查看文章

Coffee husk, a carbonaceous precursor and common agricultural waste in Vietnam, was utilized to produce activated carbon by hydrothermal carbonization (HTC) with high adsorption capacity for pollutants. The characteristics and adsorption capacity of the hydrochar produced at the first HTC step (180 °C, 6 h) were subjected to further hydrothermal activation (130 °C for 2 h) with a low concentration of potassium hydroxide (ACHC-KOH 1 M), and directly soaked in KOH medium (ACHC-KOH 1:1). The surface area of the activated hydrochar obtained was significantly increased from 33.7 m²/g (raw hydrochar) to 703.9 m²/g for ACHC-KOH 1 M and 743.8 m²/g for ACHC- KOH 1:1, respectively. The maximum methylene blue (MB) adsorption achieved by the activated carbon materials were 357.38, 314.05, and 103.62 mg/g by ACHC-KOH 1 M, ACHC-KOH 1:1, and raw hydrochar, respectively. Adsorption kinetics and …