Investigation of activated carbon efficiency in hexavalent chromium adsorption from airflow

Hexavalent chromium (VI) is a very strong oxidizing agent that, despite its many uses in various industries, duration of the exposure can lead to lung cancer, deep wounds (in the hands, arm, tongue and palate), nasal septum perforation, burning and inflammation in the nose, lung and upper respiratory tract, asthma, contact dermatitis, damage to the kidneys and liver, and skin allergy. This study aimed to determine the activated carbon efficiency in chromium adsorption (VI) from air flow and its effective parameters.
Material and In this experimental study, chromium mists were generated by a nebulizer (3A model, Italy). Performance of activated carbon in the Cr (VI) adsorption and its influencing factors such as air flow rate (1 and 3L/min), the initial Cr concentration (0.05, 0.15, 1 and 10 mg/m3) and bed depth (2.5, 5 and 10 cm) were investigated. Yoon-Nelson and Thomas models were used to predict performance of adsorbent column and correlation test was used to determine accordance between the model and actual data.
Activated carbon adsorption capacity increased with increasing of bed depth but decreased with increasing of flow rate and inlet concentration. The results showed that the Yoon-Nelson and Thomas models with a correlation coefficient above 0.9953 matched with the experimental data.
The results indicated that activated carbon has a high efficiency in Cr (VI) adsorption, so that its efficiency at flow rate of 3 L/m, depth of 5 cm and concentration of 20 TLV and TLV was 85.42 and 71.83 percent respectively.