98%
921
2 minutes
20
Ecological ditches and bioretention ponds have received widespread attention and application due to their runoff pollution control capabilities and ecological benefits. However, a single ecological ditch or bioretention pond often has problems, such as unstable nitrogen and phosphorus removal and substrate clogging in rural runoff pollution control. Thus, we connected the two facilities in a series to construct a combined system, using the ecological ditch to pretreat, therefore reducing the pollution load of the bioretention pond and mitigating substrate clogging. At the same time, the submerged area was set and an external natural carrier carbon source was added in the bioretention pond to improve the nitrogen removal. The effects of the carrier carbon source, rainfall intensity, and alternating wet and dry conditions on the control of rural runoff pollution by the combined system were explored. The results showed that adding straw and sawdust as carrier carbon sources could increase the TN removal of the bioretention pond by 19.9% and 20.4%, respectively. When the simulated rainfall intensity increased from light rain to heavy rain, the removal efficiencies of COD, NH-N, TN, and TP in the combined system with external carbon source decreased by 17.0%, 16.8%, 20.4%, and 17.2% on average, respectively. The contribution of the ecological ditch to the removal of the four pollutants decreased by 16.3%, 13.0%, 24.2%, and 22.1% on average. Alternating dry and wet operation can improve the pollutant removal. Compared with continuous inflow, the average TN removal of the sawdust group increased by 12.3% after three weeks of drought. The results of microbial community analysis showed that the α-diversity of the bioretention pond in the sawdust group and the straw group was higher than that in control group. The abundance of Thiobacillus was significantly higher in the submerged area of bioretention ponds with carbon sources than that in the control group. These research results are expected to provide technical support for the practical application of the combined system.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.13227/j.hjkx.202108100 | DOI Listing |
J Environ Manage
October 2024
School of Urban and Regional Planning, University of the Philippines Diliman, Philippines.
Lack of studies in developing countries with tropical climate such as the Philippines limit local LID adoption. This study compared the performance of different LID scenarios across different urban land use types at the sub-catchment level using peak flow, runoff volume and flood reductions as performance criteria. Results showed that the most effective strategies for each land use are: 1) combined green roof and bioretention for low-density residential (reduction up to 10% peak flow, 11% runoff volume and 33% flood volume); 2) green roof for high-density residential (8% peak flow, 6% runoff volume and 18% flood volume); 3) combined rain barrel, bioretention and permeable pavement for industrial (23% peak flow, 41% runoff volume and 56% flood volume), and 4) combined vegetative swale and detention pond for urban open spaces (81% peak flow, 8% runoff volume and 84% flood volume).
View Article and Find Full Text PDFJ Environ Manage
August 2024
Department of Urban Water Management, Swiss Federal Institute for Aquatic Research (Eawag), Überlandstrasse 133, 8600, Dübendorf, Switzerland. Electronic address:
By infiltrating and retaining stormwater, Blue-Green Infrastructure (BGI) can help to reduce Combined Sewer Overflows (CSOs), one of the main causes of urban water pollution. Several studies have evaluated the ability of individual BGI types to reduce CSOs; however, the effect of combining these elements, likely to occur in reality, has not yet been thoroughly evaluated. Moreover, the CSO volume reduction potential of relevant components of the urban drainage system, such as detention ponds, has not been quantified using hydrological models.
View Article and Find Full Text PDFEnviron Sci Technol
July 2024
Ecohydrology Research Group, Department of Earth and Environmental Sciences, University of Waterloo, Waterloo N2L 3G1, Ontario, Canada.
Data from the International Stormwater Best Management Practices (BMP) Database were used to compare the phosphorus (P) control performance of six categories of stormwater BMPs representing traditional systems (stormwater pond, wetland basin, and detention basin) and low-impact development (LID) systems (bioretention cell, grass swale, and grass strip). Machine learning (ML) models were trained to predict the reduction or enrichment factors of surface runoff concentrations and loadings of total P (TP) and soluble reactive P (SRP) for the different categories of BMP systems. Relative to traditional BMPs, LIDs generally enriched TP and SRP concentrations in stormwater surface outflow and yielded poorer P runoff load control.
View Article and Find Full Text PDFWater Sci Technol
May 2024
Department of Civil Engineering, College of Engineering and Technology, Mbeya University of Science and Technology, P.O. Box 131, Mbeya, Tanzania.
The impermeable areas in catchments are proportional to peak flows that result in floods in river reaches where the flow-carrying capacity is inadequate. The high rate of urbanization witnessed in the Kinyerezi River catchment in Dar es Salaam city has been noted to contribute to floods and siltation in the Msimbazi River. The Low-Impact Development (LID) practices that includes bio-retention (BR) ponds, rain barrels (RBs), green roofs (GRs), etc.
View Article and Find Full Text PDFWater Sci Technol
February 2024
Centre for Water Systems, Department of Engineering, University of Exeter, North Park Road, Exeter EX4 4QF, United Kingdom.