Preparation and Microstructural Analysis of Smelting Waste Non-ferrous Metal Slag Geopolymer

The geopolymer samples were prepared with smelting waste slag of non-ferrous metal as the raw material and water glass as the activator. The effect of modulus of water glass and water binder ratio on the compressive strength was studied. The results show that the strength of the geopolymer activated by water glass with modulus of 1.1 and water binder ratio of 0.28 can maintain an increasing trend in the 90 curing days. Through the analyses with XRD, SEM（EDS）, and FTIR, the main reaction products are found to be geopolymer gels, which bond the crystalline minerals to provide strength. The molecular chains of amorphous phase in slag become shorter after depolymerization-polycondensation.

Migration and distribution characteristics of soil heavy metal(loid)s at a lead smelting site

Heavy metal(loid)s contamination is a constant issue at smelting sites.It is essential to investigate the spatial distribution and migration characteristics of heavy metal(loid)s in the soil for environmental management and remediation strategies of non-ferrous smelting sites.In this study,203 soil samples from 57 sites were collected in a typical lead smelting site.The findings demonstrated that there were significant Pb,Zn,Cd,and As contamination in soil samples.The spatial distribution of heavy metal(loid)s showed strong spatial heterogeneity,the contaminated soil areas of Pb,As,Cd,and Zn were 99.5%,98.9%,85.3%,and 72.4%,respectively.Pb,Cd,and As contamination of the soil reached a depth of 5 m,which migrated from the surface to deep soil layers.The leaching contents of Zn,Pb,and As decreased obviously in 3-4 m soil layer,but the leaching content of Cd was still high,which indicated the high migration of Cd.With the increase of depth,the proportion of acid soluble fraction of heavy metal(loid)s decreased,and the residual fraction increased.The acid soluble fraction of Cd accounted for a higher proportion,and As mainly existed in reducible and residual fractions in soil.According to the calculation of the migration factor,the migration of heavy metal(loid)s in soils were ordered as Cd>Zn>Pb>As.The outcomes are advantageous for risk reduction and site remediation for non-ferrous metal smelting sites.

Effects of soil metal(loid)s pollution on microbial activities and environmental risks in an abandoned chemical smelting site

Abandoned chemical smelting sites containing toxic substances can seriously threaten and pose a risk to the surrounding ecological environment.Soil samples were collected from different depths(0 to 13 m)and analyzed for metal(loid)s content and fractionation,as well as microbial activities.The potential ecological risk indices for the different soil depths(ordered from high to low)were:1 m(D-1)>surface(S-0)>5 m(D-5)>13 m(D-13)>9 m(D-9),ranging between 1840.65-13,089.62,and representing extremely high environmental risks,of which Cd(and probably not arsenic)contributed to the highest environmental risk.A modified combined pollution risk index(MCR)combining total content and mobile proportion of metal(loid)s,and relative toxicities,was used to evaluate the degree of contamination and potential environmental risks.For the near-surface samples(S-0 and D-1 layers),the MCR considered that As,Cd,Pb,Sb,and Zn achieved high and alarming degrees of contamination,whereas Fe,Mn,and Ti were negligible or low to moderate pollution degrees.Combined microcalorimetry and enzymatic activity measurements of contaminated soil samples were used to assess the microbial metabolic activity characteristics.Correlation analysis elucidated the relationship between metal(loid)s exchangeable fraction or content and microbial activity characteristics(p<0.05).The microbial metabolic activity in the D-1 layer was low presumably due to heavy metal stress.Enzyme activity indicators and microcalorimetric growth rate(k)measurements were considered sensitive indicators to reflect the soil microbial activities in abandoned chemical smelting sites.

