12种杀菌剂制剂对半闭弯尾姬蜂的急性毒性及安全性评价

采用试管药膜法测定了12种杀菌剂制剂对半闭弯尾姬蜂成蜂的急性接触毒性,结合安全性系数评价了供试药剂对半闭弯尾姬蜂的安全性。急性毒性测定结果表明,氟硅唑和啶菌噁唑对半闭弯尾姬蜂成蜂的接触毒性最高,LC50值分别为220.022和223.115 mg·L-1;其次为多抗霉素、丙森锌和戊唑醇,LC50值分别为436.496、472.358和638.638 mg·L-1;其余7种杀菌剂制剂嘧霉胺、啶酰菌胺、苯醚甲环唑、多菌灵、嘧菌酯、嘧菌环胺和异菌脲对半闭弯尾姬蜂成蜂的触杀毒性都较低,LC50值均大于1 000 mg·L-1。安全性评价结果表明,丙森锌和啶菌噁唑对半闭弯尾姬蜂成蜂具有高风险性,安全系数分别为0.16和0.42;嘧霉胺、多抗霉素、氟硅唑和戊唑醇为中等风险性,安全系数分别为1.43、1.56、2.20和3.23;其余6种杀菌剂制剂啶酰菌胺、苯醚甲环唑、多菌灵、嘧菌酯、嘧菌环胺和异菌脲对半闭弯尾姬蜂表现为低风险性,安全系数均大于5。结果显示:甾醇脱甲基抑制剂氟硅唑、戊唑醇和啶菌噁唑以及苯胺基嘧啶类杀菌剂嘧霉胺、有机硫杀菌剂丙森锌和抗菌素多抗霉素对半闭弯尾姬蜂成蜂具有急性毒性风险,在有害生物综合治理中应谨慎使用,特别是啶菌噁唑和丙森锌,以免对半闭弯尾姬蜂造成不良影响和危害。     

Effect of solution pH on aging dynamics and surface structural evolution of mZVI particles: H<Subscript>2</Subscript> production and spectroscopic/microscopic evidence

A microscale zero-valent iron (mZVI)-based in situ reactive zone is a promising technology for contaminated groundwater remediation. Estimation of mZVI aging behavior after its injection into the subsurface is essential for efficiency and longevity assessments. In this study, batch tests were conducted to investigate the effect of initial pH on mZVI aging dynamics, as well as the formation and evolution of aging products over 112 days. Results indicated that mZVI aging accelerated with decreasing initial pH. Corrosion rates of mZVI particles under pH 6.0 and 7.5 were approximately two orders of magnitude higher than those observed at pH 9.0. The morphological, structural, and compositional evolution of mZVI particles in three systems (pH = 6.0, 7.5, and 9.0) were investigated using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. In acidic and neutral solutions, a thick passivation layer with loosely and unevenly distributed aging precipitates was observed, and Fe₃O₄ was the final aging precipitate. Nevertheless, in alkaline solutions, minute aging precipitates were detected on the mZVI surface at 112 day. Characterization results suggested that mZVI was oxidized via the Fe⁰–Fe(OH)₂–Fe₃O₄ route. These findings shed new light on mZVI aging mechanisms, particularly its physicochemical characteristics and the structural evolution of mZVI in field-scale groundwater remediation applications.     

Dynamics of copper and tetracyclines during composting of water hyacinth biomass amended with peat or pig manure

Composting is one of the post-treatment methods for phytoremediation plants. Due to a high potential of water hyacinth to accumulate pollutants, the physicochemical parameters, microbial activity as well as fates of copper (Cu) and tetracyclines (TCs) were investigated for the different amended water hyacinth biomass harvested from intensive livestock and poultry wastewater, including unamended water hyacinth (W), water hyacinth amended with peat (WP), and water hyacinth amended with pig manure (WPM) during the composting process. Pig manure application accelerated the composting process as evidenced by an increase of temperature, electrical conductivity (EC), NH₄-N, as well as functional diversity of microbial communities compared to W and WP treatments. Composting process was slowed down by high Cu, but not by TCs. The addition of peat significantly increased the residual fraction of Cu, while pig manure addition increased available Cu concentration in the final compost. Cu could be effectively transformed into low available (oxidizable) and residual fractions after fermentation. In contrast, less than 0.5% of initial concentrations of TCs were determined at the end of 60-day composting for all treatments in the final composts. The dissipation of TCs was accelerated by the high Cu concentration during composting. Therefore, composting is an effective method for the post-treatment and resource utilization of phytoremediation plants containing Cu and/or TCs.     

