Evaluation Of Water Quality Stability And Corrosion Control Under Desalination Of Seawater In A City

The current shortage of water resources in my country is becoming more and more serious.The introduction of desalinated seawater into municipal water supply will become an important measure to alleviate this problem.Desalination of seawater has water quality characteristics such as low p H value and low alkalinity value,which will lead to chemical stability problems of the water body,It will cause corrosion of the pipe network,accelerate the iron release process,and thus appear "yellow water" phenomenon.Based on both the existing water quality and the operating conditions of desalinated seawater,the study analyzes the chemical stability of the existing water quality,and explores the effect of desalinated seawater on pipeline corrosion after adopting water quality adjustment technology;the test simulates the dynamic flow of the pipe network to mix different proportions of tap water And desalinated seawater,and the use of electrochemical workstations to explore the principles and processes of corrosion to provide data basis for the future introduction of desalinated seawater scale;discussed the risks and countermeasures brought by the introduction of desalinated seawater;the study provides theoretical support for the introduction of desalinated seawater in urban water supply And technical basis,the main research conclusions are as follows:The results show that changing the mixing ratio of tap water and seawater desalination water has little effect on p H.The smaller the proportion of seawater desalination,the lower the turbidity and TDS concentration.It was found that the corrosion products on the surface of the test pieces of the five test groups were mainly Ca CO3 and iron oxyhydroxide Fe O(OH).The corrosion current density of the test groups A?E all showed a "rising-falling-stable" trend during the test.As the mixing ratio of tap water increases,the final values of polarization resistance are 75.6?·cm2,105.0?·cm2,136.7?·cm2,141.6?·cm2,and 193.3?·cm2,showing a gradually increasing trend,and the corrosion resistance increases.Increased difficulty in corrosion.The higher the mixing ratio of tap water,the more obvious the inhibitory effect on iron release,and the stronger the effect of protecting the pipeline.After the introduction of desalinated seawater,the water quality of the water supply pipe network has changed significantly.Changes in water quality conditions caused by the switching of water sources will affect the stability of the water supply pipe network,resulting in increased corrosion of the pipe network.The electrochemical analysis results of the pipe simulation test show that the corrosion current parameter of ductile iron is better than that of gray cast iron,and its corrosion resistance is stronger than that of gray cast iron.It is recommended that the main pipe of the municipal water supply pipe network be preferentially selected.The results of this study provide a scientific basis for the optimization of urban water supply pipes,help to ensure the safety of water supply and slow down the secondary pollution of water quality in the water supply network,and reflect good theoretical research and practical application value.