Experimental study of nutrient removal in an anaerobic hybrid upflow sludge blanket filtration bioreactor using response surface methodology

Abstract

In this study, a novel laboratory-scale anaerobic hybrid upflow sludge blanket filtration bioreactor was designed and operated to improve the performance of the upflow sludge blanket filtration process for nutrient removal from municipal wastewater. The effect of operating parameters, including nutrient concentration [total nitrogen (TN) and total phosphorus (TP)], biomass concentration, and hydraulic retention time (HRT), on nutrient removal were evaluated using response surface methodology. An industrial moving packed bed with 550 m2/m3 total specific surface area was used as the reactor media. It was found that increasing biomass concentration and HRT improved the removal efficiency for TN and TP. The results indicated that increasing nitrogen and phosphorus concentrations resulted in decreased removal rates. Additionally, there was an acceptable level of agreement between the experimental and model data (R2: 0.9896 and 0.9907 for TN and TP, respectively). The maximum removal efficiencies under optimum conditions were predicted by Design-Expert software to be 93% and 95% for TN and TP, respectively.