Leaching of styrene and other aromatic compounds in drinking water from PS bottles

Bottled water may not be safer, or healthier, than tap water. The present studies have proved that styrene and some other aromatic compounds leach continuously from polystyrene （PS） bottles used locally for packaging. Water sapmles in contact with PS were extracted by a preconcentration technique called as ＂purge and trap＂ and analysed by gas chromatograph-mass spectrometer （GC/MS）. Eleven aromatic compounds were identified in these studies. Maximum concentration of styrene in PS bottles was 29.5 μg/L. Apart from styrene, ethyl benzene, toluene and benzene were also quantified but their concentrations were much less than WHO guide line values. All other compounds were in traces. Quality of plastic and storage time were the major factor in leaching of styrene. Concentration of styrene was increased to 69.53 μg/L after one-year storage. In Styrofoam and PS cups studies, hot water was found to be contaminated with styrene and other aromatic compounds. It was observed that temperature played a major role in the leaching of styrene monomer from Styrofoam cups. Paper cups were found to be safe for hot drinks.     

A Review of Waste Tyre Utilisation in the Marine Environment

Waste tyres pose a major disposal problem on land creating a fire hazard and, in warmer climates, providing breeding pools for mosquitoes. the void space in tyres makes them unsuitable for land burial. Schemes to use shredded tyres for road bases and asphalt filler are being pursued in the USA. Tyre combustion for electricity production is being investigated in the UK.

The widespread availability and durability of tyres has led to their use in the marine environment for breakwaters/coastal defence structures and as artificial reefs for promoting fisheries.

Tyres have a low density and have been used in floating breakwaters. Schemes have been proposed to protect and strengthen shorelines with tyre structures.

The void space in tyres facilitates the construction of artificial reefs to attract fish. the most intensive use is in the south west Pacific and Australia. Tyre surfaces are colonised by algae and a wide range of faunal species, including corals and shellfish. the wide acceptance of tyres as a suitable reef construction material appears to be based largely on these observations. Experience of initial poor deployment practices in the USA led to tyres washing ashore after storms and resulted in the banning or restriction of their use in coastal states of the USA. A review of the scientific literature has yielded limited information on the environmental impact of tyres and in particular the leaching of heavy metals and organic compounds from tyres into sea water.

Preliminary results of tyre dust/sea water leaching studies are presented. These identify zinc as the major leachate (totalling 10mg/tyre after 3 months). Diluted leachates have not shown significant effects of the growth of the phytoplankton Phaeodactylum and Isocrysis.

Further work to characterise the sea water leaching of tyre compounds is recommended.     

Competition of Hydrogen and Manganese Ions for Adsorption Sites in Sitka Spruce Litter

The competition of hydrogen and manganese ions for adsorption sites in Sitka spruce litter was investigated in a factorial design, simulated acid rain experiment, which involved leaching of litter with simulated throughfall solutions at three pH levels (5.3, 4.3 and 3.3) and three manganese concentrations (0 to 0.2 mg1^-1). the throughfall solution at the lowest pH was the most efficient in removing exchangeable manganese from litter. the manganese concentration in the leachates was approximately proportional to the hydrogen ion concentration in the simulated throughfall solution. Under field conditions, throughfall manganese concentration also naturally tends to increase as a consequence of enhanced foliar leaching of manganese in response to increasing precipitation acidity. the manganese concentration in the simulated throughfall also affected manganese concentration in the leachates, however, and contributed to a buildup of exchangeable manganese in litter, thus counteracting to some extent possible adverse effects of excess leaching due to increased throughfall acidity.     

Effects of simulated acid rain on cation releasing in soils of South China

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离子色谱法同时测定有机和无机阴离子

用离子色谱法同时测定有机阴离子和无机阴离子，实验中采用一种新型高容量分离柱，灵敏度高，选择性好。讨论了最佳实验条件的选择测定了Ｆ＾－，Ｃｌ＾－，ＳＯ４＾２－，ＮＯ２＾－，ＳｅＯ３＾２－、Ｃ２Ｏ４＾２－、甲酸奶和乙酸根等阴离子，并且分析了沈阳地区雪样中的几种阴离子。     

铬渣的细菌解毒实验研究

采用从铬渣堆埋场附近的污泥中分离到的高效还原Cr(Ⅵ)的Ch-1菌进行细菌浸出的摇瓶实验,分别考察了不同液固比,温度,初始pH值情况下浸出液的pH值变化,Cr(Ⅵ)浓度变化及浸出过程铬渣中六价铬的浸出率变化和最终渣浸出毒性.实验结果表明,在细菌的作用下,浸出液Cr(Ⅵ)浓度均能解毒为0ppm,同时,浸出液pH值降低到8～9之间, 细菌浸出渣毒性降低到0.05ppm以下,远低于GB5085.3-1996危险废物浸出毒性鉴别标准1.5ppm.同时,渣中的Cr(Ⅵ)也大部分被有效浸出后还原为Cr(Ⅲ) 沉淀.特别是在液固比10:1,温度28℃,初始pH＝10.0的条件下,铬渣中六价铬浸出率达到了95.43%,同时浸出液pH值＝8.20,Cr(Ⅵ)浓度为0ppm,浸出渣浸出毒性0.007 ppm,均达到国家排放标准,取得了较好的解毒效果.     

还原－衍生化高分辨气相色谱法测定复杂样品中痕量硝基多环芳烃（NO2－PAH）的研究

研究了还原－七氟丁酸酐性生化高分辨气相色谱－ＥＣＤ测定痕量硝基多环芳烃的方法。该法具有选择性好，灵敏度高的特点，适合于复杂样品痕量硝基多环芳的测定。建议采用以氨基多环芳烃ＨＦＢＡ衍生物为参比的ＨＦＢＡＰＡＨ保留指数体系，利用保留指数进行双柱定性成功地在碳黑样品提取中检出包括１－ＮＯ２茈在内的９种ＮＯ２－ＰＡＨ并提出了定量结果。     

煤矸石中有害微量元素的静态淋溶试验研究

在煤矸石的静态淋溶试验的基础上。研究了7-种有害微量元素的淋溶特性，分析了微量元素析出的影响因素。结果表明，淋溶液最终pH呈弱碱性：元素溶出浓度与淋溶时间，淋溶温度，煤矸石粒径，淋溶液pH值以及元素在煤矸石中的含量，赋存状态、本身性质有密切关系。     

石灰石湿式烟气脱硫工艺中添加剂的研究

石灰石湿式烟气脱硫工艺中使用添加剂 ,可提高脱硫率和石灰石利用率等。本研究应用旋流板塔处理模拟烟气 ,系统研究了几种无机及有机添加剂对湿式石灰石脱硫过程的影响 ,选出了适宜的添加剂及其添加浓度 ;得到了脱硫率与主要操作参数之间的关系 ,为工业设计和操作提供了参考数据。并对添加剂强化过程机理进行了讨论