甘肃省土壤环境机械组成调查研究

通过对甘肃省土壤环境机械组成的调查研究，较全面、系统地获得了各种元素、土类以及各区域的土壤环境机械组成，找出了本省土壤环境机械组成特征及其分布规律。     

The Effect of Smoke from Charcoal Kilns on Soil Respiration

The objective of the work was a laboratory examination of the effect of a water-soluble fraction of the smoke, emitted during charcoaling by dry distillation, on soil metabolism. The experimental soil was exposed to smoke for ten years and the control soil was taken from a site not exposed to smoke. Oxygen uptake and carbondioxide evolution were measured in soil samples by using the method of volumetric respirometry. When an aqueous smoke solution was added to the soil, the rate of oxygen metabolism increased by a factor 15 for the experimental soil and by a factor 5 for the control soil. A similar increase was observed in carbondioxide evaluation. RQ was clearly higher for the experimental soil. Also after the addition of an aqueous smoke solution to the soil, differences were observed in changes of RQ between the experimental and control soils. These differences suggest that respiratory metabolism is changed in the soils permanently exposed to smoke, and RQ value can be an indicator of the initial stages of soil degradation.     

X-荧光光谱法在土壤调查中的应用

采用硼酸镶边、垫底压制土壤粉末样品,用X-荧光光谱仪分析其中铜、铅、铬、锌、镍等元素浓度。主要讨论了样品粒度对分析元素测定结果的影响。分析了标准样品及实际样品,其结果与标准值及化学法、原子吸收法测定结果相吻合。用土壤标准物质作精密度试验,统计结果表明,各组分RSD均小于3.74%。     

土壤Pb、Cd测定过程中溶样方法的改进

用微波消解土壤,然后电热板加热驱酸的方法对土壤样品进行前期处理的条件,并与标准法相比较,克服了标准法中湿法溶样的缺点,该法溶样完全、简便快速、消耗试剂量少,相对标准偏差均小于4·8%,回收率分别在96·1%~102·3%和94·0%~98·7%之间,具有较好的精密度和较高的回收率。     

RELATIONSHIP BETWEEN BASAL SOIL RESPIRATION RATE, TREE STAND AND SOIL CHARACTERISTICS IN BOREAL FORESTS

Soil respiration is considered to represent the overall microbial activity reflecting mineralisation of organic matter in soil. It is the most commonly used biological variable in soil studies. In long-term monitoring of forested areas, there is a need for reference values for soil microbiological variables in different forest ecosystems. In this study we describe the relationship between soil respiration rate, tree stand and humus chemical characteristics of boreal coniferous forests stands. Soil respiration rate was higher in pine dominated than in spruce dominated study sites when the result was calculated on dry matter bases. However, when calculated on area bases, the result was opposite and no difference was found when the soil respiration rate was calculated on organic carbon bases. Irrespective of the main tree species, the soil respiration rate was equal in different development classes but not equal in soil fertility classes, i.e. within forest site types based on differences in ground vegetation. Respiration rates were clearly higher in mesic sites when calculated on dry matter, C_org or area bases. However, soil respiration rate did not correlate with soil chemical variables indicating site fertility. Soil respiration rate on dry matter basis was at a lower level in the south and on more fertile sites, and on the other hand at a higher level in older stands and on sites with a thicker organic layer.     

低山丘陵区铁路建设工程弃渣场水土保持措施设计

弃渣场作为铁路建设项目水土流失最为严重的部分,其防护应提到首要位置。针对低山丘陵区铁路建设涉及的凹地型、坡地型、沟道型弃渣场,从弃渣场选址原则、不同类型的弃渣场比较、防护措施设计进行分析和阐述,构建完整的水土流失防治体系,为同类型铁路建设项目弃渣场防护措施设计提供参考。     

Assessing the bioremediation potential of arsenic tolerant bacterial strains in rice rhizosphere interface

