赫章土法炼锌区水-沉积物重金属污染的时空变化特征

对赫章土法炼锌区河流水体和沉积物重金属污染状况及时空变化特征进行了研究。结果表明,水体和沉积物受到多种重金属污染：地表水体中Pb、Zn、Cd的均值分别为137.19×10-3、1 919.38×10-3、14.21×10-3 mg.L-1,分别是地表水环境质量标准Ⅲ类水质标准的2.74、1.91、2.84倍;沉积物中Cu、Pb、Zn和Cd的均值分别为702.79、3 242.8、5 427.6、32.19 mg.kg-1,分别是土壤环境质量标准三级标准的1.76、6.49、10.86、32倍。水体和沉积物中Cu、Pb、Zn和Cd沿河流总体呈无规律性的变化,受炼锌废渣堆和铅锌选矿厂影响的地点,水体和沉积物重金属含量均较高,污染严重。近10年来,炼锌区河流水体和沉积物重金属污染仍然很严重,水体重金属污染呈加重特征,沉积物中Pb、Zn污染呈减轻趋势,Cd和Cu污染则加重。     

Study on Melting Rate of Pre reducted Pellet in Smelting Reduction Reactor

The successive approaching and rapid cooling method is applied to determine the terminal point of melting,the melting rate of pre reducted pellet is carefully measured.Various factors influencing melting rate are studied via orthogonal experiment,and the influences of main factors are carefully studied via the single factor experiment.The apparent activation energy is expounded and calculated.     

土法炼锌的环境危害及废弃矿区环境评价

统计已有的研究数据,分析土法炼锌区环境中重金属的污染状况与环境危害,采用单因子污染指数法和综合污染指数法,综合评价土法炼锌历史较久的赫章县妈姑镇废弃矿区环境质量状况.结果显示,矿区大气、土壤和食物中重金属元素Pb、Zn、Cd的总含量均超标;土壤污染严重,不适合种植粮食类作物,已收获的食物不能安全食用;河水中Pb、Zn、Cd的浓度符合Ⅲ类水质要求,但底泥和悬浮物中重金属总含量很高,是潜在的污染源,对河水水质和水生生物的生存构成威胁;建议对矿区弃渣和受污染土壤进行治理,采用农家肥、磷肥与碱石灰混合施用的方法可行.     

2种优势植物对不同粒径炼锌废渣团聚体养分及重金属赋存形态分布的影响

为评价土法炼锌废渣堆场上自然着生的优势植物对废渣团聚体中重金属的控制效应及生态修复效果,以废渣堆场上已自然定居且生长茂盛的本土植物土荆芥(Chenopodium ambrosioides L.)和大叶醉鱼草(Buddleja davidii Franch.)为研究对象,以未经修复的空白废渣为对照,分析这2种优势植物对根际、非根际废渣内不同粒径团聚体中主要养分(氮、磷、有机质)和主要重金属(Cu、Pb、Zn、Cd)赋存形态及含量分布的影响。结果表明:土法炼锌废渣堆场上自然着生的2种优势植物对根际与非根际不同粒径炼锌废渣的主要养分含量具有显著影响,且不同种类植物参与对根际与非根际废渣中有机质的贡献明显不同。养分在粒径<1 mm的团聚体废渣中分布含量较高,除大叶醉鱼草非根际废渣中的总氮含量低于对照废渣外,植物影响下的各粒径团聚体中的养分含量总体高于对照废渣。优势植物生长明显影响炼锌废渣中Cu、Pb、Zn、Cd等主要重金属在不同粒径废渣中的含量分布及赋存特征,Cu和Cd主要分布在粒径<0.25,0.25~0.5,0.5~1 mm团聚体中,Zn主要分布在粒径<0.25,2~5 mm团聚体中,Pb则在0.25~5 mm的4种不同粒径团聚体中含量分别达最高;且其降低了各粒径废渣团聚体中Cu、Pb含量,对粒径>5 mm团聚体中的Cd含量有一定的提高作用,其中,2种优势植物影响下的粒径<5 mm团聚体中的酸可溶解态Cu、Pb、Zn的比例明显降低,而残渣态Zn和酸可溶解态Cd的比例有所提升。主成分分析结果表明,2种优势植物对根际和非根际粒径<5 mm团聚体中的养分、Zn全量及酸可溶解态Cd含量贡献率高,但对粒径>5 mm团聚体中的养分影响不大。综上,自然定居且繁茂生长的土荆芥和大叶醉鱼草可显著改善铅锌冶炼废渣中的养分状况,同时可有效减小废渣中重金属Cu、Pb、Zn对环境生态的潜在风险,开展铅锌冶炼废渣堆场水土保持及生态修复相关工作时可优选这2种植物作为先锋植物。     

中南有色金属冶炼场地与周边土壤重金属污染概况及稳定化修复技术研究进展

中南地区作为中国有色金属冶炼的主要聚集区,由于长期的冶炼活动,导致冶炼场地与周边土壤重金属污染严重,对当地的生态环境带来严重的风险,迫切需要治理。为了探究中南冶炼场地与周边土壤的污染特征以及目前主要有效的稳定化修复技术,笔者概述了中南地区湘鄂赣皖四省有色金属冶炼区分布和污染状况,具有污染面积大、以复合污染为主、污染途径多样、污染程度各异和重金属活性高的污染特征。从稳定化机理和材料类型两个不同的方向综述了稳定化材料的研究进展,并在高性能、可持续、谱适、绿色的复合污染稳定化材料的研究方向上提出展望,以期为中南有色金属冶炼场地与周边土壤重金属污染稳定化修复提供参考依据。     

