Analysis of the Possibility of Heavy Metal Ions Removal from Aqueous Solutions on Fruit Pomace

Pomace from apples, grapes, blackcurrants, and oranges is a waste product of fruit processing, which is formed during the production of juices. Pomace is a rich source of biologically active compounds such as polyphenols, carotenoids, or vitamins. They also contain pectin, cellulose, lignin, proteins, and minerals. All these components, apart from having many beneficial properties for human health, also show sorption properties towards heavy metal ions. Therefore, this study aimed to evaluate the possibility of removing lead (II) and cadmium (II) ions from aqueous solutions by adding apple, grape, black currant, and orange pomace as well as to determine the adsorption efficiency of selected heavy metals. The studies were carried out in model systems. The results of the research showed that lead (II) and cadmium (II) ions are adsorbed on fruit pomace. The highest removal of cadmium (II) ions was observed in orange pomace and of lead (II) ions in apple pomace. The maximum tested cadmium ions absorption capacity was: 0.117235 mg/g in the case of freeze-dried apple pomace; 0.08618 mg/g in the case of freeze-dried currant pomace; 0.21915 m/g in the case of freeze-dried grape pomace and 0.29549 mg/g in the case of freeze-dried orange pomace. On the other hand, the maximum absorption of lead ions was: 0.457 mg/g in the case of freeze-dried apple pomace; 0.442 mg/g in the case of freeze-dried currant pomace; 0.3445 mg/g in the case of freeze-dried grape pomace and 0.421 mg/g in the case of freeze-dried orange pomace. On the basis of the performed measurements, it can be concluded that the tested waste can potentially be used as a cheap biosorbent for removing heavy metal ions from dilute aqueous solutions.