ENVIRONMENTAL IMPACTS AND BENEFITS OF STORMWATER RUNOFF TREATMENT ACROSS THE LIFE CYCLE OF BIORETENTION TANKS

Bioretention is extensively used for efficient and cost-effective stormwater treatment.Current research primarily focuses on isolated factors such as water purification efficiency and infiltration rate variations in bioretention cells.A life cycle assessment system has been established to evaluate the positive and negative environmental impacts of the system, from resource acquisition, transportation, and construction to operation, demolition, and disposal.By conducting environmental benefit monetization calculations, the evaluation indicator system for the construction effectiveness of bioretention cell systems has been improved.Following 20 years of local rainfall simulation and 40 simulated rainfall events in three stages, accompanied by tests for soil hydraulic conductivity curves, particle distribution, and pollutant contents, the variation pattern of effluent concentration was described, and an exponential relationship between operational time and stable infiltration rate (R > 0.905) was established.A life cycle assessment framework was established using experimental data and OpenLCA software, with characterization indicators covering acidification, carcinogenic emissions, eutrophication, fossil fuel consumption, greenhouse effect, non-carcinogenic emissions, ozone depletion, and respiratory impacts.Based on the variation in the stable infiltration rate, the study determined that the lifespan of bioretention cell systems ranges from 16.2 to 26.8 years.The environmental negative impacts are highest during the raw material acquisition and construction phases, accounting for 77% to 79%.The environmental positive impacts are highest during the modified media recycling and reuse phase, accounting for 61% to 80%.The monetized benefits range from 49.61 to 77.44 EURm -3 over the entire life cycle of bioretention cell systems.