Continuity and discontinuity of the riparian vegetation along a fluvial corridor

The concept of continuity/discontinuity is applied to the riparian vegetation of the corridor of the River Adour (S.W. France), in order to precisely define longitudinal structure, and to test the degree of floristic continuity of the fluvial axis. The measure of floristic connectance along the river course is based on presence/absence data, and is applied to successive stretches of the river, at various resolution levels. This analysis shows that the River Adour corridor cannot be assumed to be floristically continuous. The observed discontinuities may correspond to two types of change in the riparian vegetation: zones of slow change (high level of floristic connectance) or zones of sharp change (low level of floristic connectance).     

Analysis on the Disposal of the Industrial Solid Waste in the Three Gorges Region

The second step of water storage for Three Gorges Reservoir will be executed in Jue,2003. Because there is still a large quantity of industrial solid waste(ISW) dumped on the reservoir bottom where should be cleaned before water storage and wastes should be disposed. After a full investigation and analyze, the total amount of ISW in the Chongqing reservoir area is about 1.66 million tons. According the principles of safe, economical and reliable, this paper describes the ISW's treatment. The ordinary ISW which is harmless and non toxic after identification should be treated on-site, the ISW that exceeds the national standards should be removed and be disposed in the landfill, and the hazardous waste should be removed for disposition or storage.     

HRT Effects on Biological Nutrient Removal in Spiral Up-flow Reactor System

Overall effects of HRT ( 11 h, 9 h, 8 h, 6 h ) on the Spiral up-flow reactor (SUFR) system are analyzed. The results of the operation under different HRT condition shows that the removal efficiencies of COD, TN and TP decreased not obviously with decreasing HRT when HRT is longer than 8h. Anaerobic retention time, anoxic retention time and aerobic retention time were 1.51 h,2.25 h and 4.24 h,respectively. The removal efficiencies of COD, TN and TP is kept over 93%,87% and 90.2%, respectively. Although the removal efficiencies changed obviously when the HRT was 6 h. Anaerobic retention time, anoxic retention time and aerobic retention time are 1.13 h,1.69 h and 3.18 h,respectively. COD-removal efficiency is always up to 85%, the removal efficiencies of TN and TP is kept over 76% and 72%,also has upper removal efficiencies. It is indicated that the SUFR system, which is similar to plug-flow-reactor, has strong stability and can compensate negative effects of increasing hydraulic loading.     

Review on Nitrogen and Phosphorus Removal by the Bio-filter

In this paper, the new development of nitrogen and phosphorus removal by bio-filter in home and abroad is summarized.The factors influencing the nitrification-de-nitrification, nitration-denitration, phosphorous removal and simultaneous nitrogen and phosphorus removal in bio-filter reactor are reviewed.It is pointed out that further improving the operation, enhancing the effect of nitrogen and phosphorus removal and advancing the process of bio-filter is the aim of study in the future.     

差分分层暗原色先验去雾法

针对烟尘和雾霾等恶劣户外环境下视频图像严重退化的问题,结合大气散射模型和暗原色先验去雾的原理,针对原始算法中暗区域扩张的缺点,提出一种区分图像景深边界的方法。此方法通过对像素求差分能够将不同景深的像素点区分,进而分别求出不同景深图像的透射率,从而达到快速、准确地恢复图像的目的。实验结果表明,这种方法能够具有更高的处理速度和图像细节,更接近实时去雾的要求。     

不同N水平的富营养化水体中经济植物净化能力比较研究

为建立净化富营养化水体的生态工程，本试验选择水芹、水蕹菜、韭菜、葱、黄花菜、芹菜等6种经济植物，研究了各种植物的净化能力及其生物学特性。结果表明：每种经济植物对水体总氮、总磷均有一定的去除作用，特别是水芹和水蕹菜，其在试验的20d内，对总氮、总磷的去除百分率分别为89．5％，98．2％；同时还对6种经济植物引起水体总氮浓度下降与时间关系作回归分析，结果表明随着处理时间的延长，水体中总氮浓度呈负指数形式衰减。本文还对在植物处理过程中，水中Chla、BODs和COD的变化进行了观测。研究表明，在高N水平的富营养化水中除水芹和水蕹菜外，Chla、BOD。和COD随处理时间的延长而下降，但在韭菜和葱处理过程中，水中腥味加重。各项指标综合分析表明，在不同N水平的富营养化水体中，水蕹菜处理效果最好，水芹次之，黄花菜和芹菜居中，韭菜最差。     

Increased degradation of phenanthrene in soil by Pseudomonas sp. GF3 in the presence of wheat

A phenanthrene-degrading bacterial strain Pseudomonas sp. GF3 was examined for plant-growth promoting effects and phenanthrene removal in soil artificially contaminated with low and high levels of phenanthrene (0, 100 and 200 mg kg⁻¹) in pot experiments. Low and high phenanthrene treatments significantly decreased the growth of wheat. Inoculation with bacterial strain Pseudomonas sp. GF3 was found to increase root and shoot growth of wheat. Strain GF3 was able to degrade phenanthrene effectively in the unplanted and planted soils. Over a period of 80 days the concentration of phenanthrene in soil in which wheat was grown was significantly lower than in unplanted soil (p<0.05). At the end of the 80-d experiments, 62.2% and 42.3% of phenanthrene had disappeared from planted soils without Pseudomonas sp. GF3 when the phenanthrene was added at 100 and 200 mg kg⁻¹ soil, respectively, but 84.8% and 70.2% of phenanthrene had disappeared from planted soils with the bacterial inoculation. The presence of vegetation significantly enhances the dissipation of phenanthrene in the soil. There was no significant difference in soil polyphenol oxidase activities among the applications of 0, 100 and 200 mg kg⁻¹ of phenanthrene. However, the enzyme activities in planted and unplanted soils inoculated with the strain Pseudomonas sp. GF3 were significantly higher than those of non-inoculation controls. The bacterial isolate was also able to colonize and develop in the rhizosphere soil of wheat after inoculation.     

湿地生态系统对污水中重金属的修复作用

湿地污水处理技术的研究是国内外众多学者关注的热点之一。综合国内外在污水湿地处理技术方面的研究成果,对湿地生态系统及其各组成要素对重金属污染的修复作用及其作用机理进行了讨论,针对目前利用湿地生态系统进行重金属污染废水修复过程中应注意的几个问题进行了探讨,并对今后研究发展方向进行了评述。