引江济巢工程对改善巢湖水质的数值模拟分析

巢湖受周围城市工业化及农业生产迅速发展的影响,湖区及流域的生态环境发生了巨大变化,尤其是近几年巢湖水质达到重富营养化水平。引江济巢工程是改善巢湖水质的重要工程措施,采用EFDC生态动力学模型模拟了巢湖不同调水流量、调水线路、调水时间对水环境的影响。结果表明,引江济巢工程在一定程度、时间上使巢湖湖区水质发生一定程度的改善,但若入湖水质不达标,调水也增加了巢湖的富营养化风险。     

Environmental factors controlling phytoplankton dynamics in a large floodplain river with emphasis on cyanobacteria

Harmful algal blooms are occurring in large river ecosystems and at the mouth of large rivers with increasing frequency. In lentic systems, the chemical and physical conditions that promote harmful algal blooms are somewhat predictable but tracking prevalence and conditions that promote harmful algal blooms in lotic systems is much more difficult. We captured two of the most extreme discharge years within the last 20 years occurring in the Upper Mississippi River, allowing a natural experiment that evaluated how major shifts in discharge drive environmental variation and associated shifts in phytoplankton. Statistical models describing significant environmental covariates for phytoplankton assemblages and specific taxa were developed and used to identify management‐relevant numeric breakpoints at which environmental variables may promote the growth of specific phytoplankton and/or cyanobacteria. Our analyses supported that potentially toxin‐producing cyanobacteria dominate under high phosphorus concentration, low nitrogen concentration, low nitrogen‐to‐phosphorus ratio, low turbulence, low flushing, adequate light and warm temperatures. Cyanobacteria dominated in 2009 when low discharge and low flushing likely led to optimal growth environments for Dolichospermum, Aphanizomenon and Microcystis. Rarely will a single factor lead to the dominance, but multiple positive factors working in concert can lead to cyanobacteria proliferation in large rivers. Certain isolated backwaters with high phosphorus, low nitrogen, warm water temperatures and low potential for flushing could benefit from increased connection to channel inputs to reduce cyanobacterial dominance. Numerous examples of this type of habitat currently exist in the Upper Mississippi River and could benefit from reconnection to channel habitats.     

基因工程菌在富营养化水体中应用的试验研究

该实验模拟了自然状况下水体富营养化的一般过程 ,利用基因工程菌消氮细菌及沉淀细菌对实验水体进行生物修复。得出结论 :在微生物处理下 ,水体的营养物质浓度不断降低 ,水体的浊度下降 ,透明度升高 ,使得实验水体的水质得到了明显的改善。     

改性玄武岩岩棉去除富营养化水体中磷的研究

对废弃玄武岩岩棉通过改性去除富营养化水中的磷,进行了试验研究.结果表明,采用超声波加热、浓度为1%的NaOH改性的岩棉对磷的去除效果最佳,当水体中总磷的浓度为0.58～0.85mg/L时,在改性岩棉用量为每7g/100mL、吸附时间为90min、pH为7.2的试验条件下,总磷的去除率为50%以上,使用后的岩棉经再生可重复使用.     

关于太湖污染底泥生态疏浚工程的探讨

目前太湖面临着严峻的富营养化问题，太湖污染底泥生态疏浚工程已经开始启动，但是关于太湖清淤的问题，专家们仍存在不同的见解。针对目前存在的几种观点，认为首先要对太湖疏浚进行前期研究，然后开展太湖示范工程，对污染底泥的空间分布规律、水质影响程度和机制、疏浚和处置技术、环境和生态效应等关系的科学问题进行系统深入的研究，从而为污染底泥的疏浚和处置技术提供理论和实践依据。     

污水强化除磷工艺的现状与未来

对强化生物除磷工艺的基本概念、外加碳源的作用、脱氮除磷的关系、环境影响参数进行了阐述,并介绍了聚磷菌菌群研究的最新进展。最后探讨了如何通过生产鸟粪石(MAP)实现磷元素回收,并围绕污水除磷和回收磷这一课题,提出了研究方向。     

Phytoplankton in a polluted subarctic lake before and after nutrient reduction

Phytoplankton and water chemistry were studied in a eutrophic subarctic Swedish lake before and after nutrient reduction. Pollution started in 1964 and the lake had received about 4.5 tons of phosphorus by the time the treatment plant was built in 1974. After that only 18–20 kg P yr^?1 entered the lake. Before nutrient reduction the phytoplankton consisted principally of three species, Dictyosphaerium pulchellum var. minutum, Chromulina cv. darlecarlica and Cryptomonas cv. ovata. Two years after the P-load was reduced Chlamydomonas spp and Mallomonas akrokomos predominated in the plankton and their dominance has been maintained during the period of study. Seasonal average phytoplankton biomass decreased from 11.2 g m^?3 in 1973 to 2.9 g m^?3 in 1980. Average seasonal total phosphorus concentrations decreased from 168 μgl^?1 in 1973 to 74 μgl^?1 in 1980. Average Secchi depth readings increased from 1.3 m in 1973 to 2.1 m in 1980. Blue-green algae never had any quantitative importance in the lake and no blooms were observed.     

Continuous monitoring of short term dissolved oxygen and algal dynamics

Dissolved oxygen (DO) in coastal bays with frequent algal blooms can undergo significant diurnal changes. Short-term DO and algal dynamics in a sub-tropical, nitrogen-limited, marine ecosystem are studied by means of a specially designed telemetry system. The high resolution data show clearly the importance of the vertical DO structure, and its relationship with environmental variables (solar radiation, water temperature, wind, tidal current) and phytoplankton dynamics. The design, instrumentation and calibration, and operational experience of the system are described. The simple and robust system has proved useful in (i) providing continuous data for full testing of water quality models, and (ii) the planning of field experiments to study algal dynamics.     

Eutrophication problems in Emilia Romagna,Italy: Monitoring the nutrient load discharged to the littoral zone of the Adriatic Sea

The deteriorating eutrophic state of the northern Adriatic Sea led to the commissioning of a study between 1977 and 1979 to identify the sources and forms of the nutrients phosphorus and nitrogen discharged from the basin of the river Savio. The study investigated the reduction in the phosphorus load in sewage per head of population caused by a reduction in the phosphorus content of detergents used in the basin and by the use of septic tanks. The flow and nutrient loads carried by the river were monitored during dry and wet weather to establish annual nutrient loads carried to the sea. An extensive sampling programme was carried out to quantify the principal sources of nutrients of which the most important were pig farming, Man and chemical fertilisers. An attempt was made to balance the nutrient loads discharged from the basin.     

给水处理中藻类去除的方法

饮用水源由于富营养化而导致水体中藻类大量繁殖是影响净水厂工艺正常运行及出厂水质的一个突出问题,介绍了国内外除藻技术研究进展.通过分析各种除藻工艺的除藻效果,认为生物处理法及其组合工艺可有效去除藻类、藻毒素,出水稳定,水质安全性高,应用前景广阔.