Discharge of phosphate into aquatic environment by various human activities such as agricultural runoff,
animal waste, sewage, industry and detergents, leads to the deterioration of water quality. Hence, the
effective removal of phosphate fromwastewater is essentially required. Considering this, the efficiency of
locally available agro-waste rice husk was examined in batch mode for the removal of phosphate using
synthetic wastewater. Characterization of adsorbent was done using Fourier transform infrared, X-ray
fluorescence and X-ray diffraction spectrophotometeric analysis, which indicates the crystalline silica
nature and presence of SieOeSi group. The effect of various parameters i.e. contact time, adsorbent dose,
pH and temperature were studied. Up to 89% phosphate removal was achieved at pH 6 using 2 g/L dose in
120 min of contact time. The equilibrium adsorption data shows best fit for the Langmuir isotherm model
(R2 ¼ 0.991) and pseudo-second order kinetic model (R2 ¼ 0.978). Thermodynamic parameters (DG, DH
and DS) were also calculated and they indicate that adsorption process is exothermic. Scanning electron
microscopy reveals the rough surface of absorbent, which may increases the adsorption capacity. Based
on the current study, activated rice husk ash offers efficient and cost-effective removal of phosphate from
wastewater.