Application of Eggshell as a Natural Sorbent for the Removal of Reactive Red 123 Dye from Synthetic Textile Wastewater

Dye is one of the most important pollutants in textile industrial wastewater. The scope of this study was to evaluate the feasibility application of eggshell as a sorbent for the removal of reactive red 123 dyes from synthetic wastewater. This study is an applied- experimental research which was performed in laboratory scale and in environmental chemistry laboratory of Baqiyatallah (a.s) university of medical sciences. Eggshell as a sorbent was prepared in laboratory condition (20-25°C) and pulverized by standard ASTM sieves. The effective size (D10) and D60 were 3 and 5.1mm, respectively and uniformity coefficient (UC) was 1.7. The concentrations of dye in wastewater were 25 and 50 mg/l. In this study increasing of adsorbent dose from 1 to 5 g/100ml led to increase of the adsorption efficiency from 48 to 80.7 %. The maximum adsorption took place in first 60min of reaction. With increasing the temperature up to 45°C the pollutant adsorption was increased and increasing of pH from 5 to 8 led to increase of process efficiency from 30 to 48%. Also absorption characteristics of this pollutant on eggshell accommodated with Langmuir isotherm. Eggshell can be used as a natural adsorbent in water and wastewater treatment. This adsorbent is an appropriate media for the treatment of textile wastewater that usually have alkaline condition and high temperature.