气-水界面对病毒静态吸附实验结果的影响

气-水界面存在可能导致不能正确评价土壤对病毒的静态吸附能力.本研究通过室内一次平衡法实验,比较分析气-水界面对噬菌体MS2在不同处理（非灭菌/灭菌）的不同土壤中的吸附实验结果影响,同时评价不同程度气-水界面对没有土壤存在时的病毒回收率影响.结果表明,气-水界面存在对吸附实验结果的影响在砂质潮土上最为明显,其次为红壤土,而在红粘土上的影响几乎可忽略,这可能与土壤本身吸附/致死病毒的能力不同有关;土壤灭菌后进一步加剧气-水界面对砂质潮土吸附实验结果的偏差,而在红壤土上则有减弱趋势.气-水界面存在显著降低空白实验病毒回收率,其降低趋势随气-水界面的增加而加剧,当加入土壤后,土壤颗粒有可能阻止病毒接近气-水界面或改变病毒吸附在固-液-气界面的力量,因而气-水界面存在时的空白实验结果并非为真正的空白实验结果,这可能是导致气-水界面引起静态吸附实验结果偏差的主要原因.     

阴极pH控制对污染土壤电动修复效率的影响

就电动修复污染土壤过程中阴极电解产生的OH-对修复效率的影响进行了实验室研究. 实验选用重铬酸钾作为污染物,配制砂土和高岭土中初始w(Cr(Ⅵ))为100和500 mg/kg,施加恒定直流电压1 V/cm,运行48 h. 选用不同土壤和控制条件,实验共进行了10组. 分析了实验过程中电流变化以及实验完成后土壤pH分布和铬的迁移分布,并对每组实验Cr(Ⅵ)的去除率和电能消耗进行了计算. 结果表明:对阴极电解产生的pH进行控制可以明显提高Cr(Ⅵ)的去除率,同时电能耗变化不大;多种控制方式中,以盐酸的中和控制最为有效,可使去除率达到90.8%,但引起的土壤酸化问题应进一步进行研究;对电动过程中Cr(Ⅵ)的迁移转化应做深入研究.      

Assessment and mapping of environmental quality in agricultural soils of Zhejiang Province, China

Heavy metal concentrations in agricultural soils of Zhejiang Province were monitored to indicate the status of heavy metal contamination and assess environmental quality of agricultural soils. A total of 908 soil samples were collected from 38 counties in Zbejiang Province and eight heavy metal （Cd, Cr, Pb, Hg, Cu, Zn, Ni and As） concentrations had been evaluated in agricultural soil. It was found 775 samples were unpolluted and 133 samples were slightly polluted and more respectively, that is approximately 14.65% agricultural soil samples had the heavy metal concentration above the threshold level in this province by means of Nemerow＇s synthetical pollution index method according to the second grade of Standards for Soil Environmental Quality of China （GB15618- 1995）. Contamination of Cd was the highest, followed by Ni, As and Zn were lower correspondingly. Moreover, Inverse Distance Weighted （IDW） interpolation method was used to make an assessment map of soil environmental quality based on the Nemerow＇s pollution index and the soil environmental quality was categorized into five grades. Moreover, ten indices were calculated as input parameters for principal component analysis （PCA） and the principal components （PCs） were created to compare environmental quality of different soils and regions. The results revealed that environmental quality of tea soils was better than that of paddy soils, vegetable soils and fruit soils. This study indicated that GIS combined with multivariate statistical approaches proved to be effective and powerful tool in the mapping of soil contamination distribution and the assessment of soil environmental quality on provincial scale, which is beneficial to environmental protection and management decision-making by local government.     

淮南潘一矿塌陷水域沉积物中磷的赋存和迁移转化特征

采用改进的Pesnner分级提取方法,选取淮南潘一矿杨庄塌陷水域为研究对象,对其沉积物磷的剖面赋存形态进行分析,并结合磷的形态组成、有机质(OM)、总氮(TN)和铁锰氧化物等分布特征,研究了塌陷水域沉积物中磷的迁移转化特征.结果表明,在淹水农业耕作层上,湖泊沉积相累积明显,自表层而下,各形态磷含量均呈逐渐减少的趋势,总磷(TP)在各层次均值为204.9~343.7mg/kg,其中以无机磷(IP)为主,其含量为163.9~257.2mg/kg,占TP比例达73.3%~81.5%.NaOH-P(85.0~100.1mg/kg,28.6%~41.3%)和HCl-P (63.6~95.9mg/kg,27.4%~30.9%)所占比例较大.根据相关性结果分析,部分HCl-P和有机磷(OP)有向NaOH-P转化的趋势.     

玉门矿区污染黄土中原油的解吸研究

用振荡平衡法研究了玉门矿区原油污染黄土中原油的解吸行为，测得了解吸常数，绘出了解吸等温线。结果表明，Freundlich方程可较好地描述黄土中原油的解吸状况；黄土中原油的解吸行为受温度、溶液pH值和表面活性剂的影响；温度和pH值越高，原油解吸量越大；阴离子表面活性剂的加入有助于原油的解吸，在相同条件下使解吸率提高了5倍，阳离子和非离子表面活性剂的加入不利于原油解吸，但是阳离子表面活性剂的加入有利于原油在土壤中的截留以及回收再利用。本研究为修复玉门原油污染黄土提供了理论依据。     

