安徽某硫铁尾矿区农田土壤重金属污染特征

对安徽省某硫铁矿尾矿区农田土壤、农作物进行重金属污染分析和风险评价,为硫矿区农田重金属污染风险管理与土地利用提供理论依据。布设30个采样点采集土壤及其毛豆样品,ICP-MS法测定Cu、Zn、As、Cd、Pb重金属全量,运用单因子指数、综合污染指数、潜在生态风险指数法和生物富集系数法对重金属污染程度进行评价。结果表明,研究区土壤p H值在3. 37～4. 60,均值为4. 03,土壤呈强酸性、酸性。比对安徽省土壤重金属背景值,研究区土壤已明显遭受外源重金属污染;比对GB 15618—2018《土壤环境质量农用地土壤污染风险管控标准》风险筛选值,受到Cd、Cu重金属污染,其中60%采样点Cu超标,76. 67%采样点Cd超标,但都远低于标准风险管制值;单因子污染指数评价结果显示该研究区农田以Cu、Cd污染为主;内梅罗综合污染指数评价结果表明研究区农田土壤总体已遭受重金属污染;潜在生态危害指数评价结果显示研究区土壤总体为轻微综合潜在生态危害,Cd在67%以上检测点为中等风险水平、10%为强风险水平。研究区农田农作物毛豆籽粒中Pb、Cd、As质量比均值未超过GB 2762—2017《食品安全国家标准食品中污染物限量》规定的限量值,其对重金属的富集系数(EF)从大到小依次为Cd、Zn、Cu、As、Pb。     

Growth and metal uptake of energy sugarcane (Saccharum spp.) in different metal mine tailings with soil amendments

A pot experiment was conducted to investigate the feasibility of growing energy sugarcane(Saccharum spp.) in three different metal mine tailings(Cu, Sn and Pb/Zn tailings) amended with uncontaminated soil at different mixing ratios. The results indicated that sugarcane was highly tolerant to tailing environments. Amendments of 20% soil to Sn tailings and 30% soil to Cu tailings could increase the biomass of cane-stem for use as the raw material for bioethanol production. Heavy metals were mostly retained in roots, which indicated that sugarcane was useful for the stabilization of the tailings. Bagasse and juice, as the most valuable parts to produce bioethanol, only accounted for 0.6%– 3% and 0.6%–7% of the total metal content. Our study supported the potential use of sugarcane for tailing phytostabilization and bioenergy production.     

金属尾矿作水泥混合材活性试验研究

选取烧失量低于10%,SO3含量低于3%,SiO2、Al2O3含量较高,适于作水泥混合材的6种金属尾矿进行水泥混合材活性试验研究.6种金属尾矿分别按10%、15%、20%、25%、30%与熟料、石膏进行配比.试验结果表明:6种金属尾矿不同掺配比活性试验的R28在68.72%～76.54%之间,高于活性混合材R28为62%的判定指标,由此可认为此6种尾矿均属于活性混合材,可单独用作水泥活性混合材;6种金属尾矿掺配比在小于30%的范围内,水泥安定性、凝结时间等性能指标均符合普通硅酸盐水泥要求;6种金属尾矿掺配比在小于30%的范围内其强度均满足32.5R等级水泥强度要求;尾矿掺配比为10%时,6种金属尾矿除3号尾矿外,均满足42.5R等级水泥强度要求.符合要求的金属尾矿用作水泥混合材,将扩大水泥混合材来源,降低水泥粉磨能耗和成本,实现尾矿的资源化和水泥工业的可持续发展.     

