Banca de DEFESA: KARYN NATHALLYE DE OLIVEIRA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : KARYN NATHALLYE DE OLIVEIRA SILVA
DATA : 01/08/2018
HORA: 09:00
LOCAL: Auditório do CCET
TÍTULO:

TREATMENT OF SOIL CONTAMINATED WITH Pb EMPLOYING REMEDIATION ELECTROCYTETICS AND REACTIVE BARRIERS

PALAVRAS-CHAVES:

Lead, electrokinetic remediation, electrocoagulation, reactive permeable barrier, cork.

PÁGINAS: 95
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
ESPECIALIDADE: Processos Inorgânicos
RESUMO:

The first part of this work examines electrokinetic remediation (ER) processes for removing Pb2+ in contaminated soils. For this purpose, different cathodic supporting electrolytes (NaNO3 0.1 M, EDTA 0.1M and citric acid 0.1 M) were used into the catholyte reservoir, while in the anodic compartment, a solution of NaNO3 0.1M was used. Additionally, the application of direct current (DC) and reverse polarity (RP) for removing of Pb2+ from the soil was also evaluated. Regarding to results obtained in this study indicated that RP and citric acid favored an efficient electromigration of Pb2+, favoring its elimination from the soil. This behavior can be explained because the elimination of Pb2+ depended on the dissolution/precipitation ionic species as well as the pH in the soil, which were maintaining in different sections in the soil, contributing to maintain the pH conditions, by using RP and citric acid, promoting the lead elimination. In order to use a feasible approach for monitoring Pb2+ concentration, adsorptive stripping voltammetry (AdSV) technique was used, obtaining acceptable confidence and good sensitivity for the concentration of Pb2+ with LOD about 0.1 mg L−1. Phytotoxicity tests showed that the ER process could be useful as a treatment technique for reducing hazardous soil toxicity polluted with Pb2+. The results confirmed the significant reduction of the germination in the anodic and cathodic regions for ER by applying DC with NaNO3 and EDTA as cathodic solutions. However, high germination (60–80%) was obtained for ER by using NaNO3 and citric acid solutions in cathodic compartments by applying RP or DC, respectively. Finally, the effluent generated by ER technology, in each one of experiments, was treated by electrocoagulation with Al electrodes, obtaining complete removal of Pb2+ from liquid after 60 min. The second part of this work studies integrated technologies for the treatment of soil, using ER with permeable reactive barriers (PRB). For this purpose, different cathodic supporting electrolytes (NaNO3 0.1 M, and citric acid 0.1 M) were used into the catholyte reservoir, while in the anodic compartment, a solution of NaNO3 0.1M was used. Additionally, the application of direct current (DC) and reverse polarity (RP) for removing of Pb2+ from the soil was also evaluated. The PRB used was made of cork with 2cm of thickness, 10cm of height and 10cm of length, located in the region near the anode. In order to use a feasible approach for monitoring Pb2+ concentration, adsorptive stripping voltammetry (AdSV) technique was used, obtaining acceptable confidence and good sensitivity for the concentration of Pb2+ with LOD about 0.1 mg L−1. The results obtained in this study indicated that the removal of Pb by adsorption in cork is influenced by the pH of the medium as observed in adsorption tests. The contribution of the addition of citric acid and RP contributed positively to the transport of Pb, avoiding precipitation in the form of Pb(OH)2. At the end of the 14 days, it was possible to observe that the integration of PRB and ER resulted in a higher removal efficiency (80%) associated to pH control in the cathode reservoirs.

MEMBROS DA BANCA:
Externo ao Programa - 1645110 - CARLOS ALBERTO MARTINEZ HUITLE
Externo ao Programa - 2524058 - DOUGLAS DO NASCIMENTO SILVA
Presidente - 2275848 - ELISAMA VIEIRA DOS SANTOS
Externo à Instituição - VITOR JORGE PAIS VILAR - UNIPORTO