Research On Characteristics Particles And Its Interactions With Secondary Pollution In Pipe Of Water Distribution System And Its Emergency Treatment

With social economy rapidly developing and continuously improving quality oflife, the residents’ demand for drinking water is increasingly high, and the drinkingwater safety issues had been one of the hottest issues of social concerns. For the pastfew years, some countries and regions in the world have put the content of particlesinto the drinking water quality standards. Water quality monitoring and evaluation toreflect the water quality from the perspective of particles has become an obvioustrend. The research on performance characteristics and influence of particles in waterdistribution system has great significance to study the pipeline corrosion, reducesecondary pollution, ensure the safety of drinking water, carry out the early warning,emergency treatment measures and in turn to improve water quality.This thesis focused on cities which were important in north and south China tofinish fundamental census work for water distribution system. By monitoring theactual quality of water, we selected some representative water paths in order to getthe field samplings before and after the water supply pipe network transformation.Then by field experimentation and laboratory test, the particle size distributioncharacteristics and the other variation of the water quality were researched. Themorphology and distribution characteristics of particles were analyzed. The testresults show that:(1) the relationship between the turbidity and the number ofparticles is increased with the increase of turbidity.(2) The number of tiny particles ismuch more than larger particles.(3) The value of residual chlorine and TOC decaysin the direction of flow.The other water quality indicators have rising trend.(4) Theresidual chlorine and trichloromethane average of line one is less than line two, but itsfrequency fluctuations is greater than line two.The number of particles, turbidity,TOC and heavy metal ion is higher than line two.(5) The test was carried out that themain shape of particles is small proportion of regular and large proportion of irregularshape.The there-stage pilot trial has set up to analyze the interactive impact betweenparticle and secondary pollution. First of all, the pipes of different diameter and material are choosed. The evidence of pipeline corrosion dissolution and adsorptionto form particles can be gotten by the small test. So it can use to do the qualitative andquantitative analysis, and then the study show and prove that pipeline corrosion hasthe influence on particulate matter. At the same time, the hydraulic conditions have alarge influence on water quality in water distribution system. On the base ofanalyzing pipeline deposit corrosion, this thesis focuses on exploring themathematical relationship between the velocity, flow, pH value, alkalinity and itschange and different tubular product and particle. The test results show that:(1)while the pH is changed in the range of7to10, with the pH increasing, the releaseaggravated goes up.(2) While the water velocity is changed, all kinds of metal ionsrelease in different degree. The data has shown positive correlation between therelease degree and number of particles.(3) To reduce the release of particles andother substances in the pipe network, PVC pipes pipe is superior to other materials.On the basis of the previous test, parallel experiments hase been set up while theultrafiltration water is used as blank samples, and after more than six months timerunning, through experimental study on particles, the research can get the role ofparticles in the pipeline corrosion and secondary pollution of water quality.Finally, this thesis brings the particle collection and analysis into the dailyoperation management of water quality. The significant thing is to put forward themeasures of early warning and emergency treatment that not only improve the safetyand stability of the water, but also effectively ensure the quality.