Enhancement of Remazol Brilliant Blue R Adsorption Capacity by using Modified Clinoptilolite

In this study, the adsorption behavior of Remazol Brilliant Blue R (RBBR) from aqueous solution by using raw and modified clinoptilolites were investigated. In the experimental work, raw clinoptilolite (R-CL) was treated with Zn(NO3)2 in ethanol and produced zinc-grafted clinoptilolite (Zn-CL).The adsorption experiments were carried out under different conditions of initial concentration (25-250 mg/L), adsorption time (0-2h), solution pH (2-12), and temperature (300-353 K) to determine optimum conditions for the highest RBBR removal. The influence of these parameters on the adsorption capacity was studied using the batch process. The results indicated that the solution pH was observed to be a key factor of the RBBR adsorption process. The maximum dye adsorption was achieved with Zn-CL adsorbent at pH~6 and the corresponding adsorption capacity was found to be 42.2 mg/g, which was higher than R-CL (12.5 mg/g). Lower adsorption capacity of RBBR was found by Zn-CL between pH 8 and 12 opposite to R-CL which showed a marginal increase in adsorption capacity within the same pH range. The results proved that Zn-CL which is a modified clinoptilolite is an effective adsorbent for the removal of RBBR from aqueous solution.