Comparative Analysis of the Physicochemical and Oil Adsorption Characteristics of Clinoptilolites from Turkey and the USA

Abstract

This study reports the oil adsorption and re-use efficiency of the zeolite clinoptilolite. Three clinoptilolite samples (E-, R-, and T-TUR) from Turkey were analysed, including samples from the Aegean Region, Turkey. Analyses were compared with clinoptilolite from New Mexico, USA (C-USA). Samples were tested in replicated laboratory analyses in terms of their ability to adsorb automobile oil (AO). Analyses included: (i) clinoptilolite samples were prepared for oil adsorption, using both hydrated (HC) and dehydrated (DHC) samples; (ii) Buchner funnels were lined with Whatman filter paper and batch adsorption experiments were conducted by adding 10 ml oil to 10 g samples of clinoptilolite. The oil infiltrating through samples was measured, thus enabling calculation of the amount of adsorbed oil. There were five replicates of each treatment; (iii) oil was removed from the clinoptilolite samples by heat treatment in a muffle furnace. Treatments were carried out at 500, 700 and 900oC for 1 h. The oil adsorption experiments were repeated on the ignited samples (four replicates). Results showed that DHC samples generally adsorbed more AO than HC after 900oC treatment. The adsorption capacities of the HC and DHC were 44.10-49.71 and 43.00-48.70%, respectively. The adsorption capacities of HC and DHC were 31.27-46.09 and 47.71-54.70%, respectively, after ignition at 700oC. The adsorption capacities of HC and DHC were 68.92-80.91 and 65.57-78.94%, respectively, after the treatment at 500oC. Overall, the amount of re-cycled oil by clinoptilolite varied between 39.01 and 82.78%. Turkish clinoptilolites had similar oil adsorption properties to the USA clinoptilolite and they could potentially be re-used for AO adsorption after the clinoptilolite-oil mix was ignited.