西南碳酸盐岩石质山地土壤-植被系统中矿质养分不足问题的思考

本文提出了矿质养分不足可能是西南石漠化喀斯特山地植被生产力低和植被修复困难重要原因的观点。桂西北环江喀斯特农业生态站和黔中清镇王家寨小流域碳酸盐岩石灰土坡地的平均土壤质量厚度(<2mm),分别为21.95kg/m2和16.04kg/m2。以地上部分生产力4.8t/ha.a,灰分含量9.5%计,植被每年要从土壤中吸取45.6g/m2.a的矿质养分,相当于两地土壤总量的约千分之二。土壤总量少导致的西南碳酸盐岩石质山地土壤矿质养分不足,可能是植被生产力低下的重要原因。纯碳酸盐岩硅酸盐矿物含量低,成土速率低。长期不断的收获植物,不可避免地要带走矿物质,导致喀斯特山地土壤矿质养分的减少,进而抑制植物生长.施用矿质肥料可能是促进喀斯特石质山地植被修复的重要措施。     

采煤影响下峰峰煤炭矿区岩溶地下水水动力环境的演变

采煤影响后的岩溶地下水,强径流区的水动力特征虽未根本改变,但仍发生了明显的变化。采煤后,岩溶水的水流速率明显变慢,水力梯度加大,含水层间水力联系加强,因溶解矿物的差异也造成了水化学场的异同。因处于煤矿开发利用的不同阶段,不同径流区岩溶水水动力特征也存有明显的差异。     

6种矿质元素对青菜中硝酸盐含量的影响

通过盆栽试验 ,研究了B、K、Mn、Mg、Zn、Co对青菜中硝酸盐含量的影响。结果表明 :增施硼酸钠后第 2 0天 ,青菜硝酸盐含量比对照降低 1 4 84%～ 1 9 56 % ;增施K、Mn、Mg、Zn、Co也能降低青菜硝酸盐含量。每盆增施0 1gZnSO4 后第 1 0天 ,青菜中硝酸盐含量比对照减少 1 8 96 % ,每盆增施 0 1gK2 SO4 后第 2 0天 ,青菜中硝酸盐含量比对照减少 2 1 42 % ;矿质元素的施用量对青菜硝酸盐含量影响较大。     

土壤中重金属污染现状与防治方法

文章阐明了土壤重金属污染物来源与分布,同时对国内外土壤重金属污染治理的研究工作做了系统的综述,提出了土壤中重金属污染物防治的环境矿物学新方法,利用环境矿物材料治理土壤重金属污染物的方法,具有成本低、效果好、无二次污染及有用金属可回收利用等优点,展现出广阔的环境矿物学研究与应用前景。并提醒人们要提高土壤质量意识,保护生态环境。     

稀土元素在土壤中的释放与迁移研究进展

稀土是全球重要的战略资源,在高科技产业及日常生活中广泛应用.由于稀土资源需求量的日益增加,稀土矿大量开采,加剧了稀土矿区周边环境污染,危害居民健康.因此,探究土壤中稀土元素的释放和迁移机理及影响机制对稀土的污染防治、生态修复及潜在风险评估都具有重要的现实指导意义.文章综述了稀土元素在土壤中释放与迁移机制、形态、及其影响...     

GROUNDWATER GEOCHEMISTRY IN THE SEMINOLE WELL FIELD,CEDAR RAPIDS,IOWA1

The City of Cedar Rapids obtains its municipal water supply from four well fields in an alluvial aquifer along the Cedar River in east-central Iowa. Since 1992, the City and the U.S. Geological Survey have cooperatively studied the groundwater-flow system and water chemistry near the well fields. The geochemistry in the alluvial aquifer near the Seminole Well Field was assessed to identify potentially reactive minerals and possible chemical reactions that produce observed changes in water chemistry. Calcite, dolomite, ferrihydrite, quartz, rhodochrosite, and siderite were identified as potentially reactive minerals by calculating saturation indexes. Aluminosiicate minerals including albite, Ca-montmorillonite, gibbsite, illite, K-feldspar, and kaolinite were identified as potentially reactive minerals using hypothetical saturation indexes calculated with an assumed dissolved aluminum concentration of 1 microgram per liter. Balanced chemical equations derived from inverse-modeling techniques were used to assess chemical reactions as precipitation percolates to the water table. Calcite dissolution was predominate, but aluminosilicate weathering, cation exchange, and redox reactions also likely occurred. Microbial-catalyzed redox reactions altered the chemical composition of water infiltrating from the Cedar River into the alluvial aquifer by consuming dissolved oxygen, reducing nitrate, and increasing dissolved iron and manganese concentrations. Nitrate reduction only occurred in relatively shallow (3 to 7 meters below land surface) groundwater near the Cedar River and did not occur in water infiltrating to deeper zones of the alluvial aquifer.     

