Graywater Treatment in Sequencing Batch Reactor Using Simultaneous Nitrification, Denitrification, and Phosphorus Removal, with Kinetic Studies of Phosphate Adsorption onto Corncob

Abstract

The objective of this study was to investigate the performance of the sequencing batch reactor (SBR) for the treatment of graywater using simultaneous nitrification, denitrification, and phosphorus removal (SDNPR). The SBR reaction phase includes anaerobic (1 h), aerobic (2 h), and anoxic (1 h) phases that demonstrated significant removal of chemical oxygen demand (COD) (96.62%), biochemical oxygen demand (BOD) (97.38%), phosphate (72%), ammonia (81.68%), and surfactant (92%). Further, a batch adsorption study was carried out using corncob for the removal of phosphate from graywater. The influence of activation temperature (250°C–700°C) and initial adsorbent dosage (100–500 mg L−1) on phosphate adsorption was evaluated in the study. The highest phosphate adsorption was found at an adsorbent dosage of 500 mg L−1 and an activation temperature of 550°C. The adsorption study describes a better fit model using the Langmuir isotherm for the equilibrium data, and the adsorption rate was controlled by pseudo-first-order kinetics.