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411.
对武汉东湖3个采样点柱状沉积物中总氮、总磷、总有机碳及微生物量的垂向分布进行了测定,并对生源要素与微生物量之间垂向分布的相关性进行了研究.结果表明,东湖柱状沉积物中总有机碳与总氮之间存在明显的同步变化趋势,其含量随着沉积物深度的增加而不断降低,处于纳污区的1号点的各种营养盐含量均显著高于其它各点.沉积物中的有机质有着明显的双重来源,1号点含有较高的陆源有机质成分,而远离排污口部分的2号和3号点的有机质来源则以水生生物为主.微生物量在沉积物表层最高,随着沉积物深度的增加而不断下降.微生物量与有机质含量之间存在极显著的相关性,但是受有机质来源不同的影响,微生物量与总氮、总磷之间仅在远离排污口部分存在极显著相关性. 相似文献
412.
413.
淀山湖沉积物中重金属元素分布特征及其季节变化 总被引:7,自引:0,他引:7
分别于夏冬两季采集淀山湖表层柱状沉积物样品,分析了沉积物样品中Cd、Pb、Cu、Cr、Fe和Mn的总量分布特征,用Tess-ier连续提取法,系统地对沉积物中重金属元素的形态分布进行了研究,并初步探讨了重金属元素分布特征的季节变化的原因。结果表明:沉积物中Pb的总量存在季节变化;沉积物中Cd、Cu、Cr和Fe主要存在于残渣态中,但Pb的铁锰氧化物结合态与Cu的有机质-硫化物结合态均为各自的优势结合态;Mn主要以可交换态、铁锰氧化物结合态及残渣态存在;Cd、Pb、Cu、Cr、Fe和Mn各形态含量均存在季节变化,其总量及各形态含量的变化与温度、pH、Eh等有关。 相似文献
414.
415.
珠江口现代沉积物柱芯样多环芳烃高分辨沉积记录研究 总被引:14,自引:2,他引:12
通过对采集于珠江三角洲澳门河口区的沉积物柱状样品中多环芳烃的GC MS定量分析测定,并结合210Pb同位素定年分析,重建了珠江口近代有机污染物的污染史(1959~1996年).研究结果表明,柱芯样品中多环芳烃的浓度为0.6~4.5μg·g-1(干重计),污染程度为中等.其中在20世纪60年代和80年代分别记录到两个高的污染峰,表明这两个时间段内有较大的污染物输入.以母体化合物比值对沉积物样品中的多环芳烃来源进行了分析,结果表明是受到了以油类和不完全燃烧产物为主的混合污染,且污染来源较为单一.对沉积物毒性潜在效应的计算表明,表层沉积物毒性效应较大,且从90年代初期开始后至1996年,毒性当量浓度呈线性趋势增加. 相似文献
416.
上海市苏州河支流--桃浦河底泥重金属的污染特征 总被引:4,自引:1,他引:3
对桃浦河底泥15个柱样(75个样品)测试分析了8种金属元素.结果表明,这些金属元素的平均含量都比较高,超标顺序为Zn>Cu>Cd>Hg>Pb>As>Ni>Cr,均高于苏州河的浓度.除As、Hg与其他元素的相关性较小外,Pb、Cd、Cu、Zn、Ni、Cr等之间均具有较为显著的相关性,相关系数介于0.616~0.890间.沿河各段重金属污染程度不同,上游和下游污染最严重.底泥金属的垂直分布与其底质沉积特征相对应.这在底泥疏浚时应具体考虑. 相似文献
417.
418.