Investigation and risk assessment modeling of As and other heavy metals contamination around five abandoned metal mines in Korea

Tailings, agricultural soils, vegetables and groundwater samples were collected from abandoned metal mines (Duckum, Dongil, Dongjung, Myoungbong and Songchun mines) in Korea. Total concentrations of arsenic (As) and heavy metals (Cd, Cu, Pb and Zn) were analyzed to investigate the contamination level. Several digestion methods (Toxicity characteristics leaching procedure (TCLP), synthetic precipitation leaching procedure (SPLP), 0.1 N/1 N HCl) and sequential extraction analysis for mine tailings were conducted to examine the potential leachability of As and heavy metals from the tailings. The order of urgent remediation for the studied mines based on the risk assessment and remedial goals was suggested. The Songchun mine tailings were most severely contaminated by As and heavy metals. Total concentrations of As and Pb in the tailings were 38,600–58,700 mg/kg (av. 47,400 mg/kg) and 11,800–16,800 mg/kg (av. 14,600 mg/kg), respectively. Agricultural soils having high As concentrations were found at the all mines. Average concentrations of Cd in the vegetables exceeded the normal value at all mines areas, while As only at the Dongjung, Myoungbong, and Songchun mine area. One groundwater sample each from the Dongil and Myoungbong mines, and 4 groundwater samples from the Songchun mine had values above 10 μg/L of As concentration. The TCLP method revealed that only Pb in the Songchun tailings, 6.49 mg/L, exceeded the regulatory level (5 mg/L). Employing the 1-N HCl digestion method, the concentration of As in the Songchun mine tailings, 4,250 mg/kg, was up to 3,000 times higher than its Korean countermeasure standard. Results from the sequential extraction of As in the tailings showed that the easily releasable fraction in the Myoungbong and Songchun mine tailings was more than 30% and the residual fraction was less than 40%. Based on results showing the exposure health risk employing the hazard quotient and cancer risk of As, Cd and Zn, the Dongil mine needs the most urgent remedial action. The concentration reduction factor (CRF) of As in both soil and groundwater follows the order: Songchun>Dongjung>Dongil>Myoungbong>Duckum mine.     

广西高砷区采矿业污染河流治理探讨

本文根据前期刁江水系重金属污染的调查研究结果,并参考国内外矿山固体废物处理处置以及河流重金属污染治理的研究进展,对刁江上游矿区尾砂综合利用以及刁江水系重金属污染治理进行探讨。本文讨论建议采取措施加强刁江上游矿区水土保持和生态恢复,对采矿和选矿尾砂进行综合利用,以减少尾砂排放;对于刁江水系重金属污染,建议对严重污染的河段沉积物进行疏浚处理,对疏浚沉积物进行综合利用,以减轻刁江水系污染和防治二次污染。     

Restoration potential of pioneer plants growing on lead-zinc mine tailings in Lanping, southwest China

This study focused on the restoration potential of ten pioneer plants (Artemisia roxburghiana, Artemisia tangutica, Carex inanis, Cyperaceae hebecarpus, Plantago depresa, Cynoglossum lanceolatum, Potentilla saundesiana, Coriaria sinica, Oxyria sinensis, and Miscanthus nepalensis) during the early phase of Pb-Zn mine tailings phytostabilization, in Lanping, China. The concentrations of heavy metals (Pb, Zn, and Cu) and soil fertility (the available N, P, K, and organic matter) in the rhizosphere of these spe...     

云南省优势矿产尾矿砂捕集及矿化封存CO2潜力分析

为了解云南省尾矿库“两个清单”中保留库的碳减排潜力,使用改进的Steinour方程计算了云南省各州市不同类型尾矿砂的CO₂固定量,根据《IPCC国家温室气体列表指南》中提供的方法计算了云南省2011~2020年碳排放量.结果表明,红河州、玉溪市、昆明市尾矿砂的捕集及矿化封存CO₂的潜力较大,占云南省保留库尾矿砂CO₂矿化封存量的65.79%;铅锌矿、赤泥、锡矿的理论固碳量较高,分别为0.201, 0.173, 0.158t/t,以上3种尾矿砂的固碳量占云南省尾矿砂固碳量的79.45%;若将云南省保留库堆存的尾矿砂全部用于CO₂的矿化封存,可减少2011~2020年间云南省累积碳排放量的2.81%,工业碳累积排放量的3.16%,采矿业碳排放量的12.36%,具有较好的工业应用前景.