Recycling thin film transistor liquid crystal display (TFT-LCD) waste glass produced as glass–ceramics

The waste electrical and electronic equipment (WEEE) directives are designed to deal with the rapidly increasing waste stream comprised of electrical and electronic equipment. Recycling electrical and electronic equipment reduces the quantity of waste going to final disposal. The demand for thin film transistor liquid crystal display (TFT-LCD) panels, commonly used in everyday electronic products, is increasing. Conventionally adopted treatments of TFT-LCD waste glass cannot meet WEEE directives. This study adopts the following operating conditions in fabricating glass–ceramics: sintering temperature of 800–950 °C; sintering time of 6 h; and, temperature increase rate of 5 °C/min. The glass–ceramic samples then underwent a series of tests, including the Vickers hardness, water absorption and porosity tests, to determine product quality. The Vickers hardness was 12.1 GPa when fired at 900 °C for 6 h, and density was 2.4 g/cm³ and water absorption was 0%. Thus, TFT-LCD waste glass can be regarded as a good glass–ceramic material.     

Operational decisions in response to a performance-based regulation to reduce organic waste impacts near Atlantic salmon farms in British Columbia,Canada

Nutrient enrichment of the seafloor (benthos) has been a primary subject of investigation since the beginning of commercial salmon farming. Waste feed and feces passing through the containment nets can create zones of organic enrichment to the benthos in the vicinity of the pen cages. Early studies of salmon farming in British Columbia Canada (500–1200 metric ton production farms) showed that these effects varied greatly and were reduced where conditions of adequate water depth and strong tidal currents were present. More recent studies of farms producing in excess of 2000 tons of fish have documented measurable organic benthic impacts.The implementation of a performance-based waste regulation in British Columbia in 2002 has caused operational changes to achieve and maintain compliance. This paper describes field monitoring data for four representative farm operations including the waste impact levels prior to the implementation of regulatory standards and the effect of adaptive management actions taken to reduce organic enrichment such as modified feed delivery, relatively small position changes to the cages or reducing site production to achieve continuing compliance.Monitoring over several full production cycles at selected farms indicated that sediment impacts at maximum production levels have decreased while maintaining, and in some cases increasing overall production of salmon.     

六氯苯和重金属复合污染沉积物的电动力学修复研究

以某化工厂排污沟渠中受六氯苯(hexachlorobenzene,HCB)、锌和镍复合污染的实际沉积物为对象,研究非离子表面活性剂OP-10对沉积物中污染物的增溶解吸效果和电动力学修复污染物的强化迁移效果。解吸实验结果表明:OP-10对HCB增溶解吸效果较好,对重金属离子的解吸有一定的促进作用。电动力学修复发现,随电渗析流进入沉积物中的OP-10很快的吸附在靠近阳极沉积物上,从而阻碍了助剂的输送并影响HCB的迁移,而靠近阴极区域沉积物中的有机质迁移会促进HCB的去除。沉积物pH变化引起的重金属沉淀是制约锌迁移的主要因素。镍的整体迁移效果不明显。     

纳米ZnO对嗜热四膜虫的生态毒性研究

为评价纳米ZnO的生态安全性,研究了其对嗜热四膜虫(Tetrahymena thermophila)的水生生态毒性. 显微成像表明,嗜热四膜虫食物泡是摄取纳米ZnO的主要部位. 低ρ(纳米ZnO)对嗜热四膜虫的增殖具有促进作用(即“兴奋反应),其中100 mg/L时促进作用最明显,随着ρ(纳米ZnO)的进一步增加,其对嗜热四膜虫增殖的促进作用逐渐减弱. 随着时间的延长,“兴奋反应逐渐减弱. 纳米ZnO能降低嗜热四膜虫的超氧化物歧化酶活性,且ρ(纳米ZnO)越高,抑制效应越强. 纳米ZnO使嗜热四膜虫自由基清除能力下降,可能是其产生毒害作用的主要原因之一.      

青藏高原典型高寒草甸区土壤有机碳氮的变异特性

本研究应用地统计学的基本原理与方法(半方差分析)对青藏高原典型高寒草甸区0～10 cm土壤有机碳和全氮空间变异性进行了分析.结果表明,0～10 cm的土壤有机碳和全氮的平均含量分别为11.45 g·kg^-1和1.02 g·kg^-1,平均变异系数分别为0.23和0.21,反映出该植被区土壤肥力较为贫瘠.土壤有机碳和全氮随机因素的变异占总空间异质性变异的比率分别为44.7%和49.9%,变异尺度分别为210.9 m和200.1 m,随机因素的影响主要发生在采样尺度＜10 m的范围之内.在该研究区域上土壤有机碳和全氮均表现出空间自相关因素大于随机因素的变异格局;在空间结构的变异上,由土壤内在属性如土壤矿物质、地形等空间自相关因素和人为因素如放牧及工程施工等对土壤表层的践踏引起的随机因素共同起作用,影响程度呈中等水平.     

