Preparation, characterization and performance of chitosan membranes for ultrafiltration | |
| Author | Piyabutr Wanichpongpan |
| Call Number | AIT Diss. no. EV-99-5 |
| Subject(s) | Chitosan Ultrafiltration |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | This research deals with development and characterization of chitin and chitosan based membranes and investigations on performance of chitosan membrane for ultrafiltration of cheese whey. Chitosan with degree of deacetylation of about 75% was prepared using chitin obtained from local black tiger slu-imp shells (Penaeus monodon). Ultrafiltration membranes were prepared using casting solution of chitosan in acetic acid. The chitosan casting solution behaved as a typical non-newtonian shear-thickening fluid with a characteristic shear index value greater than I. Rheological as well as physico-chemical properties of chitosan casting solutions were also investigated. Chitosan membrane sheets with 30 µm thickness were characterized for their mechanical properties, pore size, molecular weight cutoff (MWCO), permeability for dialysis of (NH4)2S04 and compared with commercial membrane. Ultimate stress and strain of chitosan membranes were estimated under dry and wet conditions. Percentage relative crytallinities of dry and wet chitosan membranes were calculated from X-ray diffractrometry. Chitosan membranes had average pore size of about 69-70 nm with MWCO of 20000 Da, which ideally suited for ultrafiltration applications. Water flux across this chitosan membrane for given transmembrane pressure was always smaller than water flux across polysulfone membrane. For transmembrane pressure up to 4.5 bars, typical water flux values up to 60 L/m2 .h and 175 L/m2 .h were obtainable using chitosan and polysulfone membrane, respectively. Investigations were also carried out to control the pore size of chitosan membrane through: i) addition of different types of alcohols in casting solution; and, ii) alteration in process parameters. Process parameters such as evaporation rate and temperature of casting did not have significant effect as membrane pore size. Experimental results showed that pore size of chitosan membrane could be reduced by addition of t-butanol in the casting solution. The MWCO of t-butanol chitosan membrane during ultrafiltration was found to be 9400 Da as against to 20000 Da for membrane without t-butanol addition. Water flux values for t-butanol added chitosan membrane were comparable to commercially available polysulfone membranes Performance of chitosan membranes for ultrafiltration of cheese whey was comparable to commercially available polysulfone membrane. |
| Year | 1999 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Annachhatre, Ajit P.; |
| Examination Committee(s) | Suwalee Chandrkrachang ;Ozaki, Hiroaki ;Hirano, Shigehiro; |
| Scholarship Donor(s) | The Foundation for Petroleum Institute of Thailand; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1999 |