Author: | Fang, Le |
Title: | Enhancing removal of E. coli by bioretention basins during intermittent stormwater infiltration |
Advisors: | Tsang, Chiu Wa Daniel (CEE) |
Degree: | M.Sc. |
Year: | 2015 |
Subject: | Runoff -- Management Escherichia coli. Hong Kong Polytechnic University -- Dissertations |
Department: | Department of Civil and Environmental Engineering |
Pages: | ix, 84 pages : illustrations (some color) |
Language: | English |
Abstract: | To treat the stormwater preliminary, the bioinfiltration system were studied and simplified. A myriad of pollutants were exist in the stormwater, in this study, the fecal indicator bacteria (FIB)-E. coli was utilized to invest the bioinfiltration in removing bacteria. To mimic the real storm rain weather in nature, the experiments were carried out under a flow regime. There are nine columns carried out in this experiment to compare and study the geomedia of acid washed sand (AWS), iron oxide-coated quartz sand (IOCS), CEC-CTAB modified IOCS, polyDADMAC modified IOCS, biochar, H₃PO₄ modified biochar, H₂SO₄ modified biochar, amino modified biochar and KOH modified biochar. The flow regime contains two phases: (1) the saturated packed columns were contaminate by injection of stormwater and then sterile water go through the column, then followed by gravity drain and a pause for16h and (2) sterile water inducted to study the mobilization of E. coli under unsaturated condition, then go through the cycle as cycle 1. It is indicated that, the biochar and modified biochars active better than IOCS, AWS or modified IOCS, the removal efficiency can nearly 98% in the first cycle and the breakthrough concentration is low to 15% and appeared in 2 Cycle. The modification of E. coli under saturated condition, gravity drain and unsaturated drain is altered among these different geomedia. However, the KOH-modified biochar served best during the whole cycle, the removal efficiency is highest in 1 Cycle and 2 Cycle (99.9% and 99.3%, respectively), the mobilization of E. coli is also lowest. Results indicated that, the biochar modification of KOH and H₂SO₄ are successful in geomedia, the removal efficiencies are higher and mobilization ratios are lower. Incorporating the modified biochars into the geomedia of bioinfiltration systems can improve the removal efficiency of geomedia and minimize the mobilization of attached bacteria from the infiltration system. |
Rights: | All rights reserved |
Access: | restricted access |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
b28183228.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 3.83 MB | Adobe PDF | View/Open |
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