Removal of copper(II) ions and lead(II) from aqueous solutions using seeds of Azadirachta indica A. Juss as bioadsorvent

• Published in: Environmental research Vol. 183; p. 109213
• Main Authors: Costa, Wégila Davi, da Silva Bento, Amanda Maria, de Araújo, José Augusto Soares, Menezes, Jorge Marcell Coelho, da Costa, José Galberto Martins, da Cunha, Francisco Assis Bezerra, Coutinho, Henrique Douglas Melo, de Paula Filho, Francisco José, Pereira Teixeira, Raimundo Nonato
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.04.2020
• Subjects: Biosorption; Neem; Toxic metals; Toxic metals; Biosorption; Neem
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2020.109213

In recent decades, aquatic environment pollution has become a global challenge due to a rapid industrial growth. In this context, adsorption has become one of the most used methods, gaining importance especially in the last decades, given the growing concern over environmental damages caused by these pollutants. Additionally, its low cost and bioavailability are attractive. Therefore, the present study proposed to investigate the adsorption potential of A. indica seeds for Cu(II) and Pb(II) removal in synthetic solutions. Equilibrium studies were carried out via isothermal adsorption in batch systems. Kinetic studies were used to evaluate the lowest equilibrium time. The two evaluated ions were better suited to the Langmuir model and Freundlich model. When applying Langmuir's model on Neem seed powder adsorption, maximum adsorption capacities of 11.54 mg g−1 and 17.96 mg g−1, in the crude form and 11.41 mg g−1 and 19.80 mg g−1 in the alkaline form were obtained for Cu(II) and Pb(II) ions, respectively. The equilibrium time was approximately 80 and 100 min for both ions. The kinetic model best adjusted to the phenomena was the pseudo-second order (Ho Model), suggesting adsorption mainly has a chemical nature for both the studied metals. The results showed Neem seed powder may be a sustainable, efficient and low cost alternative for the removal of Cu(II) and Pb(II) metal cations present in effluents. •The A. indica seed powder could be used as an effective adsorbent to lead and copper.•The ion sorption study demonstrated the occurrence of chemisorption.•The A. indica seed powder is of a low cost, being useful for the treatment of effluents.