炼铝作业氟化物接触剂量与发病关系的分析

目的 了解炼铝作业氟的危害状况,为工业性氟病的防治提供依据.方法 对氟作业环境作职业卫生学调查.采用剂量患病率寿命表法对866名电解铝作业工人工业性氟病的发病情况进行流行病学调查,并作相关回归分析.结果 该厂接氟工人工业性氟病的总患病率为1.73%,且患病率随累积接氟量的增加而升高,呈高度正相关(r＝0.997,P＜0.01).并据所求得回归方程(y＝10.34InD-18.21)推算出接氟工人控制患病率时的允许连续工作年限和今后的发病趋势.结论 该厂电解铝车间氟危害较重,应加强卫生防护措施,并建议将车间氟最高容许浓度从目前1 mg/m3降为0.5 mg/m3为宜.     

巢湖周围池塘氮、磷和有机质研究

巢湖周围池塘众多,根据池塘位置和地表径流补给差异,池塘可以分为村庄内池塘、毗邻村庄池塘和农田区域池塘(远离村庄的池塘).本研究采集了巢湖周围136口池塘上覆水和沉积物样品,调查巢湖周围池塘中氮、磷以及有机质污染现状.结果表明,池塘上覆水中总氮、氨氮、硝态氮、亚硝态氮、总磷、溶解态磷和COD平均含量分别为2.53、0.65、0.18、0.02、0.97、0.38和51.58mg·L-1;池塘沉积物中总氮、氨氮、硝态氮、亚硝态氮、总磷、无机磷、有机磷和烧失量平均含量分别为1575.36、35.73、13.30、2.88、933.19、490.14、414.75mg·kg-1和5.44%;90%以上的池塘总氮、总磷含量达到或超过富营养化水平.位于村庄内的池塘上覆水和沉积物中总氮和氨氮的含量显著高于位于农田区域的池塘.上覆水和沉积物中无机氮表现为:氨氮硝态氮亚硝态氮.池塘上覆水和沉积物中有机质与总氮、总磷之间存在显著的正相关性.池塘中氮、磷和有机物质主要为陆源性输入,池塘位置和径流补给方式明显影响其中的氮、磷和有机质含量.通过截留径流中的氮、磷和有机质,池塘能够有效减少进入巢湖的营养盐含量.     

城市工业区环境系统中的Cd污染循环及其健康风险——以杭州市半山工业区为例

为揭示重金属元素Cd在城市环境系统多种介质中的迁移途径及其潜在危害性,系统分析了杭州市半山工业区主要环境介质（土壤-尘埃-水-底泥-生物）样品中Cd的指标含量,并用连续提取法分析了土壤、尘埃、底泥中Cd的化学形态特征.结果表明,Cd的迁移途径主要有两种,一是以尘埃为媒介在地表环境中迁移,二是通过水介质进入水体环境（水和...     

基于STIRPAT模型的能源消费碳足迹变化及影响因素——以江苏省苏锡常地区为例

定量研究经济社会发展对地区能源消费碳足迹的影响对区域实现低碳发展具有重要意义。论文计算了江苏省苏锡常地区1991-2008年能源消费碳足迹,采用岭回归函数对STIRPAT模型进行了拟合,采用脱钩指数分析了经济发展与能源消费碳足迹之间的关系。结果表明:①1991-2008年能源消费碳足迹平均增长速度为15.30%,能源消费碳足迹分配率以煤炭为主,石油所占比例呈波动下降趋势,天然气所占比例上升较快,能源消费碳足迹产值总体呈波动下降趋势;②经济增长是能源消费碳足迹的主要影响因素,两者关系模型拟合未出现环境库兹涅茨曲线;③经济增长与能源消费碳足迹之间处于相对脱钩与复钩的波动状态,从另一侧面验证了目前两者之间不存在库兹涅茨曲线假说的结论。     

1950-2009年洞庭湖流域农业水灾演变特征及分异规律

洞庭湖流域为我国重要农业生产区,而农业水灾却一直是制约农业可持续发展的最大障碍因素。以1950-2009年水灾统计资料为依据,用定性与定量相结合的方法,系统分析了该流域农业水灾演变特征及区域分异。结果表明:①年年发生流域性或区域性的农业水灾,其中重灾、特大水灾频率呈增大趋势;②在长时间尺度演变过程中,受灾率异常指数岀现2个波峰期和4个波谷期,成灾率异常指数岀现3个波峰期和3个波谷期,且水灾受灾率与成灾率大体上呈同步变化,但短时间內受灾率与成灾率却呈反向波动;③农业水灾具有突变性,但总体演变呈增加趋势;④受孕灾环境、洪涝致灾因子及经济发展水平组合差异的制约,农业相对灾情与绝对灾情在空间上的分布均呈明显的南北分异与东西分异。     

Preparation and coagulation efficiency of polyaluminium ferric silicate chloride composite coagulant from wastewater of high-purity graphite production

