Pedological characteristics of Mn mine tailings and metal accumulation by native plants

In southern China revegetation and ecological restoration of many abandoned Mn tailings has become a major concern. To determine the major constraints for plant establishment and evaluate the feasibility of remediation, a comparative study was conducted on Mn tailings and rhizosphere soils at the boundary of the tailings pond. Both tailings and rhizosphere soils had neutral to slightly alkaline pH and normal electrical conductivity. They were both enriched with organic matter (6.8-9.2%), total N (1.77-5.94 g kg(-1)), available P (41.78-73.83 mg kg(-1)) and K (146.7-906.9 mg kg(-1)), suggesting the tailings were a nutrient rich substrate for revegetation. Mn tailings were clay textured, while rhizosphere soils were silty loam or clay loam. The compaction and anoxic nature of Mn tailings were considered to be the major constraints for plant establishment. Total Mn (31903 mg kg(-1)), Cd (119 mg kg(-1)), Cu (126 mg kg(-1)) and Zn (2490 mg kg(-1)) in tailings were all at phytotoxic levels, but did not differ significantly from those in rhizosphere soils. In both tailings and rhizosphere soils, percentages of water- and DTPA-extractable metals were less than 1% and 2% of the total metal pools, respectively. Sequential extraction revealed that the majority of Mn, Cu and Zn were associated with the residual fraction, while the majority of Cd occurred as Fe-Mn oxides. The natural succession of plants around Mn tailings formed a distinctive metal-tolerant plant community, mainly comprising nine species such as Cynodon dactylon and Humulus scandens and so on. All species studied could be good candidates for revegetation of Mn tailings.     

特尔斐—模糊综合比较法评价生态环境质量变化

根据生态系统的组成,利用特尔斐测定法选定影响环境的因子,确定其权重,现场监测调查实际资料,判定各因子的作用分值,采用模糊综合法计算出生态环境变化前后的综合分值,以判定生态环境质量变化前后的好坏。     

无花果曲霉对Cu^2＋吸附的研究

采用生物吸附法,研究了经过预处理的无花果曲霉对Cu^2 吸附行为与影响吸附的主要因素,具体包括菌丝球与Cu^2 接触反应时间、Cu^2 浓度、原初pH值3个方面。结果表明：该菌丝球在吸附进行5min时,吸附量已达量2．855mg/g,在吸附进行4h以后趋于平衡。最佳pH范围为4．0－5．0,Cu62 浓度在20－100mg/L范围内吸附量为2．763－4．713mg/g,而吸附率却为32．31％－9．54％。其吸附行为在一定的温度和一定浓度范围内较好地符合Langmuir吸附等温模型。     

La—Gly—VB6对Pb—Cd复合胁迫下植物的影响

研究Pb-Cd复合污染对5种树木叶片的生理伤害和La-Gly-VB6对Pb-Cd污染胁迫的缓解作用。实验结果表明,La-Gly-VB6能明显减轻Pb-Cd污染造成的植物叶片叶绿素含量下降、质膜透性增加,过氧化氢酶活性改变和Pb富集量上升。说明La-Gly-VB6对Pb-Cd污染胁迫具有一定的防护作用。     

区域易损性分析、评估及易损度区划：—以重庆市为例

根据重庆市建国50年来的灾害统计资料,选取灾害密度、灾害频数、经济（GDP）损失模数、生命易损模数等易损性评价指标,在详尽分析了重庆市各区县市易性的基础上,对重庆市各区县市的脆弱性和易损强度进行了综合评估,并且计算出了各区县市的易损度,结合GIS方法对重庆进行了易损度区划。并借此提出域易损性分析、评估的模式、为区域防灾、减灾规划提供科学依据。     

沿海和河口城市防灾设防标准系统分析

本文针对天津、上海、青岛等三种不同类型的沿海、河口城市,运用灰色理论、随机模拟等方法进行了洪水、风暴湖、巨浪等环境因素的计算,并进行了灾害经济损失的风险分析,给出了不同的防灾设防标准。     

