铅大气污染物环境保护标准限值研究

铅因其对公众健康的影响,其大气污染物标准限值的合理性倍受关注.论文对比分析了国内外铅大气污染物环境质量与排放标准,通过计算提出基于保护环境空气质量的排放标准理论限值及建议限值.分析发现,目前国际上铅环境空气质量标准浓度限值为0.00015～0.0015 mg·m~(-3),但多采用世界卫生组织(WHO)的年均浓度限值0.0005 mg·m~(-3);建议我国今后修订标准时对铅年均浓度和季均浓度限值进一步加严.与发达国家相比,我国铅环境空气质量季均浓度限值水平已显落后;国际上目前各类排放源铅大气污染物排放浓度限值在0.04～2 mg·m~(-3)之间,金属冶炼源等主要源的排放浓度限值在1～2 mg·m~(-3),其他排放源均在0.5 mg·m~(-3)以下;我国铅、锌熔炼源正在执行的排放浓度限值(8 mg·m~(-3))较为宽松,而其他源的铅大气排放浓度限值与国际上的限值基本一致.通过计算认为,保护公众健康的铅大气污染物的理论排放限值为1.2～2.4 mg·m~(-3).考虑到我国的经济技术水平,建议铅、锌熔炼源的铅大气污染物新建企业排放浓度限值为2 mg·m~(-3);其他源的新建企业排放浓度建议限值为0.5 mg·m~(-3).经过过渡期,现有企业应达到新建企业的排放控制要求.铅的企业边界浓度排放限值是保护企业边界附近公众健康的有效屏障,但鉴于铅的污染特性,对于具体建设项目应加强环评力度,提出更具体明确的排放控制要求,并加强对企业周边环境敏感点的环境监测等,采取综合措施保护公众健康.     

Editorial: Effect of root anatomy and apoplastic barrier development on cadmium uptake in rice

<正>Cadmium (Cd) is a toxic metal with high mobility from soil and known translocation into plants (Song et al., 2015).Because the main source of human exposure to Cd is from food consumption, there has been increased research examining Cd uptake in agricultural plants (Li et al., 2014; Rizwan et al., 2016; Song et al., 2015). Rice (Oryza sativa L.) has been identified as a major crop that contains relatively high     

有机磷和无机磷材料修复铅污染土壤

近年来,城市工业污染场地严重威胁着人居环境安全,其中土壤铅污染问题比较突出。为加强对铅污染土壤的风险管控,采取磷酸氢二钠（DSP）和植酸（PA）钝化处理铅污染土壤,采用BCR形态分析法和固体废物浸出毒性浸出方法-醋酸缓冲溶液法（HJ/T 300—2007）评价土壤铅赋存化学形态和浸出毒性。结果表明：DSP与PA对污染土壤pH的影响差异比较明显,但均能有效降低污染土壤的铅浸出浓度,并满足生活垃圾填埋场入场标准限值（0.25 mg?L^?1）;随添加比例增加,DSP与PA均能促使土壤中铅元素由活泼态（酸可提取态和可还原态）向稳定态（残渣态）转变,且PA钝化效果优于DSP;两种磷材料处理后的土壤浸出毒性与酸可提取态均表现出显著相关性,同样地,PA优于DSP。可见,PA对铅污染土壤具有良好的固铅作用。     

给水厂残泥免烧陶粒对Pb与Cd的吸附特征

针对高效低廉的吸附材料——WTR（water treatment residuals,给水厂残泥）因颗粒细小在水处理工艺中难以应用的问题,利用免烧法制备出WTR陶粒,研究其对Pb和Cd的吸附特征.批量吸附试验结果表明,准二级动力学模型和Langmuir等温吸附模型能较好地描述WTR免烧陶粒对Pb和Cd的吸附动力学（R2>0.995 8）与等温吸附过程（R2>0.994 8）.在溶液pH为5、恒温25℃、振荡24 h下,Langmuir等温吸附模型计算得到的WTR免烧陶粒对Pb和Cd的最大吸附容量分别为13.97和18.60 mg/g.单因素条件试验结果表明,WTR免烧陶粒对Pb和Cd的吸附量均随溶液初始pH的升高而增加,当pH由3升至9时,WTR免烧陶粒对Pb和Cd的吸附量分别增加了1.44和0.95倍;离子强度的增加不利于WTR免烧陶粒对Pb和Cd的吸附.批量等温解吸试验结果表明,在pH为4~8的溶液中,Pb和Cd较难从WTR免烧陶粒中解吸出来,解吸率均在3.5%以内;当溶液pH为3时,Pb和Cd的解吸率分别高达65.88%和45.01%.BCR分级提取结果表明,Pb和Cd均主要以酸提取态形式（占比在68.18%以上）存在于WTR免烧陶粒中;同时,随着初始吸附量的增加,酸提取态比例显著减少,而还原态和残渣态比例显著增加.研究显示,WTR免烧陶粒对Pb和Cd具有较强的吸附能力,可作为一种高效的重金属吸附材料应用于水处理工艺中.      

