Deep bed underflow process for enhanced nitrogen removal advanced treatment of low-pollution sewage

Abstract

The invention relates to a deep bed underflow process for enhanced nitrogen removal advanced treatment of low-pollution sewage. According to the process, sewage is enabled to flow through a surface flow constructed wetland and a deep bed horizontal subsurface flow wetland in sequence; the surface flow constructed wetland comprises a first-stage surface flow wetland and a second-stage surface flowwetland; a nitrifying bacteria inoculant is added into the first-stage surface flow wetland; an aeration drop weir is arranged at the tail end of the first-stage surface flow wetland; wherein the deep-bed horizontal subsurface flow wetland is sequentially paved with a breathable impermeable sand layer, a filter layer, a denitrifying bacterium agent composite carbon source layer and an ecological gravel filler layer from bottom to top; tail water of the surface flow constructed wetland enters the deep bed horizontal subsurface flow wetland through a water collecting weir and a water passing culvert pipe and then is discharged through a water distribution channel, a subsurface flow wetland main body and a water collecting channel of the deep bed horizontal subsurface flow wetland. Accordingto the invention, the problems of nitrification reaction aeration of the subsurface wetland, lack of a carbon source in denitrification and low hydraulic load and large occupied area of the subsurfacewetland are solved, the stable operation of artificial constructed wetland system is ensured, and the low-pollution sewage is subjected to deep enhanced denitrification treatment.

Description

technical field [0001] The invention relates to a deep bed subsurface flow method for advanced treatment of low-pollution sewage, and belongs to the technical field of subsurface flow constructed wetlands. Background technique [0002] Constructed wetland is an ecological treatment technology that uses natural processes to purify wastewater. It has the advantages of low infrastructure operation costs, convenient management, and beautifying the environment. It has outstanding application advantages in watershed pollution control in developing regions. Constructed wetlands can operate in different hydraulic ways, including surface flow constructed wetlands, horizontal subsurface flow constructed wetlands, and vertical flow constructed wetlands. Constructed wetlands can effectively treat water with a water quality concentration between the second standard of GB 18918 in the Discharge Standard of Pollutants for Urban Sewage Treatment Plants and the Class Ⅳ standard of GB 3838 in...

AI Technical Summary

Problems solved by technology

[0022] Aiming at the deficiencies of existing subsurface flow constructed wetlands, the present invention proposes a deep bed subsurface flow process capable of strengthening denitrification advanced treatment of low-pollution sewage and ensuring stable operation

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