炉渣对调节稻田土壤pH和盐度的有效性分析

对炉渣调节稻田土壤pH和盐度的有效性进行研究。结果表明,稻田土壤pH和盐度随着炉渣施用量的提高而增大,并表现为炉渣施用后显著提高了稻田土壤的pH(P0.01),但对盐度的影响不显著(P0.05),不同土壤层次之间pH和盐度的差异性随着施用量的提高而减小。     

Composted sewage sludge and steel mill slag as potential amendments for urban soils involved in afforestation programs

This study aimed to assess the impacts of composted sewage sludge and steel mill slag on urban soil fertility and tree growth. The research was conducted in an urban area (Botucatu, State of São Paulo, Brazil) characterised by extremely unfertile urban soils and with high production of these wastes. Plant growth, soil physico-chemical properties, and chemical composition of leafs were analysed during a 12-month field experiment. Principal factor analysis (PFA) and canonical correspondence analysis (CCA) were applied in the evaluation of the investigated soil-plant system. The results showed that soil fertility was increased by the combination of applied waste materials, which provided good conditions for full plant development and maintenance. PFA showed that the variability of the investigated model was mainly due to the role of soil organic matter as source/sink of soil heavy metals. CCA showed that the investigated soil-plant system was characterised by time-dependent evolution, with an equilibrium reached during the final stages, suggesting that the obtained results may be realistic from a long-term perspective. This study provides evidence that composted sewage sludge and steel mill slag are acceptable alternatives for improving urban soil quality and tree growth. The reuse of these wastes could provide a low-cost alternative for their complex and expensive management and disposal with, additionally, the possibility of turning currently bulky refuse material into a commodity.     

江西上饶县茶亭镇包家村民间金矿采冶工艺调查研究

在实地调查的基础上，详细论述了包家村民间金矿采冶工艺的全过程。这种金矿采冶工艺，从总体上考论，主要是采用氰化法。其金矿砂的来源主要是该地古代金矿采冶过程中所遗留下来的尾矿中所赋存的含金矿砂以及该地矿山中富含的脉金矿因历史的风化及雨水的冲刷而沉积于该地一水库中的砂金矿。     

Evaluation of industrial wastes as sources of fertilizer silicon using chemical extractions and plant uptake

Six inorganic industrial‐waste materials (coal fly ash, bauxite‐processing mud, steel slag, two samples of air‐cooled blast furnace [BF] slag, and one sample of water‐cooled BF slag), along with wollastonite, were evaluated as fertilizer‐Si sources. Evaluation was carried out by analyzing total and extractable Si fractions in the materials, by incubating them at two rates with a Si‐deficient soil and measuring potentially available extractable Si and by measuring yield and Si uptake by two successive rice crops grown in the fertilized soils. Of the waste materials used, fly ash had the highest total Si content (29%) but a negligible quantity was present in extractable forms. Steel slag and bauxite‐processing mud had only 5%–7% Si content while BF slags contained 14%–18% Si. All materials, other than fly ash, increased the amount of extractable Si present in the soil. Additions of steel slag and bauxite‐processing mud caused greater increases in Si extractability than the air‐cooled BF slags while water‐cooled BF slag–treated soils contained notably high acid‐extractable Si. Because of the alkaline nature of the materials, and their reaction products, there was a positive relationship between extractable soil Si and soil pH. However, an equilibration experiment using NaSiO₃ as the Si source confirmed that Si solubility in the soil decreased with increasing pH. Dry‐matter yields of rice, at the lower rate of Si addition, were increased by all treatments other than fly ash. The higher rates of steel slag and bauxite‐processing mud caused yield depressions. Total Si uptake by rice was increased by all treatments, other than fly ash, and was greater at the higher rate of Si addition. It was concluded that the BF slags are the most effective waste materials as fertilizer‐Si sources and that, in slag‐amended soils, CaCl₂ and NH₄ acetate are the most reliable soil‐test extractants.     

神府矿区弃土弃渣体侵蚀特征及预测

神府矿区在煤炭开采过程中形成了弃渣体、弃土体及扰动土体等不同下垫面类型,其物质组成、结构性及产流产沙规律与撂荒地有极大差异,且已产生严重的水土流失。采用野外模拟降雨试验方法,对比研究了弃土弃渣体、扰动土体与撂荒地侵蚀特征的差异。结果表明,(1)撂荒地侵蚀速率随降雨历时先下降后逐渐稳定,扰动土体侵蚀速率呈增大后趋于稳定;35°弃土体侵蚀速率增至峰值后减小并逐渐稳定,40°时则一直处于波动状态;石多砂少和砂多石少弃渣体在产流初期侵蚀波动剧烈,并伴有泥石流现象,15 min后基本稳定。(2)同一下垫面侵蚀速率随雨强增大而增大,而各坡度间侵蚀速率差异不显著(p0.05);雨强相同时各下垫面、坡度间侵蚀速率差异均显著(p0.05),复杂疏松的物质组成是弃土弃渣体及扰动土体侵蚀特殊于撂荒地的根本原因,相同降雨条件下石多砂少弃渣体、砂多石少弃渣体、弃土体及扰动土体侵蚀速率分别是撂荒地的6.51倍~14.25倍、57.91倍~239.2倍、43.60倍~180.1倍和2.27倍~3.06倍。(3)弃土弃渣体及扰动土体侵蚀速率与中值粒径、分形维数、降雨强度、坡度及径流参数呈幂函数关系。研究结果对矿区弃土弃渣侵蚀模型建立与生态环境建设有重要的科学意义。