安徽省矿产资源现状与可持续发展初探

安徽省矿产资源种类繁多,储量丰富,特别是煤炭、Ｆｅ、Ｃｕ、Ｓ、非金属等矿产资源分布相对集中,具有南北不同的特点。矿产资源在开发利用中存在着开发利用广度大、加工程度低、综合利用率低、浪费严重、引发多种地质灾害等问题。本文对安徽省矿产资源的可持续发展对策进行了探讨     

100 MW锅炉NaOH颗粒生成的数值模拟

煤粉燃烧过程中矿物质的气化、成核、凝结等过程是炉膛中亚微米颗粒形成的主要途径。本文运用CFD软件针对某100 MW锅炉内NaOH颗粒形成进行了数值研究,计算得到了炉内的温度分布、氧浓度分布和亚微米颗粒数量浓度和质量浓度分布。结果显示,亚微米颗粒的生成数量与温度具有强烈的相关性,温度较高的区域亚微米颗粒数量浓度较大,温度较低的区域则较小;而在炉膛的高温区内,NaOH颗粒的质量浓度并不是最高,而是最低,同时随着炉膛高度的增加,NaOH颗粒的质量浓度逐渐增加。计算结果为今后数值研究燃煤过程中亚微米颗粒的形成与演化奠定基础,为研究温度等燃烧条件对亚微米颗粒形成的影响、抑制其排放等方面提供了一种有效研究手段。     

多年冻土区工程迹地人工恢复区植物和土壤的矿质元素含量特征

选择青藏高原多年冻土区工程迹地的人工恢复植物和紫花针茅草原的优势植物以及对应的土壤样品进行对照,利用原子吸收法分析了它们的矿质元素含量特征。结果表明：多年冻土区工程迹地人工恢复区植物的元素含量：＞1 000 μg/g的元素有Ca、P和Na,100～1 000 μg/g的元素有Mn、K、Fe、Mg和Al;而对照紫花针茅草原优势植物的元素含量：＞1 000 μg/g的元素有Ca和Na,100～1 000 μg/g的元素有P、Mn、K、Fe、Mg和Al。人工恢复区土壤元素含量：＞1 000 μg/g的元素有Ca、Fe和Mn,100～1000 μg/g的元素有Mg、K、Al、P和Na;对照紫花针茅草原土壤元素含量：＞1 000 μg/g的元素有Ca、Fe,100～1 000 μg/g的元素有Mn、Mg、Al、K、P和Na。该区域植物和土壤元素含量都属于Ca > K 型。人工恢复植物和对照的紫花针茅草原植物对土壤元素的吸收能力具有较高的相似性。K和Al元素的累积与其他元素没有显著的相关关系,其他元素之间为正相关关系,元素之间的吸收累积属于协同作用,无明显的撷抗作用     

Investigation of partitioning mechanism for volatile organic compounds in a multiphase system

Laboratory experiments were performed to investigate the partitioning behavior of a set of diverse volatile organic compounds (VOCs). After equilibration at a temperature of 25 °C, the VOC concentrations were measured by headspace method in combination with gas chromatography/mass spectrometry (GC/MS). The obtained data were used to determine the partition coefficients (K_P) of VOCs in a gas-liguid-solid system. The results have shown that the presence and nature of solid materials in the working solution control the air-water partitioning of dissolved VOCs. The air/solution partitioning of BTEX and C₉-C₁₀ aldehydes was most affected in the presence of diesel soot. K_P values decreased by a factor ranging from 1.5 for toluene to 3.0 for ethylbenzene. The addition of mineral dust in the working solution exhibited greater influence on the partitioning of short aldehydes. K_P values decreased by a factor of 1.8. The experimental partition coefficients were used to develop a predictive model for partitioning of BTEX and n-aldehydes between air, water and solid phases.