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.     

农田蔬菜中重金属污染和铅稳定同位素特征分析

采集南京市栖霞山铅锌矿附近农田中6种蔬菜和相应的根际土壤,测定了蔬菜(根系和茎叶)和根际土壤样品铅、镉、铜和锌含量和铅稳定同位素比率.结果表明,土壤受到铅、镉和锌污染,其中镉是最重要污染物;蔬菜根系和茎叶铅、镉、铜和锌含量具有明显的种属特异性;与<食品中污染物限量>(GB 2762-2005)、<食品中铜限量卫生标准>(GB 15199-1994)和<食品中锌限量卫生标准>(GB 13106-1991)中阈值相比.蔬菜中铅、镉和锌含量超标严重.铅稳定同位素比率表明.蔬菜的铅稳定同位素比率与土壤铅稳定同位索比率明显不同.因而土壤不是蔬菜富集铅的全部来源,大气可能是其重要来源之一.     

再生水中内分泌干扰物质的存在及处理现状

随着污水回用大力开展,人们与再生水的接触机会增加,必须保障再生水的水质安全.资料调研发现,作为再生水水源的污水处理厂出水中含有多种内分泌干扰物质,活性炭吸附、超滤、高级氧化技术及膜技术可有效去除再生水中的内分泌干扰物质,但鉴于经济和管理上的困难,目前仍不能全面推广.中国常用的澄清(混凝沉淀)/过滤工艺不能有效去除污水处理厂二级出水中的内分泌十扰物质,这对接触人群的健康产生潜在威胁,对生物种群也有一定的影响.生物处理方法未来有可能成为去除内分泌干扰物质很有前途的方法.     

Spatial distribution and seasonal variation of char-EC and soot-EC in the atmosphere over China

A previous study on PM_2.5 carbonaceous aerosols measured with the thermal optical reflectance (TOR) method in fourteen Chinese cities is extended by subdividing total EC into char-EC and soot-EC. Average char-EC concentrations show great differences between the fourteen cities and between winter and summer periods, with concentrations of 8.67 and 2.41 μg m^?3 in winter and summer, respectively. Meanwhile spatial and seasonal soot-EC variations are small, with average concentrations of 1.26 and 1.21 μg m^?3 in winter and summer, respectively. Spatial and temporal distributions of char-EC, similar to EC, are mainly influenced by local fuel consumption, as well as the East Asian monsoon and some meteorological factors such as the mixing height and wet precipitation. The small spatial and seasonal variation of soot-EC is consistent with its regional-to-global dispersion, which may suggest that soot carbon is not local carbon, but regional carbon. Char-EC/soot-EC ratios show summer minimum and winter maximum in all cities, which is in good agreement with the difference in source contributions between the two periods. As OC/EC ratio is affected by the formation of the secondary organic aerosol (SOA), char-EC/soot-EC ratio is a more effective indicator for source identification of carbonaceous aerosol than previously used OC/EC ratio.     

厌氧氨氧化无纺滤布生物膜反应器的运行

氧气是厌氧氨氧化菌的抑制因素,通过无纺滤布生物膜系统内部形成适合厌氧氨氧化菌的厌氧环境,运行62 d,实现0.617 kg N/(m³·d)氮容积去除负荷,稳定运行阶段氨氮和亚硝氮的去除率分别为97.9％和98.7％;98 mg N/L NO^-₂-N经24 h接触产生完全抑制,通过将进水亚硝氮浓度降至20～40 mg N/L,运行31 d,成功恢复厌氧氨氧化活性,试验末期氮容积去除负荷为0.641 kg N/(m³·d)。     

漂浮植物塘协同处理农村分散生活污水研究

通过实验考察了漂浮植物塘对经模拟化粪池简易处理的农村分散生活污水的深度净化效果,结果表明：水葫芦、大薸、聚草塘对上述污水均具有良好的净化效果,水葫芦塘对TP的去除效果最好,大薸塘对TN和NH⁺₄-N的去除效果最好。当水力停留时间为20 d时,3种漂浮植物塘的出水污染物含量可低于GB/T 18921-2002观赏性景观环境用水河道类标准。在南方农村宅沟园河内种植漂浮植物是构建农村实用生活污水收集处理系统、控制农村生活污水对河道污染的一种有效措施。     

A/O和A2/O工艺对膜生物反应器处理焦化废水影响的研究

为提高膜生物反应器对焦化废水的处理效果,采用A/O和A²/O两种工艺的膜生物反应器处理焦化废水,通过对比处理效果、分析膜污染情况,寻求膜生物反应处理焦化废水的最优工艺。实验结果表明：A²/O工艺系统对酚、NH₃-N、COD的去除率分别为99%、90%和95%;A/O工艺系统对酚、NH₃-N和COD的去除率分别为97%、75%和93%。A²/O膜生物反应器系统对焦化废水中NH₃-N的去除效果明显优于A/O膜生物反应器系统,其反硝化率为50%～70%。对膜污染分析表明不同工艺对膜污染的影响不显著,A²/O工艺膜通量衰减59%,A/O工艺膜通量衰减56%。研究表明在膜生物反应器中,A²/O工艺对焦化废水的去除效果要优于A/O工艺。     

Organotin pollution in China: an overview of the current state and potential health risk

In recent years, considerable amounts of organotin compounds have entered the environment due to the wide industrial applications in China. Organotins were found in various environmental media. An overview of organotin contamination and distribution in China from various environmental samples, including waters and sediments, is presented to better understand the current state of organotin pollution in China and to improve environmental monitoring and management of organotin contamination. Exposure to organotin contaminated water and sediments induces accumulation of organotins in molluscs and biological effects such as imposex. Potential harmful effects on human health may also result from consumption of contaminated seafoods. Detailed information on distribution, impacts and assessment of risk to human health and marine ecosystems is discussed and monitoring of TBT using biomarkers is described. This review highlights the serious organotin contamination of coastal cities in China and emphasizes the need for long-term monitoring and the development of an effective regulatory program.     

聚苯乙烯基硫代磺酸钾树脂对水中卤代物的选择性结构分析

本文用聚苯乙烯基硫代磺酸钾树脂为选择性试剂与水中卤代物作用,排除水体中其它化合物对结构分析的干扰,采用动态恒温柱法及Ｃ－１８柱富集法作为该反应发生的途径,结果表明：前一种途径的检测结果由样品反应活性决定,而后者检测结果还受到萃取率的影响,两种方法均可达到１０－２０ｍｇ·ｌ＾－１的检测水平。     

Selenium geochemistry of paddy soils in Yangtze River Delta

Selenium (Se) content both in total and bioavailable forms were very low (25-35 and 9.5 micrograms/kg, respectively) in waterlogged paddy soils in the central Yangtze River Delta. This was due to changes in geochemistry and the inherent properties of the parent materials of these lowland paddy soils. The very low Se content (23 micrograms/kg) in the parent material resulted in low total Se content in the soil. The main chemical changes under long-term waterlogged conditions are depletion of molecular oxygen, decrease of redox potential, and reduction of Fe (III) to Fe (II) and SeO3(2-) to Se0. This led to low availability of Se in soils, and subsequently low Se content (29 micrograms/kg) in brown rice grain produced in this region. It has been suspected that low Se content in staple food might be one of the major reasons for a high infection rate of the intestine and stomach cancers and the higher death rate caused by these diseases in the region. Foliage spray of Na2SeO3 at early heading stage of rice plant growth improved the Se content of brown rice grain, hull, and straw, and would improve human and animal health.