Relationship between groundwater cadmium and vicinity resident urine cadmium levels in the non-ferrous metal smelting area,China

Cadmium(Cd)has received widespread attention owing to its persistent toxicity and non-degradability.Cd in the human body is mainly absorbed from the external environment and is usually assessed using urinary Cd.Hunan Province is the heartland of the Chinese non-ferrous mining area,where several serious Cd pollution events have occurred,including high levels of Cd in the urine of residents.However,the environmental factors influencing high urinary Cd levels(UCLs)in nearby residents remain unclear.Therefore,211 nearby residents’UCLs and the corresponding sociological characteristics from nine groundwater samples in this area were analyzed using statistical analysis models.Groundwater Cd concentration ranged from 0.02 to 1.15μg/L,aligning with class III of the national standard;the range of UCL of nearby residents was 0.37–36.60μg/L,exceeding the national guideline of 0–2.5μg/L.Groundwater Cd levels were positively correlated with the UCL(P<0.001,correlation coefficient 95%CI=9.68,R^(2)=0.06).In addition,sociological characteristics,such as smoking status and education level,also affect UCL.All results indicate that local governments should strengthen the prevention and abatement of groundwater Cd pollution.This study is the first to systematically evaluate the relationship between groundwater Cd and UCL using internal and external environmental exposure data.These findings provide essential bases for relevant departments to reduce Cd exposure in regions where the heavy metal industry is globally prevalent.

典型钢铁冶炼场地重金属污染空间分布特征及风险评价

以上海某关停钢铁冶炼厂为研究对象,结合专业判断布点法与系统布点法布设83个土壤点位,采集表、中、深层共249个土壤样品,分析As、Pb、Cd、Ni、Hg、Cu这6种重金属的分布特征、污染状况、潜在生态风险及健康风险。结果表明,As、Pb出现部分样品超标,Cd、Pb为强变异,其他重金属变异程度中等;重金属平均含量在垂向上呈现自上而下逐渐降低的趋势,且最高值均分布在表层,累积区域主要为扒渣厂房、钢渣处理区和废钢配料间;地累积指数评价结果显示,Cd和Pb的污染相对较为严重,重污染及以上的样品比例分别为8.43%、3.61%。潜在生态风险评价结果显示,场地整体的生态风险较高,Cd为主要贡献因子,较强风险及以上的样品占比高达51.81%;人体健康风险评价结果显示,Pb、As和Cd可能对人体产生一定的健康风险,因此有必要开展土壤的风险管控或修复以保证场地的再开发利用。

山西翼城冶南汉代冶铁遗址初步调查

冶南遗址位于山西省临汾市翼城县冶南村,面积约1.2 km^(2),考古年代为西汉。采用X射线荧光分析仪(EDX)、扫描电镜及能谱分析仪(SEM-EDS)、金(矿)相显微镜等对冶南遗址采集的6个炉渣和2个金属铁块进行了基体成分和显微组织检测分析。结果表明,6个炉渣样品为硅钙铝系低铁渣;2个铁块样品为熟铁,可能是生铁炒钢产品。判断该遗址为生铁冶炼遗址,同时也是生铁炒钢遗址。该遗址是目前山西地区确认的第一处大型生铁冶炼及炒钢的汉代官铁遗址。

河北平山战国冶铁遗址初步调查

平山战国冶铁遗址位于河北省石家庄市平山县北白家岸村西侧,面积约47000 m^(2)。2022年7月对该遗址进行田野调查并获取炉渣、炉壁等冶金遗存。采用X射线荧光光谱分析仪(EDX)、扫描电镜及能谱分析(SEM-EDX)、金(矿)相观察等科学试验方法,对10个炉渣等样品进行检测分析,结合炉渣的化学成分和显微组织讨论该遗址的冶炼性质与技术特征。结果表明,该遗址为冶铁遗址,技术类型为生铁冶炼,炼铁渣属于钙硅铝系高钙炉渣。

A practical method for identifying key factors in the distribution and formation of heavy metal pollution at a smelting site

Smelting activities are the main pathway for the anthropogenic release of heavy metals(HMs)into the soil-groundwater environment.It is vital to identify the factors affecting HMs pollution to better prevent and manage soil pollution.The present study conducted a comprehensive investigation of HMs in soil from a large abandoned Zn smelting site.An integrated approach was proposed to classify and quantify the factors affecting HMs pollution in the site.Besides,the quantitative relationship between hydrogeological characteristics,pollution transmission pathways,smelting activities and HMs pollutionwas established.Results showed that the soils were highly contaminated by HMs with a pollution index trend of As>Zn>Cd>Pb>Hg.In identifying the pollution hotspots,we conclude that the pollution hotspots of Pb,As,Cd,and Hg present a concentrated distribution pattern.Geo-detector method results showed that the dominant driving factors for HMs distribution and accumulation were the potential pollution source and soil permeability.Additionally,the main drivers are variable for different HMs,and the interaction among factors also enhanced soil HMs contamination.Our analysis illustrates how the confounding influences from complex environmental factors can be distilled to identify key factors in pollution formation to guide future remediation strategies.

