg／L、高锰酸钾与TCE的摩尔比为2：1,离子浓度〈0．1mol／L时,TCE去除率可达98％以上,Na^＋、Cl^-、HCO3-对TCE的去除率影响甚微,但离子强度对MnO2的沉淀生成影响显著;0．1mol／L的K^＋对TCE的去除有一定程度的抑制;0．1mmol／L的Fe^2＋和腐殖酸对TCE的氧化有显著负面影响。泥浆系统实验进一步验证了有机质对高锰酸钾氧化TCE的影响很大。     

Tissue radionuclide concentrations in water birds and upland birds on the Hanford Site (USA) from 1971-2009

Historical operations at the Hanford Site (Washington State, USA) have released a wide array of non-radionuclide and radionuclide contaminants into the environment. As a result, there is a need to characterize contaminant effects on site biota. Within this framework, the main purpose of our study was to evaluate radionuclide concentrations in bird tissue, obtained from the Hanford Environmental Information System (HEIS). The database was sorted by avian group (water bird vs. upland bird), radionuclide (over 20 analytes), tissue (muscle, bone, liver), location (onsite vs. offsite), and time period (1971-1990 vs. 1991-2009). Onsite median concentrations in water birds were significantly higher (Bonferroni P < 0.05) than those in onsite upland birds for Cs-137 in muscle (1971-1990) and Sr-90 in bone (1991-2009), perhaps due to behavioral, habitat, or trophic species differences. Onsite median concentrations in water birds were higher (borderline significance with Bonferroni P = 0.05) than those in offsite birds for Cs-137 in muscle (1971-1990). Onsite median concentrations in the earlier time period were significantly higher (Bonferroni P < 0.05) than those in the later time period for Co-60, Cs-137, Eu-152, and Sr-90 in water bird muscle and for Cs-137 in upland bird muscle tissue. Median concentrations of Sr-90 in bone were significantly higher (Bonferroni P < 0.05) than those in muscle for both avian groups and both locations. Over the time period, 1971-2009, onsite median internal dose was estimated for each radionuclide in water bird and upland bird tissues. However, a meaningful dose comparison between bird groups was not possible, due to a dissimilar radionuclide inventory, mismatch of time periods for input radionuclides, and lack of an external dose estimate. Despite these limitations, our results contribute toward ongoing efforts to characterize ecological risk at the Hanford Site.     

中国污染场地分类管理程序与方法研究

借鉴发达国家对污染物场地的管理方法,探索了我国污染场地分类管理的程序:从疑似污染场地的申报建档、疑似污染场地的初步调查、场地的危害分级、污染场地的详细调查、污染场地风险评估,到污染场地的治理修复,以及贯穿场地管理始终的环境监测.在上述管理程序中还缺失危害分级的方法,其他步骤已有相关技术文件支持.本文进一步构建了其中场地危害分级的方法:即根据污染源是否存在,污染物的性质、赋存状态、迁移性、含量水平,周围是否有敏感目标及其类型,分成不同的危害级别和管理级别,并实施不同的管理措施.以江苏省八家氯丹、灭蚁灵生产企业场地为例,经初步调查和危害分级,将8个场地分为3类:B类场地(有1个场地)环境介质中无超标污染物检出,但场地上的有害废弃物需要处置;C类场地(包括3个场地)局部有超标污染物检出,但场地不具备详细调查采样和修复的条件,需要对污染区进行隔离处置,以降低人体健康风险;还有D类场地(包括4个场地)需要详细采样以确定污染范围并进行风险评估.根据最后一类4个场地进一步调查评估的结果,并考虑到场地实施修复的经费、技术可行性及场地相关利益方的意见,决定优先对其中1个场地实施修复治理.     

离子色谱-衍生-分光光度法同时测定水中三价铬和六价铬

本文建立了离子色谱法同时测定水中三价铬和六价铬的方法。样品中的三价铬经柱前衍生后,泵入分析柱,与样品中的六价铬分离,分离后的样品经在线柱后衍生,流入可变波长检测器,分别在365 nm和540 nm检测。利用正交实验找出最佳分析条件:水浴加热2 min,加热温度80℃,柱后衍生液流速1.1 ml/min。方法在10 min内完成水中三价铬和六价铬分析,三价铬和六价铬线性范围分别为0.05～10 mg/L和0.005～1 mg/L,方法检出限低,分别为18.1μg/L和0.267μg/L,精密度分别为1.16%(0.4 mg/L Cr3+,n=7)和3.07%(0.08 mg/L Cr6+,n=7),样品分析时的加标回收率在96%～102%之间。     

ICP-AES法测定土壤中铬含量的不确定度评定

根据等离子体原子发射光谱(ICP-AES)法测定土壤中铬的过程,建立相应的数学模型并对模型中各个参数进行了不确定度来源分析。结果表明,测定结果的不确定性主要来源于标准曲线的浓度与光谱强度拟合直线方程求铬含量的不确定度、标准溶液和配置标准工作溶液时的不确定度,其次为重复性不确定度;定容体积和样品称量过程的不确定度对测量结果的不确定度贡献相对较小。     

农业生态环境污染监测技术探讨

农业生态环境污染监测是以农产品污染监测为中心的各环境要素的污染监测。依据农业区域中污染源排放危害农产品的特征污染物选择大气环境污染物、水环境污染物、土壤环境污染物、农产品污染物作为监测指标;依据农业区域中各类污染源的特点布设大气环境污染、水环境污染、土壤环境污染、农产品污染监测点位;在农产品生长期或生产期,大气环境污染及水环境污染同步监测一次,农产品污染在收获时监测一次,依据污染源污染物排放强度确定土壤环境污染监测频次。     

Amendment of arsenic and chromium polluted soil from wood preservation by iron residues from water treatment

An iron-rich water treatment residue (WTR) consisting mainly of ferrihydrite was used for immobilization of arsenic and chromium in a soil contaminated by wood preservatives. A leaching batch experiment was conducted using two soils, a highly contaminated soil (1033 mg kg⁻¹ As and 371 mg kg⁻¹ Cr) and slightly contaminated soil (225 mg kg⁻¹ As and 27 mg kg⁻¹ Cr). Compared to an untreated reference soil, amendment with 5% WTR reduced leaching in the highly contaminated soil by 91% for Cr and 98% for As. No aging effect was observed after 103 d. In a small field experiment, soil was mixed with 2.5% WTR in situ. Pore water was extracted during 3 years from the amended soil and a control site. Pore water arsenic concentrations in the amended soil were more than two orders of magnitude lower than in the control for the upper samplers. An increased release of arsenic was observed during winter in both fields, mostly in the deepest samplers. This is likely due to the formation of a pseudo-gley because of precipitation surplus. Stabilization of arsenic and chromium contaminated soil using WTR is a promising method but the transformation of ferrihydrite in soil proves a concern in case of waterlogged soils. Still the amendment minimized the leaching of arsenic, even in cases of seasonal releases.