应用地积累指数法和生态危害指数法对关中西部某铅锌冶炼区周边土壤重金属污染评价

采用近年常用于重金属污染的地积累指数法及生态危害指数评价法对关中西部某铅锌冶炼区表层土壤中重金属污染情况进行了评价.结果表明,两种方法均能对人为污染行为作出较为科学的评价,且两种方法可得到相似的评价结果:该冶炼区周边土壤Cd元素为中重度污染,Pb为中等污染,Zn和Cu为轻微污染.生态危害指数评价法和地积累指数评价法两种方法都是基于沉积学理论提出,两者各有侧重点,对于重金属污染的系统评价各具合理性;但在对土壤重金属污染进行评价时,有一定的局限性,建议在修正其参数后综合应用.     

Enteromorpha flexuosa (Wulfen) J. Agardh (Chlorophyta: Ulvales)--evaluation as an indicator of heavy metal contamination in a tropical estuary

The use of bioindicators for contaminant monitoring ispopular in all sectors of the environment but quite oftenbioindicators are utilised without rigorous evaluation oftheir viability as an indicator. We report field andlaboratory investigations into the value of a commonlyfound macroalga, Enteromorpha flexuosa (Wulfen) J.Agardh (Chlorophyta: Ulvales) as an indicator of copper,zinc and lead contamination in a tropical estuary inFiji. In the laboratory, metal content of E.flexuosa after 60 days of growth in seawater containingincreasing concentrations of the metals showed almostperfect correlation with metal concentrations in waterfor all three metals, and concentration factors obtainedwere generally higher than values reported for otherspecies of Enteromorpha. Performance in the fieldwas evaluated by a one-year monitoring of metals in E. flexuosa, water and sediments from a contaminatedestuary. Metal concentrations in water were always belowdetection limits and field concentration factors couldnot be determined but the concentration of lead in E. flexuosa showed a high correlation with the leadcontent of sediments. Lack of such correlation forcopper and zinc in the field suggests that otherenvironmental factors besides metal load in the physicalenvironment could be controlling the bioaccumulation ofthese two metals. Whilst demonstrating E. flexuosato be a viable bioindicator for lead, these results alsohighlight the need for proper assessment before anorganism is considered for environmental monitoring.     

Assessment of a Smelter Impact Area Using Surface Soils and Plants

The concentrations of 37 trace elements (Ag, Ba, Be, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Ga, Gd, Ge, La, Li, Mo, Nb, Nd, Ni, Pb, Pr, Rb, Sb, Sm, Sn, Sr, Tb, Th, Tl, U, V, W, Y, Yb, Zn and Zr) were determined by ICP-MS in surface soils and plants (Sida rhombifolia) sampled around a lead smelter in Lastenia, Province of Tucuman, NW Argentina. Soil and plant patterns of Pb, Cd, Ag, Zn and Cu demonstrate the effects of pollutant dispersion plumes following the prevalent wind directions. The high element concentrations observed, especially Pb (>5,000 mg/kg), could cause serious environmental problems in areas of close proximity to the smelter. Consequently, measures to assess potential consequences for the local population should be considered to determine if measures to protect the environment are necessary.     

Lead removal from contaminated water using mineral adsorbents

This study records experiments undertaken to determine the suitable conditions for the use of naturally occurring minerals (talc, chalcopyrite and barite) as an adsorbent for the removal of lead ions from liquid wastes. The adsorption of lead ions from solutions containing different initial lead concentrations (50, 100, 200, 400, 600, 800 and 1000 mg l^–1 Pb as lead nitrate) using different size fractions (<63 m, 63–150 m) of talc, chalcopyrite and barite at different pH (3, 5, 7 and 9) and different adsorption times (24, 48, 72 and 96 hr) was examined. The results revealed that of the studied minerals, the chalcopyrite fraction at 63–150 m showed the highest adsorption capacity. The adsorption data of Pb ions was also analyzed with the help of the Langmuir and Freundlich models to evaluate the mechanistic parameters associated with the adsorption process. The adsorption isotherms obtained from the Langmuir and Freundlich equations were generally linear and the adsorption of Pb by the studied minerals was correlated with the adsorption maximum and binding energy constant of the Langmuir equation and equilibrium partition constant and binding partition coefficient of the Freundlich equation. It was concluded that the equilibrium time of adsorption was 72 hr at an optimum pH from 7 to 9. This technique might be successfully used for the removal of lead ions from liquid industrial wastes and wastewater.     

铅锌矿采选项目对环境影响与治理措施

通过铅锌矿项目建设,以环境评价工作为重点,指出污染物排放分析及治理措施。     

Characterisation of particulate matter for toxic metals in ambient air of Kochi City, India

Measurement of respirable suspended particulate matter (RSPM) and analysis of toxic metals in air of Kochi city was carried out for a period of one year, 1997. Seasonal variations of RSPM and toxic metals are analysed to identify the influence of meteorological parameters. The air pollution problem with respect to RSPM and lead is moderately significant especially in winter season. The profile of other toxic metals in RSPM is not much significant. Domestic fuel used mainly coal/wood and petrol/diesel fueled motor vehicles are the major contributors to the RSPM and toxic metals. Various control strategies are delineated for reduction of ambient RSPM and toxic metals in air of Kochi city.