Alginate-based composites for environmental applications: a critical review

Abstract

Alginate-based composites have been extensively studied for applications in energy and environmental sectors due to their biocompatible, nontoxic, and cost-effective properties. This review is designed to provide an overview of the synthesis and application of alginate-based composites. In addition to an overview of current understanding of alginate biopolymer, gelation process, and cross-linking mechanisms, this work focuses on adsorption mechanisms and performance of different alginate-based composites for the removal of various pollutants including dyes, heavy metals, and antibiotics in water and wastewater. While encapsulation in alginate gel beads confers protective benefits to engineered nanoparticles, carbonaceous materials, cells and microbes, alginate-based composites typically exhibit enhanced adsorption performance. The physical and chemical properties of alginate-based composites determine the effectiveness under different application conditions. A series of alginate-based composites and their physicochemical and sorptive properties have been summarized. This critical review not only summarizes recent advances in alginate-based composites but also presents a perspective of future work for their environmental applications.

Keywords:

• Alginate
• hydrogel
• nanocomposites
• dyes
• heavy metals
• antibiotics

Acknowledgments

The authors would like to thank Dr. Elizabeth George and two anonymous reviewers for their comments and suggestions. The views expressed in this article are those of the authors and do not necessarily reflect the views or policies of the funding agencies or the U.S. Environmental Protection Agency.

Additional information

Funding

This work was financially supported by the National Key Research and Development Program of China (2016YFC0502602), the Key Agriculture R & D Program of Guizhou Province (NZ [2013]3012), the International Scientific and Technological Cooperation Project of Guizhou Province (G[2012]7050), the High-Level Overseas Talent Innovation and Entrepreneurship Project of Guizhou Province and the Opening Fund of State Key Laboratory of Environmental Geochemistry (SKLEG2018907).