Investigation of the improvement sorption behavior of Zn(II) from wastewaters by bentonite as affected by solution chemistry

Clay minerals have been studied extensively due to their strong sorption and complexation ability towards various environmental pollutants. Zinc is widely used in many important industrial applications such as dry battery, electroplating industry, insecticides, foundry, metallurgy, pigments and explosive manufacturing. Zinc is often found in high concentrations in wastewater from many sources, including mine drainage, galvanizing plants, pharmaceuticals production, and pigments manufacturing. Known as an inorganic pollutant of the Priority Pollutants List.In this study, the removal of zinc from wastewaters by (Na,Ca)bentonite was studied in batch technique as a function of various solution chemistry conditions such as pH, concentration of adsorbent, concentration of metal ion, stirring speed and temperature under ambient conditions.The experiments were studied using metal ion concentration of Zn(II) between 50 and 250mg L−1 at an adsorbent concentration between of 20 and 100 mgL−1. At pH 3-10, stirring speed between 500 and 1000 rpm and a temperature of 25 °C.The results show that adsorption of Zn(II) by Na-exchanged bentonite is more effective than by Ca-bentonite and the percentage of Zn(II) removal increased with increasing adsorbent concentration, contact time ,stirring speed and pH and decreased with increasing metal ion concentration

کلیدواژه ها:

Clay ، (Ca ، Na)bentonite ، adsorption ، PH and Zn(II)