Response of ammonia-oxidizing archaea and bacteria to long-term industrial effluent-polluted soils,Gujarat, Western India

Soil nitrifiers have been showing an important role in assessing environmental pollution as sensitive biomarkers. In this study, the abundance and diversity of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) were investigated in long-term industrial waste effluent (IWE) polluted soils. Three different IWE polluted soils characterized as uncontaminated (R1), moderately contaminated (R2), and highly contaminated (R3) were collected in triplicate along Mahi River basin, Gujarat, Western India. Quantitative numbers of ammonia monooxygenase α-subunit (amoA) genes as well as 16S rRNA genes indicated apparent deleterious effect of IWE on abundance of soil AOA, AOB, bacteria, and archaeal populations. Relatively, AOB was more abundant than AOA in the highly contaminated soil R3, while predominance of AOA was noticed in uncontaminated (R1) and moderately contaminated (R2) soils. Soil potential nitrification rate (PNR) significantly (P?<?0.05) decreased in polluted soils R2 and R3. Reduced diversity accompanied by apparent community shifts of both AOB and AOA populations was detected in R2 and R3 soils. AOB were dominated with Nitrosospira-like sequences, whereas AOA were dominated by Thaumarchaeal “group 1.1b (Nitrososphaera clusters).” We suggest that the significant reduction in abundance and diversity AOA and AOB could serve as relevant bioindicators for soil quality monitoring of polluted sites. These results could be further useful for better understanding of AOB and AOA communities in polluted soils.     

Characteristics of surface ozone at an urban site of Xi'an in Northwest China

Surface ozone concentrations in Xi'an, China were monitored from March 23, 2008 to January 12, 2009 using the Model ML/EC9810 ozone analyzer. The daily average O(3) ranged from <1 ppb to 64.2 ppbv with an annual average of 16.0 ppbv. The seasonal average of O(3) in summer (32.5 ppbv) was more than 10 times higher than that in winter (3.0 ppbv). A significant positive correlation was found between ozone concentration and ambient temperature, indicating that the intensity of solar radiation was one of the several major factors controlling surface ozone production. Using the NOAA HYSPLIT 4 trajectory model, the three longest O(3) pollution episodes were found to be associated with the high biogenic volatile organic carbon (BVOC) emissions from the vegetation of Qinling Mountains. No significant weekday and weekend difference in O(3) levels was detected due to the non-significant change in NO(x) emissions. O(3) depletion by NO emission directly emitted from vehicles, low oxygenated VOC concentrations, and low-level solar radiation caused by high aerosol loading all contributed to the low levels of O(3) found in Xi'an compared to other cities and rural areas.     

Spatial distribution and human contamination quantification of trace metals and phosphorus in the sediments of Chaohu Lake,a eutrophic shallow lake,China

Distinguishing and quantifying anthropogenic trace metals and phosphorus accumulated in sediment is important for the protection of our aquatic ecosystems. Here, anthropogenic proportion and potential sources of trace metals and phosphorus in surface sediments of Chaohu Lake were evaluated based on the exhaustive geochemical data. The analysis shows that concentrations of major and trace metals, and phosphorus, displayed significant spatial diversity and almost all elements were over the pre-industrial background value, which should be related to the variations of sediment composition partially. Therefore, conservative element normalization was introduced and calculated enrichment factors (EFs) of the elements were referenced highlighting the human contamination. EFs of the major and trace metals, except Zn, Pb, and Cu, were all nearly 1.0, indicating the detrital origin. The EFs of Zn, Pb, Cu and phosphorus were 1.0–10.4, 1.0–3.8, 1.0–4.9, and 1.0–7.6, respectively, showing moderate to significant contamination. Higher EFs of Zn, Pb and Cu occurred in the mouth areas of Nanfei River and Zhegao River, and they decreased to the lake center in the northwest and northeast lake areas, respectively. We deduced that anthropogenic Zn, Pb, and Cu were mainly from urban and industrial point sources and the non-point sources of atmospheric deposition contributed little to their contamination. The EFs of phosphorus showed similar spatial degradation with that of Zn, Pb, and Cu. Moreover, higher EFs (>1) of phosphorus also occurred in other areas adjacent to the river mouths besides Nanfei River and Zhegao River. This indicated that the non-point agricultural source may also be responsible for the contamination of phosphorus in Chaohu Lake in addition to the urban sewage sources. Anthropogenic phosphorus was mainly concentrated in the speciation of NaOH-P, which had higher potential biological effects than the detrital proportion. Concentrations of Zn, Pb and Cu surpassed the threshold effect concentrations (TEC) of consensus-based sediment quality guidelines of freshwater ecosystems, especially in the contaminated northwest area of Chaohu Lake. This highlighted the contributions of anthropogenic contamination to the elevated potential biological effects of trace metals. Though there had been no obvious human contamination of Cr and Ni in Chaohu Lake, concentrations were all over the TECs, which may be due to higher background levels in the parent materials of soils and bedrocks in Chaohu Lake catchment.     

