Response surface methodology for cobalt removal from aqueous solutions using Isparta pumice and zeolite 4A adsorbents

Heavy metals are toxic pollutants ceaselessly released into the aquatic environment as a result of urbanization, developing of industry and agricultural activities [9]. They do not undergo biodegradation being predisposed to accumulate into the organisms and entering into the food chains [21]. As regards radioactive wastes, these types of pollutants include a variety of radionuclides and appear in a variety of physical and chemical forms. One of the common radionuclides present in radioactive wastes deriving from production and application of radioisotopes is 60Co. 60Co is an artificial isotope produced in nuclear reactors by irradiation of stable 59Co, and applied in industry and medicine – in cancer therapy as a “cobalt bomb”. The radioactive cobalt is also released from nuclear reactors as a corrosion and activation product and it is one of the main impurities in reactor waters. Treatment of liquid wastes is required to produce a waste product suitable for long-term storage and disposal [18]. The applying of adsorption techniques for removal of heavy metals and radionuclides from waste waters, as an alternative method of treatment, is of great interest. Therefore, the investigation and comparison of different sorbent materials is also very important. Pumice is a volcanic rock, which can have acidic or basic character. The structure of pumice, a shapeless Response surface methodology for cobalt removal from aqueous solutions using Isparta pumice and zeolite 4A adsorbents Ekrem Cicek, Corneliu Cojocaru, Grazyna Zakrzewska-Trznadel, Agnieszka Jaworska, Marian Harasimowicz