A Study on the Improvement of Nitrogen & Phosphorus Removal of a Sequence Batch Reactor with Internal Circulation and Multi-Step Addition

Autor: Pul-Eip Lee, Duckhui Lee, Bum-Su Kim, Yuhoon Hwang, Tae-Jin Lee
Jazyk: English<br />Korean
Rok vydání: 2020
Předmět:
Zdroj: 대한환경공학회지, Vol 42, Iss 5, Pp 280-288 (2020)
Druh dokumentu: article
ISSN: 1225-5025
2383-7810
DOI: 10.4491/KSEE.2020.42.5.280
Popis: Objectives The purpose of this study is to increase the denitrification and phosphorus removals by the oxygen control of the anaerobic or anoxic period using the circulation of the supernants through the settled sludge and multi-step addition of raw wastewater during the operation of the internal circulation sequence batch reactor (ICSBR). Methods The internal circulation pipe at the bottom of SBR is installed to circulate the supernatant into the settled sludge layer to create anoxic condition of non-aeration period instead of a stirrer in a SBR. And it is attempted to develope the SBR that properly uses the organic materials of the raw wastewater as a carbon source by the feeding the raw wastewater at a suitable time of the reaction period. Results and Discussion Dissolved oxygen (DO) concentration of the reactor decreases more rapidly with an internal circulation to which the uniform pressure division method is applied, increasing the efficiency of about 40%. As the multi-step addition of raw wastewater proceeds, the nitrogen concentration of effluent is lowered and the C/N (Carbon/Nitrogen) ratio is higher, the nitrogen removal rate is higher. Conclusions Circulating the supernatant to the bottom through settle sludge was effected to properly control the dissolved oxygen in the reaction tank, thereby improving the denitrification efficiency by about 68%. Even the higher the C/N ratio at the step addition can be expected the higher the nitrogen removal, it is noteworthy that the optimum feeding ratio of the multi-step addition may be different depending on the C/N ratio.
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