给水处理除藻技术最新进展

我国地表水源富营养化日趋严重,进而导致严重的藻类污染。藻类及其副产物的污染不仅给传统净水工艺带来了诸多不利影响,增加了水处理难度,而且使得供水安全难以保证。文章对饮用水中藻类去除技术进行了具体的论述,并系统分析各技术去除效果、局限性,展望了藻类去除技术发展前景。指出目前控制饮用水中藻类污染必须将水源污染的综合治理、开发高效低廉的新工艺结合起来。     

Changes to lake ecosystem structure resulting from fish cage farm emissions

This study demonstrates how a given lake (Lake S. Bullaren, Sweden) would respond to emissions from a fish cage farm. The main questions to be answered are: How would emissions of feed spill and faeces from a fish farm influence the production and biomass of key functional organisms and how long would such changes remain if the fish farm is closed down? The work is based on a comprehensive lake ecosystem model, LakeWeb, which accounts for production, biomass, predation, abiotic/biotic interactions of nine key functional groups of organisms, phytoplankton, bacterioplankton, two types of zooplankton (herbivorous and predatory), two types of fish (prey and predatory), as well as zoobenthos, macrophytes and benthic algae. The LakeWeb model gives seasonal variations (the calculation time is one week). It has been calibrated and critically tested using empirical data and regressions based on data from many lakes. These tests have demonstrated that the model can capture typical functional and structural patterns in lakes very well, lending credibility to the results presented in this study. To the best of the author's knowledge, this is the first time that effects from fish cage farm emissions on lake ecosystem structure have been quantified at the ecosystem scale. To carry out studies such as these in the traditional manner, by extensive field work in one or a few lakes, would be very demanding, in terms of costs, personnel and time. This work has demonstrated that fish farm emissions would cause significant increases in the biomass of wild fish, without corresponding increases in algal volume. Thus, it is concluded that the fish farm emissions influence the lake's secondary production more markedly than primary production. Although this finding might seem to be a paradox, it is related to the fact that wild fish directly consume food spill and faeces from the fish farm, thereby creating a specific foodweb pathway, as described in this study.     

基于分形理论的水体富营养状况评价及其验证

在简要介绍分形维数算法的基础上,以乌梁素海2006年5月实测资料为例,初步分析分形理论在水体营养状况评价中的适用性;将基于分形理论的评价结果与国家环境保护部推荐使用的综合营养状态指数法评价结果进行比较分析。结果表明:在对22个采样点的评价中,二者评价的一致性达到91%。两种方法的评价结果仅有两个采样点不同。从全湖的评价结果看,乌梁素海已经达到富营养重富营养水平,与已有的研究成果相一致。评价结果充分说明分形维数法可以应用于乌梁素海的富营养化评价研究,但其在其他水体的普适性尚待进一步验证。另外,分析了分形理论在水体营养状况评价研究中存在的问题和不足,并对未来的发展趋势进行展望。     

陡河水库富营养化趋势分析与防治对策

分析电厂运行前后及引滦前后电厂温排水和引滦调水对陡河水库水体富营养化的影响 ,证明水库温升和库容减少加剧了库区水体的富营养化进程。引滦入陡河使水体运动加速 ,温升幅度缓解 ,从 1983～ 1985年的富营养化状态向中富营养化状态回落。但水体中营养盐超标以及水库受温排水影响所造成的全库性温升仍为不利因素。最后提出了营养盐的控制措施及改善水库换水周期 ,加强水库水质和水温监测的建议。     

水培油菜处理富营养化水体的研究

中国湖区水体环境污染问题日趋严重,典型的污染 形式是面源污染造成的水体富营养化。为此利用水上生物浮岛,探索油菜水上移栽技术,通 过油菜生长代谢吸收水体中的氮磷等,在治理水体污染的同时,将水体中的氮磷等转化成农产品。     

Mitigating cyanobacterial blooms: how effective are ‘effective microorganisms’?