Risk assessment of heavy metals in soil of Tongnan District (Southwest China): evidence from multiple indices with high-spatial-resolution sampling

Assessment of heavy metal (HM) pollution in soil is critical for human health, ecological remediation, and soil conservation. In this study, statistical analyses and geochemical approaches such as enrichment factor (EF), the index of geoaccumulation (Igeo), and potential ecological risk index (RI) were used for characterization and risk assessment of soil HMs through a high-spatial-resolution 385 samples from Tongnan District, an important agricultural practice area in Chongqing Municipality in Southwest China. Igeo and EF indicated that Hg and Cd could be considered as low and moderate polluted, respectively, and others HMs were not a major concern. Comprehensive ecological risk information further demonstrated that the HMs have caused a moderate risk. Principal component analysis (PCA) extracted two principal components (PCs) with eigenvalue >1 explaining about 66.1% of the total variance in the HM data sets, demonstrating major source of anthropogenic activity, phosphate fertilizers, vehicle, and pesticides. These multi-index methods have the capacity of HM assessment in soil, which are useful for soil conservation and ecological remediation.     

一种新的处理甲基汞废水的树脂:石油亚砜萃淋树脂

本文对从高硫原油很容易制取的一种新的廉价萃取剂——石油亚砜(PSO)所合成的树脂,即PSO萃淋树脂处理低浓度甲基汞废水的可能性进行了研究。研究结果表明:在中性范围内(pH5—8)树脂对甲基汞的吸附能力很强,吸附率≥99％(废水浓度为10—20ppb);随着流速的增加,吸附率下降幅度很小;树脂易再生, 十倍树脂体积的再生剂(4mol HCl),洗脱率可达97.9％,再生五个周期后,净化率未见明显变化;Mg~(2+)、Fe~(2+)(Fe~(3+)、Ag+、cu~(2+)、Hg~(2+)、PA(黄腐酸)及Cl~-的干扰实验表咀除Hg~(2+)、Ag+外,其他离子基本没有影响。     

城市河流与湖库中痕量有机污染物的研究

通过采用ＧＤＸ－５０２富集,ＧＣ－ＭＳ分析,对城市河流、湖库中的痕量有机污染物进行分析,共检出５８种有机污染物,其中含有多种美国ＥＰＡ公布的重点污染物,从而为痕量有机污染物的研究建立了灵敏度高,分辨率好的测试方法。     

Development and comparison of methods using MS scan and selective ion monitoring modes for a wide range of airborne VOCs

Adsorbent sampling with analysis by thermal desorption, gas chromatography and mass spectrometry (TD/GC/MS) offers many advantages for volatile organic compounds (VOCs) and thus is increasingly used in many applications. For environmental samples and other complex mixtures, the MS detector typically is operated in the scan mode to aid identification of co-eluting compounds. However, scan mode does not achieve the optimal sensitivity, thus compounds occurring at low concentrations may not be detected. This paper develops and evaluates the application of a more sensitive TD/GC/MS method using selective ion monitoring (SIM) that is applicable to VOC mixtures found in ambient and indoor air. Based on toxicity and prevalence, 94 VOCs (including terpenes, aromatic, halogenated and aliphatic compounds) were selected as target compounds. Two analytical methods were developed: a conventional full scan method for ions from 29 to 270 m/z; and a SIM method using 16 time windows and different ions selected for the compounds in each window. Both methods used the same Tenax GR adsorbent sampling tubes, TD and GC parameters, and target and qualifier ions. Laboratory tests determined calibrations, method detection limits (MDLs), precisions, recoveries and storage stability. Field tests compared scan and SIM mode analyses for duplicate samples of indoor air in 51 houses and outdoor air at 41 sites. Statistical analyses included the development of error/precision models. The laboratory tests showed that most compounds demonstrated excellent precision (<10% for concentrations exceeding approximately 0.5 microg m(-3)), good linearity, near identical calibrations for scan and SIM modes, a wide dynamic range (up to 1500 microg m(-3)), and negligible storage losses after 1 month (7 compounds showed moderate losses). SIM mode MDLs ranged from 0.004 to 0.27 microg m(-3), representing a modest (1.1 to 22-fold) improvement compared to scan mode. However, in field tests the SIM method detected significantly more compounds (e.g., styrene and chloroform). Error models fit most compounds and allow quantification of errors at selected percentiles. Overall, while the new SIM method is somewhat time-consuming to develop, it offers greater sensitivity and maintains the high selectivity of traditional scan methods.     