Spatial distribution, environmental risks, and sources of potentially toxic elements in soils from a typical abandoned antimony smelting site

The rapid development of the smelting industry increases the release of antimony(Sb)into the soil environment,which threatens human health and ecosystems.A total of 87 samples were collected from an abandoned Sb smelting site to evaluate pollution characteristics and environmental risks of the potentially toxic elements(PTEs).The contents of As,Cu,Ni,Pb,Sb,and Zn in the fresh soils determined by P-XRF were 131,120,60,145,240,and 154 mg/kg,respectively,whilst following drying,grinding,and sieving pretreatments,the corresponding contents increased to 367,179,145,295,479,and 276 mg/kg,respectively.There was a significant correlation between the data obtained by P-XRF and ICP-OES in the treated samples,which showed the application feasibility of P-XRF.The average contents of Sb and As were 440.6 and 411.6 mg/kg,respectively,which exceeded the control values of the development land in GB 36600-2018.The ecological risk levels of the six PTEs decreased in the following order:As>Sb>Pb>Zn>Ni>Cu.Non-carcinogenic risk revealed that As,Pb,and Sb posed health risks for children,whilst for carcinogenic risk,the risk values for As and Ni were higher than the limit values for both children and adults.Anthropogenic sources accounted for more than 70.0%of As,Pb,and Sb concentrations in soils,indicating a significant influence on PTEs accumulation.The findings provide a basis for quick determination of the contamination characteristics and risk control of PTEs at Sb smelting sites.

废弃铅锌冶炼场地土壤和地下水重金属迁移及预测

长期的金属冶炼活动会导致重金属在场地土壤和地下水中的富集和扩散。基于机器学习模型研究了某废弃铅锌冶炼场地土壤中重金属向地下水的迁移规律并进行了含量预测。结果表明,场地土壤重金属主要累积在杂填土和素填土层,并存在垂向迁移到地下水的现象。场地土壤中As、Cd和Pb含量平均值均明显超过场地土壤风险筛选值。地下水中Zn、Cd、Pb和As的平均浓度均超过了相应的地下水Ⅵ类限值。土壤重金属污染主要集中在火法冶炼区、湿法冶炼区和原料堆存区。土壤中Cd以活性态为主,Pb以还原态为主。当冶炼场地地下水位低于5 m且土壤Cd含量超过344 mg/kg时,或土壤中活性Pb含量超过5425 mg/kg时,需要对场地土壤和地下水进行协同修复。

铅冶炼场地粉尘重(类)金属的迁移转化

粉尘是铅冶炼场地土壤重(类)金属的来源之一,但粉尘中重(类)金属的迁移转化机制尚不明确。本文系统研究了此过程中重(类)金属的地球化学行为和解离机制。实验结果表明,两类粉尘样品中Pb、Zn、Cd和As的总量和浸出均超过标准,其中,两类粉尘中约有80%的Pb、Zn为生物可利用态,底吹炉粉尘中70%以上的As为弱酸提取态,而还原烟化炉粉尘弱酸提取态的重金属为Cd,占比为60%。Pb同位素结果显示,表土中97.12%的Pb来自冶炼过程中排放的粉尘。XRD和MLA结果表明,粉尘中的主要矿物为PbSO_(4)、ZnSO_(4)和CdSO_(4),表土中的矿物主要是石英、方解石、白云石和白云母。利用地球化学模型对主要矿物进行拟合发现,在酸性条件下,Pb、Zn和Cd的解离主要依赖于硫酸盐矿物,而As的解离与氢氧化铁的吸附作用有关。

