Optimization of phenol removal from wastewater by activation of persulfate and ultrasonic waves in the presence of biochar catalyst modified by lanthanum chloride

Abstract

Abstract In this paper, the effects of phenol concentration, pH, catalyst dose, persulfate concentration, temperature and contact time on the phenol removal from wastewater by activation of persulfate (S 2 O 8 −2 ) in the presence of biochar modified by lanthanum chloride and ultrasonic waves (US) are optimized. Experimental design and optimization were carried out by response surface methodology. The optimum conditions for the maximum phenol removal were obtained pH of 4, phenol concentration of 86 mg/L, catalyst dose of 43 mg/L, persulfate concentration of 86 mg/L, temperature of 41 °C and contact time of 63 min. The optimum phenol removal from synthetic wastewater was attained 97.68%. Phenol removal by the mentioned system was fitted with the first‐order kinetic model. The combination of the ingredients of ‘S 2 O 8 −2 /US/Biochar‐LaCl 3 ’ system had a synergistic effect on the phenol removal.