Biochar pyrolytically produced from municipal solid wastes for aqueous As(V) removal: Adsorption property and its improvement with KOH activation

• Published in: Bioresource technology 2014-10, Vol.169, p.622-629
• Main Authors: Jin, Hongmei, Capareda, Sergio, Chang, Zhizhou, Gao, Jun, Xu, Yueding, Zhang, Jianying
• Format: Article
• Language: English
• Subjects: Adsorption; Adsorption property; Applied sciences; Aqueous As(V); Arsenic - isolation & purification; Biochar; Biological and medical sciences; Biomass; Charcoal - chemical synthesis; Charcoal - chemistry; Cities; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Hot Temperature; Hydrogen-Ion Concentration; Hydroxides - chemistry; Kinetics; KOH activation; Municipal solid wastes; Pollution; Porosity; Potassium Compounds - chemistry; Solid Waste; Texas; Time Factors; Wastes; Water Pollutants, Chemical - isolation & purification; Water Purification - methods
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2014.06.103

•Excellent adsorption performance of aqueous As(V) by MSW biochars.•2M KOH activated MSW biochars were more favorable for As(V) adsorption.•Second-order model and Langmuir equation for better description of adsorption.•Porosity and functional group changes promoted As(V) adsorption on MSW biochars. Biochar converted from waste products is being considered as an alternative adsorbent for removal of aqueous heavy metal(loid)s. In this work, experimental and modeling investigations were conducted to examine the effect of biochars pyrolytically produced from municipal solid wastes on removing aqueous As(V) before and after activated by 2M KOH solution. Results showed that the highest adsorption capacity of pristine biochars was 24.49mg/g. The pseudo-second-order model and Langmuir adsorption isotherm model can preferably describe the adsorption process. The activated biochar showed enhanced As(V) adsorption ability with an adsorption capacity of 30.98mg/g, which was more than 1.3times of pristine biochars, and 2–10times of modified biochars reported by other literatures. Increase of surface area and changes of porous texture, especially the functional groups on the surface of activated biochars are the major contributors to its more efficient adsorption of As(V).