Growing environmental awareness coupled with stricter regulations has pushed various industries to look for appropriate technologies to treat wastewater. Natural coagulants have recently been used as part of water and wastewater technologies due to their performance, cost-effectiveness when compared to chemical coagulants, they produce less sludge and are safer for humans. A huge effort has also been taken to find new plant species and ingredients that may be used as natural coagulants, and hence improve the efficacy of existing plant-based natural coagulants. The purpose of this research is to assess the progress of various natural coagulants used for water and wastewater treatment. Besides, several plant-based natural coagulants are also summarized and reviewed. The results reveal that natural coagulants are more successful than chemical coagulants at removing heavy metals and suspended particles from wastewater, with better removal efficiency exceeding chemical coagulants and being more environmentally friendly.
