Setting up the Goal of Eliminating Outbreaks of Blue-green Alga, Innovating the Idea of Controlling the Taihu Lake, and Ensuring the Safety of Water Supply in the Taihu Lake

Since the water supply crisis in the Taihu Lake on May 29,2007,the control of the Taihu Lake has achieved remarkable results,and the eutrophication has been greatly reduced.Existing problems are as follows:outbreaks of blue-green alga still appear seriously every year,and there is no goal to eliminate outbreaks of blue-green alga;the load into the lake greatly exceeds the environmental capacity;reed wetlands are greatly reduced;there is still the possibility of a water supply crisis;the research of eliminating outbreak of blue-green alga is weak.In this paper,the experience of controlling the Taihu Lake is summarized,and the ultimate goals of eliminating eutrophication and outbreaks of blue-green alga and restoring wetlands and biodiversity are proposed.Control measures are proposed,such as deepening the promotion of the lake chief system,establishing the lake chief system in an all-round way,and increasing applied scientific and technological efforts and capital investment.The necessity and possibility of further controlling the Taihu Lake to eliminate outbreaks of blue-green alga should be recognized.Relying on controlling eutrophication alone cannot eliminate outbreaks of blue-green alga.The point that phosphorus control is the key to eliminate outbreaks of blue-green alga is not suitable for the Taihu Lake.The integration ideas of"three types"of technologies should be innovated.The first one is"double reduction and double increase"measures to eliminate eutrophication,of which"double reduction"is to reduce external point sources and non-point sources and internal blue-green alga in sediment;for external sources,the treatment standard of sewage plants should be paid special attention to.The second one is"double algae removal"measures to salvage blue-green alga,suppresses and kills algae.The blue-green alga on the surface,middle and bottom of water should be thoroughly salvaged and eliminated from various water areas.The third one is"double restoration"measures to restore wetlands and biodiversity.The area of wetlands should be restored to the area from the 1960s to the 1970s before outbreaks of blue-green alga,and vegetation coverage reaches 25%-30%.The Taihu Lake is controlled in different waters to ensure water supply safety in water sources.Five suggestions are proposed,such as revising the"Overall Plan for the Comprehensive Treatment of Water Environment in the Taihu Lake Basin"again,incorporating the goal of eliminating outbreaks of blue-green alga in the plan,setting up this research topic,greatly improving sewage treatment standards in local legislation.

Review on corrosion and corrosion scale formation upon unlined cast iron pipes in drinking water distribution systems

The qualified finished water from water treatment plants(WTPs) may become discolored and deteriorated during transportation in drinking water distribution systems(DWDSs), which affected tap water quality seriously. This water stability problem often occurs due to pipe corrosion and the destabilization of corrosion scales. This paper provides a comprehensive review of pipe corrosion in DWDSs, including corrosion process, corrosion scale formation, influencing factors and monitoring technologies utilized in DWDSs. In terms of corrosion process, corrosion occurrence, development mechanisms, currently applied assays, and indices used to determine the corrosion possibility are summarized, as well as the chemical and bacterial influences. In terms of scale formation, explanations for the nature of corrosion and scale formation mechanisms are discussed and its typical multilayered structure is illustrated. Furthermore, the influences of water quality and microbial activity on scale transformation are comprehensively discussed. Corrosion-related bacteria at the genus level and their associated corrosion mechanism are also summarized. This review helps deepen the current understanding of pipe corrosion and scale formation in DWDSs, providing guidance for water supply utilities to ensure effective measures to maintain water quality stability and guarantee drinking water safety.

Review of water pollution control in China

Water resource shortage and pollution has seriously threatened the survival and development of developing countries.Because of China’s specific economical and social circumstances,complete adoption of developed countries’experience is unrealistic.At present,China needs to develop strategies and technologies in source water pollution control and municipal environmental remediation that embrace the country’s specific need to battle the water resource problem.Among them,efficient source water pretreatment is a critical step to ensure a safe municipal water supply.Unlike developed countries,it is not yet feasible in China to treat water supplied to the household and have it meet the standard of direct drinking;therefore,it is more appropriate to refer to it as service water.As a beneficial supplement,an additional community drinking water network and household drinking water apparatus can be considered.