Red Reactive 2 Dye Removal from Aqueous Solutions by Pumice as a Low-Cost and Available Adsorbent

Background & Aims of the Study: Azo dyes are used in industrial processes such as textile industry to produce large quantities of colored effluents that contain organic and non-organic materials. So, effective and efficient treatment of them is important for the environmental protection. The aim of this study was to evaluate the efficiency of powder and granular pumice for the removal of red reactive 2 in an aqueous solution. Materials & Methods: This is an experimental study on a laboratory scale. Powder and granular pumice were prepared in a laboratory condition as an adsorbent. The study conducted on synthetic samples that contain red reactive 2 dye. The efficiency of pumice in powder and granular form, with different concentration, pH and contact time was tested. Results: Absorption of red reactive 2 is a function of the amount of adsorbent, impressed by pH and contact time. By increasing the amount of adsorbent from 0.5 to 2 gr, the absorption rate increased around 50% to 96%. The maximum uptake for each of testing procedures was accrued in acidic solution (pH=3) and 40 minute contact time. Langmuir and Freundlich isotherms models were derived from the experimental procedures. Conclusions: The results showed that the efficiency of powders form was better than granules. Due to the abundance of quarries in Iran, it could be used as a useful adsorbent in wastewater.