The Analyses On The Origin Of The Iron And Manganese In Xi'an Drinking Water System And Control

With their understanding of water quality about safe getting deeper, people have paid more and more attention to the drinking water quality in recent years. The problem of iron and manganese overstep appeared in Xi'an water supply system is an important factor which influences the municipal water quality. Therefore, it is of great significance to investigate the distribution of iron and manganese in original water, treated water and the water of pipe network and the effect of treatment in original water, study the variational characters of the water quality during water distribution process, and analyze resource and factors, all what will help a lot in improving the water quality and protecting the inhabitants' health.By understanding the situation about the source groundwater and water supply system, based on the water quality survey in ground water source area of Xi'an and water quality monitor data, the paper investigates the basic characters of the groundwater quality and pollution, synthetically evaluates the water quality, analyzes the situation of the iron and manganese overstep and distribution in original water, treated water and the water of pipe network, and studies groundwater contamination and the influencing factors on iron and manganese in water supply system.Based on the water quality data of recent years, by means of using the cluster method, Xi'an water supply system's supply subregion is successfully achieved to analyze the water quality variation. On the basis of DPS data processing systems, time series model is used to study systemic and statistics research about iron and manganese variation in drinking water and it is found that time series model is instable and has periodicity and seasonal character. The correlation degree between iron and manganese is the biggest while analyzing grey correlation assessment of water target, and iron and manganese has a close relation to alkalinity, hardness, dissolved solid, sulfate and chloride. It carried out a research on the effect of iron and manganese's removal in the surface water works through measuring water leakage samples from every craft of treatment. The results showed that the traditional water treatment could achieve a very good removal rate of iron and manganese; Nan Jiao water plant which uses iron coagulant doesn't lead to iron overstep in treated water. Chlorination which is added advance is advantageous in helping follow-up treatment, and can enhance the processing effect. According to carry out a fluent track experiment, it studied the variation regularity of iron and manganese along the supplying water pipeline, and analyzed that the factors which influenced iron content in water pipe network of Xi'an, were pipe material, residual chlorine, retention time, the stability of water quality and so on. In addition, it is still found that drinking water quality is unstable in biology and chemistry of Xi'an, and brings out safety hidden trouble to municipal water supply system. Therefore, it pointes out the main factor which influences the sources of iron and manganese, and proposes some effective steps, such as enhancing the protecting of raw water area, improving water treatment, and improving water quality in pipeline and so on, so as to control iron and manganese content.