Banca de DEFESA: PAULA FABIANE PINHEIRO DO NASCIMENTO
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.STUDENT : PAULA FABIANE PINHEIRO DO NASCIMENTO
DATE: 04/08/2020
TIME: 09:30
LOCAL: ONLINE
TITLE:
STUDY OF METHODOLOGIES FOR TREATMENT OF COCONUT HAND DUST FOR Cu² and Cd² ADSORPTION
KEY WORDS:
bio-absorbent, coconut shell powder, monoethanolamine, sodium octanoate, steam explosion, desorption.
PAGES: 148
BIG AREA: Engenharias
AREA: Engenharia Química
SUMMARY:
In view of the environmental problem of the pollution of water bodies by heavy metals, caused by human activities in general, and the inadequate destination of certain solid agro-industrial residues, there is a great need to develop research that improves the technique of removing these inorganic pollutants from aqueous solutions. One way would be to take advantage of agro-industrial waste as agents that remove these pollutants. As the coconut shell powder (CP) is a residue generated from its processing, the present work aims to provide studies related to three treatment methodologies so that the CP adsorption capacity be empowered and then be reused to remove two toxic metals widely found in wastewater, Cu+ 2 and Cd+ 2 that are widely found in wastewater from effluents from the mining, metallurgy and dye industries. The applied methodologies included the physical and chemical treatment of the PC surface, developed separately, according to the sequence: chemical treatment through the impregnation of Monoethanolamine in the proportion 1: 1, using ethanol as solvent; chemical treatment through the impregnation of the sodium octanoate surfactant by microemulsion; and physical modification using the steam explosion technique (T = 210 °C and P = 20 atm). The efficiency of the proposed treatments was evaluated through characterization analyzes, where changes were observed in the specific contact area, chemical composition and crystallinity of the adsorbent material. The evaluation of the monocomponent adsorption capacity of Cu+2 and Cd +2 ions in the PC was performed using a batch mixing reactor of the synthetic solutions of CuSO4.5H2O and CdSO4.8 / 3H2O. After chemical treatment, the insertion of functional groups increased the metal - adsorbent interaction confirmed by the values of the kinetic constants of the studied models. It was observed that the coconut shell powder impregnated with OS (PCµE) adsorbed more Cu + 2 ions in relation to the impregnated with MEA (PCA). The treatment with steam explosion, depolymerized the coconut shell powder (PCD), which caused an increase in the total pore volume and crystallinity, consequently, making the adsorbent surface more accessible for adsorption. The behavior of equilibrium isotherms is satisfactorily represented by the Langmuir model and the adsorption capacities (mg / g) of the coconut shell powder after treatments follow the order: PCµE (26.32)> PCD (18.86)> PCA (15.94)> PC (7.88) for Cu+2 and PCD ions (17.90)> PCA (14.02)> PC (4.91) for Cd+2 ions, respectively, emphasizing that the impregnation methodology with surfactants did not significantly improve the interaction of PC with Cd+2. The stability of the impregnation with MEA and OS was evaluated from the desorption study. After the adsorption-desorption cycles, the amount of Cu+2 adsorbed on the PCµE decreased by 36.6%, while for the PCA the reduction was 22.8%. Regarding the adsorption of Cd+2, a reduction of 14% and 10% was observed for PCµE and PCA, respectively. This shows that, after the five adsorption-desorption cycles, the impregnation of monoethanolamine in the coconut shell powder is stronger, remaining with greater removal than the PCµE and thus, it can be reused for more cycles in the adsorption-desorption process.
BANKING MEMBERS:
Externo à Instituição - ALFREDO JOSÉ FERREIRA DA SILVA
Presidente - 1308273 - EDUARDO LINS DE BARROS NETO
Externo à Instituição - FRANCISCO WENDELL BEZERRA LOPES - UnP
Interno - 350247 - JOAO FERNANDES DE SOUSA
Externo ao Programa - 1566922 - LINDEMBERG DE JESUS NOGUEIRA DUARTE
Externa à Instituição - ROSANGELA DALA POSSA