某废弃冶炼场地土壤不同粒径组分重金属的特征及其对修复策略的启示

颗粒粒径组分对土壤重金属的分布与赋存具有重要影响,而当前对受冶炼活动影响的不同区域间土壤各粒径组分重金属分布的比较研究较少。本研究以某废弃铅冶炼场地为研究对象,选取三个土壤剖面(冶炼固废堆存区、交通区和邻近的农田),对比研究了不同土壤颗粒粒径组分(>150、45~150和<45μm)中重金属的地球化学分布特征及赋存形态。结果显示,冶炼场地与周边农田土壤各粒径组分重金属的分布特征具有明显差异。随着粒径的增大,冶炼固废堆存区土壤重金属的富集因子从0.78增至1.14,这与该区粗粒废渣的堆放与机械混合相关;而农田土壤重金属的富集因子从1.49降至0.60,这与冶炼过程释放富集重金属的细颗粒沉降有关。同时,冶炼场地土壤的较粗组分(>45μm)具有较高的重金属质量负载量(>50%),且废渣颗粒对土壤重金属的贡献显著,故物理分离技术可用于该场地的土壤污染修复。此外,石膏和莫来石可能是该场地受冶炼活动影响土壤的指示矿物。本研究将冶炼活动影响与土壤不同粒径组分重金属的赋存形态相关联,对修复策略具有一定的指导意义。

土壤和地下水中重金属污染物迁移模型:以某有色金属冶炼厂为例

冶炼厂表层土壤重金属污染严重。由于数据采集和计算量的限制,大多数数值模拟将土壤和地下水分开,这与实际情况不符。本文以某冶炼厂为研究对象,将土壤和地下水视为一个整体系统,建立了土壤-地下水反应性溶质迁移三维耦合数值模型,以定量表征重金属在土壤和地下水中的迁移规律。模型采用反应系数(λ)和滞留系数(R)来描述重金属的释放和吸附能力。模型结果与现场实际污染分布一致,表明土壤-地下水修复技术对严重污染土壤和局部污染地下水均有良好的修复效果。所构建的土壤-地下水反应性溶质迁移三维耦合模型很好地描述和预测研究地点重金属的分布和迁移扩散行为。

中南某废弃铅冶炼场地土壤剖面重金属污染成因及风险评估

城镇化和产业升级在中南地区形成了大量废弃冶炼场地,这些场地的环境污染风险已严重制约了当地社会可持续发展。为厘清废弃冶炼场地重金属的污染特征及成因,以中南某废弃铅冶炼场地为例,采集不同冶炼功能区和周边农田的土壤剖面样品,分析其重金属含量、分布和迁移特征,采用主成分分析和风险评估编码法等方法进行污染源解析和风险评估。结果显示,该场地土壤重金属污染严重,主要来源有冶炼源、交通源和自然源;场地重金属污染的空间异质性强且受来源控制显著;场地土壤Pb、Zn、Cu、Cd和As含量超过筛选值,Pb、Cd和As是最主要的生态风险因子,土壤Cd的迁移能力沿剖面从表层向下逐渐增强,存在危害地下水和场地周边农作物的风险。

某铜选冶场地土壤重金属污染特征及风险评价

【目的】了解铜选冶场地重金属污染特征,为场地污染评价及土壤修复提供科学依据。【方法】测定场地土壤重金属(Cd、As、Hg、Cu、Cr、Ni、Pb)含量,采用单因子污染指数法、内梅罗综合污染指数法、地累积指数法及潜在生态危害指数法评价场地土壤重金属污染情况,结合相关性分析、主成分分析对重金属来源进行分析。【结果】研究区土壤重金属含量相对较高,Cu、Pb、Cd、As、Hg 5种重金属元素的平均含量均高于云南省土壤背景值。重金属单因子污染结果表明Cr元素属于重度污染,As元素属于轻度污染,其余Cu、Ni、Pb、Cd、Hg元素均为清洁状态。内梅罗综合污染指数分析表明研究区属于重度污染。地累积指数结果显示Hg元素为中度累积,Cd、As元素为偏中度累积,Cu元素为轻度累积,Pb、Cr、Ni元素为无累积。重金属潜在生态危害单项指数Hg>Cd>As>Cu>Pb>Ni>Cr, Hg、Cd元素为很强生态风险,其余5种重金属均为轻微生态风险,整体上研究区生态风险属于强生态风险。研究区属于复合污染,土壤重金属污染受人类活动和自然因素共同影响。【结论】研究区土壤中Hg、Cd、As元素风险较高,应重点关注并采取相关污染治理措施,以改善土壤质量及周围环境。

