Applied Mechanics and Materials Vols. 316-317

Abstract: Water quality security is the guarantee of social development, the effective management of water quality information is the key to protect the water from pollution. This article focuses on the system architecture design and technology of Web-based water quality monitoring and information management system. Real-time communication between the Flex-written pages and the SQL Server database is achieved through the application of FluorineFx. The system realizes the visualized management of water quality information by visual components such as data table and data curve and so on.

Abstract: The flexibility and instantaneity of existing water environment warning system seems difficult to satisfy the increasingly severe water environment security situation and water pollution events. A dynamic early warning system structure based on pollutant dispersion simulation has been put forward, with some research on the construction of pollutant dispersion model, dynamic trigger optimization model , dynamic display of simulation results and other key techniques in detail. Take the Qiantang River in Hangzhou section for example, this paper builds the water hydrodynamic model and the convection diffusion model, simulates the dispersion of assumed pollutants and then displays the fuctions of providing dynamic early warning services.The application shows that this system can provide accurate and convenient warning of the influence range and degree of water pollutants. It also provides decision support for relevant government departments, water companies and other enterprises to take emergency measures timely and effectively.

Abstract: Water contamination events of urban water supply often show the characteristics of abruptness and variety, and the on-line water quality monitoring parameters usually are difficult to cover various contaminant parameters. With the help with routine detection and on-line water quality monitoring, it is possible to detect and judge whether a water quality event has happened or not and to identify its type indirectly, and obtain the relevant information of qualitative and quantitative analysis. These will be significant to the decision making by the concerning sectors and units. Taking the events of ammonium iron sulfate in the distribution system for example, the relationship of water between contamination concentration and conventional water quality monitoring parameters is investigated, and the quantitative method based on D-S evidence theory is given.

Abstract: Nowadays water pollution is a major problem facing our country, how to detect the water quality anomalies quickly is a major issue which needs to be solved urgently. In this paper, using PCA and cluster analysis methods, the similarities and differences of different water samples are analyzed. Meanwhile, two water samples belonging to the same river can be classified into different clusters due to different pollution degrees. It is promising that detecting the abnormal events based on the ultraviolet spectrum of water is possible. The research and results of this paper provide theoretical support and feasibility roadmap of the technology.

Abstract: The classification methods for water quality event detection are discussed, and the feasibility of water quality event detection based on single factor analysis is confirmed through the experiment. The process of water quality detection is introduced and one of Linear Filter algorithms is investigated. The test shows that autoregressive algorithm performs well for water quality abnormity detection.

Abstract: As disinfection by-products, the taste and odor (T&O) compounds were produced by chlorination at the end of water treatment. The existence of T&O compounds causes the pipe water with unpleasant odor and reducing water quality. Based on the latest research achievements at home and abroad, the characteristics and formation mechanisms of typical T&O compounds produced by chlorination are introduced. The new analytical method of electronic nose is also expounded. In addition, the common control technologies, such as pre-oxidation, activated carbon adsorption and bio-membrane, are reviewed. Since the precursors of T&O compounds shows small molecular, stable structure and low concentration, some coupling technologies including ozone-GAC, permanganate-PAC, and bio-membrane and GAC treatments, are employed effectively.Key words: chlorination; odor and taste compounds; disinfection by-products; precursor; electronic nose

Abstract: The experiment was carried out to measure the effect of membrane treatment on the kinetics of chlorine decay in PE pipes in the water distribution systems. The results revealed that water had the potential to form halomethane compounds with chloroform being the most dominant. The formation of THMs is no longer relatively exponential relationship with the reaction time, but also decided by complex elements, including DOC, pH, conductivity, flow rate, and several other indexes. Since Chloroform (CHCl₃) has the maximum concentration of the four THMs, clear understanding of its causes, pathway and mechanism will help to regulate and solve the THMs problem.

Abstract: To analysis the effect of different types of packing on the biofilm, combined packing, elastic packing and novel bamboo packing were selected as the testing packing in the contact oxidation tank and studied in the static condition. The indexes such as the total bacteria count and water quality changes were investigated to illustrate the characteristics of membrane and the effect of biofilm colonization in different membrane system.

Abstract: This paper presents monitoring investigation of water quality parameters in Fuchunjiang and Hangzhou reaches of Qiantang estuarine zone by YSI 6600 V2-4-M multi-parameter water quality sonde. The 7 monitoring cross-sections were streamwise placed, and the 2 vertical lines respectively located in flood plain and main channel at each cross-section. Surface, intermediate and bed layers were chosen at each vertical line in main channel, and surface and bed layers at each vertical line in flood plain. At each vertical line, the main water quality parameters such as dissolved oxygen, salinity, turbidity, pH value, electrical conductivity and oxidation reduction potential were monitored, variation of these parameters along longitudinal and vertical directions analyzed, and water quality conditions at each monitoring cross-section assessed.

Abstract: Water shortage emerges and restricts the urban construction and the social-development due to the rapid expansion of the cities. Recent research mainly focuses on the water resources management or water distribution network management separately. In this paper, a joint optimal model for water allocation and water distribution network management is developed. In the first phase, a multi-objectives linear programming is used for the optimal allocation on multi-water resources for multi-users, in which cost and water conservation are regards as objectives. In the second phase, a non-linear model is proposed, which is solved by single-objective GA linking to EPANET hydraulic solver. The result of the first phase is a parameter of the objective in the second phase.