Possible applications of clinoptilolites for natural water purification

Abstract

Possible applications of clinoptilolites (CP) in natural water purification processes from various contaminants are evaluated. Sorption properties of CP in various deposits of Russia are studied in relation to heavy metal ions. It was found that the studied specimens have a considerable sorption exchange capacity not only for ions of toxic (Hg2+, Cd2+, Pb2'), but also other heavy metals (Cu2+, Co2+, Ni2+, Zn2+, Ba2+ , Sr2+). It is shown that CP sorption capacity is more efficient when a Mn2+ ion is removed from natural water compared to synthetic ion-exchange resins and activated coals. The dynamic sorption capacities for a Mn2+ ion up to a breakthrough 0.01 mg/1 and 0.1 mg/1 is determined. The CP sorption capacity is insignificant for various halide ions except a fluoride ion the removal of which from natural underground waters is possible with the help of sorption on CP. It was proposed to use CP for removing natural radionuclides (radium 226 and potassium 40) from deep wellbore waters. The purification efficiency with the initial radium 226 concentration at the level 3,0 Bq/I (30 MPC) was not below 96%. The efficiency of removing potassium 40 natural isotope depends on the CP form and is maximal for Na form. Post treatment of natural waters after their coagulation treatment with the use of CP has been studied. It is shown that sorption filters with CP allow not only post-treatment of waters from excessive aluminum and zinc, but also additional reduction of odor, color, and ammonium ion content.

Keywords

• natural zeolites
• clinoptilolite
• purification of natural waters