沈阳细河流域土壤和作物中汞的潜在生态危害及健康风险评价

为研究沈阳市细河流域土壤汞(Hg)的污染和健康风险状况,对该区土壤和农作物中Hg的含量和分布进行了调查和分析。采用Hakanson潜在生态风险危害指数法评价土壤Hg的污染状况,并利用健康风险评价模型对Hg通过不同暴露途径所引起的健康风险作出评价。研究结果表明,细河流域土壤Hg的潜在生态危害相对较大,其中43.21%样品处于中等危害程度,26.62%属于强及以上风险级别。健康风险评价模型计算表明,人体经食物摄取是土壤Hg暴露的主要途径,Hg日平均暴露剂量依次为食物摄取呼吸暴露皮肤暴露;成人和儿童的非致癌危害指数分别为0.315和0.713,均低于风险阈值1,表明Hg不会对人体造成健康危害。     

Microbiota associated with the migration and transformation of chlorinated aliphatic hydrocarbons in groundwater

Pollution of groundwater with chlorinated aliphatic hydrocarbons (CAHs) is a serious environmental problem which is threatening human health. Microorganisms are the major participants in degrading these contaminants. Here, groundwater contaminated for a decade with CAHs was investigated. Numerical simulation and field measurements were used to track and forecast the migration and transformation of the pollutants. The diversity, abundance, and possible activity of groundwater microbial communities at CAH-polluted sites were characterized by molecular approaches. The number of microorganisms was between 5.65E+05 and 1.49E+08 16S rRNA gene clone numbers per liter according to quantitative real-time PCR analysis. In 16S rRNA gene clone libraries constructed from samples along the groundwater flow, eight phyla were detected, and Proteobacteria were dominant (72.8 %). The microbial communities varied with the composition and concentration of pollutants. Meanwhile, toluene monooxygenases and methane monooxygenases capable of degradation of PCE and TCE were detected, demonstrating the major mechanism for PCE and TCE degradation and possibility for in situ remediation by addition of oxygen in this study.     

高炉煤气洗涤水脱氰研究

氯碱法处理高炉煤气洗涤水,运用正交实验设计方法设计实验,根据直观分析和方差分析方法整理实验数据,得出最佳反应条件,影响因素顺序,显著因素。     

历史让我们在这里沉思:2003年黄河大水灾回眸

2003年是中国历史上不平凡的一年。先是突如其来的“非典”,后是新疆巴楚-伽师、青海德令哈和云南大姚地震。到了7—8月的主汛期,大江大河安澜度过,人们迎着凉凉的秋风,把自然灾害的伤痛留给了历史。     

Bronchial Rn dose survey for residences

The bronchial dosimeter for Rn progeny proposed by Yu and Guan in 1998 was employed to survey the bronchial dose from Rn progeny in 30 residences in Hong Kong. An average bronchial deposition fraction of Rn progeny was obtained as 0.0334, which gave an average dose conversion factor (DCF) of 8.5 mSv WLM-1. The mean values of potential alpha energy concentration (PAEC) deposited in the tracheobronchial region (PAECT-B), total PAEC in air (PAECT), annual effective dose (E), concentration of Rn gas (RC) and annual dose conversion factor (ADCF) for all the residential sites combined were 0.11 +/- 0.05, 3.1 +/- 1.4 mWL, 1.2 +/- 0.5 mSv yr-1, 23 +/- 10 Bq m-3 and 0.055 +/- 0.020 (mSv yr-1 per Bqm-3), respectively, with air-conditioned sites (AC sites) and non-AC sites having significantly different mean ADCF values. The indoor relative humidity affected PAECT and RC with high confidence levels (> 95%).     

中国沿海开放地区工业污染控制的探讨

在环境保护工作由污染问题治现向清洁生产转变过程中，中国沿海开放地区、外资，合资、集体和个体企业在其工业结构中所占比重较大，且要求有良好投资环境，当前控制工业污染，须按社会主义市场经济规律征收资源费和排污费，同时要加强环境规划，建立环境管理系统，有效调工业污原杂源，为保证受损环境得以恢复，须加强环境建设和环境投资。     

建筑施工伤亡事故高发原因分析及对策探讨

随着经济的迅速发展,建筑队伍随之壮大,但伴随而来的建筑施工伤亡事故也迅速增加.建筑施工伤亡事故有三大特点:一是事故高峰出现在夏秋季节;二是高空坠落、触电、起重伤害事故占建筑施工伤亡事故的90%以上;三是违章指挥、违章作业、违反劳动纪律"三违"造成的事故占绝大多数.     

流域农村生活垃圾收运、处理模式探析研究——以巢湖流域为例

流域农村生活垃圾产量大,无害化处理水平低,已成为威胁流域水环境安全的重要因素.以巢湖流域为例,构建了农村生活垃圾收运、处理模式.从技术、经济、环境三方面分析,得出结论：农村“桶装车载直运模式”和“垃圾综合处理模式”可以充分利用现有垃圾处理设施,经村庄收集、乡镇转运,最终实现垃圾减量化、资源化、无害化.     

Fractal analysis of polyferric chloride-humic acid （PFC-HA） flocs in different topological spaces

The fractal dimensions in different topological spaces of polyferric chloride-humic acid (PFC-HA) flocs, formed in flocculating different kinds of humic acids (HA) water with different initial pH (9.00, 7.00, 5.00) and PFC dosages, were calculated by effective density-maximum diameter, image analysis, and N2 absorption-desorption methods, respectively. The mass fractal dimensions (Df) of PFC-HA flocs, being more than 2.0, calculated by bi-logarithm relation of effective density-maximum diameter and Logan empirical formula at initial pH of 7.00 had 11-13 percentage greater than those at pH 9.00 and 5.00, indicating the most compact flocs formed in flocculated HA water at initial pH of 7.00. The image analysis for those flocs indicates that after flocculating the HA water at initial pH greater than 7.00 with PFC flocculant, the fractal dimensions of D2 (logA vs. logdL) and D3 (logVsphere vs. logdL) of PFC-HA flocs decreased with the increase of PFC dosages, and PFC-HA flocs showed a gradually looser structure. At the optimum dosage of PFC, the D2 (logA vs. logdL) values of the flocs show 14%--43% difference with their corresponding Df, and they even had different tendency as the change of initial pH values. However, the D2 values of the flocs formed at three different initial pH in HA solution, calculated from the horizontal projected images with magnification about 9, had a same tendency with the corresponding Df. Based on fractal Frenkel-Halsey-Hill (FHH) adsorption and desorption equations, the pore surface fractal dimensions (Ds) for dried powders of PFC-HA flocs formed in HA water with initial pH 9.00 and 7.00 were all close to 2.9421, and the Ds values of flocs formed at initial pH 5.00 were less than 2.3746. It indicated that the pore surface fractal dimensions of PFC-HA flocs dried powder mainly show the irregularity from the mesopore-size distribution and some marcopore-size distribution.     

三峡库区消落带湿地生态过程及生态安全分析—以开县澎溪河湿地自然保护区为例

三峡库区的生态安全与长江中下游的生态环境问题有着直接关系,同时也涉及整个长江流域的可持续发展。本文从库区蓄水后形成的消落带湿地入手,对三峡库区的国土安全、水安全和生物安全等进行分析。基于以上研究,本文提出一些建议,促使消落带湿地的保护及三峡库区生态安全得以保障。