Study on Greenhouse Gas Emission Characteristics of Subsurface Flow Constructed Wetland Treating Farmland Recessed Water
Constructed wetlands,as an ecological and low-cost wastewater treatment technology,are associated with the generation and emission of greenhouse gases while removing pollutants.This study investigates the impact of different operational modes,wetland configurations,and hydraulic retention time on greenhouse gas emissions based on a medium-sized constructed wetland system used for treating agricultural run off.The findings demonstrate that the operational mode is constrained by the hydraulic retention time in terms of greenhouse gas emissions.When the hydraulic retention time is set at 1 day,the CH4 emission flux from continuously operated horizontal subsurface flow wetlands[-0.062 mg/(m2·h)]is significantly higher than that from intermittently operated horizontal subsurface flow wetlands[-0.225 mg/(m2·h)](P<0.01).The N2O emission flux from intermittently operated horizontal subsurface flow wetlands is slightly higher than that from continuously operated ones.For a hydraulic retention time of 1-3 days,both CH4 and N2O emission fluxes from horizontal subsurface flow wetlands are significantly higher than those from vertical subsurface flow wetlands(P<0.01).Furthermore,there is a positive correlation between hydraulic retention time and greenhouse gas emission flux.These research findings provide insights into reducing the greenhouse gas emissions from constructed wetlands.
Subsurface Flow Constructed WetlandGreenhouse gasesMode of OperationWetland ConfigurationHydraulic Retention Tim
NETL
NSTL
万方数据
