Study of degradation of cellulose-acetate membrane in osmotic technique for bentonite soil characterisation

Bentonite clays are promising materials for disposal of high-level nuclear waste (HLW). Malaysia has recently discovered bentonite could therefore potentially be useful in managing the nation’s HLW should Malaysia decide to embark on a nuclear power programme. This report presents comprehensive data...

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Main Author:	Muhammad Afiq, Mohd Tadza
Format:	Thesis
Language:	English
Published:	2018
Subjects:	Q Science (General) T Technology (General)
Online Access:	http://umpir.ump.edu.my/id/eprint/25561/1/Study%20of%20degradation%20of%20cellulose-acetate%20membrane%20in%20osmotic%20technique.pdf
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spelling	my-ump-ir.255612021-08-12T03:51:11Z Study of degradation of cellulose-acetate membrane in osmotic technique for bentonite soil characterisation 2018-08 Muhammad Afiq, Mohd Tadza Q Science (General) T Technology (General) Bentonite clays are promising materials for disposal of high-level nuclear waste (HLW). Malaysia has recently discovered bentonite could therefore potentially be useful in managing the nation’s HLW should Malaysia decide to embark on a nuclear power programme. This report presents comprehensive data on physical, chemical, mineralogical and microbiological information on the local bentonite. The soil-water retention curve (SWRC) study was conducted to elucidate characteristic soil-water interactions and to obtain further knowledge and understanding of the bentonite engineering properties and behaviour. In order to enable a wide range of suction on the soil sample, the above study was conducted by utilising the vapour equilibrium technique (VET) as well as the osmotic technique. However, since the cellulose acetate semipermeable membrane tends to degrade during testing, resulting in the intrusion of polyethylene glycol (PEG) molecules into the soil sample, there was a concern that the accuracy of the SWRC readings could be jeopardised. The presence of cellulase enzymes on the degraded membranes led to the suspicion that the degradation could have been caused by the fungi Trichoderma atroviridae and Paecilomyces lilacinus, which are found in soil. To confirm the suspicion, two antifungal agents namely chloroxylenol and iodine, were tested to eliminate the fungi. To test the efficacy of the antifungal agents, concentrations of 1 % to 20 % in 100 μl of PEG solution were used during fungal plating to determine the Minimum Inhibitory Concentration (MIC). The MIC test results showed that 8 % concentration of iodine was able to eliminate all traces of fungi whilst chloroxylenol was effective at 10 % concentration. The osmotic technique conducted in the presence of iodine showed no signs of intrusion but for chloroxylenol, there was still indication of intrusion. Field Emission Scanning Electron Microscopy (FESEM) confirmed the presence of fungus on untreated membrane samples as well as evidence of defects and tunneling. Screening by atomic-force microscopy (AFM) revealed evidence of degradation or enlarged pore sizes for the chloroxylenol-treated membranes. This was believed to be due to the abrasive chlorine component of chloroxylenol, thus creating possibility of PEG intrusion into the soil sample. As for the iodine-treated membranes, although there was pore size enlargement, it was not sufficient for the intrusion of PEG. 2018-08 Thesis http://umpir.ump.edu.my/id/eprint/25561/ http://umpir.ump.edu.my/id/eprint/25561/1/Study%20of%20degradation%20of%20cellulose-acetate%20membrane%20in%20osmotic%20technique.pdf pdf en public masters Universiti Malaysia Pahang Faculty of Industrial Sciences and Technology
institution	Universiti Malaysia Pahang Al-Sultan Abdullah
collection	UMPSA Institutional Repository
language	English
topic	Q Science (General) T Technology (General)
spellingShingle	Q Science (General) T Technology (General) Muhammad Afiq, Mohd Tadza Study of degradation of cellulose-acetate membrane in osmotic technique for bentonite soil characterisation
description	Bentonite clays are promising materials for disposal of high-level nuclear waste (HLW). Malaysia has recently discovered bentonite could therefore potentially be useful in managing the nation’s HLW should Malaysia decide to embark on a nuclear power programme. This report presents comprehensive data on physical, chemical, mineralogical and microbiological information on the local bentonite. The soil-water retention curve (SWRC) study was conducted to elucidate characteristic soil-water interactions and to obtain further knowledge and understanding of the bentonite engineering properties and behaviour. In order to enable a wide range of suction on the soil sample, the above study was conducted by utilising the vapour equilibrium technique (VET) as well as the osmotic technique. However, since the cellulose acetate semipermeable membrane tends to degrade during testing, resulting in the intrusion of polyethylene glycol (PEG) molecules into the soil sample, there was a concern that the accuracy of the SWRC readings could be jeopardised. The presence of cellulase enzymes on the degraded membranes led to the suspicion that the degradation could have been caused by the fungi Trichoderma atroviridae and Paecilomyces lilacinus, which are found in soil. To confirm the suspicion, two antifungal agents namely chloroxylenol and iodine, were tested to eliminate the fungi. To test the efficacy of the antifungal agents, concentrations of 1 % to 20 % in 100 μl of PEG solution were used during fungal plating to determine the Minimum Inhibitory Concentration (MIC). The MIC test results showed that 8 % concentration of iodine was able to eliminate all traces of fungi whilst chloroxylenol was effective at 10 % concentration. The osmotic technique conducted in the presence of iodine showed no signs of intrusion but for chloroxylenol, there was still indication of intrusion. Field Emission Scanning Electron Microscopy (FESEM) confirmed the presence of fungus on untreated membrane samples as well as evidence of defects and tunneling. Screening by atomic-force microscopy (AFM) revealed evidence of degradation or enlarged pore sizes for the chloroxylenol-treated membranes. This was believed to be due to the abrasive chlorine component of chloroxylenol, thus creating possibility of PEG intrusion into the soil sample. As for the iodine-treated membranes, although there was pore size enlargement, it was not sufficient for the intrusion of PEG.
format	Thesis
qualification_level	Master's degree
author	Muhammad Afiq, Mohd Tadza
author_facet	Muhammad Afiq, Mohd Tadza
author_sort	Muhammad Afiq, Mohd Tadza
title	Study of degradation of cellulose-acetate membrane in osmotic technique for bentonite soil characterisation
title_short	Study of degradation of cellulose-acetate membrane in osmotic technique for bentonite soil characterisation
title_full	Study of degradation of cellulose-acetate membrane in osmotic technique for bentonite soil characterisation
title_fullStr	Study of degradation of cellulose-acetate membrane in osmotic technique for bentonite soil characterisation
title_full_unstemmed	Study of degradation of cellulose-acetate membrane in osmotic technique for bentonite soil characterisation
title_sort	study of degradation of cellulose-acetate membrane in osmotic technique for bentonite soil characterisation
granting_institution	Universiti Malaysia Pahang
granting_department	Faculty of Industrial Sciences and Technology
publishDate	2018
url	http://umpir.ump.edu.my/id/eprint/25561/1/Study%20of%20degradation%20of%20cellulose-acetate%20membrane%20in%20osmotic%20technique.pdf
_version_	1783732098143617024

Study of degradation of cellulose-acetate membrane in osmotic technique for bentonite soil characterisation

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