石煤提钒区土壤钒污染和微生物响应特征（英文）

通过野外调查研究湖南省某石煤提钒冶炼区周边土壤中钒的含量、形态、活性以及微生物响应特征。结果表明,该区域土壤钒含量范围为168~1538 mg/kg,均超过加拿大土壤质量钒的最高允许值(130 mg/kg)。废弃区土壤平均钒含量高达1421 mg/kg,尾渣区、原矿区和冶炼中心区的土壤平均钒含量分别为380、260和225 mg/kg。BCR顺序提取结果表明,土壤活性态组分(包括酸提取态、可还原态和可氧化态)中钒含量为19.2~637.0 mg/kg,占总钒含量的7.4%~42.3%。土壤中五价钒含量为21.9~534.0 mg/kg。此外,土壤高含量钒抑制了土壤酶活性和基础呼吸率。石煤提钒区土壤钒污染和潜在生态风险值得关注。     

氟石膏的改性及其综合利用

氟石膏是氢氟酸生产过程中的副产品,主要用于水泥和建筑材料行业。采用外加添加剂,辅以适宜的工艺条件对氟石膏进行改性改善其胶凝性能、增强其机械强度,拓宽氟石膏综合利用的新途径,已成为近年来研究的热点。对氟石膏的化学组成与相态变体、水化硬化机理与表面改性作用进行了讨论,对氟石膏的主要改性措施与改性材料、生产工艺和主要应用领域进行了综述,并就改性氟石膏综合应用中存在的关键问题进行了展望。     

中国钒矿资源的区域分布与石煤中钒的提取工艺

我国钒矿资源,尤其是石煤资源储量丰富。统计表明:我国钒矿资源保有储量(以V2O5计)约3400万t,累计查明资源储量约3600万t,主要分布在四川、陕西、湖南、安徽、湖北等地,5省合计储量占全国的90.1%,累计查明储量占全国的88.9%。含钒石煤是我国一种独特的钒矿资源,其中V2O5储量约1128万t,占钒矿资源总储量的37.0%,主要分布在湖南、湖北、浙江、贵州等地,其中有工业开采价值的(w(V2O5)0.8%)石煤中钒储量占62.6%。含钒石煤是我国钒矿资源利用的一个重要发展方向,本文综述了火法-湿法联用、湿法从石煤中提取钒的工艺以及存在的问题,对生物浸出钒及其它有价金属前景进行了展望。     

Spatial distribution and environmental characterization of sediment-associated metals from middle-downstream of Xiangjiang River, southern China

The contamination and environmental risk assessment of the toxic elements in sediments from the middle-downstream (Zhuzhou—Changsha section) of the Xiangjiang River in Hunan Province of China were studied. The results show that As, Cd, Pb and Zn are major contaminants in sediments, and average concentrations of these elements significantly exceed both the Control Standards for Pollutants in Sludge of China (GB4284-84) for agricultural use in acidic soils and the effect range median (ERM) values. The average concentrations of As, Cd and Pb in the river water slightly exceed the limit of Surface Water Environment Quality Standard (GB3838—2002). The concentrations of As and Cr in depth profiles extensively change, but slight changes are observed in Pb and Zn. Cd and Zn in most sediment samples can easily enter the food-chain and bring possible ecotoxicological risk to organisms living in sediments according to the risk assessment code.     

Liquefaction of metal-contaminated giant reed biomass in acidified ethylene glycol system： Batch experiments

Giant reed is a suitable pioneer plant for metal-contaminated soil phytoremediation,however,it is imperative to dispose the metal-contaminated biomass after harvesting.The liquefaction of metal-contaminated giant reed biomass in ethylene glycol system with sulfuric acid as catalyst for the precursors of polyurethane compounds was studied.The results show that giant reed biomass from metal-contaminated soil is potentially liquefied and significantly affected by solvent/solid ratio,liquefaction temperature and liquefaction time （P〈0.05）.The liquefaction rate of biomass in acidified ethylene glycol system can reach 85.2% with optimized conditions of 60 min,170 ℃,3% sulfuric acid and solvent/biomass ratio of 5：1.The hydroxyl value of liquefied products is of 481 mg KOH/g while reactive hydroxyl groups of them are abundant,which is promised as potential precursors for polyurethane compounds.The solvent liquefaction is a potential method to dispose the metal-contaminated biomass,however,the containing-metal liquefied products should be studied deeply in order to get the suitable precursors in future.     

