L Pelaz1, A Gómez2, A Letona2, G Garralón3, M Fdz-Polanco4. 1. Department of Chemical Engineering and Environmental Technology, Escuela de Ingenierías Industriales. Sede Dr. Mergelina, University of Valladolid, C/ Dr. Mergelina, s/n, P.C. 47011, Valladolid, Spain. Electronic address: lara.pelaz@iq.uva.es. 2. CADAGUA S. A. Gran Vía 45-7, P. C. 48011, Bilbao, Spain. 3. Independent Researcher, Madrid, Spain. 4. Department of Chemical Engineering and Environmental Technology, Escuela de Ingenierías Industriales. Sede Dr. Mergelina, University of Valladolid, C/ Dr. Mergelina, s/n, P.C. 47011, Valladolid, Spain.
Abstract
A denitrification/nitrification pilot plant was designed, built and put into operation, treating the effluent of an anaerobic reactor. The operation of the plant examined the effect of the nitrate recycling and the COD/N ratio on the nitrogen and the remaining organic matter removal at 18 °C. The system consisted of a two-stage treatment process: anoxic and aerobic. The hydraulic retention time (HRT) of the system was 1 h for the anoxic bioreactor and 2 h for the aerobic one. The increase in the nitrate recycling ratio did not cause a significant improvement in the nitrogen removal due to the insufficient carbon source. The wastewater to be treated had a C/N ratio of 1.1 showing a lack of organic carbon. The addition of methanol was a key point in the denitrification process used as a model for the traditional wastewater by-pass in the WWTP. The maximum nitrogen and organic matter removal (87.1% and 96%, respectively) was achieved with a nitrate recycling ratio of 600% and a C/N of 8.25, adjusted by methanol addition.
A denitrification/nitrification pilot plant was designed, built and put into operation, treating the effluent of an anaerobic reactor. The operation of the plant examined the effect of the nitrate recycling and the n class="Gene">COD/N ratio on the nitrogen and the remaining organic matter removal at 18 °C. The system consisted of a two-stage treatment process: anoxic and aerobic. The hydraulic retention time (HRT) of the system was 1 h for the anoxic bioreactor and 2 h for the aerobic one. The increase in the nitrate recycling ratio did not cause a significant improvement in the nitrogen removal due to the insufficientcarbon source. The wastewater to be treated had a C/N ratio of 1.1 showing a lack of organic carbon. The addition of methanol was a key point in the denitrification process used as a model for the traditional wastewater by-pass in the WWTP. The maximum nitrogen and organic matter removal (87.1% and 96%, respectively) was achieved with a nitrate recycling ratio of 600% and a C/N of 8.25, adjusted by methanol addition.
Authors: Yunhui Pu; Jialing Tang; Xiaochang C Wang; Yisong Hu; Jin Huang; Shengwang Pan; Yuyou Li Journal: Environ Sci Pollut Res Int Date: 2019-10-25 Impact factor: 4.223