中国金矿开采区环境汞污染

汞是金矿区环境的特征污染物。金汞同源性导致金矿床一般汞含量偏高,且在以混汞法为代表的提金过程影响下,导致了中国金矿区严重的环境汞污染问题。本文介绍了中国金矿分布与开采及选冶概况,研究了导致金矿区环境汞污染的原因,分析了金矿石选冶过程中汞的释放,并综述了金矿开采所致矿区土壤、水体、大气、生物体中汞污染状况,最后讨论了金矿区汞污染环境管理与生态修复。     

基于分解模型与VEC模型的沈阳经济区经济与环境时空关系研究

选择GDP、工业废水排放量、工业废气排放量、工业废物产生量4个指标,从横向的空间作用关系及纵向的时间作用关系对沈阳经济区经济增长与环境演化关系进行了动态综合分析.对于空间作用关系,采用完全分解模型,利用沈阳经济区内8个城市的面板数据,将经济与环境关系分解为经济规模效应、空间结构效应和技术效应,判定了由于经济增长造成的工业废物排放的增减变化而带来的区域环境压力扰动程度.对于时间作用关系,选择协整与向量误差修正模型(VEC),依次对指标序列进行了单位根检验、VAR估计、Johansen协整检验及向量自回归的VEC修正,进而对沈阳经济区经济与环境指标前期与当期作用关系进行了长期修正与短期校正.结果表明:对于工业废物排放,技术效应发挥了最突出的减量作用,经济效应的增量效应凸显,而空间结构效应的作用不明显;GDP与工业废水排放量、工业废气排放量、工业废物产生量之间的作用关系均经历了由波动到平稳的过程,但在研究期内GDP与工业废水排放之间的稳定性相对较弱,保持GDP与工业废气排放、工业废物产生各自的均衡关系,对各变量的优化有促进作用,而保持GDP与工业废水排放的均衡关系,则对各变量的优化有抑制作用.     

Shrinkage and fragmentation of grasslands in the West Songnen Plain,China

In the past century, especially the past five decades, the grasslands of the West Songnen Plain, Northeast China, were rapidly converted into croplands and salinized wasteland, and experienced a fragmentation process that is still ongoing. Almost no information is available on the spatial-temporal changes of grasslands in this area. In this study, grassland cover change, agricultural reclamation and salinized wasteland expansion were investigated during the past five decades. Grassland fragmentation was studied based on four landscape metrics. The grassland cover change was detected from a time series of topographic maps from 1954, satellite images of Landsat TM in 1986, 1995, and 2000 using remote sensing and geographic information systems (GIS). In addition, the land use changes were analyzed using a transition matrix of land use types, while the driving forces were explored according to climatic changes and socioeconomic developments. The results indicated a significant decrease in grassland area. Of the 1 418 945 ha of native grassland in 1954, approximately 64% was removed by 2000, while the number of patches (NP) increased from 865 to 2035 and the mean patch size (MPS) decreased from 1640 ha to 252 ha. During the whole study period, the average annual decrease rate of grassland was 34 894 ha/year. Cropland and salinized wasteland were the two main land use types into which grassland converted. During the past decades, obvious climatic changes occurred, which supplied a favorable potential environment for agricultural development but damaged grassland productivity. On the other hand, population, GDP and livestock number increased significantly as grassland quality decreased. According to the results, the shrinkage and fragmentation of grasslands may well be explained by socioeconomic development and aided by changing climatic conditions.     

临江灌区工程环境影响评价中盐分平衡的分析与计算

灌区盐分平衡状态的分析与计算是灌区工程环境影响评价工作中的重要内容之一。通过以临江灌区工程为例,详细分析和计算了该灌区建成前后的盐分平衡状况,为灌区生态与环境保护提供了科学依据。盐分平衡动态过程的分析应建立在灌区水量平衡的基础上,应获取灌区土壤、地表水、地下水、灌区水源水以及灌区排水中的盐分浓度,同时还应获取灌区建成前后化肥使用量变化、地表生物量的累积变化以及生物质中的盐分含量等相关参数。文中所提供的灌区盐分平衡分析与计算方法对丰富农林水利类工程的环境影响评价理论具有参考意义。     

Simultaneous photocatalytic treatment of Cr(VI), Ni(II) and SDBS in aqueous solutions: Evaluation of removal efficiency and energy consumption

