Optimization Of Reclaimed Water System In Residential Area In Dalian

The shortage of water resources in Dalian seriously limits the development of the city.Building reclaimed water system is one of the best choices to solve the shortage of water resources,and is also an important part of the ecological civilization development.It has great significance to water resource protection,pollution control and sustainable development.In this paper,the reclaimed water system construction situation of Dalian city was introduced detailly.The development of reclaimed water system was late and uncomplete,and there were lots of serious problems,including the unreasonable of water collection system construction,the poor water treatment process selection,and the high construction cost of the water supply system.At the same time,the necessity and technical feasibility of the construction of reclaimed water system in residential area were analyzed.Then,the optimization method and analysis model of water collection system,water treatment system and water supply system were introduced separately.And finally,the most appropriate method and model were found for the optimization of reclaimed water system in residential area.The reclaimed water system of a residential area in Dalian city was chosen as an example to establish the optimization model.The researches of the optimization of water balance,water treatment process,and water supply system were studied,as well as the economic analysis.It was found that the main comprehensive sewage was used as raw water,and the daily water value 700 m~3/d.The production value of the reclaimed water was about 630 m~3/d,and the productive rate was about 90%.The use of reclaimed water mainly included flushing water,car washing water,road pouring water,landscape replenishing water and green water,and the total consumption was 472 m~3/d.The water production was greater than the dosage,meet the use.That meant the water recycling system can save 472 m~3 of tap water every day,and the water-saving efficiency was as high as 54%,indicating that the establishment of the water recycling system was economic and environmentally significant.The three kinds of water treatment processes,like coagulation sedimentation process,membrane bioreactor process and biological contact oxidation process,were analyzed by the analytic hierarchy model.The results shown that the combination weight of coagulation sedimentation process was highest.Therefore,we chosen the coagulation sedimentation process as treatment process,the construction system mainly included the grille,adjusting pool,ICEAS reaction pool,coagulation sedimentation tank,filtering system and contact disinfection pool,etc.The frequency conversion water supply system was chosen for the water supply due to the village water supply was changing with the season fluctuation.In the economic field,the split water supply scheme could save?0.28million a year than the traditional water supply scheme,the cost ratio of water supply scheme against the traditional water supply was 1:2.21,illustrating that the split water supply scheme in residential area was economically viable.This study provided theoretical support and application demonstration for the construction of reclaimed water system in residential area,and promoted the development of the construction of reclaimed water system in residential area in Dalian.