二次铝灰烧结制备钙铝黄长石/镁铝尖晶石复相材料

以再生铝行业二次铝灰为主要原料,开展二次铝灰烧结制备钙铝黄长石/镁铝尖晶石复相材料的研究。热力学计算表明,二次铝灰添加氧化钙和氧化镁,理论上可以制备出钙铝黄长石/镁铝尖晶石复相材料。结果表明,当二次铝灰、氧化钙和氧化镁质量分数依次为70.80%、18.58%和10.62%,在1100~1500℃范围内,均能制备出钙铝黄长石/镁铝尖晶石复相材料;随烧结温度升高,钙铝黄长石/镁铝尖晶石复相材料纯度和结晶度明显提高,抗压强度呈升高趋势,显气孔率呈下降趋势。当烧结温度为1500℃时,所制备出钙铝黄长石/镁铝尖晶石复相材料显气孔率和抗压强度分别为33.87%和40.18 MPa。     

改良剂对As、Cd、Pb污染土壤上芦竹生长及重金属吸收的影响(英文)

通过室内盆栽试验研究在As、Cd和Pb复合污染土壤中施用醋酸、柠檬酸、EDTA、海泡石和磷石膏5种改良剂对芦竹生长及重金属吸收的影响。结果表明,施加5.0mmol/kg柠檬酸或2.5mmol/kgEDTA时,芦竹地上部生物量较没添加的对照的分别增加了24.8%和15.0%,芦竹叶片中过氧化氢酶及过氧化歧化酶活性较对照的无显著变化。与对照相比,添加2.5mmol/kg醋酸、2.5mmol/kg柠檬酸、5.0mmol/kgEDTA及4.0g/kg海泡石时,地上部中As、Cd、Pb的浓度显著增加(P0.05)。改良剂能明显提高芦竹地上部重金属累积量,地上部中As、Cd的累积量在上述条件下均显著增加(P0.05),Pb累积量在添加4.0g/kg海泡石和8.0g/kg磷石膏时显著高于对照(P0.05)。醋酸、柠檬酸和海泡石可作为合适改良剂促进重金属污染土壤上芦竹对土壤中重金属的累积。     

Environmental availability and profile characteristics of arsenic, cadmium, lead and zinc in metal-contaminated vegetable soils

Environmental availability and profile characteristics of arsenic (As), cadmium (Cd), lead (Pb) and zinc (Zn) were studied in contaminated vegetable soils from the Pb/Zn mining and smelting areas in Hunan Province of China, and the potential environmental risks of these metals were also assessed. The results show that the concentrations of As, Cd, Pb and Zn in vegetable soils are higher than the levels of Soil Environmental Quality of China (GB15618-1995). The mobility of metals in soil profiles is mainly characterized by the low pH and organic matter content of soil. The major part of As, Cd, Pb and Zn is restricted to the upper soils and the contamination of these metals in soils is significantly influenced by the long-term Pb/Zn mining and smelting activities. Based on the results from the BCR sequential extraction, the fraction of Cd in the soil profiles is predominantly existed in the acid-extractable form and the large amount of Pb is closely associated with reducible fraction. The environmental availability of Cd and Pb is predominantly higher than that of As and Zn in the soil profiles, suggesting Cd and Pb have more huge potential risk for human health and surrounding environment.     

模拟酸雨淋溶条件下锌冶炼挥发窑渣重金属释放特征

模拟pH值分别为4.0、5.6、7.0酸雨干湿交替淋溶(对应pH4.0、pH5.6、pH7.0处理组)和pH=4.0雨水持续淋溶(CL pH4.0处理组), 开展50 d锌挥发窑渣柱淋溶实验, 研究渣中Cd、Cu、Pb、Zn释放和赋存形态变化特征。结果表明, pH4.0处理组在整个淋溶期间Pb的释放较高, 淋溶第35~50 d促进Cd、Cu和Zn释放。pH4.0和CL pH4.0处理组淋出液Cd、Cu、Zn浓度均在前期第5 d达到峰值, pH5.6和pH7.0处理组于第10 d达到峰值。各处理组淋溶50 d后淋出液中Cd、Cu、Pb和Zn浓度变化范围分别为150~1 438、1.88~234、1.30~5.96和15.2~120 mg/L, 远超GB 25466—2010《铅、锌工业污染物排放标准》限值1 500~14 380、3.76~468、1.30~5.96和7.60~60倍。淋出液Cd浓度较高与其渣中高比例活性态相关, 且酸雨淋溶会促进Cu活化。矿物溶解控制重金属元素溶出释放, 淋溶后PbSO₃衍射峰消失, Cu和Zn赋存矿物衍射峰强度降低。酸雨淋溶下锌挥发窑渣中重金属具有较大环境风险, 需加强降雨淋滤污染防治管控。     

柱撑改性海泡石钝化修复砷镉复合污染土壤

采用羟基Fe、羟基Al及羟基Fe/Al柱撑液改性海泡石,通过扫描电镜(SEM)、X射线衍射(XRD)分析海泡石柱撑前后理化特性变化,研究其对As、Cd复合污染土壤的钝化修复效果。结果表明,改性海泡石对土壤As、Cd钝化效果均优于原海泡石,且随钝化时间延长,效果更显著。其中,羟基Fe/Al海泡石对As、Cd的钝化效果最佳,处理42 d时土壤As、Cd有效态含量较对照处理可分别降低67.0%和47.6%,土壤有效态As含量从占总量比例1.5%降低到0.5%,有效态Cd含量由占总量比例22.5%降低到11.3%。改性海泡石处理降低了土壤酸可提取态Cd含量,使残渣态Cd含量增加,Cd更趋向稳定,但对土壤中As的形态变化影响不明显。