我国3种自然土壤中稀有金属的化学形态分布特征研究

以我国3种典型土壤黑土、潮土和红壤为研究对象,在相对清洁未扰动自然土壤区域采集了土壤的剖面样品,分析了土壤中的稀有金属银(Ag)、铋(Bi)、铟(In)、锡(Sn)的含量水平,利用元素富集率(ER)的垂向分布探讨了外源污染对金属含量的影响,并采用连续逐级提取法研究了土壤中稀有金属的化学形态分布特征,用金属可交换态和碳酸...     

煤矸石堆附近耕作层土壤中重金属污染状况与评价

通过对鲁西南煤炭基地若干混堆的煤矸石山周围(10～100m)耕作层土壤的实际调查及分析测试资料,研究了煤矸石堆附近耕作层土壤中重金属污染状况。结果表明,土壤局部已经受到Cd、Ni的污染,但未出现多金属复合污染状况。煤矸石堆附近土壤已经受到采矿等人类活动的影响,其中Cd、Hg的人为影响最大。从8种重金属元素含量随深度的变化曲线形态来看,Hg、Cd 2种元素与Cr、Ni、Cu、Zn、Pb、As6种元素曲线形态显示差异性,Hg、Cd元素在土壤中赋存、迁移等应具特殊性,有待进一步研究。     

Bacterial community succession during the enrichment of chemolithoautotrophic arsenite oxidizing bacteria at high arsenic concentrations

To generate cost-effective technologies for the removal of arsenic from water, we developed an enrichment culture of chemolithoautotrophic arsenite oxidizing bacteria (CAOs) that could effectively oxidize widely ranging concentrations of As(III) to As(V). In addition, we attempted to elucidate the enrichment process and characterize the microbial composition of the enrichment culture. A CAOs enrichment culture capable of stably oxidizing As(III) to As(V) was successfully constructed through repeated batch cultivation for more than 700 days, during which time the initial As(III) concentrations were increased in a stepwise manner from 1 to 10-12 mmol/L. As(III) oxidation activity of the enrichment culture gradually improved, and 10-12 mmol/L As(III) was almost completely oxidized within four days. Terminal restriction fragment length polymorphism analysis showed that the dominant bacteria in the enrichment culture varied drastically during the enrichment process depending on the As(III) concentration. Isolation and characterization of bacteria in the enrichment culture revealed that the presence of multiple CAOs with various As(III) oxidation abilities enabled the culture to adapt to a wide range of As(III) concentrations. The CAOs enrichment culture constructed here may be useful for pretreatment of water from which arsenic is being removed.     

北京及周边地区夏季大气颗粒物区域污染特征

本地排放和区域传输共同影响着北京及周边地区的空气质量.2007年8月在北京清华大学、密云水库、河北任丘和内蒙古商都采集颗粒物样品并获得了PM_2.5质量浓度和TSP中22种无机元素的时空分布特征. 4个观测点PM_2.5质量浓度高低顺序为任丘>清华>密云>商都.二次污染元素S和一次污染元素Zn、Pb、Cu、As、Sb、Ni、Cd、In、Se在任丘的PM中含量最高,表明该观测点受人为源影响最为显著,其较弱的日变化幅度表明高浓度PM主要由本地源贡献;商都地区污染元素浓度随时间变化波动最为剧烈,受气象条件导致的传输影响较大;清华和密云的S、Pb、Cd、In、As、Zn的相关系数均大于0.70,其来源具有一定相似性;在锯齿型污染过程的开始和结束,密云各元素浓度值达到和区域背景点商都观测期间最低值相近的水平,表明密云可以表征西北洁净空气的区域特征; PM峰值阶段,整个地区高浓度硫酸盐的均匀分布（约10 μg/m³）证实了锯齿型区域污染的二次性本质.结合元素富集因子的不同分布特征讨论了各地区PM的可能来源及相互影响     

五氯酚在表面微层水与表层水间的分配行为

利用玻璃板采样器采工分析市南排污河下游至渤变入口处水体表面微层（ＳＭ）中五氯酚（ＰＣＰ）的富体系数,然后在实验室中进行了微宇宙模拟实验,初步探讨了富集原因,现场测结果表明：ＰＣＰ在水体表面微层中有一定程度的富集一般富集系数在１．１６～４．１１之间;其富集可能与悬浮颗粒物在ＳＭ中的富集、盐度、大气沉降过程等有关,与ＴＯＣ无关。实验室研究结果表明：ＰＣＰ在水体表面微层中富集倍数随悬浮颗粒物浓度和盐度增     

天津市大气降水化学组分变化趋势及来源研究

2001—2013年对天津市降水样品进行了采集,分析了p H、电导率(EC)、主要离子浓度(SO2-4、NO-3、Cl-、F-、NH+4、Ca2+、Mg2+、Na+、K+).结果表明:2001—2013年,降水的雨量加权平均p H、EC分别为5.48、87μS·cm-1.降雨的p H、EC及总离子当量浓度呈现上升趋势,酸雨频率呈现下降趋势.降水中各离子雨量加权平均当量浓度排列顺序为:SO2-4Ca2+NH+4NO-3Cl-Mg2+Na+F-K+,SO2-4、Ca2+、NH+4和NO-3是降水中的主要离子,占离子总量的84.8%.SO2-4雨量加权平均当量浓度表现为先轻微上升,后显著下降趋势.NO-3、Ca2+雨量加权平均当量浓度表现为明显上升趋势.NH+4雨量加权平均当量浓度显示为下降趋势.F-、Cl-、K+、Mg2+、Na+等雨量加权平均当量浓度变化趋势基本保持平稳.SO2-4对总阴离子的分担率、NH+4总阳离子的分担率均呈现下降趋势.NO-3对总阴离子的分担率、Ca2+对总阳离子的分担率均呈现明显上升趋势.[NO-3]/[SO2-4]、[Ca2+]/[NH+4]呈现出明显上升趋势.富集因子计算结果表明:Ca2+主要来自地壳.Mg2+和K+部分来自海源输入,但绝大部分来自地壳.大部分Cl-来自海源的输入,其余小部分来自地壳和人为排放.降水中SO2-4、NO-3主要来自人为活动.     

