垃圾焚烧灰治理垃圾渗滤液重金属污染的试验研究

通过垃圾焚烧灰对模拟垃圾渗滤液重金属废水的正交吸附实验研究,并讨论其对重金属吸附的一般规律及pH、加入量和振荡时间几个影响因素对吸附效果的影响.研究结果表明:在一定的pH、加入量和振荡时间下,垃圾焚烧灰对Pb、Ni、Cd、Mn、Zn、Cr有一定的吸附效果,最大吸附率分别可以达到100%、84.18%、96.74%、93.52%、99%、81.69%.焚烧灰对重金属的吸附能力表现为Pb＞Mn＞Cd＞Zn＞Ni＞Cr.各影响因素对重金属吸附效率的影响大小顺序表现为pH＞加入量＞振荡时间,pH值对吸附率的影响最大,为主要影响因素.     

柱撑蛭石吸附去除废水中重金属离子的实验研究

分别利用有机柱化剂十二烷基磺酸钠(SDS)和无机柱化剂聚羟基铝(HA)对蛭石进行柱撑制得十二烷基磺酸钠柱撑蛭石(SDS-V erm icu lite)和聚羟基铝柱撑蛭石(HA-V erm icu lite),并通过XRD、红外光谱、ZETA电位等表征手段对柱撑蛭石进行表征,同时针对柱撑蛭石对Cu2 ,Cd2 ,C r3 3种重金属离子的吸附进行研究,结果表明:吸附去除率受反应时间、重金属离子的初始浓度、pH值等因素的影响,经柱撑后的蛭石对重金属离子吸附的吸附性能比蛭石原矿要强。柱撑蛭石吸附3种重金属离子的动力学吸附过程可用E lov icb方程和双常数方程进行较好的拟合。     

福建省兴化湾有毒重金属的输入输出

基于对兴化湾大气干、湿沉降,沉积物及河(海)水的取样分析数据,主要考虑河流输入及与外海的物质交换,大气干、湿沉降和沉积作用过程重金属物质的迁移量,估算了兴化湾重金属的输入输出量.结果表明,As、Cr、Pb主要来自于河流输入,其河流输入量分别占总输入量的76.4%,78.2%和68.9%,Hg主要来自于河流输入和与外海的物质交换,Cd主要以大气干、湿沉降为输入方式,该方式的输入量占输入总量的78.8%.沉积作用是5种有毒重金属的主要输出方式,占输出总量的88.2%～100%,潮汐作用可将部分As、Cr、Pb输向外海,但也可能将Hg带入兴化湾,兴化湾Cd污染有加剧的趋势.     

浙江省衢州市上方镇重钙方解石矿工艺指标影响因素

重质碳酸钙的白度和色相值(Lab)是最重要的工业指标,但影响因素尚不清楚.本文通过扫描电镜、粉晶X射线衍射(XRD)和电感耦合等离子体发射光谱(ICP-OES)等分析手段,对浙江衢州上方镇的重钙方解矿石进行了研究,以期阐明重质碳酸钙白度和色相的影响因素.结果表明,矿石随研磨粒度的减小白度逐渐增加,在100～400目,白...     

宁夏一次大暴雪天气过程的物理成因

在分析大气环流及其诸层物理量场特征基础上,结合逐时卫星云图资料对2002年10月17～18日宁夏南部山区一次大暴雪天气过程成因进行了探讨,发现此次暴雪中低层存在着较明显的3股气流的共同作用,指出低涡及暖式切变线是本次过程重要的天气影响系统,降水水汽主要来自于低层输入,同时分析还表明宁夏强降雪也具有中小尺度特征。     

中国西南典型地质背景区土壤重金属分布及生态风险特征

中国西南有22.3％的耕地重金属含量超标,区内广泛分布的峨眉山玄武岩和碳酸盐岩被认为是土壤中重金属的主要母质来源.目前,中国西南地区,尤其是峨眉山玄武岩分布区土壤重金属生态风险的研究程度仍有待提升,不同地质背景区(成土母岩)土壤中重金属含量、空间分布与生态风险缺乏对比.本文选择四川省典型地质背景区采集土壤样品,采用原子...     

Heavy metals,polycyclic aromatic hydrocarbons and organochlorine pesticides in the surface sediments of mangrove swamps from coastal sites along the Leizhou Peninsula, South China