The aim of the present work was to produce a polyaluminium ferric silicate chloride (PAFSiC) coagulant from acidic and alkaline wastewater of purifying graphite by roasting, and subsequently to evaluate coagulation efficiency of the reagent by treating surface water from the Yellow River as well as municipal wastewater in comparison with the conventional coagulant polyaluminium chloride (PAC). The PAFSiC coagulant was prepared by co-polymerization. The effects of (Al+Fe)/Si molar ratio, OH/(Al+Fe) molar ratio (i.e., value), coagulant dosage and pH value of test suspension on the coagulation behavior of FAFSiC and the stability of the PAFSiC were also examined. Results showed that PAFSiC performed more efficiently than PAC in removing turbidity, chemical oxygen demand (COD), and total phosphate (TP). The PAFSiC with a value of 2.0 and (Al+Fe)/Si ratio of 5 (PAFSiC 2.0/5) showed excellent coagulation effect for both turbidity and COD, while PAFSiC 1.0/5 was the best for TP. The optimum coagulation pH range of PAFSiC 2.0/5 was 5.0–9.0, slightly wider than that of PAC (6.0–8.0). The process can be easily incorporated into high-purity graphite production plants, thereby reducing wastewater pollution and producing a valuable coagulant.     

Sedimentary record of polycyclic aromatic hydrocarbons in Lake Erhai, Southwest China

The temporal distribution of polycyclic aromatic hydrocarbons (PAHs) was investigated in a sediment core from Lake Erhal in Southwest China using gas-chromatography/mass spectrometry (GC/MS) method.The total organic carbon (TOC) normalized total PAHs concentrations (sum of US Environmental Protection Agency proposed 16 priority PAHs) ranged from 31.9 to 269 μg/g dry weight (dw),and were characterized by a slowly increasing stage in the deeper sediments and a sharp increasing stage in the upper sediments.The PAHs in the sediments were dominated by low molecular weight (LMW) PAHs,suggesting that the primary source of PAHs was low- and moderate temperature combustion processes.However,both the significant increase in high molecular weight (HMW) PAHs in the upper sediments and the vertical profile of diagnostic ratios pointed out a change in the sources of PAHs from low-temperature combustion to high-temperature combustion.The ecotoxicological assessment based on consensus-based sediment quality guidelines implied that potential adverse biological impacts were possible for benzo(ghi)perylenelene and most LMW PAHs.In addition,the total BaP equivalent quotient of seven carcinogenic polycyclic aromatic hydrocarbons (BaA,CHr,BbF,BkF,BaP,DBA and INP) was 106.1 ng/g,according to the toxic equivalency factors.Although there was no great biological impact associated with the HMW PAlls,great attention should be paid to these PAH components based on their rapid increase in the upper sediments.     

淀山湖入湖水质净化的生态工程实践研究

作为上海境内最大的天然淡水湖泊以及黄浦江上游重要的水源保护地,淀山湖的水质状况对上海市饮用水水源安全起着举足轻重的作用。文章运用生物治理与工程措施相结合的手段,在淀山湖大朱厍港实施了净化人湖水质的生态工程试验。研究表明工程示范区域存在风浪大、水位较深、水流较急等特点,是水生植被尤其是沉水植物恢复的重要限制因素。通过选择...     

淀山湖沉积物碳-氮垂直分布特征

近年来,经过一系列污染治理措施,淀山湖的营养水平持续下降,但每年仍有不同程度的蓝藻水华暴发,严重影响其作为水源地的安全性。为了进一步探讨淀山湖水质改善策略,本研究对淀山湖沉积物营养状况进行了调查研究,分析了淀山湖沉积物碳、氮分布特征及垂直变化规律,并用沉积物肥力评价了淀山湖沉积物营养程度。结果表明,淀山湖沉积物营养盐存在明显的富集作用,二十多年来沉积物碳、氮含量大幅上升,表层沉积物均属于重污染状态。空间分布上,沉积物营养盐北部高,南部低,北部样点大部分属于重污染状态,南部样点基本属于中污染状态。垂直分布上,受航道回淤与北部围网养殖影响,部分样点营养盐垂直分布规律不显著,其他样点均表现出随深度增加营养盐显著降低的趋势。除出水口D1样点外,淀山湖有机质与TN表现出显著的同源相关性,表明有机质是淀山湖内源负荷的主要来源。     

土著微生物修复城市小型湖泊实验研究

利用生物制剂及生物修复技术对鞍山市英泽湖进行了净化治理.研究结果表明,经过8～30 d的生物净化,该湖水中的COD、植物营养元素浓度及浊度都有了大幅度的下降.其中COD降至20 mg/L以下,去除率达到70%以上;氨氮降至0.2 mg/L以下,去除率达97%;总磷降低至0.02 mg/L以下,去除率达到60%以上;浊度...