藻源性颗粒有机物对磷饥饿微囊藻磷富集与生长的影响

以藻源性颗粒有机物为切入点,分别以正磷酸盐（K₂HPO₄）、多聚磷酸盐（Na₅P₃O₁₀）、磷酸单酯（G-6-P）、磷酸二酯（卵磷脂）为参考,对比研究了不同形态的磷对磷饥饿微囊藻生长及对磷富集的影响.研究发现密度为（1.9±0.1）×10⁶cells/mL磷饥饿处理的微囊藻对不能直接利用的Na₅P₃O₁₀、卵磷脂的短期富集作用分别为2.034mg/L、1.030mg/L要明显高于K₂HPO₄的0.491mg/L、G-6-P的0.034mg/L和藻源性颗粒物的0.573mg/L,可能与这些磷素不能迅速进入细胞内,因而被大量的积聚在细胞膜与细胞壁之间有关.微囊藻通过释放碱性磷酸酶等酶系可以大量快速的利用藻源性颗粒物,藻源性颗粒物组中微囊藻生长率0.148d^-1稍低于K₂HPO₄组的0.156d^-1,但均高于其他实验组.实验结束时微囊藻对藻源性颗粒物的利用率57.8%高于K₂HPO₄组的32.5%和卵磷脂组的24.4%.通过液相核磁分析,藻源性颗粒物中磷的组分主要为正磷酸盐、磷酸单酯,并通过计算验证了其对磷饥饿铜绿微囊藻的磷富集与生长的影响.综上,藻源性颗粒物有着极强的生物可利用性,对蓝藻的爆发和持续性有着重要影响.     

Enrichments of Trace Metals in Particulate Matter From the Southern East China Sea,North of Taiwan

Abstract

This study investigates the distributions and enrichments of trace metals in suspended and sinking particulate matter from southern East China Sea (ECS) north of Taiwan during the period April 1992 to April 1993. According to these results, concentration of suspended particulate matter in the inner shelf of southern China Sea, the upwellinginfluenced shelf break, and in Kuroshio water are 1.30 (surface)–4.2 (bottom) mg1^?1, ca. 0.4 mg1^?1 and 0.1–0.2 mg1^?1, respectively, reflecting various influences of terrestrial inputs. A benthic nepheloid layer (BNL), apparently owing to resuspension of local and/or remote bottom sediments, formed over the shelf region. Temporal variations in trace metal contents and enrichments in suspended matter from the shelf region reflect the variation of metal inputs from Chinese rivers, particularly from the Changjiang runoff. the enriched metals are more likely to be derived from anthropogenic input, rather than from biological accumulation. in addition, a decrease in metal contents and an increase in salinity confirm the transport of suspended particulate metals from the East China Sea shelf to the open ocean. the feature of metal plume in the intermediate layer (550–800m) of Kuroshio water also verifies this occurrence. Moreover, the sinking particles collected from a sediment trap on the upper slope are relatively enriched in lithogenic matter and trace metals, suggesting the deposit of anthropogenic metals in the slope area.     

Distribution,enrichment, accumulation and potential ecological risks of mercury in the sediments of Kaohsiung Harbor,Taiwan

The distribution, enrichment, accumulation and potential ecological risks of mercury (Hg) in the surface sediments of Kaohsiung Harbor, Taiwan, were investigated. Sediment samples from 20 locations throughout Kaohsiung Harbor were collected quarterly from 2006 to 2011, and characterised for mercury, aluminium, water content, organic matter, total nitrogen, total phosphorous, total grease and grain size. The results showed that Hg concentrations varied from 0.06–6.73 mg kg^?1 with an average of 0.54±0.71 mg kg^?1. The spatial distribution of Hg reveals that the Hg concentration is relatively higher in the river mouth regions, especially at the Love River and Canon River mouths from where it gradually diminishes toward the harbour entrance region. The results from the enrichment factor and geo-accumulation index analyses reveal that the sediments near the Love River and Canon River mouths experience severe enrichment and strong accumulation of Hg that originates from upstream sources of pollution. The assessment of biological effects indicates that concentrations of 92.5% Hg found in the sediment are higher than effects range low, implying that the harbour sediments may cause an adverse impact on aquatic lives. The results of a potential ecological risk index indicate that the sediment has higher to serious levels of ecological potential risks.     

Fates and partitioning of heavy metals in municipal solid waste incineration process

The fate and partitioning of heavy metals (including Hg, Cd, Pb, Zn, As, Cr, Ni, and Cu) from MSW incinerators located in Taiwan were determined. Results of stack sampling indicate that most Hg and As (more than 80%) exists in the gas phase while other metals partition differently among bottom ash, fly ash, and flue gases. Removal efficiencies of existing air pollution control devices for Hg and As are lower (about 70%) than other metals. Bottom ash contains higher concentration of Cd compared with European incinerators. In addition, strong enrichment of Cd on fly ash particles is observed.