Contents of heavy metals, polycyclic aromatic hydrocarbons （PA Hs）, dichlorodiphenyltrichloroethanes （DDTs） and hexachlorcy- clohexanes （HCHs） in surface sediments from mangrove areas of the Leizhou Peninsula were analyzed in July and November 2005. Risk assessment criteria applied by Long E R et al. （1995） and Long E D et al. （1995） （effects range low, ERL; effects range mean, ERM） of chemicals in sediments from the gulf or estuary were used to assess the potential ecological risks of heavy metals, PAHs, DDTs and HCHs to aquatic organisms in the studied area. The results indicated that the average contents of zinc, nickel, chromium, lead, copper, arsenic and mercury were （61.97 ± 55.87）, （59.99 ± 39.01 ）, （47.93 ± 28.37）, （26.64± 13.00） , （23.45 ± 41.96）, （9.32 ± 3.62）, （0.14 ± 0.18） mg/kg in dry weight in the sediment samples col- lected from five studied sites in the Leizhou Peninsula, respectively. Cadmium was not calculated due to its content being below the detection limit （ 〈 0.3 mg,/kg）. The average levels of Cr, Cu, Ni, Pb, Zn and Hg exceed their background values. The average contents of Ni were higher than ERM. The contents of PAHs in the sediments from the five studied sites were （79.78 ± 43.70） ng/g in dry weight, far lower than ERL（4 022 ng/g）. The contents of DDE, DDD and DDTs in the sediments from five studied sites were （2.60 ± 4.68）, （ 17.52 ± 27.25 ）, （27.78 ± 46.64） ng/g in dry weight respectively, clearly higher than ERL, and the average contents of DDT were （7.66 ± 15.93） ng/g in dry weight, much higher than ERM. HCHs could be detected in the sediments only from Gaoqiao sampling site, with the average contents （0.07 ± 0.08） ng/g in dry weight.     

中国主要红树林表层沉积物中重金属的分布特征及其影响因素

红树林生态系统处于海洋与陆地的动态交界面,遭受海水周期性浸淹,因而在结构与功能上具有既不同于陆地生态系统,也不同于海洋生态系统的特性。红树林作为初级生产者,为林区动物、微生物提供食物与营养,为鸟类、昆虫、鱼虾等提供栖息、繁衍场所。因此,红树植物对维护生态平衡、保护海岸生态系统起着重要的作用[1-2]。近年来由于工农业的发展,沿海城市人口与经济的增长,大量的污染物汇集于河口、海湾区,使这些地区的重金属污染日趋严重,特别是在直接向红树林区倾污排废的地区更是如此。     

琉球群岛以东海区沉积物重矿物分布及来源

琉球群岛东部海区沉积物中富含大量火山碎屑矿物、岛屿岩石遭受风化蚀变形成的普通角闪石以及水生的铁锰微结核,其重矿物种类、特征、组合分区等与火山作用、沉积环境、地形、物质来源等内外生因素密切相关。通过对本区重矿物的种类、特征及组合分区的研究,初步判断位于研究区北部、菲律宾板块向欧亚大陆俯冲而导致的正在活动的的琉球岛弧区为火山碎屑的主要源区,重矿物成分主要为水携成因来源,受同期火山作用控制;少量紫苏辉石来自先期形成的海岭或海底高原(如冲大东海岭、奄美海岭及九州海岭等)上的火山岩系,是经过剥蚀、搬运再沉积的产物;琉球群岛、九州等火山活动产物受海底高地等阻隔而在本区表现为向南或东南影响力逐渐减小;本区地质历史上的及正在进行的岩浆活动主要以基性及中性岩浆为主。此外,流经本区的黑潮对自生铁锰微结核的富集具有重要影响。     

Detecting environmental change in estuaries: Nutrient and heavy metal distributions in sediment cores in estuaries from the Gulf of Finland,Baltic Sea

Historical sediment nutrient concentrations and heavy metal distributions were studied in four estuaries in the Gulf of Finland, Baltic Sea to examine the response of these estuaries to temporal changes in human activities. Cores were collected using a 1-m Mackereth corer and dated using ²¹⁰Pb and ¹³⁷Cs. The cores were analyzed for total carbon (TC), total nitrogen (TN), total phosphorus (TP), organic phosphorus (OP), inorganic phosphorus (IP), biogenic silica (BSi), loss-on-ignition (LOI), Cu, Zn, Al, Fe, Mn, K, Ca, Mg and Na. Principal component analysis (PCA) was used to summarize the trends in the chemical variables and to compare the trends at the different sites. Applying the 1986 ¹³⁷Cs date as a reference point, ²¹⁰Pb chronologies were constructed for the sites using either the CRS model or a composite model (using both CIC and CRS). Significant increases were observed in sedimentation rates, TP and TN concentrations in all of the cores. Copper showed clear increases from 1850 towards present at all sites. Furthermore, redundancy analysis (RDA) was used to correlate environmental variables (catchment land use, catchment size, estuary surface area, depth and lake percentage) to sediment geochemistry. Based on redundancy analysis (RDA), the percentage of agriculture in the catchment was the most important factor affecting the sediment accumulation rate. Urban land-use types and industry correlate well with sediment Cu and Ca concentrations. Forest areas were related to high sediment BSi concentrations. Catchment land use was the most significant factor affecting sediment geochemical composition and sediment accumulation rates in these coastal embayments. Our results demonstrate that the coastal estuaries of the Gulf of Finland respond to the increased nutrient loading with the increased sedimentation and nutrient accumulation rates.