Kinetics of soil ozonation: an experimental and numerical investigation

This study investigates the use of ozone for soil remediation. Batch experiments, in which ozone-containing gas was continuously recycled through a soil bed, were conducted to quantify the rate of ozone self-decomposition and the rates of ozone interaction with soil organic and inorganic matter. Column experiments were conducted to measure ozone breakthrough from a soil column. Parameters such as ozone flow rate, soil mass, and ozonation time were varied in these experiments. After ozone concentration had reached steady state, the total organic carbon concentration was measured for all soil samples. The ozonation efficiency, represented by the ratio of soil organic matter consumed to the total ozone input, was quantified for each experiment. Numerical simulations were conducted to simulate experimentally obtained column breakthrough curves. Experimentally obtained kinetic rate constants were used in these simulations, and the results were in good agreement with experimental data. In contrast to previous studies in which soil inorganic matter was completely ignored, our experiments indicate that soil inorganic matter may also promote depletion of ozone, thus reducing the overall ozonation efficiency. Three-dimensional numerical simulations were conducted to predict the efficacy of ozonation for soil remediation in the field. These simulations indicate that such ozonation can be very effective, provided that effective circulation of ozone is achieved through appropriately placed wells.     

炻器餐饮具的抗菌研究

以一种特种陶瓷--炻器为载体,分别用负载TiO2光催化薄膜和添加抗菌剂的方法进行炻器餐饮具的抗菌研究.结果表明,在紫外光和日光下,表面负载了TiO2膜的炻器灭菌率分别为90%和88%,均高于未负载TiO2膜的炻器,且灭菌率随光强的增加而提高.复合银盐显示了很好的杀菌效果,当釉表层银含量为0.2%时,24 h内对所有细菌的灭菌率为94.6%、总大肠菌群为96.9%.复合锌盐也有一定的灭菌效果,当釉表层锌含量为1.1%时,24 h内对所有细菌的灭菌率为56.8%,总大肠菌群为59.3%.但将TiO2粉末加入炻器表层的釉中,却未显示灭菌作用.对掺杂的炻器表面层成分和掺杂后Ag 、Zn2 的溶出量进行了测定,对灭菌结果和机理也进行了讨论.     

Practical field application of a novel BOD monitoring system

A biochemical oxygen demand (BOD) monitoring system, based on electrochemically-active bacteria in combination with a microbial fuel cell, has been developed for the purpose of on-site, on-line and real-time monitoring of practical wastewater. A microbial fuel cell that had been enriched with electrochemically-active bacteria was used as the basis of the measurement system. When synthetic wastewater was fed to the system, the current generation pattern and its Coulombic yield were found to be dependent on the BOD5 of the synthetic wastewater. A linear correlation between the Coulombic yields and the BOD5 of the synthetic wastewater were established. Real wastewater obtained from a sewage treatment plant also produced a highly linear correlation between the Coulombic yield and BOD5 in the system. To examine on-site, on-line and real-time monitoring capability, the BOD monitoring system was installed at a sewage treatment plant. Over 60 days, the measurement system was successfully operated with high accuracy and good stability with the measuring period for a sample being 45 min. This application showed that the application of the measurement system was a rapid and practical way for the determination of BOD5 in water industries.     

Physicochemical factors affecting the sensitivity of Ceriodaphnia dubia to copper

The effects of physicochemical conditions, such as pH, water hardness, flow rates and natural organic substances on the sensitivity of Ceriodaphnia dubia to the toxic effects of copper were investigated using static bioassay cups and specially designed flow-through bioassay chambers. We found that C.dubia was very sensitive to pH changes and the total copper LC50 values of C. dubia neonates increased by 15-fold as the pH increased from pH 7 to 10. It was also observed that the LC50 values increased sharply upon increasing the water hardness value to 2.4 meq. In addition, increasing flow rates from zeroto 50 mL hr^-1 also increased its sensitivity to copper, which was possibly due to hydrodynamic stress.The presence of natural organic substances (humic acid and dissolved organic matter) and suspended particles decreased thetoxic effect of copper. This significant decrease in the toxicity of copper in the presence of natural organic materialscan be explained by a reduction in the free ion concentration due to complexation. Furthermore, we observed that the kinetics of copper interactions with natural organic materials are a significant factor in the toxic effect of copper and that the acute LC50 values increased with increasing reaction time betweensolubilized copper and water-borne organics.     

