resumo
Biphasic apatite-carbon biochar-type materials were prepared from pyrolysed cod fish bones and were assessed for the adsorption of persistent organic pollutants (pharmaceuticals diclofenac and fluoxetine), and heavy metals (Pb(II)). The materials, prepared with a simple pyrolysis process at different temperatures (200-1000 degrees C), were characterised with XRD, FTIR, Raman and SEM. Results showed that the pyrolysis temperature had a significant effect on the features/composition of the materials: up to 800 degrees C, carbonate apatite Ca-10(PO4)(6)(CO3) was the main component, while for higher temperatures oxyapatite Ca-10(PO4)(6)O was the dominant phase. Graphitic carbon was also detected. The mixed apatite-carbon products (bone char) exhibited high adsorption efficiency. Graphite carbon was the main adsorber for the pharmaceuticals, the best performing material being that pyrolysed at 1000 degrees C. X-m values of 43.29 and 55.87 mg/g were observed (Langmuir fitting), while K-F values of 5.40 and 12.53 (mg/g)(L/mg) nF were obtained with the Freundhlich model (diclofenac and fluoxetine respectively). This is the first time that a biochar-like material has been used for fluoxetine adsorption. For Pb (II), the powder pyrolysed at 600 degrees C was the most effective, with the apatite playing a key role (X-m = 714.24 mg/g). This work shows that a by-product of the fish industry could be converted into efficient materials for environmental remediation; according to the pyrolysis conditions, powders effective in the removal of either organics or heavy metals can be obtained. Moreover, with pyrolysis at intermediate temperatures, materials capable of adsorbing both kinds of pollutants can be produced, even if less efficient.
palavras-chave
PHOSPHATE-BASED MATERIALS; WASTE-WATER TREATMENT; AQUEOUS-SOLUTION; ORGANIC CONTAMINANTS; FLUORIDE REMOVAL; HYDROXYAPATITE; BIOCHAR; CHAR; HYDROXYLAPATITE; PHARMACEUTICALS
categoria
Engineering
autores
Piccirillo, C; Moreira, IS; Novais, RM; Fernandes, AJS; Pullar, RC; Castro, PML
nossos autores
Rob Pullar
Colaborador
Rui Miguel Novais
Professor Auxiliaragradecimentos
This work was financially supported by FCT - Fundacao para a Ciencia e a Tecnologia - through the project UID/Multi/50016/2013. C. Piccirillo and I.S. Moreira thank the FCT for the grants IF/01050/2015 and SFRH/BDP/87251/2012, respectively. R.C. Pullar and R.M. Novais thank the FCT grants IF/00681/2015 and PTDC-CTM-ENE-6762-2014 for supporting this work. This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement.