resumo
Potentially toxic elements (PTEs) have been found in high levels in rainwater, highlighting the importance of removing them when the water is intended for domestic use. In this work, white bean peel was evaluated as sorbent for the removal of a mixture of PTEs from rainwater, namely Zn(II), Cu(II) and Pb(II). A uniform experimental design was used to evaluate the sorption and to optimize the removal process by response surface methodology. The biosorbent reduced the PTEs concentration in the solution, and their removal increased with the increase of the initial concentration and with time. The removal of Cu(II) and Pb(II) was affected by the pH of the solution since, at pH 7.0 for Cu(II), and at pH 5.6 and 7.0 for Pb(II), a decrease occurred in the removal. The optimal conditions for removal, 6 h of contact time between the sorbent and the solution, were applied to rainwater samples spiked with the mixture of PTEs and resulted in removals of 30-90% for Zn(II), 11-78% for Cu(II), and 11-97% for Pb(II), generally lower than those expected by the models, 91% for Zn(II) and 52% for Cu(II), highlighting that the rainwater matrix interferes with the removal of PTEs by peel. However, the white bean peel may be an alternative as sorbent to reduce Zn(II), Cu(II), and Pb(II) concentrations in rainwater, since it is a natural and sustainable material.
palavras-chave
WET DEPOSITION; TRACE-ELEMENTS; PRECIPITATION; MATTER
categoria
Chemistry; Engineering; Materials Science; Physics
autores
Cabral, GH; Estrada, AC; Santos, PSM
nossos autores
Ana Cristina Estrada
Investigador JúniorProjectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
This research had financial support from Fundacao para a Ciencia e a Tecnologia (FCT), due to FCT/MCTES (PIDDAC) for the financial support to CESAM (UIDP/50017/2020 + UIDB/50017/2020 + LA/P/0094/2020) and CICECO-Aveiro Institute of Materials (UIDB/50011/2020 (DOI: 10.54499/UIDB/50011/2020), UIDP/50011/2020 (DOI: 10.54499/UIDP/50011/2020) and LA/P/0006/2020 (DOI: 10.54499/LA/P/0006/2020)) through national funds. This research also had financial support provided by CNRS-INEE, LabEx DRIIHM, and OHMI-Estarreja. The research contract of A.C.E. was funded by FCT/National funds (OE) in the scope of the framework contract foreseen in Numbers 4, 5, and 6 of Article 23 of the Decree-Law 57/2016 of 29 August, changed by Law 57/2017 of 19 July (DL 57/2016/CP1482/CT0007; DOI: 10.54499/DL57/2016/CP1482/CT0007). The research contract of P.S.M.S. was funded by the FCT Scientific Employment Stimulus-Individual 2017 (CEECIND/01835/2017; DOI: 10.54499/CEECIND/01835/2017/CP1459/CT0017).