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651.
苏州河沉积物中的硅藻及其污染指示作用 总被引:6,自引:0,他引:6
阐述了苏州河的北新泾处状沉积物中的硅藻丰度、种类及其数量的变化,优势种属的相对含量的变化。整段沉积物中上、中、下层硅藻的丰度、种类相对很少,苏州河一期污水截流工程建成后,水质有所改善,有利于藻类生长和繁殖,沉积下来的硅藻也增多。结果表明,该柱状沉积物中的硅藻变化能有效地反映苏州河的污染变迁趋势;苏州河的水质污染以前极其严重,近年来有所改善,其主要污染类型为有机污染。 相似文献
652.
东海特定海区柱状沉积物中磷的存在形态及其环境指示意义 总被引:5,自引:0,他引:5
对国家海洋二所1998年5月调查过程中采自长江口外特定海区的柱状沉积物样品进行了系统的总磷及各形态磷分析。邻近长江口,杭州湾的MESO站位,总磷(TP)、铁结合态磷(Fe-P)和有机磷(OP)增色高于其它站位,表明来自长江、钱塘江水系的污染物已对东海海域的环境造成了一定影响。在垂直方向上,各站位TP、OP和Fe-P的含量自下而上增高,此外,Fe-P和OP由于还原溶解与生物降解等作用,倾向于进入孔隙水,参与海洋磷的再循环。吸附态磷(Ad-P)与钙结合态磷(Ca-P)的含量向上递减,与成岩期自生磷灰石的沉淀,以及磷的吸附-解吸附再平衡有关。 相似文献
653.
水中脱铬技术研究进展 总被引:2,自引:1,他引:2
简要回顾了国内外废水脱铬技术的研究进展情况,简单介绍了还原沉淀法、吸附法、离子交换法、萃取法及超滤法等几种常用的脱铬方法。 相似文献
654.
探讨了用蚕豆根尖细胞微核技术测试大庆地区主要排水干渠水质及底质的遗传毒性。并且通过污染指教PI值来研究水质底质的的综合毒性。结果表明作为一种灵敏度高、成本低廉的生物毒性监测方法,将在环境监测领域中有着广阔的应用前景。 相似文献
655.
656.
苏州河的污染底泥评价 总被引:3,自引:0,他引:3
以底泥与流动水相的边界环境为研究对象,应用苏州河底的释放与耗氧规律,在控制地面水水质标准的环境基础上拟定了底泥评价分级标准,将评价的有机污染指标确定为未污染,污染、重污染底泥的类型级别。应用拟定的分级标准对苏州河的污染底泥进行评价,指出若对属于重类型的部分河段底泥进行整治,则整个市区段底泥释放至水相的深度,将接近地面水三级标准。 相似文献
657.
中小型印染厂废水处理方法研究 总被引:3,自引:0,他引:3
介绍了利用自制的混凝剂与电石渣联用处理印染废水的一种新方法,该方法工艺流程简单,投资少,运行费用低,易于操作,CODcr去除率高,为中小型印染厂废水治理开辟一条新的途径. 相似文献
658.
A mathematical model was developed to estimate nitrate release from ocher pellets in benthic sediment. Ocher pellets, called “limnomedicine,” consisting of ocher and calcium nitrate were used to suppress phosphorus release from contaminated sediment under anaerobic conditions. The proposed model represents the fate and transport of nitrate released from the pellets, in both the water column and the sediment. Most of the nitrate (83.6%) released from the pellets was consumed in the degradation of organic matter and FeS in the sediment over a period of 12 days. While an increase in pellet dosage helps to accelerate the sediment treatment rate, it also has the effect of increasing the mass of nitrate that diffuses into the water column. Quantitative analysis of these effects using the proposed mathematical model makes it possible to determine the proper pellet dosage based on sediment conditions such as organic matter content. 相似文献
659.
The marine environment is being increasingly exploited by fisheries and the oil and gas industry. Conservationists urgently
need the ability to identify the processes that determine patterns of abundance of marine species. We describe a preliminary
Geographic Information System (GIS) in which spatial data on environmental variables (seabird colony locations, sea depth
and seabed sediments) are integrated with realistic energy constraints faced by marine birds during the breeding season. A
simple foraging model predicts the spatial variation in the quality of given locations as potential feeding sites under different
feeding conditions and stages of the breeding cycle. We show how the approach can be used to help managers identify key marine
areas and assess the impacts of environmental change or damage. 相似文献
660.
Channel incision is a widespread phenomenon that results in stream and riparian habitat degradation. Fishes and physical habitat
variables were sampled at base flow from three incised stream channels and one reference stream in northwest Mississippi,
USA, to quantify incision effects on fish habitat and provide a basis for habitat rehabilitation planning and design. Incised
channels were sampled in spring and autumn; the reference channel was sampled only in the autumn. Incised channel habitat
quality was inferior to the reference channel despite the presence of structures designed to restore channel stability. Incised
channels had physical habitat diversity levels similar to a nonincised reference channel, but contained fewer types of habitat.
At base flow, incised channels were dominated by shallow, sandy habitats, moderate to high mean local Froude numbers, and
had relatively little organic debris in their beds. In contrast, the reference stream had greater mean water depth, contained
more woody debris, and provided more deep pool habitat. Fish assemblages in incised channels were composed of smaller fishes
representing fewer species relative to the reference site. Fish species richness was directly proportional to the mean local
Froude number, an indicator of the availability of pool habitat. 相似文献