Adsorption of acetic acid and hydrogen sulfide using NaOH impregnated activated carbon for indoor air purification

Abstract

Excessive exposure to hydrogen sulfide (H 2 S) and acetic acid (CH 3 COOH) gases is extremely dangerous in a confined space. An effective indoor air pollutant removal porous carbon filter was developed using NaOH impregnated on activated carbon (NaOH/AC) for the adsorption of H 2 S and CH 3 COOH. Activated carbon (NaOH/AC) filter was characterized using various methods, indicating good physical and chemical properties (especially -OH functional groups) for the adsorption of air pollutants. The prepared NaOH/AC filter was cured at different curing temperatures and residence times to understand the effect of the curing conditions on the adsorption performance. The best results were obtained with NaOH/AC filter cured at 100 • C for 20 minutes as it eliminated the initial concentration of 400 ppm of CH 3 COOH in 15 minutes and H 2 S in 30 minutes at 20 • C and 60% relative humidity. Isotherm and kinetic models were used to analyze the adsorption process. Langmuir isotherm and pseudo-second order kinetic models provided the best fit to the adsorption of CH 3 COOH and H 2 S on NaOH/AC filter. The adsorption mechanism was controlled by the intraparticle diffusion combined with film diffusion. The maximum adsorption capacity of NaOH/AC filter was 473 mg/g for H 2 S adsorption, and 550 mg/g for CH 3 COOH adsorption. In addition, the spent NaOH/AC filter was regenerated for reuse.This study is expected to develop low-cost and effective porous carbon filter using NaOH-modified activated carbon for indoor air purification.

Probing adsorbent heterogeneity using Toth isotherms

“…According to Hunston, 28 N(K) can produce a continuous distribution spectrum that will closely simulate the affinity parameters that can be obtained from the discrete distribution models. Expressions similar to eq (7) does frequently appear in literature in several scientific areas and within the context of adsorption, this expression represent the basic integral equation commonly used to describe the adsorption on heterogeneous surface. Eq (7), the Fredholm integral equation of first kind, is difficult to solve as it has no general analytical solution.…”

“…Expressions similar to eq (7) does frequently appear in literature in several scientific areas and within the context of adsorption, this expression represent the basic integral equation commonly used to describe the adsorption on heterogeneous surface. Eq (7), the Fredholm integral equation of first kind, is difficult to solve as it has no general analytical solution. Thus several attempts have been made to find an approximate solution and some of these methods were recently reviewed.…”

“…This technique can be easily applied by identifying a suitable continuous distribution model (like., Freundlich, Toth, Sips and Redlich-Peterson isotherm) that best represent the experimental equilibrium data. Eq (7), the Fredholm integral equation of the first kind, is difficult to solve as it has no general analytical solution. Thus, Hunston used a finite difference method based on a method developed by Ninomiya and Ferry 38 to estimate N(K).…”

“…Recently, porous materials, especially those with high surface area, are investigated for: the storage of fluids such as CH4 and H2; to capture CO2 from flue gas, for air filtration; and to capture of toxic gases and volatile organic vapours. 1,2,[11][12][13][14][3][4][5][6][7][8][9][10] For instance, carbon nanotubes and metal-organic frameworks (MOFs) can potentially 'recognize' (i.e. specifically interact with) small molecules and thus be used for gas sensing.…”

Characteristic evaluation of adsorption efficiency of activated wood charcoals in adsorbing acetic acid

“…Several researchers [24][25][26][27][28][29][30][31] have proposed the effectiveness wood type material and seeds, peels, leaves from plant source activated carbon was used in treating industrial wastewater. Ademiluyi et al, 32 investigated the adsorption and treatment of organic contaminants using activated carbon from waste Nigerian bamboo by carbonizing at 400 o C-500 o C and activated with acid at 800 o C forming granular activated carbon (GAC).…”