Influence of Pyrolysis Temperature on Cadmium and Zinc Sorption Capacity of Sugar Cane Straw–Derived Biochar

Leônidas C. A. Melo, Aline Renee Coscione, Cleide Aparecida Abreu, Aline Peregrina Puga, Otávio Antonio Camargo

Abstract


The effect of pyrolysis temperature on the characteristics and metal sorption capacity of sugar cane straw derived–biochar (BC) was investigated. Biochar was produced at four temperatures (400, 500, 600, and 700 °C) before characterization for yield, ash and moisture content, pH, EC, pHPZC, elemental composition, nutrient content, CEC, TGA, and functional groups (FT-IR). Biochar alone and in mixtures containing 10%, w/w biochar with one of two different tropical soils (Entisol and Oxisol) was shaken for 24 h with a 2.0 mM solution (pH 4.5) of Zn or Cd in a batch sorption test. Increasing the pyrolysis temperature led to a reduction in the O/C and H/C molar ratios. The sorption capacity of biochar pyrolyzed at 700 °C was nearly four times greater than that produced at 400 °C. In the Entisol mixture, there was an increase up to seven-fold in the sorption of both Cd and Zn compared with the control (without BC). In the Oxisol mixture, there was a maximum 20% increase in sorption compared with the control. For the remediation of Cd- and Zn-contaminated substrates, the use of higher pyrolysis temperature biochars are recommended because of their higher metal sorption capacities.

Keywords


Heavy metals; Biomass; Tropical soils; Zinc

Full Text: PDF

Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126