凤冈富硒富锌茶园土壤中的锌及其形态分析

采用Tessier连续化学浸提技术,对凤冈茶园土壤进行了可交换态、碳酸盐结合态、铁锰氧化物结合态、有机结合态、残渣态锌的提取,应用火焰原子吸收光谱法(FAAS)对茶园土壤总锌和各结合态锌进行了测定,并讨论了土壤全锌含量及各形态锌含量与土壤pH的关系。测定结果表明,在测试的39件土壤样品中,土壤pH值在3.92～5.16之间,平均pH值为4.66,属酸性土壤。全锌的最高含量为245.7mg/kg,最低含量为31.1mg/kg,平均含量为116.0mg/kg,超过了我国茶园土壤锌的平均含量100mg/kg。在采样的四个茶园中,总的来说土壤锌结合态的分布规律为:残渣态(铁锰氧化物结合态(有机结合态(可交换态(包括水溶态)(碳酸盐结合态。     

碳氮源对光合细菌混合菌群产氢性能的影响

碳源和氮源是产氢光合细菌生长发育过程中不可缺少的营养物质,与光合细菌菌株产氢能力相关。以从花园土壤中富集分离出来的光合细菌混合菌群为研究对象,在血清瓶中于30℃下采用厌氧培养方式间歇培养8天,分别考察不同的碳源、氮源、碳氮源组合及其浓度变化对光合细菌产氢行为的影响。结果表明,碳氮源种类对光合细菌产氢能力有显著影响,与氮源相比,碳源对产氢量的影响更为显著,最佳碳源为葡萄糖,最佳氮源为草酸铵。最佳碳氮源组合为葡萄糖和谷氨酸钠组合,葡萄糖和谷氨酸钠浓度分别为3g/L和1g/L时,产氢量和最大产氢速率分别达41.35mLH2/(L-培养基)和0.328mLH2/(L-培养基·h)。研究结果为进一步探索产氢光合细菌生长的营养生理奠定了基础,对大规模培养条件的优化提供了依据。     

天津港环境风险防范及管理对策研究

分析了天津港主要的环境风险类型.并重点分析了天津港溢油事故风险、陆域储运事故风险、港口及其附近海域赤潮风险的发生原因及趋势.针对港口环境风险事故的成因提出了相应的防范对策议,并在此基础上建立了天津港环境风险应急响应程序和风险事故应急决策支持系统.最后,结合环境风险防范及应急体系中存在的障碍和天津港未来的发展趋势,提出了提高天津港突发性环境事件应急水平的建议,并可为其他港口所借鉴.     

Effects of arbuscular mycorrhizal fungi inoculation on arsenic accumulation by tobacco (Nicotiana tabacum L.)

A pot experiment was conducted to study the e ects of arbuscular mycorrhizal (AM) fungi (from contaminated or uncontaminated soils) on arsenic (As) uptake of tobacco (Nicotiana tabacum L.) in As-contaminated soil. Mycorrhizal colonization rate, dry weight, As and P uptake by plants, concentrations of water-extractable As and As fractions were determined. A low mycorrhizal colonization rate (< 25%) was detected. Our research indicated that AM fungi isolated from polluted soils were no more e ective than those from unpolluted soils when grown in symbiosis with tobacco. No significant di erences were observed in roots and stalks dry weights among all treatments. Leaves and total plant dry weights were much higher in Glomus versiforme treatment than that in control treatment. As contents in roots and stalks from mycorrhizal treatments were much lower than that from control treatment. Total plant As content exhibited the same trend. P concentrations in tobacco were not a ected by colonization, nor were stalks, leaves and total plant P contents. Roots P contents were remarkably lower in HN treatments than in other treatments. Meanwhile, decreased soil pH and lower water-extractable As concentrations and higher levels of As fraction bound to well-crystallized hydrous oxides of Fe and Al were found in mycorrhizal treatments than in controls. The protective e ect of mycorrhiza against plant As uptake may be associated with changes in As solubility mediated by changing soil pH. These results indicated that under As stress, proper mechanisms employed by AM fungi can protect tobacco against As uptake. Results confirmed that AM fungi can play an important role in food quality and safety.     

