Soil fungistasis and its relations to soil microbial composition and diversity: A case study of a series of soils with di erent fungistasis

Fungistasis is one of the important approaches to control soil-borne plant pathogens.Some hypotheses about the mechanisms for soil fungistasis had been established,which mainly focused on the soil bacterial community composition,structure,diversity as well as function.In this study,the bacterial community composition and diversity of a series of soils treated by autoclaving,which coming from the same original soil sample and showing gradient fungistasis to the target soil-borne pathogen fungi Fusarium gr...     

Nitrogen pollution and source identification of urban ecosystem surface water in Beijing

Nitrogen contamination of surface water is a worldwide environmental problem with intensive agricul- ture and high population densities. We assessed the spatial and seasonal variation in concentrations of total nitrogen and different nitrogen species present in surface-water in Beijing, China. Also, chemical （NO3-N/C1-） and isotopic （615Nnitrate） indicators were used to identify nitrate sources. The results showed that, during 2009 and 2010, nitrate nitrogen concentrations ranged from 0.7 to 7.6 mg· L^-1, ammonium nitrogen from 0. I to 3.4 mg· L^-1, and total nitrogen from 2.4 to 17.0mg· L^-1. Inorganic nitrogen accounted for between 60 and 100% of total nitrogen at the ten monitoring sites. Nitrate nitrogen, ammonium nitrogen, and total nitrogen concentrations at the 2 downstream monitoring sites in south-eastern Beijing were significantly higher than those at the other eight upstream monitoring sites （P 〈 0.01）. Examination of seasonal variation showed that there was a significant inverse relationship between nitrate nitrogen concentrations and precipitation, and that nitrate nitrogen concentrations peaked in the dry seasons. The information given by the 15Nnitrate values and nitrate nitrogen concentrations, combined with the NO3-N/C1- ratio distribution, showed that domestic sewage was the major source of nitrate in Beijing. Methods to control and reduce sewage pollution are urgently needed to help manage surface water quality in Beijing.     

Total phosphorus concentrations in surface water of typical agro- and forest ecosystems in China, 2004–2010

The concentrations of total phosphorus （TP） from 83 surface water sampling sites in 29 of the Chinese Ecosystem Research Network （CERN） monitored ecosystems, representing typical agro- and forest ecosystems, were assessed using monitoring data collected between 2004 and 2010 from still and flowing surface water. Results showed that, TP concentrations were significantly higher in agro-ecosystems than those in forest ecosystems both for still and flowing surface water. For agro- ecosystems, TP concentrations in the southern area were significantly higher than those in the northern and north- western areas for both still and flowing surface water, however no distinct spatial pattern was observed for forest ecosystems. In general, the median values of TP within agro- and forest ecosystems did not exceed the Class V guideline for still （0.2mg.L-1） or flowing （0.4mg.L-1） surface water, however, surface water at some agro- ecosystem sampling sites was frequently polluted by TE Elevated concentrations were mainly found in still surface water at the Changshu, Fukang, Linze and Naiman monitored ecosystems, where exceedance （〉 0.2 mg.L-1） frequencies varied from 43% to 78%. For flowing water, elevated TP concentrations were found at the Hailun, Changshu and Shapotou monitored ecosystems, where exceedance （〉 0.4 mg. L-1） frequencies varied from 29% to 100%. Irrational fertilization, frequent irrigation and livestock manure input might be the main contributors of high TP concentrations in these areas, and reduced fertilizer applications, improvements in irrigation practices and centralized treatment of animal waste are necessary to control P loss in these TP vulnerable zones.     

Zero-valent manganese nanoparticles coupled with different strong oxidants for thallium removal from wastewater

• Nano zero-valent manganese (nZVMn, Mn⁰) is synthesized via borohydrides reduction. • Mn⁰ combined with persulfate/hypochlorite is effective for Tl removal at pH 6-12. • Mn⁰ can activate persulfate to form hydroxyl and sulfate radicals. • Oxidation-induced precipitation and surface complexation contribute to Tl removal. • Combined Mn⁰-oxidants process is promising in the environmental field. Nano zero-valent manganese (nZVMn, Mn⁰) was prepared through a borohydride reduction method and coupled with different oxidants (persulfate (S₂O₈²⁻), hypochlorite (ClO⁻), or hydrogen peroxide (H₂O₂)) to remove thallium (Tl) from wastewater. The surface of Mn⁰ was readily oxidized to form a core-shell composite (MnO_x@Mn⁰), which consists of Mn⁰ as the inner core and MnO_x (MnO, Mn₂O₃, and Mn₃O₄) as the outer layer. When Mn⁰ was added alone, effective Tl(I) removal was achieved at high pH levels (>12). The Mn⁰-H₂O₂ system was only effective in Tl(I) removal at high pH (>12), while the Mn⁰-S₂O₈²⁻ or Mn⁰-ClO⁻ system had excellent Tl(I) removal (>96%) over a broad pH range (4–12). The Mn⁰-S₂O₈²⁻ oxidation system provided the best resistance to interference from an external organic matrix. The isotherm of Tl(I) removal through the Mn⁰-S₂O₈²⁻ system followed the Freundlich model. The Mn⁰ nanomaterials can activate persulfate to produce sulfate radicals and hydroxyl radicals. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy suggested that oxidation-induced precipitation, surface adsorption, and electrostatic attraction are the main mechanisms for Tl(I) removal resulting from the combination of Mn⁰ and oxidants. Mn⁰ coupled with S₂O₈²⁻/ClO⁻ is a novel and effective technique for Tl(I) removal, and its application in other fields is worthy of further investigation.     