Simultaneous photocatalytic reduction of poisonous Cr(VI) and Ni(II) ions, coupled with photocatalytic oxidation of sodium dodecyl benzene sulfonate (SDBS) were studied with a trace amount of commercial titania nanoparticles and by means of a direct-photo-irradiation reactor. The co-presence of metal ions and SDBS causes metal ions reduction as well as SDBS oxidation to enhance and energy efficiency to improve. XRD, XPS and FTIR analysis were used to characterize TiO₂ particles before and after usage with the aim of evaluating the mechanism of reactions. The effect of major operating parameters, pH and temperature, was investigated. Under conditions of [Cr(VI)]₀ = [Ni(II)]₀ = 5 mg/L, [SDBS]₀ = 10 mg/L, [TiO₂] = 40 mg/L, pH 6 and T = 35 °C; the removal efficiencies of 55.4%, 71.2% and 57.2% were obtained, respectively, for Cr(VI) and Ni(II) reduction, as well as for SDBS oxidation, after 110 min operation. The relevant kinetic model jointed with the Arrhenius equation was introduced. Pseudo-first-order reactions are relevant. Energy consumption (electrical and thermal) evaluations revealed that operations at higher temperatures provide significant cost reduction. Meantime, a criterion was proposed for a consistent assessment of this kind of processes.     

Spatial Variation and Space Optimization of the Development of China＇s Circular Economy

China＇s circular economy is still at the initial stage, whose development has many difficulties and problems requir- ing immediate resolution theoretically and practically. Due to the differences of re...     

基于SARIMA模型的黑龙江省冰雪旅游国际需求预测

选取黑龙江省1990-2011年冰雪旅游入境人次的月度时间序列为研究样本，建立SARIMA模型对黑龙江省冰雪旅游国际需求进行分析预测。结果表明，SARIMA（4，1，4）（1，1，1）。模型的拟合度和短期预测效果都较好。通过应用SARIMA模型进行冰雪旅游预测，以期对黑龙江省旅游企业的冰雪旅游国际客源市场开发及政府部门制定冰雪旅游发展战略和政策调整提供重要的理论依据。     

Evaluation of efficiency of aircraft liquid waste treatment and identification of daily inspection indices: a case study in Changchun, China

Evaluation of the efficiency of aircraft liquid waste treatment has previously been conducted to prevent pollution of the environment. The current study aimed to provide a set of practical methods for efficient airport sanitary supervision. Aircraft liquid waste was collected at Longjia International Airport, Changchun from multiple flights. The efficiency of liquid waste treatment as well as the water quality of the wastewater processed via a second-stage wastewater facility were examined by measuring a number of physical, chemical, and biological indices. Our results indicated that treatment solely via resolvable sanitizing liquid was not sufficient. Although the contents of first-class pollutants all met the requirements of the standard criteria, the contents of a number of second-class pollutants did not satisfy these criteria. However, after further treatment via a second-stage wastewater facility installed at the airport, all indices reached second-grade requirements of the discharge standard. We suggest that daily inspection and quarantine indices at airports should include the suspension content, biological oxygen demands after 5 days, chemical oxygen demand total organic carbon content, amino nitrogen content, total phosphorous content, and the level of fecal coliforms.     

经济与环境发展关系研究进展与述评

经济与环境发展关系一直备受关注。国内外关于经济与环境关系的研究多年来有不同程度的发展。文章对经济与环境协调发展研究的基本特征、研究形式进行了探讨。在经济与环境关系的实证研究方面,主要3种表现形式:①对投入产出模型、非线性的扩展型生产函数及新古典经济模型等经典模型进行了应用研究;②以协调发展指标、环境承载力对区域经济与环境的协调发展进行评判;③以环境库兹涅茨曲线来表现区域经济与环境的关系。未来对于经济与环境关系的研究应该注意:通过采用时间序列和横截面相结合的方法来减少环境数据欠缺的限制;注重经济发展与环境建设的相互作用的研究;注重探究经济与环境背后作用机制;通过拓宽环境指标、模型改进、改变内生缺陷等方式来完善环境库兹涅茨曲线研究。     

东北玉米低温冷害时空分布与多时间尺度变化规律分析

利用东北地区48个农业气象观测站1961-2010年逐日温度资料和近20多年玉米生育期资料,基于热量指数构建生育阶段冷害指数,采用EOF分析、Mann-Kendall法、子波变换等方法系统分析了近50年东北玉米4个生育阶段低温冷害时空分布及周期特征。结果表明:整个生育期全区平均冷害强度呈极显著的减弱趋势,地区间冷害变化趋势呈现差异化特征,冷害强度减弱趋势由西南向东北方向呈阶梯状递增;4个生育阶段冷害指数EOF第一模态均呈冷害空间变化趋势一致的特征;冷害强度呈较明显的减弱趋势,第1到第4生育阶段减弱趋势逐渐增大,突变均发生在1990年代中期;冷害强度具有较强的周期性,出苗—七叶、出苗—抽雄存在明显的23、25年周期,出苗—乳熟、出苗—成熟均具有较明显的3年周期振荡。