This work aims to the analysis of arsenic desorption from an exhaust activated carbon used for the purification of a natural water. This last was used to mimic the properties of common groundwater or drinking water. Different low-cost and harmless eluting solutions were considered, including distilled water, natural water, saline (NaCl, CaCl2 and NaNO3) and basic (NaOH) solutions. Experimental results showed that, for 1 g of activated carbon with arsenic loading close to the maximum value available for the model natural water (omega approximate to 0.1 mg/g), it is possible to recover more than 80% of the arsenic using 20 ml of 0.1 M sodium chloride solution. A temperature variation within 20 and 40 degrees C has scarce effect on desorption efficiency. A comparison between desorption data and adsorption isotherms data suggests that arsenic adsorption is actually a reversible process. Therefore, it is virtually possible to increase arsenic recovery efficiency close to 100% by increasing the NaCl concentration or the volume of the desorption solution, but a preliminary cost benefit analysis lead to consider a NaCl 0.1 M solution as an optimal solution for practical application.
Desorption of arsenic from exhaust activated carbons used for water purification / DI NATALE, Francesco; Erto, Alessandro; Lancia, Amedeo. - In: JOURNAL OF HAZARDOUS MATERIALS. - ISSN 0304-3894. - 260:(2013), pp. 451-458. [10.1016/j.jhazmat.2013.05.055]
Desorption of arsenic from exhaust activated carbons used for water purification
DI NATALE, Francesco
;ERTO, ALESSANDRO;LANCIA, AMEDEO
2013
Abstract
This work aims to the analysis of arsenic desorption from an exhaust activated carbon used for the purification of a natural water. This last was used to mimic the properties of common groundwater or drinking water. Different low-cost and harmless eluting solutions were considered, including distilled water, natural water, saline (NaCl, CaCl2 and NaNO3) and basic (NaOH) solutions. Experimental results showed that, for 1 g of activated carbon with arsenic loading close to the maximum value available for the model natural water (omega approximate to 0.1 mg/g), it is possible to recover more than 80% of the arsenic using 20 ml of 0.1 M sodium chloride solution. A temperature variation within 20 and 40 degrees C has scarce effect on desorption efficiency. A comparison between desorption data and adsorption isotherms data suggests that arsenic adsorption is actually a reversible process. Therefore, it is virtually possible to increase arsenic recovery efficiency close to 100% by increasing the NaCl concentration or the volume of the desorption solution, but a preliminary cost benefit analysis lead to consider a NaCl 0.1 M solution as an optimal solution for practical application.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.