太湖地区水稻土颗粒中重金属元素的分布及其对环境变化的响应

采用原状土样分离技术，研究了太湖地区几种主要水稻土示同颗粒中重金属元素Pb、Cr、Cd的分布，结果表明这些元素在不同粒径的土壤颗粒中分配迥异，重金属含量在＞0．25mm的粗颗粒和＜0．002mm的细颗粒中较高，且与土壤有机碳有密切的关系；重金属元素主要积累于＞0．25mm的粗颗粒中，Cd的粗颗粒积累比Pb、Cr更强烈，耕层土壤重金属的颗粒分配因土壤种类不同而异，并响应于土壤环境变化，提出以分馏系数表示重金属在土壤颗粒的分配特点。     

Bacterial diversity in soils around a lead and zinc mine

Five samples of soil collected from a lead and zinc mine were used to assess the effect of combined contamination of heavy metals on soil bacterial communities using a polyphasic approach including characterization of isolates by culture method, community level catabolic profiling in BIOLOG GN microplates, and genetic community fingerprinting by denaturing gradient gel electrophoresis of 16S rDNA fragments amplified by PCR from community DNA （PCR-DGGE）. The structure of the bacterial community was affected to a certain extent by heavy metals. The PCR-DGGE analysis of 16S rRNA genes showed that there were significant differences in the structure of the microbial community among the soil samples, which were related to the contamination levels. The number of bacteria and the number of denaturing gradient gel electrophoresis （DGGE） bands in the soils increased with increasing distance from the lead and zinc mine tailing, whereas the concentration of lead （Pb） and cadmium （Cd） was decreased. Heavily polluted soils could be characterized by a community that differs from those of lightly polluted soils in richness and structure of dominating bacterial populations. The clustering analysis of the DGGE profiles showed that the bacteria in all the five samples of soil belonged to three clusters. The data from the BIOLOG analysis also showed the same result. This study showed that heavy metal contamination decreased both the biomass and diversity of the bacterial community in soil.     

中国粮食主产区耕地土壤重金属时空变化与污染源分析

土壤重金属污染威胁着农田生态系统安全和人类健康.基于2000年以来中国五大粮食主产区3 006个耕地样点的土壤重金属实测数据和20世纪80年代的土壤重金属历史数据,采用单因子指数法评估了粮食主产区耕地土壤重金属的污染现状和变化趋势,并基于地累积指数,结合区位环境污染探讨了其污染来源.结果表明,中国粮食主产区耕地土壤重金属点位超标率为21.49%,整体以轻度污染为主,其中轻度、中度和重度污染比重分别13.97%、2.50%和5.02%.四川盆地、长江中游及江淮地区、黄淮海平原、松嫩平原和三江平原的耕地点位超标率分别为43.55%、30.64%、12.22%、9.35%和1.67%,南方耕地污染重于北方.主要污染物为Cd、Ni、Cu、Zn、Hg,超标率分别为17.39%、8.41%、4.04%、2.84%、2.56%.自20世纪80年代以来,耕地土壤重金属含量呈增加趋势,整体上点位超标率增加了14.91%,其中Cd、Ni、Cu、Zn和Hg的污染比重分别增加了16.07%、4.56%、3.68%、2.24%和1.96%.除三江平原外,其他4个粮食主产区耕地土壤重金属点位超标比重增加趋势显著,且南方地区的Cd、Ni和Cu重金属超标比重变化量高于北方,而Hg和Cr增速低于北方.Cd、Hg以人为污染源为主,其他6种重金属以自然污染源为主,但Pb、Zn和Cu约有20.00%的点位受人为活动的影响.矿业、工业、污灌水是主要的污染源,除污灌水来源北方重于南方外,其余污染来源均是南方污染重于北方,污染物种类也多于北方.     

大清河流域表层土壤中多环芳烃的污染特征及来源分析

采集大清河流域72个表层七壤(0～20cm)样品,利用GC/MS分析技术,研究了土壤中16种优控多环芳烃的含量和组分特征,根据多环芳烃分布特征和苯并[a]蒽/(苯并[a]蒽+麓)和荧葸/(荧蒽+芘)比值分析了其污染来源,并初步评价了其污染水平.结果表明,表层土壤中16种多环芳烃含量范围为54.2-3231.6μg·kg-1,均值和中位数分别为405.1和233.2μg·kg-1.多环芳烃组分特征表现出以萘、菲等2-3环多环芳烃为主,其含量占到总含量的49%,4环和5～6环含量分别为31%和20%.大清河流域土壤多环芳烃污染主要来自于燃烧源,并表现出以生物质和煤的燃烧为主要来源的特征.相对于国内外其它地区多环芳烃检测结果和土壤标准,大清河流域土壤多环芳烃处于中等偏低污染水平,Nap和Fla是主要的超标化合物.     

Effect of organic matter and pH on mercury release from soils

An investigation was conducted on the effect of organic matter(OM)and pH on mercury(Hg)release from soils.Hg release flux was measured using the dynamic flux chamber(DFC)combined with the Lumex multifunctional mercury analyzer in both laboratory experiment and field monitoring.The results showed that Hg emission from the OM-added soils was apparently low because of the high affinity of OM to Hg,resulting in the reverse order as the amount of OM addition.Meanwhile,Hg release flux from different pH value soils exhibited the same trend for both Hg~(2 )and Hg_2~(2 )treatment,increasing the Hg flux with pH value of soils increasing.The trend of Hg release in the pH dependence experiment has been well in agreement with that from the field test.In addition,Hg release seemed to be related to its species in the soil,the flux from Hg~(2 )-added soil was obviously higher than that of Hg_2~(2 )-added soil by the laboratory experiment.