新疆环境保护投资状况与问题分析

环境保护投资对预防和治理环境污染、改善环境状况具有重要作用。新疆经济发展基础薄弱,环境保护投资任务艰巨,从投资规模、投资结构、投资方向、投资主体等方面,分析了新疆环境保护投资状况及存在的主要问题,为决策部门提供参考。     

Concentrations of U,U, U,Th, Th,Th, Ra,Ra, Ra,Po, Pb and Pb in drinking water in Italy: reconciling safety standards based on measurements of gross α and β

Some important naturally occurring α- and β-radionuclides in drinking water samples collected in Italy were determined and the radiological quality evaluated. The mean activity concentrations (mBq L⁻¹) of the radionuclides in the water samples were almost in the order: 26 ± 36 (²³⁴U) > 21 ± 30 (²³⁸U) > 8.9 ± 15 (²²⁶Ra) > 4.8 ± 6.3 (²²⁸Ra) > 4.0 ± 4.1 (²¹⁰Pb) > 3.2 ± 3.7 (²¹⁰Po) > 2.7 ± 1.2 (²¹²Pb) > 1.4 ± 1.8 (²²⁴Ra) > 1.1 ± 1.3 (²³⁵U) > 0.26 ± 0.39 (²²⁸Th) > 0.0023 ± 0.0009 (²³⁰Th) > 0.0013 ± 0.0006 (²³²Th). The mean estimated dose (μSv yr⁻¹) to an adult from the water intake was in this order: 2.8 ± 3.3 (²¹⁰Po) > 2.4 ± 3.2 (²²⁸Ra) > 2.1 ± 2.1 (²¹⁰Pb) > 1.8 ± 3.1 (²²⁶Ra) > 0.94 ± 1.30 (²³⁴U) > 0.70 ± 0.98 (²³⁸U) > 0.069 ± 0.087 (²²⁴Ra) > 0.036 ± 0.044 (²³⁵U) > 0.014 ± 0.021 (²²⁸Th) > 0.012 ± 0.005 (²¹²Pb) > 0.00035 ± 0.00029 (²³⁰Th) > 0.00022 ± 0.00009 (²³²Th). It is obvious that ²¹⁰Po, ²²⁸Ra, ²¹⁰Pb and ²²⁶Ra are the most important dose contributors in the drinking water intake. As far as the seventeen brands of analysed drinking water were concerned, the committed effective doses were in the range of 2.81–38.5 μSv yr⁻¹, all well below the reference level of the committed effective dose (100 μSv yr⁻¹) recommended by the WHO. These data throw some light on the scale of the radiological impact on the public from some naturally occurring radionuclides in drinking water, and can also serve as a comparison for the dose contribution from artificial radionuclides released to the environment as a result of human practices. Based on the radionuclide composition in the analysed waters, comment was made on the new screening level for gross α activity in guidelines for drinking-water quality recommended by the WHO, 2004.     

济南城市防洪现状及对策分析

2007年7月18日突然袭击的特大暴雨洪水,给济南市带来特大灾害.分析了造成济南"7.18"洪水的一些原因,论述了目前济南城市防洪的现状,提出了可能采取的应对济南城市防洪问题的一些对策,包括工程及非工程方面的措施.