Porous activated carbons derived from bamboo pulp black liquor for effective adsorption removal of tetracycline hydrochloride and malachite green from water

Abstract

As a kind of wastewater produced by papermaking industry, bamboo pulp black liquor (BPBL) discharged into water causes serious environmental problems. In this work, BPBL was successfully converted into porous carbon after activation with potassium hydroxide (KOH) through one-step carbonization, and adsorption properties of porous carbon derived from bamboo pulp black liquor (BLPC) for tetracycline hydrochloride (TCH) and malachite green (MG) were studied. The adsorption capacities of BLPC for TCH and MG are 1047 and 1277 mg/g, respectively, due to its large specific surface area of 1859.08 m2/g. Kinetics and isotherm data are well fitted to the pseudo-second-order rate model and Langmuir model, respectively. Adsorption experiments and characterizations reveal that the adsorption mechanism involved in TCH and MG adsorption on BLPC mainly depends on the synergistic effect of pore filling, H-bonding, π-π interactions and weak electrostatic interactions. In addition, BLPC shows excellent photothermal properties, and the adsorption capacity of TCH and MG on BLPC can reach 584 and 847 mg/g under the irradiation of near infrared lamp for 50 min, respectively. The synthesized BLPC with high adsorption efficiency, good recovery ability, improved adsorption under near-infrared irradiation can be a promising and effective adsorbent for TCH or MG or other pollutes.