ZHANG Ting-xiu,LI Tian.Removal Efficiency of Polycyclic Aromatic Hydrocarbons in Road Runoff by Dry Grass Swale with Shallow Substrate Layer[J].China Water & Wastewater,2021,37(11 11):96-103.
Removal Efficiency of Polycyclic Aromatic Hydrocarbons in Road Runoff by Dry Grass Swale with Shallow Substrate Layer
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第37卷
Number:
11 11
Page:
96-103
Column:
Date of publication:
2021-06-01
- Keywords:
- road runoff; polycyclic aromatic hydrocarbons (PAHs); dry grass swale; low impact development; sponge city development
- Abstract:
- The average concentration of polycyclic aromatic hydrocarbons (PAHs) in road runoff in Shanghai is 3 996 ng/L, which is higher than that in other countries. A field test was carried out in a pilot-scale dry grass swale system with shallow substrate layer which had been operated stably for one year, and the control performance and removal mechanism of 16 kinds of priority controlled PAHs proposed by US EPA were explored. During the monitoring period, PAHs concentration in the effluent of the facility was significantly lower than that in the influent (p＜0.05), and concentrations of ∑16PAHs and ∑6PAHs (carcinogenicity or suspected carcinogenicity) in the effluent were 172.40-365.05 ng/L and 9.70-99.97 ng/L, respectively. PAHs in the road runoff could not be effectively removed by the pre-sedimentation tank. The removal rate of high molecular weight PAHs was positively correlated with the removal rate of TSS, indicating that the removal of these PAHs mainly depended on filtration and interception of TSS by substrate. Low molecular weight PAHs were mainly removed by adsorption, and the removal performance was affected by the increase of hydraulic load. The removal rate of benzo(a)pyrene was 98.00%, and its concentration in the effluent was lower than the limitation (30 ng/L) in Integrated Wastewater Discharge Standard (GB 8978-1996) with compliance rate of 100%, indicating that the dry grass swale with shallow substrate layer could effectively control the PAHs pollution in road runoff to receiving water body.
Last Update:
2021-06-01