Infiltration characteristics of non-aqueous phase liquids in undisturbed loessal soil cores

The widespread contamination of soils and aquifers by non-aqueous phase liquids (NAPL), such as crude oil, poses serious environmental and health hazards globally. Understanding the infiltration characteristics of NAPL in soil is crucial in mitigating or remediating soil contamination. The infiltration characteristics of crude and diesel oils into undisturbed loessal soil cores, collected in polymethyl methacrylate cylindrical columns, were investigated under a constant fluid head (3 cm) of either crude oil or diesel oil. The infiltration rate of both crude and diesel oils decreased exponentially as wetting depth increased with time. Soil core size and bulk density both had significant effects on NAPL infiltration through the undisturbed soil cores; a smaller core size or a greater bulk density could reduce oil penetration to depth. Compacting soil in areas susceptible to oil spills may be an effective stratage to reduce contamination. The infiltration of NAPL into soil cores was spatially anisotropic and heterogeneous, thus recording the data at four points on the soil core is a good stratage to improve the accuracy of experimental results. Our results revealed that crude and diesel oils, rather than their components, have a practical value for remediation of contaminated loessal soils.     

Removal of metals by sorghum plants from contaminated land

The growth of high biomass crops facilitated by optimal of agronomic practices has been considered as an alternative to phytoremediation of soils contaminated by heavy metals. A field trial was carried out to evaluate the phytoextraction efficiency of heavy metals by three varieties of sweet sorghum (Sorghum biocolor L.), a high biomass energy plant. Ethylene diamine tetraacetate (EDTA), ammonium nitrate (NH₄NO₃) and ammonium sulphate ((NH₄)₂SO₄) were tested for their abilities to enhance the removal of heavy metals Pb, Cd, Zn, and Cu by sweet sorghum from a contaminated agricultural soil. Sorghum plants always achieved the greatest removal of Pb by leaves and the greatest removal of Cd, Zn and Cu by stems. There was no significant difference among the Keller, Rio and Mray varieties of sweet sorghums in accumulating heavy metals. EDTA treatment was more efficient than ammonium nitrate and ammonium sulphate in promoting Pb accumulation in sweet sorghum from the contaminated agricultural soil. The application of ammonium nitrate and ammonium sulphate increased the accumulation of both Zn and Cd in roots of sorghum plants. Results from this study suggest that cropping of sorghum plants facilitated by agronomic practices may be a sustainable technique for partial decontamination of heavy metal contaminated soils.     

北京某小学室内外VOC浓度及有毒害物种识别

采用美国EPA推荐的TO14/15方法定量分析了北京市某小学室内外夏季观测的空气样品,得到82种挥发性有机物（VOCs）的浓度水平及组成特征,对其中可能危害儿童健康的有毒有害物质进行了识别.结果表明,室内总VOCs浓度高于室外,烷烃是含量最丰富物种,平均占室内外空气中定量VOCs总浓度的32.8%.室内外VOCs组成相似,异戊烷、苯、甲苯、丙醛、丙烯和二氯甲烷为浓度优势物种,受到室外源的影响较大,室内的对二氯苯、环己烷及间二氯苯较为特征,前2种物质室内/室外浓度比例平均值分别为65.8和10.5,间二氯苯室内平均浓度为2.02×10^-9（体积分数）,而室外浓度低于检测限,这3种物质可能来自室内源. 1, 3-丁二烯、氯乙烯、苯和氯甲烷4种物质在学校室内、室外及儿童家中都超过1×10^-6的癌症风险值,平均风险值分别为1.3×10^-5、 6.4×10^-6、 5.1×10^-6和3.3×10^-6,小学室外、室内及儿童家中的累积癌症风险超过1×10^-6的癌症风险值24～39倍.丙烯醛未确认具有致癌性,但具有毒有害性,在室内外及儿童家中超过基准浓度13～72倍.     