聚磷激酶基因在假单胞菌中的整合和表达

为了构建高效除磷的微生物,将来源于大肠杆菌的聚磷激酶基因(ppk)插入广宿主载体pBBR1MCS-2多克隆位点区,得到质粒pBBR1MCS-2-ppk.以该质粒为模板,通过PCR扩增出携带有载体启动子和终止子序列的ppk基因,插入自杀型质粒pUTmini-Tn5中得到重组质粒pUTmini-Tn5-ppk.pUTmini-Tn5-ppk经三亲接合作用进入Pseudomonas putidaKT2440,同时mini-Tn5通过转座作用将ppk整合到宿主菌株的染色体DNA中,获得基因工程菌Pseudomonas putidaKT2440-PPK,用于表达ppk.RT-PCR结果显示,ppk基因在KT2440-PPK中得到较高量的表达,而在原始菌株KT2440中表达微弱.人工模拟污水实验结果表明,接种1 h时KT2440-PPK中聚磷含量达到最大,为3.05 mg/g,约是对照菌株KT2440的15倍.测定模拟污水中磷酸盐的含量表明,KT2440-PPK可以去除该模拟污水中90%以上的磷酸盐.     

鲢鱼、草鱼和尼罗罗非鱼热休克蛋白70基因cDNA全序列的克隆与分析

采用RT-PCR技术和RACE技术分别从淡水食毒藻鱼类鲢鱼（Hypophthalmichthys molitrix）、尼罗罗非鱼（Oreochromis nilotica）及草食性鱼类草鱼（Ctenopharyngodon idella）肝脏扩增出热休克蛋白70（HSP70）cDNA全序列,并与其它鱼类、两栖类和哺乳类动物的HSP70氨基酸进行了同源性比较. 结果表明,鲢鱼、草鱼和尼罗罗非鱼肝脏HSP70基因cDNA全长分别为2356 bp、2348 bp和2242 bp,分别编码649、649和638个氨基酸.鲢鱼、草鱼和尼罗罗非鱼HSP70与其它鱼类、两栖类和哺乳类动物HSP70氨基酸同源性均较高,表明其在进化上高度保守,且承担着重要的生理功能.构建系统进化树发现,鲢鱼、草鱼与其它鲤科鱼类斑马鱼、银鲫（Carassius auratus gibelio）的HSP70氨基酸同源性较高,处于同一进化树分枝;而尼罗罗非鱼HSP70未与其它鲈形目鱼类,如鲷科鱼类聚为一枝,而是占据一个独立的分枝,这与克隆得到的鲢鱼、草鱼肝脏HSP70基因可能为结构型HSP70,而尼罗罗非鱼肝脏HSP70基因可能为诱导型HSP70的结果相一致.     

贵州省红枫湖饮用水源地微囊藻毒素含量与水体中氮、磷含量等的相关性

2008年6~9月对贵州省红枫湖饮用水源地A、B、C采样点及取水口采样,研究了水体中微囊藻毒素即总藻毒素(total microcystin RR和total microcystin LR,TMC-RR、TMC-LR),胞外藻毒素(extracellular microcystin RR和extracellular microcystin LR,EMC-RR、EMC-LR)和胞内藻毒素(intracellular microcystin RR和intracellular microcystin LR,IMC-RR、IMC-LR)含量及相关的TN、TP、NH4-N、NO2-N、COD、Ch1a、pH等理化指标的变化情况,讨论了理化指标与藻毒素含量之间的相互关系。结果表明藻毒素在时间及空间上分布不均,无明显规律性。藻类高发期间藻毒素以胞内毒素为主要存在形式,去除藻毒素保障饮用水安全最重要的是去除饮用水源水中的藻类。相关性分析表明藻毒素含量与pH、NO2-N、Ch1a具有统计学意义上的相关性,综合回归分析的结果,pH是影响藻毒素的重要因子,因此贵州省喀斯特弱碱性特殊水环境与藻毒素产生的环境条件值得各方面高度关注。     

Catchment-wide assessment of the cost-effectiveness of stormwater remediation measures in urban areas

The cost effectiveness of catchment-wide funding for the environmental remediation of urban waterways on the scale of a major metropolitan catchment is examined considering the typical land-use and pollutant-export characteristics of urban catchments. The evaluation is performed by comparing the effectiveness of the major stormwater treatment modes for the pollutants of concern with the proportion of pollutant export to which the measure applies. The heavy metals copper, lead, and zinc in the aqueous phase or bound to fine particulates are identified as representative of the pollutants of concern in drainage from urban catchments. The analysis suggests that these priority pollutants are predominantly (79–87%) derived from runoff from residential property and roads as disseminated urban surfaces. Analysis of a specific case of catchment-wide funding of stormwater remediation in the Sydney Harbour catchment, Australia reveals that the funding allocation cannot be expected to have achieved reductions in the loads of priority pollutants due to the types of treatment measures implemented and the sources addressed. The apportionment of funding in better accordance with the maximum potential effectiveness of stormwater treatment modes and the pollutant-export characteristics of urban catchments could thus be expected to achieve a more cost-effective result from such funding initiatives.