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In this study, rice husk was the precursor for a KOH-activated carbon with high surface area and high micro-porosity. CO2 adsorption capacity of this material was measured by thermogravimetric analysis. The CO2 adsorption kinetic showed that equilibrium was reached 30 min after the solid-gas phases came into contact and is well-described by the pseudo-first order model (R2 > 0.99 and 95 % confidence level). Intraparticle diffusion model revealed multilinearity over the CO2 adsorption range. Isotherm data at 25, 35, and 45 °C were well-fitted by the Freundlich model, revealing the adsorbent's surface heterogeneity and the exothermic behavior of the process. The material reached a maximum CO2 adsorption capacity of 2.54 mmol/g. A comparison with literature data showed a good agreement. [ABSTRACT FROM AUTHOR]

The study to reduce heavy metals pollution from water using the KOH-activated carbon was studied the factors affecting the adsorption capacities of Cu(II) and Pb(II), in particular, initial metals concentration, pH of the solution, and contact time in static conditions. Using X-ray photoelectron spectroscopy and FTIR analysis to determine the elemental composition and surface functional groups of the activated carbon surface, the presence of oxygen-related functional groups was observed. The maximum adsorption capacities were 135.8 mg g-1 and 31.0 mg g-1 for removal of lead and copper solutions with the initial concentration of 300 mg L-1 of metal at 318 K, respectively. The removal percentage was found to be higher for Pb (II) when compared with Cu (II).

This review covers research on the use of potassium hydroxide (KOH) to produce and modify activated carbon. The methods employed for activation by considering the activation process, carbonization, temperature, activation time, and KOH ratio to material are described and how the surface area, surface morphology, and functional groups are affected by the KOH ratio. Characterization techniques and preparation conditions are summarized. The activated carbon pore structure mainly depends on the burn‐off size and the time for activation is linked to the overall activation reaction rate. The increase in surface area and pore size depends on the ratio of KOH, showing that KOH affects the surface chemistry of the activated carbon. The sorbent‐sorbate interactions are strongly influenced by different parameters, which were also calculated in this review and used to evaluate such interactions. [ABSTRACT FROM AUTHOR]

The study to reduce heavy metals pollution from water using the KOH-activated carbon was studied the factors affecting the adsorption capacities of Cu (II) and Pb (II), in particular, initial metals concentration, pH of the solution, and contact time in static conditions. Using X-ray photoelectron spectroscopy and FTIR analysis to determine the elemental composition and surface functional groups of the activated carbon surface, the presence of oxygen-related functional groups was observed. The maximum adsorption capacities were 135.8 mg/g and 31.0 mg/g for removal of lead and copper solutions with the initial concentration of 300 mg/L of metal at 318 K, respectively. The removal percentage was found to be higher for Pb (II) when compared with Cu (II). [ABSTRACT FROM AUTHOR]