Enhanced PAHs removal using pyrolysis-assisted potassium hydroxide induced palm shell activated carbon: Batch and column investigation

Abstract

The distress in evacuation of toxic contaminants at low concentration has prompted the investigation of effective adsorbents for expulsion of overwhelming metals. The present study deals with the synthesis of palm shell activated carbon (PSAC) and to investigate the effect of potassium hydroxide induced palm shell activated carbon (K-PSAC) followed by pyrolysis-assisted potassium hydroxide induced palm shell activated carbon (PK-PSAC) for the removal of polycyclic aromatic hydrocarbon (PAH) from aqueous solution. The SEM and HPLC analysis of PK-PSAC before and after adsorption were investigated. Acenaphthene removal was studied at different operating conditions like initial concentration, pH, contact time and temperature. The maximum adsorption capacity for K-PSAC and PK-PSAC was found to be 96.54 and 131.7 mg/g, respectively. The isotherm and kinetic studies for PAH adsorption onto PK-PSAC was well described by pseudo first order and Freundlich model, respectively. Thermodynamic parameters confirmed that adsorption process was an exothermic in nature. The fixed-bed column studies showed optimum values of the operating parameters at an inlet flow rate of (10–15 mL/min), acenaphthene concentration of 50 mg/L and bed height of 200 mm for the aqueous sample. The results proved that the quantity of acenaphthene adsorption reduced with an increase in flow condition and hiked when each of the PAH concentrations increased. The dynamic behavior of the adsorption column was predicted using Yoon Nelson model and Thomas-Adams model. This examination exhibited that pyrolysis could be utilized as a productive elective strategy for upgrading the adsorbent limit with respect to the compelling evacuation of dangerous contaminants.