Explanation of heavy metal pollution in coal mines of china from the perspective of coal gangue geochemical characteristics

Environmental Science and Pollution Research - In the process of coal gangue surface accumulation and underground filling disposal, the heavy metals contained in coal gangue will inevitably...     

不同扰动下外源磷在形态磷间的分布规律

研究了3种扰动方式对外源磷在上覆水、间隙水、底泥中的数量分布的影响,并分析了内源磷形态间的转化过程.结果表明,与对照实验相比,物理扰动能促进上覆水中磷向底泥迁移,并高于生物扰动和组合扰动的促进作用,并且,三者均高于对照实验.这可归因于溶解氧的渗入.物理扰动能降低间隙水中DIP的平均含量,相比对照实验降低了12.13%(第6 d和第10 d平均值),但降低程度不如生物扰动(38.63%)和组合扰动(50.79%).3种扰动均能促进Fe/Al-P和Ca-P的形成,其中,物理扰动下Fe/Al-P和Ca-P平均形成量最大,物理扰动下AAP含量一直在减小,暗示物理扰动明显促进了AAP向闭蓄态的Fe/Al-P或者Ca-P转化.     

活性污泥中硝化螺菌(Nitrospira)的富集及其动力学参数

采用连续进水的进水方式对污水处理厂活性污泥系统中的Nitrospira富集培养并对其相关动力学参数进行研究.结果表明,在控制反应器亚硝酸盐浓度不高于2 mg·L~(-1)的条件下可以成功富集出以Nitrospira为优势种属的活性污泥,其最大比亚硝酸盐氧化速率(以N/VSS计)为48.72 mg·(g·h)~(-1).荧光原位杂交结果显示Nitrospira占活性污泥总微生物量的75%左右,而Nitrobacter仅占总微生物的0.1%.此外通过对Nitrospira在20℃时的动力学参数进行测定,结果表明Nitrospira的最适生长温度为30~35℃,温度修正系数τN为1.046,其基质半饱和常数KS和氧半饱和常数KO分别为(0.32±0.03)mg·L~(-1)和(1.52±0.09)mg·L~(-1).Nitrospira动力学参数的研究为污水处理厂的设计运行及工艺优化提供理论参考.     

长江口海域底栖生态环境质量评价——AMBI和M-AMBI法

AMBI(AZTI’s Marine Biotic Index)和M-AMBI(Multivariate-AMBI)指数可以有效地评价河口和近岸海域软底质海洋大型底栖动物群落对人为和自然扰动的响应.本研究根据2009年4月在长江口采集的大型底栖动物资料,首次在长江口海域同时运用栖息密度和生物量计算AMBI(BAMBI)和M-AMBI(M-BAMBI),对其进行底栖生态质量评价.结果表明,长江口底栖生态环境皆受到不同程度的干扰,其中受干扰最严重的区域集中在杭州湾、舟山及长江口门区附近海域,与该海域的陆源排污、富营养化以及大量的海岸工程建设等有密切的关系.单因素方差分析表明,运用栖息密度和生物量计算出的两个指数值,评价结果无明显的差异.与AMBI相比,M-AMBI与本研究生物群落结构参数以及环境因子的匹配度更高,能够更有效地评价长江口底栖生态环境质量.Pearson相关分析和一元线性回归分析表明,M-AMBI与底层水体的富营养化指数之间存在线性显著负相关关系,而与表层水体的呈非线性显著负相关;AMBI与富营养化指数之间却无显著相关关系,说明M-AMBI更适合指示长江口水域的富营养化压力.     

应用相平衡分配法建立湘江衡阳段沉积物重金属质量基准

采集湘江衡阳段29个站点的表层沉积物样品,测定沉积物中4种重金属(Cu、Pb、Zn和Cd)含量及赋存形态、以及孔隙水中重金属含量,根据相平衡分配法的基本理论,考虑参与沉积物-水相平衡分配的重金属组成,实测法计算重金属的沉积物-水相平衡分配系数(Kp),分别引用美国EPA制定保护水生生物不受重金属慢性毒性影响的基本连续浓度(CCC)和我国地表水环境质量标准(GB 3838-2002)Ⅰ类水质标准,建立两种湘江衡阳段沉积物重金属质量基准(SQC)进行对比分析,其中基于美国CCC建立的湘江衡阳段沉积物重金属质量基准与国内外研究成果相比可比性较好,4种重金属(Cu、Pb、Zn和Cd)的SQC值分别为64.62、55.57、1 360.40和2.34μg.g-1,此SQC具有保护长期生活于沉积物中的底栖生物不受重金属慢性毒性影响的意义.通过单因子评价法将湘江衡阳段沉积物中重金属总量与沉积物质量基准值(SQC)进行比较,结果表明,湘江衡阳段沉积物中Cd和Pb含量水平对底栖生物具有较大的慢性毒性影响,Cd污染不容忽视.     

Fenton法处理竹制品废水生化出水的研究

采用Fenton法对竹制品废水生化出水的脱色和有机物去除进行了研究.在综合考虑经济性和去除效果的基础上,起始COD质量浓度为430 mg·L-1、色度为1 500倍的废水,在反应条件:t=30℃,pH为3.5,ρ(H2O2)=1 665 mg·L-1,c(Fe2+)/c(H2O2)=0.072,反应时间3 h的情况下,Fenton氧化处理后,COD和色度的去除率分别高达87.5%和94.4%.研究发现,色度的去除率要优于有机物(以COD计)的去除率,且受外界因素影响小.GC-MS分析结果表明:经过Fenton处理后,废水中的发色团和助色团基本上完全被去除.中间产物主要是脂类衍生物,副产品有1-碘十三烷和正辛基醚等.     

