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Yu H.,Sun Yat Sen University | Yu J.,Nanjing University of Information Science and Technology | Xu L.,Pearl River Hydraulic Research Institute of PRWRC | Kim Y.,Hanseo University
Chinese Journal of Environmental Engineering | Year: 2013

Integrated constructed wetlands have been applied in the management of no-point source pollution. The pollutants removal mechanisms are different in different types of constructed wetlands. And the wetlands performance is variable under different operation conditions; it can be affected by many factors. A pilot-scale wetland was constructed for the control of nonpoint source pollution (NPS) in Korea. Its performance on the nitrogen removal was analyzed. Results indicated that the efficiencies of ammonia (NH4-N), nitrate (NO3-N), total Kjeldahl nitrogen (TKN) and total nitrogen (TN) were 13%, 29%, 35.3% and 26%, respectively. Furthermore, the removal of organic-nitrogen was the main factor affecting the nitrogen removal in this wetland. The effects of hydraulics loading rate and antecedent dry days on the nitrogen removal were determined. The lower hydraulic loading rate and the longer antecedent dry days can result in a higher nitrogen removal. Source


Yu J.,Nanjing University of Information Science and Technology | Yu H.,Sun Yat Sen University | Xu L.,Pearl River Hydraulic Research Institute of PRWRC
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2013

Recycling device-modified bio-filter filled with woodchip was used to dispose urban runoff. The recycling number was set as 2, 4 and 8. The effect of recycling on the treatment performance was compared based on the monitoring and experiments. Results indicated that there was a maturation or acclimation phase as usually observed in a filter and biofilm process, and the acclimation duration was different with different pollutants. During the period of the acclimation, the total inflow volume was about 8.5 times the porosity volume for chemical oxygen demand; the corresponding values were 7.2 for nitrate and total phosphorus, and 5.3 for total suspended solids and total nitrogen. The modified bio-filter can remove total suspended solids and nitrate effectively with efficiencies higher than 90%. However, it showed a lower treatment for organics removal, with the average efficiency around 30%. In terms of the effect of recycling, it contributed to the improvement of total suspended solids, ammonia and total phosphorus treatment, while showed little effect on the removal of total nitrogen and nitrate and decreased the chemical oxygen demand removal due to the release of organics during the recycling process. Source


Yu H.,Sun Yat Sen University | Yu J.,Nanjing University of Information Science and Technology | Xu L.,Pearl River Hydraulic Research Institute of PRWRC | Kim Y.,Hanseo University
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2013

Road-deposit sediment samples were collected from twelve parking lots in the urban coastal area of Korea during April-June of 2004. The particle size distribution and concentrations of pollutants including total nitrogen, total phosphorus, chemical oxygen demand and volatile solids were analyzed. The sediments collected from different parking lots were distinct from each other and typically included contents of branches, cigarette-ends, animal wastes and water constituents. The particle size distribution and uniformity also differed from site to site. Particles in the range of 106~500 μm contributed to a large portion of the sediments with a mass fraction of 59.9%. Compared with larger particles, the smaller particles were determined as highly polluted. Around 18.9% of total nitrogen, 17.8% of total phosphorus, 20.41% of chemical oxygen demand and 18.9% of volatile solids were associated with particles less than 106 μm, which accounted for only 3.9% of the total solids. Thus, more attention should be paid to these particles in managing non-point source pollution in parking lots. In addition, different methods should be employed for the treatment of particles with different sizes. Source


Yu J.,Nanjing University of Information Science and Technology | Yu H.,Sun Yat Sen University | Xu L.,Pearl River Hydraulic Research Institute of PRWRC
Environmental Science and Pollution Research | Year: 2013

Many best management practices have been developed and implemented to treat the nonpoint source pollution of the aquatic environment in Korea's four major river basins. The performance and cost of these facilities were evaluated and compared using broad categories, including grassed swales, constructed wetlands, vegetated filter strips, hydrodynamic separators, media filters, and infiltration trenches, based on the monitoring and maintenance work undertaken between 2005 and 2012. Constructed wetlands, media filters, and infiltration trenches generally performed better in removing pollutants than other types of facilities, while media filters were the most expensive factor in terms of construction and operational costs. In addition, constructed wetlands incurred the least operational cost, as well as helping to control the quantity of runoff. This illustrates that a high cost facility does not necessarily give a better performance. A slightly more expensive facility, such as wetland, could prove to be a reasonably effective treatment. The selection of the most appropriate treatment for stormwater runoff should be based on an overall analysis of performance and cost. © 2013 Springer-Verlag Berlin Heidelberg. Source


Yu J.,Nanjing University of Information Science and Technology | Xu L.,Pearl River Hydraulic Research Institute of PRWRC | Gao Y.,Nanjing University of Information Science and Technology | Yu Z.,China Union Weifang Branch | Kim Y.,Hanseo University
Chinese Journal of Environmental Engineering | Year: 2015

Many best management practices have been developed and implemented to treat the non-point source pollution of the aquatic environment in Korean 4 major-river basins. The performance and cost of these facilities were evaluated and compared using broad categories, including grassed swales, constructed wetlands, vegetated filter strips, hydrodynamic separators, media filters, and infiltration trenches. Results indicated that constructed wetlands, media filters and infiltration trenches generally performed better in removing pollutants than other types of facilities, while media filters were the most expensive factor in terms of construction and operational costs. In addition, constructed wetlands incurred the least operational cost, as well as helping to control the quantity of runoff. This illustrates that a high cost facility does not necessarily give a better performance. ©, 2015, Science Press. All right reserved. Source

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