Investigation of the adsorptions of cr+ compounds with zeolite in cement suspensions

In this study, It has been investigated that the adsorption capacity of Cr+6,+3 compoudsin clinoptilolite type zeolites which is both natural and the one which has been activated.Zeolites have been taken from Manisa-Gördes area. Thermal, acidic and basic activations havebeen applied to zeolites to increase the adsorption capacity. Calsination temperatures have beenchosen as 400˚C, 500˚C and 600˚C to see the effect of different temperatures. It has been usedHNO3 and H2SO4 for acidic and KOH and NaOH for basic activations.One of the two aim in this study is to prevent the re-oxidation because of the adsorptionof +3 value chrome by adding of the zeolites to the cements in which the iron sulfate chromehas been degraded from +6 to +3. Another aim is determine the investigation of adsorption of+6 value chrome. By this aim, clinoptilolites have been added to the pure cements which have 2ppm and 14 ppm chrome +6 values as 5, 10, 20, 40 wt% ratios. The samples have beenanalyzed to determine the chrome +6 content throughout 6 month. By the time, the cementwhich includes iron sulfate +3 chrome has been oxidated. However, the cements has been addedclinoptilolite have not been oxidated. At the end of 6 months, the chrome +6 concent of theportland cements has been increased to 9 ppm, meanwhile chrome concent of the cement whithclinoptilolite has been remained 0-1 ppm. It has been reduced to 4 ppm chrome content to thecement which has 14 ppm chrome content by adding the clinoptilolite. The best results havebeen got with acids (HNO3> H2SO4). The results of the basic activations could not be affectedas acidic and thermal activations. However, it can be arranged like KOH > NaOH. It has beenobserved that the different calcination temperatures does not affect the adsorption capacity.Keywords: Activation, Adsorption, Cement, Chromium, Clinoptilolite, Zeolite