A new desorption method for removing organic solvents from activated carbon using surfactant

Abstract

Objectives:A new desorption method was investigated, which does not require toxic organic solvents. Efficient desorption of organic solvents from activated carbon was achieved with an ananionic surfactant solution, focusing on its washing and emulsion action. Methods: Isopropyl alcohol (IPA) and methyl ethyl ketone (MEK) were used as test solvents. Lauryl benzene sulfonic acid sodium salt (LAS) and sodium dodecyl sulfate (SDS) were used as the surfactant. Activated carbon ( 100 mg ) was placed in a vial and a predetermined amount of organic solvent was added. After leaving for about 24 h, a predetermined amount of the surfactant solution was added. After leaving for another 72 h, the vial was heated in an incubator at 60°C for a predetermined time. The organic vapor concentration was then determined with a frame ionization detector (FID)-gas chromatograph and the desorption efficiency was calculated. Results: A high desorption efficiency was obtained with a 10% surfactant solution ( LAS 8% , SDS 2% ) , 5 ml desorption solution, 60°C desorption temperature, and desorption time of over 24 h, and the desorption efficiency was 72% for IPA and 9% for MEK. Under identical conditions, the desorption efficiencies for another five organic solvents were investigated, which were 36%, 3%, 32% , 2% , and 3% for acetone, ethyl acetate, dichloromethane, toluene, and m-xylene, respectively. Conclusions: A combination of two anionic surfactants exhibited a relatively high desorption efficiency for IPA. For toluene, the desorption efficiency was low due to poor detergency and emulsification power.

Characteristics of Adsorption of Organic Solvent Vapors by a New Porous Carbon Material Made of Rice Husk as Measured by Breakthrough Curves

“…Coconut shell activated carbon is commonly used in respirator cartridges and canisters for organic vapors. Activated carbon is also used in the solid adsorption method for measuring organic solvent vapors in the working environment [1,2], and in air purifier filters, water purifier cartridges, and refrigerator deodorizers in houses and residences.…”

Research on Regenerating Activated Carbon in 2,4,6‐Trinitrotoluene (TNT) Explosives Manufacturing Industry by Microwave Radiation and Ionized Nitrogen

“…There are several methods to regenerate activated carbon that scientists have researched and proposed such as using heat, ultrasonic waves and chemicals. However, the use of heat to regenerate activated carbon will destroy the structure, and it causes air pollution [23], the method of using ultrasonic waves must be done with high frequency and it will cause minor disruption of activated carbon [24], while the method of using chemicals is costly and it creates secondary waste water which makes treatment difficult [25]. Several studies have shown that nitroaromatic compounds will gradually be destroyed and transformed into simpler forms under the influence of microwave radiation and ionizing current [26,27].…”