Effects of H19/SAHH/DNMT1 on the oxidative DNA damage related to benzo[a]pyrene exposure

Environmental Science and Pollution Research - The mechanisms that long noncoding RNA (lncRNA) H19 binding to S-adenosylhomocysteine hydrolase (SAHH) interacted with DNA methyltransferase 1 (DNMT1)...     

热喷涂粉尘理化特性及危害研究

通过对热喷涂现场粉尘进行采样和监测,分析了热喷涂粉尘的质量浓度、粒径分布、微观形貌及成分组成等理化特性,依此评估热喷涂粉尘潜在的危害。结果表明:热喷涂作业区域粉尘浓度普遍高于职业卫生标准规定的浓度限值;热喷涂粉尘粒径分布范围广,其中包含大量的微纳米粉尘颗粒,这些超细颗粒粉尘由于质量轻,受重力影响小,很难自然沉降,清除周期较长;粉尘含有多种金属元素,包括一些重金属,如铬、镍、铜等。这些特性决定了热喷涂粉尘危害的严重性,因此有必要采取保护措施减少其对从业人员的危害。     

环境监测质量控制现状与对策研究

环境监测的质量控制在监测工作中发挥着至关重要的作用。从质控制度、制度执行力、质控措施、人员素质、试剂材料、检测方法和纠正措施方面对环境监测站质量控制现状进行了阐述,提出了制度执行力低下、质控措施不够全面、监测人员业务素质不高、实验材料达不到要求、分析检测方法更新不及时、纠正措施欠缺的问题,有针对性地提出了完善质量控制的对策,包括提高质控意识、强化措施的落实、健全质控措施、注重人员培训、发挥纠正措施作用。     

伊宁市“一五”期间环境质量噪声变化分析及措施

根据伊宁市“十一五”期间环境噪声质量监测结果,分析了环境噪声的变化趋势,总结了经验,提出进一步提高环境质量的措施。     

基于行业碳排放分析的低碳城市建设研究——以秦皇岛市为例

文章计算了2007年秦皇岛市23个行业的市内调出、市外国内购进与进口产品中隐含碳排放量,得出秦皇岛是一隐含碳量调入大于输出的区域;本区行业较为优化,但是依然有提高的空间.依据计算结果,以降低本区隐含碳排放量为目标,基于区域贸易、比较优势与低碳经济理论,从影响区域隐含碳排放的三个方面,分析了贸易规模、结构、碳完全产生系数等因素在行业隐含碳排放中的贡献,为降低本区碳排放,提出有符合当前本区社会经济发展阶段的措施,为决策者确定发展侧重点及协调区域间关系提供有益参考.此外,区域尺度经济结构在低碳排放方面的优化,在区域间贸易与合作及比较优势理论的作用下,会促进更大区域尺度经济结构在低碳排放方面的优化.     

Particle-bound polycyclic aromatic hydrocarbons in typical urban of Yunnan-Guizhou Plateau: Characterization,sources and risk assessment

• The sampling was conducted in city on the Yunnan-Guizhou Plateau for one year. • The groups of PAHs revealed their different environmental fates and migration paths. • Seasonal biomass burning could affect the concentration by long-distance transport. • Industrial sources and traffic emissions were the main contributor of PAHs. • Living in industrial areas or winter had higher health risk by exposure PAHs in PM_2.5. Monthly particle-phase ambient samples collected at six sampling locations in Yuxi, a high-altitude city on the edge of Southeast Asia, were measured for particle-associated PAHs. As trace substances, polycyclic aromatic hydrocarbons (PAHs) are susceptible to the influences of meteorological conditions, emissions, and gas-particulate partitioning and it is challenging job to precise quantify the source and define the transmission path. The daily concentrations of total PM_2.5-bound PAHs ranged from 0.65 to 80.76 ng/m³, with an annual mean of 11.94 ng/m³. Here, we found that the concentration of PM_2.5-bound PAHs in winter was significantly higher than that in summer, which was mainly due to source and meteorology influence. The increase of fossil combustion and biomass burning in cold season became the main contributors of PAHs, while precipitation and low temperature exacerbated this difference. According to the concentration variation trend of PM_2.5-bound PAHs and their relationship with meteorological conditions, a new grouping of PAHs is applied, which suggested that PAHs have different environmental fates and migration paths. A combination of source analysis and trajectory model supported local sources from combustion of fossil fuel and vehicle exhaust contributed to the major portion on PAHs in particle, but on the Indochina Peninsula the large number of pollutants emitted by biomass burning during the fire season would affect the composition of PAHs through long-range transporting. Risk assessment in spatial and temporal variability suggested that citizens living in industrial areas were higher health risk caused by exposure the PM_2.5-bound PAHs than that in other regions, and the risk in winter was three times than in summer.