喀什地区农村改水后饮水状况研究

喀会地区农村改水后，水质仍较差，饮用符合Ⅰ、Ⅱ、Ⅲ级水及饮用水不合格水的人数的百分比分别是５．４％、９．９％、２６．０％和５４．１％。     

玉米粒为载体的流化床生物膜反应器处理印染废水

以废弃玉米粒为载体,在生物膜流化床试验装置上进行印染废水处理试验研究。结果表明,与炉渣载体比较成膜时间缩短2 d;形成的生物膜生长到载体内部,结合牢固;曝气量(20~30 L/h.L)受流化状况控制,比非生物质载体时略大,玉米粒含量为2~4 g/L时,COD、色度和浊度的去除率分别为72%、85%和86%。     

东京大城市防灾应急管理体系及启示

本文详细的介绍了日本东京防灾应急管理体系的建设,以及国家危机管理体制,全政府型危机管理体制,应急管理规划和应急预案,社会参与与演习训练等,对于北京及我国各大中城市有一定启示和借鉴作用.     

金沙江下游水质现状调查及研究

对金沙江下游水质现状监测分析表明，巧家至宜宾河段水质日趋恶化，污染物增长明显，主要污染物为总磷、铅、矿物油和氨氮，在考虑合理开发利用水资源时，应把控制下游污染作为重点内容。     

TiO2-assisted photo-catalysis degradation process of dye chemicals

ＩｎｔｒｏｄｕｃｔｉｏｎＡｓｏｎｅｏｆｔｈｅｍａｉｎ ｐｏｌｌｕｔｉｏｎｓｏｕｒｃｅｓｉｎＣｈｉｎａ ,ｔｈｅｔｅｘｔｉｌｅｄｙｅｉｎｇａｎｄｆｉｎｉｓｈｉｎｇｉｎｄｕｓｔｒｙａｎｎｕａｌｌｙｃｒｅａｔｅｓ 9— 12× 10 8ｍ3ｗａｓｔｅｗａｔｅｒｗｉｔｈｈｉｇｈｏｒｇａｎｉｃｓｔｒｅｎｇｔｈａｎｄｃｏｌｏｕｒ(Ｌｉ,1999ｂ) .Ｄｙｅｓａｒｅｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｃｌａｓｓｏｆｓｙｎｔｈｅｔｉｃｏｒｇａｎｉｃｃｈｅｍｉｃａｌｓ.Ｉｎ ｇｅｎｅｒａｌ,ｃｏｎｖｅｎｔｉｏｎａｌｂｉｏｌｏｇｉｃａｌｔｒｅ…     

中国主要类型锑矿床氢、氧、碳同位素组成及地球化学特征

中国主要类型锑矿床中主要矿物的δ18O值从 +5.2‰～ +2 5.84‰ ,离差值为2 0 .64 ;实测与计算的δ18OH2 O值从 -8.0 3‰～ +1 5.9‰ ,离差值高达 2 3 .93 ;矿物包裹体分析的δDH2 O值变化范围从 -1 2 4 .3‰～ -3 8.0‰ ,离差值达 86.3 ;矿物样品的δ13C值变化范围为 -9.73‰～ +1 .79‰ ,离差值为 1 1 .52。经综合研究后认为锑矿床的成矿流体是多源的 ,既有岩浆水、变质水和大气降水 ,也有地层封存水、海水和吸附水加入成矿流体。因此 ,锑矿床的成因较复杂 ,应根据成矿物质来源、成矿作用等的差异 ,分别研究各类矿床的特征 ,才能较好地指导找矿勘查工作。