Production of non-activated biochar based on Biden pilosa and its application in removing methylene blue from aqueous solutions
Supin Sangsuk, Pinanong Napanya, Siwabhorn Tasen, Phannida Baiya, Chatchai Buathong, Khemissara Keeratisoontornwat, Sirisak Suebsiri
Abstract
Biden pilosa (BP) is a type of weed commonly found in Thailand that needs to be removed from agricultural areas for protecting main crops. This research proposed a method to reduce BP by using BP as a feedstock for biochar production. Non-activated BP biochar from fresh BP was produced in pilot scale using a drum kiln with a heat-transferring duct at a pyrolysis temperature of 550 °C at a slow heating rate. The physical properties of the non-activated BP biochar were investigated using scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, and a surface area analyzer. A batch experiment was used to study the adsorption behavior of methylene blue (MB) on BP biochar. The microstructure study of the BP biochar indicated that it has a cell structure similar to that of BP, which shows the non-destructive nature of the proposed technique for BP production. Six dominant peaks at 3283, 2915, 1559, 1403, 1116, and 863/839 cm ⁻1 were observed in the FTIR spectrum. The BP biochar exhibited a surface area of 5.21 m 2 /g and a pore size of 8 nm. The adsorption of MB on the BP biochar followed the Langmuir adsorption isotherm and pseudo-second-order kinetics. The Langmuir-based maximum adsorption capacity of MB on the BP biochar was 200 mg/g at 303 K.