2001 Fiscal Year Final Research Report Summary
Study on Coagulation and Filtration Systems for the Removal of DXNs in Leachate from Sanitary Landfills
| Project/Area Number |
12650542
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Civil and environmental engineering
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| Research Institution | MURORAN INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
HOZUMI Hitoshi the department of Technology, professor, 工学部, 教授 (80002921)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIDA Hideki the department of Technology, assistant, 工学部, 助手 (70210713)
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| Project Period (FY) |
2000 – 2001
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| Keywords | SS / Color / COD / Coagulation / FeCl_3 / DXNs |
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| Research Abstract |
This research yielded the following results:
(1) Coagulation tests by using FeCl_3 in laboratory showed the optimum condition for the coagulation of the leachate samples from a sanitary landfill. When the amount of coagulant was fixed at 100mg-Fe^<3+>/L, the optimum pH for the removal of SS, COD and Color in the samples was around 4〜5. Such condition gained the best removal rate, more than 50% of every component in the samples. Especially more than 90% of suspended solids was removed at any pH. When the pH was fixed at 4〜5, the removal rate of COD and Color components in the samples was getting larger with the amount of added coagulant. More than 90% of suspended solids was removed at 20 mg-Fe^<3+>/L, the amount of coagulant. However, only 50% of COD and Color components were removed at 100 mg-Fe^<3+>/L, the amount of coagulant. When the coagulant increased by 300 mg-Fe^<3+>/L, the removal rate was improved to be 70〜80%. The optimum conditions of the addition of coagulant are different for the removal of suspended solids or COD and Color components.
(2) The questionnaire about the conditions of the operation of 51 leachate treatment plants in Hokkaido, Japan was carried out. 40% of the plants used FeCl_3. 60% of the plants controlled pH as 7〜8, which is not optimum condition for the coagulation of COD and Color components. Half of the plants controlled coagulant addition as less than 100 mg-Fe^<3+>/L. The operation data at the plants showed that suspended solids were controlled at less than 60mg/L but more than 10m/L, which is the criteria for the removal of DXNs in leachate. The removal of suspended solids at the plants should be improved by controlling of the operation of coagulation.
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