生活垃圾填埋操作方式对覆土中Ⅰ型甲烷氧化菌的影响研究

填埋场覆土中的甲烷氧化菌可削弱填埋场的温室气体释放,其中I型甲烷氧化菌对环境条件的改变反应灵敏.实验采用16S rDNA特异性聚合酶链式反应(polymerase chain reaction,PCR)结合变性梯度凝胶电泳(denaturing gradient gel electrophoresis,DGGE)基因指纹技术研究不同填埋操作方式,包括高密度聚乙烯膜(high-density polyethylene liner,HDPE)隔离、渗滤液亚表面灌溉和植被种植,对城市生活垃圾填埋场表层覆土中I型甲烷氧化菌的群落结构和多样性的影响.16S rDNA序列的系统发育分析结果表明,供试土壤中的I型甲烷氧化菌均属于甲基杆菌属(Methylobacter).从香农-威纳多样性指数(Shannon-Wiener diversity index)和主成分分析的结果可以归纳得到:渗滤液亚表面灌溉和植被种植比HDPE膜隔离对表层覆土中I型甲烷氧化菌群落结构的影响更大,它们会降低I型甲烷氧化菌的多样性,并且推测渗滤液亚表面灌溉会抑制Methylobacter的生长.无HDPE膜隔离的土壤中,即有填埋气体侵入的土壤中,随填埋气体作用于土壤时间的延长,I型甲烷氧化菌的群落结构会发生变化;覆土时间分别为3周、1.5 a和5 a的土壤中,I型甲烷氧化菌的香农.威纳多样性指数在覆土1.5a时达到最大值.     

太湖周边典型区域水体污染的遗传毒性研究

 应用SOS/umu法对太湖周边12个典型区域水体的遗传毒性进行研究,结果表明:各采样点水样的遗传毒性诱导率IR与提取物的水样体积呈较明显的剂量-效应关系,其中,T1、T2、T3、T7、T8、T9、T10水样提取物有遗传毒性效应;各区域水体遗传毒性随水情期大小排序为:汛前期>汛期,对于污染源较稳定的区域,水体遗传毒性在各水期变化较小.     

泉州湾悬浮颗粒物中重金属的分布特征及其影响因素

(1.国家海洋局第三海洋研究所,厦门361005;2.中国海洋大学海底科学与探测技术教育部重点实验室,青岛266100)摘要:利用等离子质谱仪(ICP-MS)对泉州湾6个13h连续站悬浮颗粒物及2个13h连续站(Q2和Q4站)表层沉积物中Cr、Ni、Cu、Zn、As、Pb和Cd等元素的含量进行测试,悬浮颗粒物中其平均含量分别在1.610～0.359、0.730～0.150、2.249～0.319、6.421～1.266、0.131～0.027、4.176～1.101μg/L和17.526～2.260ng/L之间,从内湾向外湾逐渐降低;表层沉积物中其平均含量分别在65.3～82.6、37.8～39.8、37.4～51.4、121.0～172.8、3.3～3.4、42.2～76.9和0.217～0.493μg/g之间,Q2站含量一般高于Q4站的.综合分析1个潮周期内重金属含量及其分布特征发现:河口及其附近海域悬浮颗粒物中重金属含量变化相对较大,其分布特征与潮汐及河口过程相关;外湾的含量变化相对较小,其变化受局地表层沉积物再悬浮的影响要大于潮汐影响下的河流输入影响;表层沉积物中重金属的含量变化与悬浮颗粒物中的可以相对应,指示了两者之间的交换.本研究结果为全面了解泉州湾重金属的分布、运移和交换提供了重要参考.