Banca de DEFESA: ALFREDO JOSÉ FERREIRA DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ALFREDO JOSÉ FERREIRA DA SILVA
DATA : 23/08/2019
HORA: 09:00
LOCAL: AUDITÓRIO NUPEG
TÍTULO:

Adsorption of copper ions using bioadsorbent and argilomineral: kinetic, thermodynamic and equilibrium study.

PALAVRAS-CHAVES:

adsorption, heavy metals, bentonite, carnauba straw powder and isotherms .

PÁGINAS: 155
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Química
RESUMO:

The toxicity, non-biodegradability and bioaccumulation presented by industrial effluents containing heavy metals has become a deep environmental concern. Given this fact, there are already several treatment techniques to remove heavy metals from industrial effluents, but they have some disadvantages, such as inefficiency in treatment, high cost, use of chemicals in the treatment and problems with the disposal of waste. sludge formed. From this finding, there has been research with materials that can be used to overcome these deficiencies, presenting satisfactory results in the removal of heavy metals in the treatment of industrial effluents. Carnauba straw dust and bentonite in their natural and modified forms were used as adsorbents to remove copper in aqueous solution. The experiments were performed from the evaluation of the influence of the variables pH, contact time, adsorbent mass, initial metal concentration, effects of binders and co-ions on the metal removal efficiency and adsorbent regeneration capacity. From the experimental data, it was possible the kinetic, thermodynamic and equilibrium study of the adsorption process. FTIR, BET, FRX, XRD and Potential zeta analyzes were also performed to characterize the materials used in the adsorption process and to ensure the efficiency of their modifications. In the kinetic study, all adsorbents adjusted to the pseudo second order kinetic model and it was observed that, in general, the adsorbents used presented a fast kinetics, in which PPC, PPCTB, BNAT, BSOD reached equilibrium time. 5, 25, 100 and 100 minutes, respectively. The equilibrium study showed that the experimental data of the adsorbents studied supported the Langmuir model. The maximum adsorption capacity of PPC, PPCTB, BNAT, BSOD were 8.48, 21.97, 12.92 and 24.51 mg/g, respectively. Studies showed that although the materials had a low surface area, they had other positive characteristics, such as PPC and PPCTB with functional groups (hydroxyl and carbonyl) with good interaction capacity, and BETNAT and BETSOD with good exchange capacity cationic. The thermodynamic parameters obtained in the adsorption experiments showed that for PPCTB, BNAT, BSOD the process was non-spontaneous and endothermic, whereas for PPC the process was spontaneous and exothermic. In the desorption and regeneration study of natural and sodium bentonites, 4 cycles of dsorption and desorption were required. The desorption efficiency of copper ions using sodium and natural clay decreased from the first to the last cycle from 69.47% to 41.33% and from 48.36% to 22.46%, respectively.

 

MEMBROS DA BANCA:
Presidente - 1308273 - EDUARDO LINS DE BARROS NETO
Externo à Instituição - FRANCISCO KLEBSON GOMES DOS SANTOS - UFERSA
Externo à Instituição - FRANCISCO WENDELL BEZERRA LOPES - UnP
Externo ao Programa - 1566922 - LINDEMBERG DE JESUS NOGUEIRA DUARTE
Externo à Instituição - LUIS FERREIRA DE LIMA - UFRN
Externa à Instituição - ROBERTA PEREIRA DA SILVA - UFERSA