Distribution, accumulation and mobility of mercury in superficial sediment samples from Tianjin, northern China

Seventeen sediment samples at three representative sites (the Yuqiao Reservoir, the Haihe River and the Haihe River Estuary) in Tianjin, northern China, were analyzed to investigate the pollution status, accumulation and mobility of mercury (Hg). The results show that the Haihe River has to be considered as moderate to strongly contaminated with Hg (2 < mean I(geo) = 2.35 < 3), where total Hg contents were ca. 3 to 24 orders of magnitude greater than the regional background value. The sediments collected near a coal-fired power plant in an urban area were found to have very high Hg concentrations, which were significantly related to Hg emissions from coal-fired utility boilers. In the Yuqiao Reservoir, the surface sediments have to be considered as unpolluted with Hg (mean I(geo) = -0.05 < 0) and the Haihe River Estuary sediments have to be considered as unpolluted to moderately polluted with Hg (0 < mean I(geo) = 0.18 < 1). Sediment-bound Hg in the Yuqiao Reservoir and the Haihe River Estuary was found to be predominantly associated with the organo-chelated phase of the sediment (38.3% and 50.5%, respectively). However, unlike the Yuqiao Reservoir and the Haihe River Estuary, Hg in the Haihe River sediments existed mainly as sulfide Hg and elemental Hg, which accounted for 54.2% and 30.7% of total Hg, respectively. The availability of this element seemed restricted. The majority of Hg contamination in the Haihe River sediments had been attributed to historic and modern atmospheric deposition and Hg released from the Haihe River sediments didn't seem to be an important pollutant pathway into the Haihe River Estuary. The results provide new insights into Hg contamination in this region.     

淮河流域旱涝易发区农田的陆气相互作用——CO_2通量、能量交换和水汽输送的季节变化特征

利用淮河流域旱涝易发区的安徽省寿县农田下垫面陆气相互作用观测试验资料,重点分析观测期内CO2通量、能量交换和水汽输送的季节变化,并讨论了与此有关的辐射分量通量、下垫面反射率、波恩比、能量闭合守恒、土壤温度和土壤湿度的季节变化。结果表明:CO2通量、能量分配受地表农作物长势影响明显,其中,水稻灌浆、成熟期,被稻田吸收的CO2通量最大可超过2 mg.m-2.s-1,潜热通量达到正的极大值。稻田光合作用最旺盛时期吸收的CO2通量和释放的潜热通量均大于小麦田光合作用最旺盛时期的对应量。较大土壤热通量对应于较低的土壤水含量。试验观测期的下垫面平均反射率为0.14。作物生长期,稻田表面潜热是下垫面吸收能量的主要消费者,小麦田表面潜热和感热相当。能量闭合率ε的变化范围为0.4~1。     

IC反应器处理高浓度硫酸盐废水的启动研究

采用木糖生产废水,进行了(IC)反应器处理高浓度硫酸盐有机废水的启动研究.结果表明,接种厌氧颗粒污泥,当进水COD/SO2-4值约为3.5时,控制COD负荷提高幅度为每次20%左右,经过26 d的驯化培养,COD和SO2-4负荷分别可达20 kg/(m3·d)和5.5 kg/(m3·d),COD去除率达到80%以上,硫...     

餐饮业外排烹调油烟气的危害及净化方法研究进展

我国快速发展的餐饮业外排的油烟气污染日趋严重,其毒性研究结果表明其中所含的污染物对人体健康有较大危害;油烟气形态及组成的特殊性使其净化处理较困难,国内外研究者针对这一问题相继作出了不少研究,取得了一定程度的进展.但对中国而言,仍然缺乏实用高效的油烟气净化技术.     

制备方法对MgAl水滑石衍生氧化物负载钯催化剂丙烷完全氧化活性的影响

以沉积沉淀法(DP)、浸渍法(IM)和共沉淀法(CP)制备MgAl水滑石衍生氧化物负载钯催化剂,用ICP、XRD、SEM、TEM、EDS、TPR以及比表面测定等手段对催化剂进行了表征.ICP和XRD数据表明用上述3种方法均可成功制备水滑石为前体载钯催化剂.SEM、TEM、EDS数据表明不同方法制备的样品具有不同的形貌以及钯在其中的分散度.综合各类表征数据可知Pd在催化剂中暴露的活性位是影响其活性的主要因素.     

流量调节因子在非稳态河网水质计算中的应用

对平原河网水流流向不定引起的非稳态水质变化问题,引入流量调节因子加以校正,对调节因子在不同流向的形式进行了分析,在水质显格式离散方程中建立对应的水质模型,利用研究区河网枯水期实测的水质资料进行相应验证,结果表明校正的水质模型有较高的精度,具有一定的实用性。为非稳态情况下河网水质问题的决策分析提供了可行计算途径。     

蚯蚓生态滤池处理农村生活污水现场试验研究

对蚯蚓生态滤池处理太湖流域农村生活污水进行现场试验研究.通过对蚯蚓同化容量与污染负荷进行单因素分析,得出蚯蚓生态滤池处理农村生活污水的运行参数与运行方式,并据此进行连续运行试验.结果表明,在表面水力负荷1 m3/(m2*d)、湿干比(布水时间和落干时间之比)1∶3、蚯蚓负荷(以单位体积填料中蚯蚓的质量计)12.5 g/L的条件下,蚯蚓生态滤池处理农村生活污水具有可行性与高效性,单级系统的COD、总氮、氨氮和总磷的去除率分别在81%、66%、82%和89%左右.改进蚯蚓床填料、设计通风结构和采取适宜运行方式,是蚯蚓生态滤池成功应用于农村生活污水处理的三大重要因素.     

Informal Emptying Business in Mandalay: Its Reasons and Financial Impacts

Environmental Management - Globally, 2.8 billion people use on-site sanitation facilities, which need regular emptying of accumulated fecal sludge. Illegal dumping from informal emptying...     

金黄色葡萄球菌的演相培养及A蛋白的提取

对金黄色葡萄球菌（Ｓｔａｐｈｙｌｏｃｏｃｃｕｓａｕｒｅｕｓ）ＣｏｗａｎⅠ的培养及Ａ蛋白提取工艺进行了优化研究．结果表明：在培养基中分别增加牛肉膏和蛋白陈的含量，有利于提高菌体生物量及Ａ蛋白的得率；少量酵母浸膏及葡萄糖对生物量及Ａ蛋白得率有促进作用，但当达到一定浓度时则会产生基质抑制作用；恒定培养过程的ｐＨ值有利于Ａ蛋白得率的增加，０．０３（）／ｍｉｎ通气量、搅拌速度２００ｒ／ｍｉｎ是能满足菌体生长的条件．根据Ａ蛋白耐热性强这一特性，采用加热法除去大部分杂质，然后用ＩｇＧ－琼脂糖凝胶亲和层析实现了Ａ蛋白的提纯．     

运用灰色系统理论对广州市环境噪声污染的原因进行分析

运用灰色系统关联度的分析方法，对广州市环境污染的原因进行分析，结果显示：影响广州市环境噪声的因素中，占主要地位的是城市机动车数量，其次是人口密度。