黑龙江阿城西川冶铁遗址初步调查研究

西川冶铁遗址位于黑龙江省阿城市小岭镇西川屯300 m处,面积约5000 m^(2),考古年代为金代。2021年7月对该遗址进行了田野考察取样。采用X射线荧光仪、金(矿)相显微镜等手段对西川冶铁遗址17个冶炼炉渣、炉壁残块等样品进行基体成分分析和显微结构观察。结果表明,西川冶铁遗址为生铁冶炼遗址,生铁炉渣类型为硅锰铁铝钙多元系炉渣,生铁炉渣中铁颗粒的显微结构以片状石墨和珠光体为主。炉渣样品中的高铁炉渣可能为生铁炒钢渣。

有色冶炼场地重金属污染特征与修复研究进展

重金属污染是世界各国面临的重大环境问题。随着有色金属产业升级,资源型城市及周边地区出现大面积的工业遗弃场地,存在极大的环境风险。针对我国有色冶炼工艺多样、地质条件复杂、污染溯源难等问题,对2002~2022年间发表的冶炼场地污染特征研究和工程修复案例进行系统分析。综述了有色金属冶炼场地的精细刻画、污染形成、污染传输、污染阻控等方面的研究进展;明晰土壤-地下水系统重金属的生物地球化学过程,厘清污染物在复杂水文地质条件下的迁移转化规律,探讨污染场地土壤-地下水协同修复技术耦合与策略制定;分析了重金属污染场地修复技术的优缺点,提出了有色冶炼场地土壤-地下水协同修复的主要研究方向,为工业遗弃场地的环境风险管控与重金属污染防治提供科学参考。

基于随机模拟的冶炼场地重金属污染及生态风险评价

选择某铅冶炼场地,采用地统计学和铅同位素示踪法分析重金属空间分布格局和污染来源,并基于不确定性理论的风险模型,系统评估场地重金属生态风险。结果表明,土壤铅、锌、砷、镉、铬和汞污染严重,空间异质性强。采用MixSIAR模型解构3个潜在源的铅同位素贡献密度分布,土壤重金属主要来自冶炼活动(49.9%),燃煤(16.4%)和土壤母质(33.7%)。基于随机模拟的潜在生态风险指数(RI)表明,场地重金属处于中等生态风险;其中冶炼活动对RI累积贡献最大;镉、砷、铅和汞对RI的方差贡献最大,对场地的污染起主导作用。因此,应该优先关注场地土壤镉、砷、铅和汞污染的防控及潜在冶炼源的处置。

黄河流域某铜冶炼场地重金属污染评价及源解析

选取黄河流域某铜冶炼厂场地为研究对象,测定土壤中As、Cd、Cr(Ⅵ)、Cu、Pb、Hg、Ni、Zn的含量,利用反距离插值法分析重金属空间分布特征,通过污染指数法、地质累积指数法、潜在生态危害指数法评价重金属污染程度和生态风险水平,运用皮尔逊相关系数、主成分分析、聚类分析方法解析重金属来源。结果表明:研究区内土壤重金属含量较高,且离散程度、空间分差异大;表层土壤的重金属含量高于深层土壤,在垂向上呈下降趋势,污染主要集中在深度2 m以内的土壤中;8种重金属元素都存在地质累积,Cd、Hg累积明显;土壤生态风险处于超高水平,Cd、Hg导致的生态风险高;As、Cd、Hg、Pb、Cu和Zn主要来源于冶炼活动,Ni主要来源于自然源,Cr(Ⅵ)来源于自然源和冶炼活动。

从金盆垴遗址调查及遗物分析看黄石矿冶工业遗产的间续发展

黄石矿冶工业遗产内容丰富,历史悠久,但在历史价值凸显方面,从时间跨度和历史阶段延续性等的阶段性展现方面尚待实证性调查成果的进一步补充。基于上述情况,对黄石地区矿冶遗址开展了一系列专项调查工作,调查发现,阳新金盆垴遗址存在商周——唐代的文化层叠压,自商周时期周到唐代早期的叠压地层中皆发现冶铜炉渣。对遗址各时期地层出土、地表采集冶炼渣运用扫描电子显微镜能谱仪(SEM-EDS)成分分析等科学方法进行观察。检测分析工作表明,该处遗址在红铜冶炼技术等方面存在延续性与技术演进的趋势。该研究工作也为黄石地区矿冶工业遗产的时间序列的完整性提供了较为科学的矿冶遗址调查证据,对丰富黄石矿冶工业遗产的历史价值提供了实证。