Study On The Energy Demand Characteristics Of Taiyuan City Based On The Composition Evolution Of Water-soluble Ions

Taiyuan is one of the most polluted cities in China,and its unfavorable terrain makes it easier for air pollutants to accumulate.Atmospheric precipitation is an important way to remove atmospheric pollutants.Changes in the physical and chemical properties of precipitation can reflect the changing characteristics of air pollution in the local area,which is of great significance to the evaluation of the effects of pollution prevention and control measures.In this study,precipitation from 2011 to 2018 in Taiyuan city was collected at a fixed point,and the long-term evolution trends of p H value,ionic fluxes and 9 water-soluble ions(Na⁺,NH₄⁺,K⁺,Mg²⁺,Ca²⁺,F^-,Cl^-,NO₃^-,and SO₄^2-)were analyzed.Combined the details of the concentration level of air pollutants and energy consumption in recent years,the evolution process of different sources of air pollutants was analyzed,the actual effect of air pollution prevention and control measures was evaluated.Finally,this study planned the energy structure of Taiyuan city and its surrounding areas in 2030 briefly.The main conclusions are as follows:?1?PH value of precipitation was negatively correlated with precipitation amounts,and the frequency of acidic rain decreased year by year in 8 years.Ca²⁺?NH₄⁺?SO₄^2-and NO₃^-were the most abundant cations and anions,accounting for84.68%of the total.?2?The emission of SO_x was still the main cause of precipitation acidity,but the contribution of NO_x increased year by year.The continuous control of coal combustion leaded to a significant decline in SO₄^2--S wet deposition flux,while the rising trend of NO₃^--N was mainly related to the increasing number of vehicles.?3?The results of correlation analysis and PMF model showed that coal combustion and vehicle mixing source?56.25%?,dust?23.09%?,agriculture and coal coking mixing source?15.32%?and biomass burning?5.34%?were the four main sources of water-soluble ions in precipitation.?4?Backward trajectory analysis showed that the deterioration of air quality in Taiyuan was greatly affected by the short-distance air masses transport from the southwest and southeast in Shanxi Province,and air masses volume accounted for 40.03%and 14.42%of the total,respectively.And the air masses from northeast and northwest accounted for 20.86%and 24.69%of the total,respectively.?5?In order to successfully achieve the emission reduction targets of SO₂?46.55%?and NO_X?56.73%?in Shanxi Province from 2017 to 2030,the joint atmospheric control efforts of Taiyuan and its surrounding areas will be strengthened.By predicting the future energy structure of the major cities in Shanxi,some suggestions were put forward to reduce coal consumption in different ways and accelerate the development of clean energy.Before 2030,the annual growth rate of new energy in all cities in Shanxi needs to over 6.9%stably.