The arsenic tolerant bacterial strains Staphylococcus arlettae(NBRIEAG-6), Staphylococcus sp.(NBRIEAG-8) and Brevibacillus sp.(NBRIEAG-9) were tested for their roles in enhancing plant growth and induction of stress-related enzymes in rice(Oryza sativa L. cv. NDR-359) plants at two different concentrations, 30 and 15 mg/kg of As(V) and As(III), respectively. An experiment was conducted to test the effect of these strains on plant growth promotion and arsenic uptake. We found 30%–40% reduction in total As uptake in bacteria-inoculated plants, with increased plant growth parameters compared to non-inoculated plants. Moreover, the bacteria-inoculated plants showed reduced activity of total glutathione(GSH) and glutathione reductase(GR) compared to their respective controls, which suggests the bacteria-mediated reduction of oxidative stress in plants. Thus, these strains were found to be beneficial in terms of the biochemical and physiological status of the plants under arsenic stress conditions.Furthermore, one-way ANOVA and principal component analysis(PCA) on enzymatic and non-enzymatic assays also revealed clear variations. The results support the distinction between control and treatments in both shoots and roots. Therefore, this study demonstrates the potential of rhizobacteria in alleviating arsenic stress in rice plants.     

我国农用地土壤环境基准与标准制定研究

在分析我国现行土壤环境质量标准不足的基础上,综述了国外制定农用地土壤环境筛选值的现状,在此基础上提出我国农用地土壤环境基准制定方法学的建议以及我国农用地土壤环境标准体系的框架建议,服务于我国农用地土壤的污染预防、风险筛选和污染农用地的安全利用、修复和风险管控。     

海口市蔬菜土壤重金属含量特征研究

采用野外调查法结合实验室分析法对海口市郊区蔬菜土壤重金属含量特征进行研究,测定了Cr、As、Cd、Cu、Zn、Pb、Ni、和Hg 8种重金属全量、有效态含量及蔬菜土壤pH值和有机质含量,重金属全量与有效态含量间的相关性及土壤pH值,有机质含量与蔬菜土壤中重金属全量间的相关性。结果表明,海口市蔬菜土壤中各种重金属均表现出一定的累积趋势;8种重金属元素有效态含量与全量呈正相关,重金属有效态占全量比例在1.86%~13.47%之间,其中Cd、Pb和Hg较高,分别为13.47%、10.23%和8.42%,三者表现出较大的潜在污染风险;土壤p H值和有机质含量与重金属全量表现出一定的相关性,相关性大小与重金属种类有关;重金属全量并不能全面正确评价土壤的环境效应,对蔬菜土壤重金属污染程度进行评价时,应把重金属全量、有效态含量与土壤基本理化性质结合起来进行研究。     

Uranium and thorium in soils,mineral sands,water and food samples in a tin mining area in Nigeria with elevated activity

The activity concentrations of uranium and thorium have been determined in soils and mineral sands from the Nigerian tin mining area of Bisichi, located in the Jos Plateau, and from two control areas in Nigeria (Jos City and Akure) using high-purity germanium detectors (HPGe). High resolution sector field inductively coupled plasma mass spectroscopy (HR-SF-ICP-MS) was used to determine uranium and thorium in liquids and foodstuffs consumed locally in the mining area. The activities of uranium and thorium measured in the soils and mineral sands from Bisichi ranged from 8.7 kBq kg⁻¹ to 51 kBq kg⁻¹ for ²³⁸U and from 16.8 kBq kg⁻¹ to 98 kBq kg⁻¹ for ²³²Th, respectively. These values were significantly higher than those in the control areas of Jos City and Akure and than the reference values reported in the literature. They even exceeded the concentrations reported for areas of high natural radioactive background. Radionuclide concentrations in samples of the local foodstuffs and in water samples collected in Bisichi were found to be higher than UNSCEAR reference values. The results reveal the pollution potential of the mining activities on the surrounding areas.