液化气装置平台的抗震加固

针对装置平台抗震能力的现状 ,研究了江苏油田真武液化气装置平台的抗震加固。即在原设备不拆除的情况下 ,提出了对框架梁、柱采用钢构套进行加固 ,并对框架柱采用钢构斜支撑加翼补强的加固设计方案和具体的加固措施。经加固后的装置平台 ,整体抗震性能得到提高 ,从而消除了隐患 ,增强了日常工作的可靠性。     

Evaluating Controlling Factors to Ali/(Ca + Mg) Molar Ratio in Acidic Soil Water, Southern and Southwestern China: Multivariate Approach

Al_i/(Ca + Mg) molar ratio in soil water has been used as an indicator to the effects of acid deposition on terrestrial ecosystems. However, the main factors controlling this ratio have not been well documented in southern and southwestern China. In this study, we presented the variation in inorganic aluminum (Al_i) and Al_i/(Ca + Mg) molar ratio in different sites and soil horizons based on two to three years monitoring data, and evaluated the main factors controlling Al_i/(Ca + Mg) molar ratio using principle component analysis (PCA) and partial least square (PLS) regression. Monitoring data showed although Al_i/(Ca + Mg) molar ratios in most soil water were lower than assumed critical 1.0, higher molar ratios were found in some soil water at TSP and LXH site. Besides acid loading, both soil properties and soil water chemistry affected the value of Al_i/(Ca + Mg) molar ratio in soil water. Partial least square (PLS) indicated that they had different relative importance in different soil horizons. In A-horizon, soil aluminum saturation (AlS) had higher influence on Al_i/(Ca + Mg) molar ratio than soil water chemistry did; higher soil aluminum saturation (AlS) led to higher Al_i/(Ca + Mg) molar ratio in soil water. In the deeper horizons (i.e., B₁-, B₂- and BC-horizon), inorganic aluminum (Al_i) in soil water had more and more important role in regulating Al_i/(Ca + Mg) molar ratio. On regional scale, soil aluminum saturation (AlS) as well as cation exchange capacity (CEC) was the dominant factor controlling Al_i/(Ca + Mg) molar ratio. This should be paid enough attention on when making regional acid rain control policy in China.     

A combined plasma photolysis (CPP) method for removal of CS2 from gas streams at atmospheric pressure

A combined plasma photolysis (CPP) reactor that utilizes a dielectric barrier discharge (DBD) plasma and 207 nm UV radiation from discharge-driven KrBr^* excimers was designed and constructed. Gas streams containing CS₂ were treated with stand-alone DBD and CPP at atmospheric pressure. In comparison to DBD, CPP greatly enhanced the removal efficiency at the same applied voltage, waste gas concentration and gas residence time. Thus the applied voltage could be reduced to a certain extent in the plasma processing of industrial wastes. Influences of the KrBr^* radiation, inlet CS₂ concentration and gas residence time on CS₂ removal by CPP were also studied. In addition, the likely reaction mechanisms for the removal of CS₂ by CPP are suggested based on the byproducts analysis. The enhanced removal efficiency and reaction mechanisms implied that the CPP process would probably be suitable for the removal of a large number of gaseous pollutants.     

Ca(OH)2、高岭土与FeCl3组配处理含Pb2+废水

采用Ca（OH）2、高岭土与FeCl3组配处理含Pb^2＋废水。考察了Ca（OH）2加入量、高岭土加入量、FeCl3加入量、废水pH、搅拌转速、沉淀时间等因素对Pb^2＋去除率的影响。在Ca（OH）2加入量50mg／L、高岭土加入量90mg／L、FeCl3加入量13．2mg／L、废水pH7．0～8．0、搅拌转速170r／min、沉淀时间90min的条件下,该法可将废水中金属离子（包括Pb^2＋及少量的Zn^2＋,Cu^2＋,Cr^3＋,Ni^2＋）的质量浓度由42．4mg／L降至1．0mg／L以下,达到了GB18918--2002〈《城镇污水处理厂污染物排放标准》。