Research On Pricing Of Reclaimed Water Resources Based On System Dynamics

Reclaimed water is a kind of new water resource which can meet certain water quality requirements after deep processing and deep treatment of urban sewage.It is widely used in agricultural irrigation,industrial cooling,ecological construction,surface water recharge and groundwater recharge.The full utilization of renewable water resources can effectively alleviate water shortage and water quality shortage.The key to make full use of reclaimed water resources lies in setting reasonable water price for reclaimed water.However,there is a lack of scientific methods for setting the price of reclaimed water,which hinders the development of the market of reclaimed water to a great extent.It is worth of discussing how to make reasonable price of reclaimed water.Firstly,the system dynamics method and the cost method are combined to study the price of reclaimed water in this paper which are based on the analysis to the current situation of domestic and foreign research on the price of reclaimed water and the actual situation of our country.Secondly,the constituent elements and some influencing factors of reclaimed water price are analyzed,various factors are analyzed which integrate into a system.Then the time and space boundaries of the system are divided,the price system model of reclaimed water is built on this basis.The price system is divided into three subsystems:reclaimed water demand subsystem,reclaimed water supply subsystem and reclaimed water cost subsystem.The relationship between variables is analyzed and the equation of variables is determined according to the flow chart of each subsystem.Finally,on the premise that the validity and sensitivity of the model are verified,the price trend of reclaimed water is simulated by Vensim-PLE software in Hangzhou from 2007 to 2025,which is based on the actual situation of Hangzhou.The simulation results show that the price of reclaimed water in Hangzhou remained between 1-1.20 yuan during 2007-2025,especially after 2015,the price of reclaimed water declined slightly,and has been in a steady downward trend.The simulated reclaimed water price and the tap water price in life are not much different.At this time,the reclaimed water price has no absolute advantage and needs further optimization.Three optimization schemes are designed after the price system model of reclaimed water is simulated.The price of reclaimed water is optimized from three aspects:sewage treatment cost,user demand,supply and demand structure.The three schemes are simulated and analyzed to verify the feasibility.The results show that:(1)By improving wastewater treatment capacity and reducing wastewater treatment cost,the cost of wastewater treatment can be effectively reduced,which provides more space for formulating reasonable water price for reclaimed water.(2)According to the demand of different users,the corresponding reasonable reclaimed water price is determined which is based on the consideration of the user's acceptance ability.(3)Improving the supply-demand structure and reducing the supply-demand ratio which can set a reasonable price for reclaimed water.