福建省地级市人为源活性氮排放及其特征分析

在人口增长和快速城市化的背景下,活性氮排放对生态环境的影响日益加剧.为研究省级尺度活性氮排放规律,采用排放因子法建立2000、2005及2010年福建省人为源活性氮排放清单,分析各地市3个年份活性氮排放量及排放强度特征.结果表明,3个年份福建省活性氮排放总量分别为538.4、587.0和619.97 Gg,呈整体增加趋势.在9个地级市中,增速最快的为莆田市,而漳州市排放量有所下降.排放量最大的为漳州和泉州,排放量最小的为宁德与厦门.从排放来源看,90%以上的排放来自农田生态系统和畜禽养殖系统.能源活动贡献较小,但其排放增长最为显著.2010年,各地市单位面积活性氮排放强度呈"东南沿海高西北内陆低"的格局,最高为厦门市,最低为三明市;GDP和人口排放强度则呈"东南沿海低西北内陆高"的格局,最高为南平市,最低为厦门市.在分析各地市活性氮排放源特征的基础上,探讨了不同地区活性氮减排重点,研究结果可为福建省及下辖各地市活性氮减排提供科学依据.     

基于车载测试的重型柴油车尾气典型烷烃排放特征

本文采用车载排放测试系统对11辆国Ⅰ~国Ⅳ标准重型柴油车进行实际道路测试,利用GC-MS对样品中典型烷烃进行定量分析,解析重型柴油车尾气典型烷烃排放特征及规律.结果表明,排放标准对重型柴油车尾气中正构烷烃、藿烷类有机物排放有显著影响,总体呈现随排放标准的加严而降低的趋势,相比于国Ⅰ测试车辆,国Ⅳ测试车辆正构烷烃、17α(H),21β(H)-C30藿烷(C30-藿烷)、22S-和22R-17α(H),21β(H)-C31升藿烷(22S-C31升藿烷;22R-C31升藿烷)总排放因子分别降低了72.23%,64.95%,70.78%和74.68%.气相正构烷烃呈双峰前锋型,以C17~C18为主峰碳,固相呈单峰前锋型,以C18~C21为主峰碳.藿烷类有机物其22S-C31升藿烷/(22S-C31升藿烷+22R-C31升藿烷)的比值在0.46~0.56之间,平均值为0.50,符合石油中藿烷的分布特征.正构烷烃总排放因子与17α(H),21β(H)-C30藿烷总排放因子呈现出一定的线性关系,其R~2为0.926 8.此外,行驶工况对测试车辆正构烷烃及藿烷类有机物排放有较大影响,非高速工况下排放因子是高速工况的1.69~2.42倍.     

Re-evaluation of thyroid hormone signaling antagonism of tetrabromobisphenol A for validating the T3-induced Xenopus metamorphosis assay

We developed the T3-induced Xenopus metamorphosis assay, which is supposed to be able to sensitively detect thyroid hormone(TH) signaling disruption of chemicals. The present study aimed to validate the T3-induced Xenopus metamorphosis assay by re-evaluating the TH signaling antagonism of tetrabromobisphenol A(TBBPA), a known TH signaling disruptor. According to the assay we developed, Xenopus tadpoles at stage 52 were exposed to 10–500 nmol/L TBBPA in the presence of 1 nmol/L T3. After 96 hr of exposure, TBBPA in the range of 10–500 nmol/L was found to significantly inhibit T3-induced morphological changes of Xenopus tadpoles in a concentration-dependent manner in term of body weight and four morphological endpoints including head area(HA), mouth width(MW), unilateral brain width/brain length(ULBW/BL), and hind-limb length/snout-vent length(HLL/SVL).The results show that these endpoints we developed are sensitive for characterizing the antagonistic effects of TBBPA on T3-induced metamorphosis. Following a 24-hr exposure,we found that TBBPA antagonized expression of T3-induced TH-response genes in the tail,which is consistent with previous findings in the intestine. We propose that the tail can be used as an alternative tissue to the intestine for examining molecular endpoints for evaluating TH signaling disruption. In conclusion, our results demonstrate that the T3-induced Xenopus metamorphosis assay we developed is an ideal in vivo assay for detecting TH signaling disruption.     

Applicability of LIVE/DEAD BacLight stain with glutaraldehyde fixation for the measurement of bacterial abundance and viability in rainwater

Rainwater contains substantial bacteria and rain is an efficient pathway for the dissemination of bacteria from the atmosphere to land and water surfaces.However,quantitative information on rainwater bacteria is very limited due to the lack of a reliable method.In this study,the epifluorescence microscopy enumeration with the LIVE/DEAD BacLight Bacterial Viability Kit stain was verified to quantify the abundance of viable and non-viable bacterial cells in rainwater,with the 4',6-diamidino-2-phenylindole(DAPI) stain for the reference of total cell counts.Results showed that the total counts of bacterial cells by LIVE/DEAD BacLight staining were consistent with those by DAPI staining,and the average detection efficiency was(109 ± 29)%.The ratio of cell count with glutaraldehyde fixation to that without fixation was(106 ± 5)%on average.The bacterial concentration in negative control was usually an order of magnitude lower than that in rainwater samples.However,in case of small precipitation,the abundance in negative control could be more than that in rainwater samples.These results indicate that the enumeration with LIVE/DEAD BacLight bacterial viability assay coupled with glutaraldehyde fixation and careful negative control investigation is an approach applicable to the measurement of the concentration and viability of bacterial cells in rainwater.