Optimal Control Based On The Dynamical Model Of Constructed Wetland

With the rapid development of industry and agricultural,and the deepened effects of human production and life,lots of industry,agricultural and life sewage drains into the waters directly,which leads to severe water pollution.The pollution not only threaten human health,but also severely damaged ecological balance,and thus,adopts a series of measure,that managing water pollution and protecting water resources,is an immediate emergency.The constructed wetland,as a new type of ecological wastewater treatment technology,has been given more and more attention.Its mechanism of denitrification and affecting factors were widely and thoroughly studied.In this paper,from the angle of ecology and economy,based on the effects of algae amount on sewage treatment and the mechanism of nitrogen transform processes,and used the optimal impulsive control,modern control theory and other principles,algae population model and nitrogen dynamical models of constructed wetland were analyzed and researched.The main contents of the dissertation are as follows:Firstly,based on Logistic growth models of algae population,the algae population management model,with impulsive effect and aimed at total cost,was constructed.According to the optimal impulsive control,the best time and level for management was gotten,and then,the validity of the results was verified by numerical simulation.Secondly,on the basis of the restrain and transform relationship of nitrate nitrogen,ammonium nitrogen and organic nitrogen,and used the modern control theory,an existed nitrogen dynamical model of constructed wetland was introduced,and its controllability and stability were analyzed.Besides that,the shortest time of drainage to meet the water quality was calculated by applying time optimal control method.Furthermore,based on the system stability,the relationships between the shortest time meet the water quality and the time meet the system stability were discussed,and the implementations of water feeding and draining were analyzed,which applied an effective method for managing constructed wetland.