“…In the past decade, these materials have been widely used as adsorbents to replace existing technologies. For example, Melaleuca diosmifolia leaf [ 13 ], tomato leaf powder [ 14 ], rice husk [ 15 ], pine cone [ 16 ], olive pomace [ 17 ], pineapple stem [ 18 ], coffee husk [ 19 ], coffee waste [ 20 ], cauliflower leaf [ 21 ], rubber leaf [ 22 ], Formosa papaya seeds [ 23 ], parsley stalks [ 24 ], potato peel waste [ 25 ], cucumber peel [ 26 ], and water hyacinth [ 27 ] have been studied, and it has been found that these agricultural wastes have fine remediation effects on metal polluted wastewater. Compared with other adsorbents, these adsorbents not only have the advantages of fine remediation effects but also are agricultural wastes, which can be widely obtained and are inexpensive.…”