重金属离子对黑根霉菌生长抑制作用微量热研究

用微量热法测定了Cu~(2+),Cd~(2+),Hg~(2+),Pb~(2+)等四种重金属离子对黑根霉菌生长抑制的产热曲线,得到了黑根霉菌在不同条件下的生长速率常数k,抑制率I,半抑制浓度IC_(50)等参数。实验结果表明,抑制顺序为:Cd~(2+)>Hg~(2+)>Pb~(2+)>Cu~(2+);半抑制浓度分别为:Cd~(2+)0.8μg·ml~(-1);Hg~(2+)1.7μg·ml~（-1）;Pb~（2+）48.0μg·ml~(-1);Cu~(2+)110.0μg·ml~(-1)。     

冷原子吸收法测汞用干燥剂

试验了几种常用的干燥剂在冷原子吸收法测定水中汞时,对汞蒸气的干燥性能及对测定灵敏度的影响。结果表明,以无水氯化钙和无水高氯酸镁效果最好     

Patterns and sources of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in surficial sediments of Lakes Erie and Ontario

This study determines spatial trends and congener patterns of 2378-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in surficial sediments of Lakes Erie and Ontario. Sediments are enriched in 2378-PCDFs in Lake Ontario, and the PCDD/F concentrations increased from shallow near-shore sediments towards deep-water depositional zone sediments. In Lake Erie, sediments were dominated by octachlorodibenzo-p-dioxin, and the highest PCDD/F concentrations were observed in the western basin and the southern shoreline of the central basin with a decrease towards the eastern basin and the northern shoreline of the central basin. Principal components analysis revealed that chemical manufacture and disposal of chemical waste along the Niagara River has been a major PCDD/F source to Lake Ontario; while PCDD/Fs in Lake Erie are from multiple sources including industrial sources along the Detroit River, major tributaries along the southern shoreline of the lake, and atmospherically-derived material from the upper lakes and connecting channels.     

粉煤灰对苯酚废水的吸附研究

在静态条件下研究了粉煤灰对苯酚的吸附性能,结果表明:平均粒径29.06μm,孔隙率64.0686%,在吸附时间50min,粉煤灰用量120 g/L,pH=7.45条件下,对75 mL浓度为30 mg/L的苯酚模拟废水,吸附效果最好,可达82.4%。粉煤灰吸附苯酚机理复杂,偏向于单分子层吸附的Langmuir吸附等温线模式:q=0.042Ce/(1+0.095Ce),吸附反应为一级反应,速率方程为lnC=-0.0096t+3.3097(C0=30 mg/L)。     

区域环境质量评价与模糊聚类分析

近年来区域环境质量评价虽进展迅速,但加权与分级仍为其中最无把握、且最易引起争议的问题,迄今仍未妥善解决。本文基于上海某区的环境质量评价提出了一种新方法的应用,即模糊聚类分析,它自然而简捷地解决了上述问题。首先,它在被分级的元素之间建立一个模糊相似关系,再通过模糊矩阵的复合运算,由细到粗地逐步绘出一棵动态聚类树,最后根据地方环境状况确定一个λ值以后,就可获得一个客观的模糊聚类的质量分级。通过将其结果与系统分级的比较。显示了两者的某些差异。     

无锡市碳排放的因素分解模型及实证分析

在计算无锡市2000~2011年二氧化碳排放量的基础上,采用对数平均权重Divisia分解法,建立无锡市人均碳排放的因素分解模型,定量分析能源结构、能源效率、经济发展情况等因素对无锡市人均碳排放的影响。结果显示经济发展对拉动无锡人均碳排放的贡献率呈指数增长趋势,相比之下,能源效率及能源结构对碳排放的抑制作用并不明显。据此提出开发可再生能源,转变能源消费结构,发展清洁煤技术,提高能源利用率等对策。     

One century sedimentary record of lead and zinc pollution in Yangzong Lake, a highland lake in southwestern China

Reconstruction of trace metal pollution histories and sources may help us to regulate current pollutant discharge. This is especially important for the highland lakes in southwestern China, which are facing trace metals pollution. We present sedimentary records of 11 metals accumulated in Yangzong Lake since the 1870's, a highland lake in southwestern China. Pollution of lead and zinc (Pb and Zn) was differentiated based on principal component analysis, geochemical normalization, and lead isotope ratios. Nearly all the metals as well as grain size composition show generally constant values before the mid-1980's, denoting stable detrital input in the catchment. Fluctuations in the concentrations of the metals as well as grain size composition since the mid-1980's indicate an increase in soil erosion with strengthened human disturbance in the catchment. After geochemical normalization, Pb and Zn showed constant values before 1990 AD and then a gradual increase in parallel with the variations in ²⁰⁸Pb/²⁰⁶Pb and ²⁰⁷Pb/²⁰⁶Pb ratios, indicating that Pb and Zn pollution occurred. Combining the data of ²⁰⁸Pb/²⁰⁶Pb and ²⁰⁷Pb/²⁰⁶Pb ratios in the sediments of Yangzong Lake, leaded gasoline, Pb-Zn ore and coal, and consumption or production historical trends, we deduced that the enhanced Pb and Zn pollution in Yangzong Lake is caused primarily by ore mining and refining.