Structural characterization and water turbidity removing efficacy of Portulaca mucilage–alginate (PMA) beads

Abstract

The focus of the present study includes the isolation, characterization, and a correlation of water clarification efficacy of mucilage from Portulaca oleracea leaves, a food-grade polysaccharide and its encapsulated calcium alginate beads. The characterization of mucilage powder was conducted for its physical and chemical properties. Portulaca mucilage was encapsulated in calcium alginate to develop Portulaca mucilage–alginate (PMA) beads. The developed beads were characterized by scanning electron microscopy, energy dispersive X-ray analysis, thermo gravimetric analysis, differential scanning calorimetric analysis, and fourier transform infrared spectroscopy techniques to study various physicochemical aspects. Efficiency of PMA beads for water clarification in low as well as high turbid water was investigated. Percentage turbidity removal was found to be 97 and 87%, respectively, in high and low turbid waters. Efficiency of recycled beads was also studied. Mucilage and PMA beads showed varied surface morphologies before and after treatment with turbid water. Relevancy of these variations to the turbidity removal is discussed. Swelling studies revealed that the beads were swelled at low pH range (pH < 5) and at higher pH range (pH > 9). The findings of this study lead to the potential production of new environmentally friendly composite beads for water clarification.

Keywords:

• Portulaca mucilage
• PMA beads
• Sodium alginate
• Water turbidity removal
• Swelling behavior
• Natural coagulant

Acknowledgments

This work was supported by the Department of Science and Technology (DST) funded project-SR/S1/PC-59/2009, GAP-0311 of IICT. The authors are grateful to the Director, IICT.