Comparative efficiency of peanut shell and peanut shell biochar for removal of arsenic from water.
Contamination of surface water and groundwater streams with carcinogenic chemicals such as arsenic (As) has been a major environmental issue worldwide, and requires significant attention to develop new and low-cost sorbents to treat As-polluted water. In the current study, arsenite (As(III)) and arsenate (As(V)) removal efficiency of peanut shell biochar (PSB) was compared with peanut shell (PS) in aqueous solutions. Sorption experiments showed that PSB possessed relatively higher As removal efficiency than PS, with 95% As(III) (at pH 7.2) and 99% As(V) (at pH 6.2) with 0.6 g L-1 sorbent dose, 5 mg L-1 initial As concentration, and 2 h equilibrium time. Experimental data followed a pseudo-second-order model for sorption kinetics showing the dominance of chemical interactions (surface complexation) between As and surface functional groups. The Langmuir model for sorption isotherm indicated that As was sorbed via a monolayer sorption process. The X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy analyses revealed that the hydroxyl (-OH) and aromatic surface functional (C=O, C=C-C, and -C-H) groups contributed significantly in the sorption of both As species from aqueous solutions through surface complexation and/or electrostatic reactions. We demonstrate that the pyrolysis of abandoned PS yields a novel, low-cost, and efficient biochar which provides dual benefits of As-rich water treatment and a value-added sustainable strategy for solid waste disposal.
['Sattar|Muhammad Sohail|MS|', 'Shakoor|Muhammad Bilal|MB|http://orcid.org/0000-0002-3115-0234', 'Ali|Shafaqat|S|', 'Rizwan|Muhammad|M|', 'Niazi|Nabeel Khan|NK|', 'Jilani|Asim|A|']
D000327:Adsorption D010367:Arachis D001151:Arsenic D002606:Charcoal D003247:Conservation of Natural Resources D006863:Hydrogen-Ion Concentration D007700:Kinetics D013499:Surface Properties D014874:Water Pollutants, Chemical D018508:Water Purification
Peanut shell Biochar Arsenic Sorption XPS Speciation