Comparison of Decolourizing Efficiency of Waste Pisum Sativum Pod Adsorbent on Single and Mixture of Synthetic Dyes

The synthetic dyes cause water pollution when discharged into water bodies due to their bright colour and adsorption is found to be a simple and cost effective method for decolourizing synthetic dyes. This research is carried out to investigate the decolourization efficiency of eco-friendly, cost effective adsorbent from waste Pisum sativum pods on synthetic dyes (Crystal Violet, Methylene Blueand Malachite Green) and their mixtures. At 12.5 mg/L initial concentration, the percentage dye removal of single dyes Malachite Green and Methylene Blue were found to be 86.96% and 76.47%. However for Crystal Violet dye, 61.9% removal was observed at 62.5mg/L. For mixtures of dyes, at 25 mg/L initial concentration, the highest percentage dye removal was 84.1% for Crystal Violet +Malachite Green, followed by 74% for Crystal Violet +Methylene Blue, 69.8% for Crystal Violet +Methylene Blue+Malachite Green and 65.5% for Methylene Blue+Malachite Green. Hence Pisum sativum pod adsorbent was efficient in decolourizing Malachite Green and Methylene Blue at 12.5 mg/L and mixture of Crystal Violet +Malachite Green and Crystal Violet +Methylene Blue at low concentration at 25 mg/L and Crystal Violet at higher concentration of 62.5 mg/L. From isotherm studies it was ascertained that Freundlich Isotherm had good fit for all the single dyes and all mixtures except Crystal Violet +Malachite Green. Langmuir Isotherm showed good fit for all single and mixture of dyes. Temkin Isotherm had good fit with Malachite Green, Methylene Blue dyes and mixture of Crystal Violet + Methylene Blue and Methylene Blue + Malachite Green dyes.