This study examined the effects of ‘Effective Microorganisms (EM)’ on the growth of cyanobacteria, and their ability to terminate cyanobacterial blooms. The EM was tested in the form of ‘mudballs’ or ‘Bokashi‐balls’, and as a suspension (EM‐A) in laboratory experiments. No growth inhibition was observed for a laboratory strain of Microcystis aeruginosa and for M. aeruginosa from the field at the recommended dosage of 1 EM‐mudball per square‐metre (≈0.1–0.3 g L^?1). Cyanobacteria were inhibited only at very high concentrations (5–10 g L^?1 cyanobacteria), and a bloom was reduced, being attributed to the high amount of clay and high water turbidity. For these high dosage treatments, the dissolved oxygen concentration dropped initially to very low levels, with longer incubation indicating that nutrients were released from the material. The EM‐A suspension appeared ineffective in hampering cyanobacterial growths at recommended usage concentrations. EM‐mudballs released phosphate (160 μg P g^?1) and metals (aluminium, copper, traces of lead and lanthanum). The results of this study did not support the hypothesis that EM are effective in preventing cyanobacterial proliferation or in terminating blooms, thereby suggesting lake restoration by ‘Effective Microorganisms’ is not a convincing eutrophication control option.     

Evaluation of phosphate removal from water by immobilized phosphate-binding protein PstS

The phosphate (P(i))-binding protein PstS is a member of a family of periplasmic proteins that act as high-affinity receptors for active transport systems in bacteria. PstS protein purified from Pseudomonas aeruginosa was immobilized to N-hydroxysuccinimide-activated Sepharose, packed into a plastic column (5 x 70 mm), and examined for its potential ability to remove P(i) from water. The PstS-Sepharose column completely removed P(i) from 32P-labeled pond water containing about 0.5 microM P(i) (0.015 mg P per liter). More than 90% of 32P-P(i) that was retained in the column could be eluted by washing with low-pH water.     

Bioavailability of particle‐associated nutrients as affected by internal regeneration processes in the Nyanza Gulf region of Lake Victoria

Land‐use changes have been implicated a lot in the eutrophication of many lakes while forgetting the role of internal loading as influenced by the hydrological regimes of a given lake. The phosphorus loading of Nyanza Gulf is influenced both by internal and external loading with the internal loading playing a greater role in its eutrophication. The shear on the Apatite Phosphorus (AP) rich residual rock in the western end of the gulf through strong currents across the Rusinga Channel erodes the rock into non‐apatite inorganic phosphorus (NAIP) which is readily available for primary productivity. The current suspends the phosphorus rich apatite sediment together with the reserved phosphorus within sediments to the water column. The NAIP concentration on the western end of the gulf is exceptionally high, >1500 mg kg^?1, and together with the hydrological forcing; is believed to be the driving force of Nyanza Gulf eutrophication. External loading through rivers and municipal discharges exacerbates the problem. The external loading mainly influences the inner gulf on the eastern shore while the internal loading affects mainly the western end of the gulf. Nyanza Gulf eutrophication can be managed by adopting the following measures: (i) the Mbita Causeway needs to be opened and a bridge erected in its place in order to reduce the strong current through the Rusinga Channel and the residence time within the gulf, by increasing the flushing rates; (ii) the farming communities within the basin need to be sensitized on the controlled use of fertilizers; (iii) the municipal wastes should be treated to tertiary level before discharge into the lake; and (iv) reduce erosion within the basin through re/afforestation.     

分布式富营养水质预警在线监测系统设计

针对我国大型湖库水质富营养化愈趋严重的问题,为了实现对这些湖库水域环境自动化监测系统性,从应用的角度出发．提出一种新型的分布式富营养水质预警在线监测系统的设计方法。该设计综合利用了ARM嵌入式系统、GPRS无线网络通信等先进技术,对大范围的湖库水域分布式的设置监测节点,实现了对富营养化相关数据参数的实时在线监测、处理与传输的功能。该系统具有制造成本低、使用便捷、可靠性高、布点灵活等特点,非常适用于水质的远程连续在线监测．并具有一定的推广价值。     

Fertilizers and eutrophication in southwestern Australia: Setting the scene

An excess of plant nutrients has caused serious eutrophication in aquatic ecosystems of southwestern Australia manifested by excessive growth and accumulation of green and bluegreen algae. Phosphorus is generally the limiting nutrient for algal growth and phosphatic fertilizers applied to nutrient-deficient, leaching, sandy soils are the main source of P, supplemented by rural industry point sources. Nitrogen is the limiting nutrient in marine embayments with little drainage from the land. Measures to reduce the load of P delivered to drainage include basing fertilizer application rates on soil testing for P and the use of less soluble P fertilizers. Catchment management plans are being implemented with community involvement to reduce P loads and maintain agricultural production. This introductory paper reviews the history of eutrophication in southwestern Australia and of studies into its causes, principally in the large Peel-Harvey estuary. It briefly summarises other papers in this special issue concerned with different aspects of the problem: how to fertilize the land without causing eutrophication.