Third-Party Governance of Groundwater Ammonia Nitrogen Pollution: An Evolutionary Game Analysis Considering Reward and Punishment Distribution Mechanism and Pollution Rights Trading Policy

With the acceleration of Chinese industrialization, industrial wastewater is discharged in large quantities, leading to a groundwater environment with high ammonia nitrogen characteristics in many places, which seriously endangers people's health and makes the treatment of ammonia nitrogen by enterprises an urgent issue. Therefore, based on the principle of "no-fault responsibility", this paper combines China's pollution trading rights policy and the reward and punishment distribution mechanism to provide a three-party governance model for groundwater ammonia nitrogen treatment under the benefit sharing of emissions trading. By constructing a tripartite evolutionary game model of groundwater ammonia nitrogen pollution treatment among sewage discharge enterprises, third-party governance enterprises and local governments, the role mechanisms of the strategic choices of different participating actors are analyzed. Finally, the validity of the model is verified via simulation, and the influence of key variables on the evolutionary stability of the system and the strategic choices of the participating parties under different situations are discussed. The research results show that setting reasonable reward and punishment allocation coefficients is the basis for promoting active pollution treatment among sewage discharge enterprises and third-party governance enterprises; a change in pollution rights trading revenue is a key factor affecting the strategic choices of the three parties; sewage discharge enterprises show stronger revenue sensitivity than third-party governance enterprises; and an environmental treatment credit system built by the government can effectively enhance the enthusiasm of enterprises to control pollution. Based on the research results of this paper, the participation of third-party governance enterprises in pollution rights trading is explored, which effectively promotes enterprises to actively carry out groundwater ammonia nitrogen treatment and provides a reference for the government to improve the construction of a sustainable development system for the water environment.