Date palm petiole-derived biochar: effect of pyrolysis temperature and adsorption properties of hazardous cationic dye from water

Palm petioles (PPs), a lignocellulosic and rich-carbon material, can be an attractive precursor to prepare carbonaceous porous adsorbents. Date palm petioles were used as raw material to produce biochar in this work. The effect of pyrolysis temperature (500, 600, and 800 degrees C) on the physicochemical properties and adsorption behavior of PP-biochar toward methylene blue (MB) dye in aqueous media was studied. The resulting PP-biochar samples were characterized by TGA/DTG, FTIR, N-2 adsorption-desorption, BET method, SEM-EDX, and point of zero charges (pH(PZC)). Results indicate that the BET surface area and total pore volume increased with increasing temperature, but the pyrolysis yield was decreased. The highest surface area and porosity were found for the PP-800 biochar (S-BET = 767.4 m(2)/g and V-pores = 0.53 cm(3)/g). The obtained values of the pH(PZC) were 8.27, 7.68, and 5.80 for samples PP-500, PP-600, and PP-800, respectively. The experimental amount of MB dye adsorbed reached 103.86 mg/g (for the PP-600 sample). Adsorption process occurred rapidly, and the kinetic data were well described by PFO and PSO models. The efficient PP-biochar can be produced by considering the temperature value of pyrolysis to find the desired properties (textural and surface characteristics).