Barbra C. Utley George Vellidis Richard Lowrance Matt C. Smith 《Journal of the American Water Resources Association》2008,44(3):742-753
Abstract: Sediment oxygen demand (SOD) is believed to be an important process affecting dissolved oxygen (DO) concentrations in blackwater streams of the southeastern coastal plain. Because very few data on SOD are available, it is common for modelers to take SOD values from the literature for use with DO models. In this study, SOD was measured in seven blackwater streams of the Suwannee River Basin within the Georgia coastal plain for between August 2004 and April 2005. SOD was measured using four in situ chambers and was found to vary on average between 0.1 and 2.3 g O2/m/day across the seven study sites throughout the study period. SOD was found to vary significantly between the watersheds within the Suwannee River Basin. However, land use was not found to be the driving force behind SOD values. Statistical analyses did find significant interaction between land use and watersheds suggesting that an intrinsically different factor in each of the watersheds may be affecting SOD and the low DO concentrations. Further research is needed to identify the factors driving SOD dynamics in the blackwater streams of Georgia’s coastal plain. Results from this study will be used by the Georgia Department of Natural Resources – Environmental Protection Division as model input data for the development and evaluation of DO total maximum daily loads in the Georgia coastal plain. 相似文献
419.
The Distribution and Sources of Polycyclic Aromatic Hydrocarbons in Surface Sediments Along the Egyptian Mediterranean Coast 总被引:2,自引:0,他引:2
El Nemr A Said TO Khaled A El-Sikaily A Abd-Allah AM 《Environmental monitoring and assessment》2007,124(1-3):343-359
Coastal marine sediment samples were collected from 31 sampling stations along the Egyptian Mediterranean Sea coast. All sediment
samples were analyzed to determine aliphatic and polycyclic aromatic hydrocarbons (PAHs) as well as total organic carbon (TOC)
contents and grain size analysis. Total concentrations of 16 EPA-PAHs in the sediments were varied from 88 to 6338 ng g−1 with an average value of 154 ng g−1 (dry weight). However, the concentrations of total aliphatic were varied from 1.3 to 69.9 ng g−1 with an average value of 15.6 ng g−1 (dry weight). The highest contents of PAHs were found in the Eastern harbor (6338 ng g−1), Manzala (5206 ng g−1) and El-Jamil East (4895 ng g−1) locations. Good correlations observed between a certain numbers of PAH concentrations allowed to identify its origin. The
average total organic carbon (TOC) percent was varied from 0.91 to 4.54%. Higher concentration of total pyrolytic hydrocarbons
(∑COMB) than total fossil hydrocarbons (∑PHE) declared that atmospheric fall-out is the significant source of PAHs to marine
sediments of the Egyptian Mediterranean coast. The selected marked compounds, a principal component analysis (PCA) and special
PAHs compound ratios (phenanthrene/anthracene vs fluoranthene/pyrene; ∑COMB/∑EPA-PAHs) suggest the pyrogenic origins, especially
traffic exhausts, are the dominant sources of PAHs in most locations. Interferences of rather petrogenic and pyrolytic PAH
contaminations were noticed in the harbors due to petroleum products deliveries and fuel combustion emissions from the ships
staying alongside the quays. 相似文献
420.
Heavy metal contamination in sediments of the Karasu spring was investigated in the presented study. In this respect, sediment
samples were collected from contaminant sites along the spring starting from the spring water manifestation site, base of
the Akkaya dam to the dam exit site. Heavy metal concentrations were determined by X-ray Fluorescence Spectrometer. Cobalt,
copper, arsenic, tin, nickel, zinc, cadmium, lead, aluminum, iron, titan, chromium and manganese contents of the Karasu creek
sediments are found as 18.30–69.00, 12.40–595.0 5.50–345.3, 5.80–15.1, 10.9–64.1, 28.90–103,300, 4.1–356.2, 7.70–37,840, 13,460–109,400,
11,740–62,900, 22.18–59.04, 41.70–369 and 12.09–3,480 mg/kg, respectively. Results indicate the presence of a contamination
in the Karasu creek. All the metal concentrations were found to be exceeding their acceptable limit values. Eutrophication
is developed in the Karasu creek and the Akkaya dam. It is thought that heavy metal accumulation in the creek is originated
from discharge from mine quarries, industrial and domestic wastes. Protection zones should be defined and all necessary measures
must be taken along the Karasu creek. 相似文献