Abstract: Lake plays an important role in the maintenance of water security, ecological security, and environment security. However, affected by the unreasonable artificial exploitation of water and soil resources and the global change, some lakes have being degenerated due to pollution, disordered reclamation, and the occupied ecological and environmental water requirements, resulting in the reduction of their ecological services and social economic values. Therefore, the ecological restoration of lake has become one of the resources and environmental problems, being jointly concerned by the government, academic circle, and social public. In the process of lake ecological restoration, artificial wetland system could efficiently reduce lake pollution load, and effectively regulate and control the abiotic environment of lake ecological system. In addition, it could help to conduct directive cultivation, proliferation, and protection. The lake pollution load reduction through artificial wetland system mainly includes the ecological interception of exogenous pollution load and the ecological extraction of endogenous pollution load. According to the inflow modes of exogenous pollution load, the ecological interception includes the zonal interception aimed at the unorganized discharge pollution load (mainly includes slope runoff in cropland and urban surface runoff) and the pre-reservoir interception and linear interception aimed at the organized discharge pollution. In the process of lake ecological restoration by utilizing artificial wetland system, there is a need to appropriately establish artificial wetland system and composite system at the right time and in the right place, and to fully exert the integrated ecological restoration function of artificial wetland system in the light of water-saving and land-saving principle, connecting with basic features, ecological degradation dynamic mechanism, and ecological restoration objective. In particular, it is necessary to avoid the damages of exogenous species to the lake ecosystem on the basis of multipart argumentation and ecological risk control.

Key words: Combined pollution, Orthogonal test, Hydrolase, Activity