Abstract

This study assessed the adsorption capacity of heavy metals such as lead (Pb), copper (Cu) and zinc (Zn) in the aqueous solution of biochar. Biochar was obtained from bamboo handicraft scraps by a pyrolysis method and was used as an economical absorbent. The bamboo biochar was characterized by scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy (SEM-EDS) and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The parameters such as contact time, biochar dosage, pH of the initial solution, and initial concentration of metal ions affected sorption capacity were investigated. Experiment results showed thatthe bamboo biochar mainly contained carbon and oxygen elements and a high number of C=O,C-O and O-H functional groups. The maximum adsorption uptake on biochar was Pb(II)>Zn(II)>Cu(II) under 1.0 g adsorbent L^-1, 20 mg L^-1 initial concentration of all metal ions, pH 4, contact time 120 min and at ambient temperature. From Langmuir isotherm fitting showed the maximum adsorption capacity was 41.15, 30.21 and 34.48 mg g^-1 for Pb(II), Cu(II), and Zn(II), respectively.Pseudo-second order kinetic model can best describe the adsorption process of all ions in solution mainly via monolayer adsorptiononto a homogeneous adsorbent surface and chemisorption as ion exchange, complexation, and surface mineral precipitation of metal ions. Appling the bamboo biochar for the removal of metal ions in groundwater found it was able to eliminate manganeseat more than 95% within an hour of contact time. All research findings suggest that bamboo biochar has broad potential for water purification applications.

Keywords:Bamboo biochar, Heavy metal, Removal, Groundwater