RT info:eu-repo/semantics/article
T1 Assessment of the performance of a symbiotic microalgal-bacterial granular sludge reactor for the removal of nitrogen and organic carbon from dairy wastewater
A1 Bucci, Paula
A1 Marcos Montero, Enrique José
A1 García Depraect, Octavio
A1 Zaritzky, Noemí
A1 Caravelli, Alejandro
A1 Muñoz Torre, Raúl
K1 Bacterial granules
K1 Cheese whey
K1 Chlorella sorokiniana
K1 Nitrogen
K1 Simultaneous nitrification and denitrification
AB Cheese whey (CW) is a nutrient deficient dairy effluent, which requires external nutrient supplementation for aerobic treatment. CW, supplemented with ammonia, can be treated using aerobic granular sludge (AGS) in a sequencing batch reactor (SBR). AGS are aggregates of microbial origin that do not coagulate under reduced hydrodynamic shear and settle significantly faster than activated sludge flocs. However, granular instability, slow granulation start-up, high energy consumption and CO2 emission have been reported as the main limitations in bacterial AGS-SBR. Algal-bacterial granular systems have shown be an innovative alternative to improve these limitations. Unfortunately, algal-bacterial granular systems for the treatment of wastewaters with higher organic loads such as CW have been poorly studied. In this study, an algal-bacterial granular system implemented in a SBR (SBRAB) for the aerobic treatment of ammonia-supplemented CW wastewaters was investigated and compared with a bacterial granular reactor (SBRB). Mass balances were used to estimate carbon and nitrogen (N) assimilation, nitrification and denitrification in both set-ups. SBRB exhibited COD and ammonia removal of 100% and 94% respectively, high nitrification (89%) and simultaneous nitrification-denitrification (SND) of 23% leading to an inorganic N removal of 30%. The efficient algal–bacterial symbiosis in granular systems completely removed COD and ammonia (100%) present in the dairy wastewater. SBRAB microalgae growth could reduce about 20% of the CO2 emissions produced by bacterial oxidation of organic compounds according to estimates based on synthesis reactions of bacterial and algal biomass, in which the amount of assimilated N determined by mass balance was taken into account. A lower nitrification (75%) and minor loss of N by denitrifying activity (<5% Ng, SND 2%) was also encountered in SBRAB as a result of its higher biomass production, which could be used for the generation of value-added products such as biofertilizers and biostimulants.
PB Elsevier
SN 0045-6535
YR 2024
FD 2024
LK https://uvadoc.uva.es/handle/10324/72891
UL https://uvadoc.uva.es/handle/10324/72891
LA eng
NO Chemosphere, 2024, vol. 351, 141250
NO Producción Científica
DS UVaDOC
RD 23-dic-2024