| Related citation: | Hong-Jun Han,Qian Zhao,Chun-Yan Xu,Hai-Feng Zhuang,Peng Xu.Coal Gasification Wastewater Pretreatment with Coagulation and N2 Flotation Combined System[J].Journal of Harbin Institute Of Technology(New Series),2013,20(5):20-24.DOI:10.11916/j.issn.1005-9113.2013.05.004. |
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| Author Name | Affiliation | | Hong-Jun Han | State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China | | Qian Zhao | State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China | | Chun-Yan Xu | State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China | | Hai-Feng Zhuang | State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China | | Peng Xu | State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China |
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| Abstract: |
| A N2 flotation tank combined with coagulation was developed as a pretreatment equipment of biological process to remove oil and other pollutants in coal gasification wastewater (CGW). With optimal PAC dosage of 20 mg/L, the sole coagulation process achieves removal efficiencies of 29.34％ and 26.83％ for oil and COD, respectively. For the sole N2 floatation process, the optimal N2 flux and HRT are 20 m3/h and 20 min. Meanwhile, the oil and COD removal efficiencies are 35.41％ and 14.26％, respectively. For the combined system of coagulation and N2 floatation, the optimal parameter values are the same as the ones of separate processes. Correspondingly, the removal efficiencies are 46.28％ and 31.89％ for oil and COD, respectively. Besides, BOD5/COD of the effluent is improved. In contrast with conventional dissolved air floatation, the inert gas-N2 prevents the formation of cyclopentenone, pyridine derivatives, and other heterocyclic aromatic hydrocarbons, thus improving the biodegradability of influent for the subsequent biological processes. |
| Key words: N2 flotation tank coagulation coal gasification wastewater oil biodegradability |
| DOI：10.11916/j.issn.1005-9113.2013.05.004 |
| Clc Number:X 703.1 |
| Fund: |
