| Author | Biswadeep, Basu |
| Call Number | AIT Thesis no. EV-94-05 |
| Subject(s) | Pervaporation
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of
Engineering, School of Environment, Resources & Development |
| Publisher | Asian Institute of Technology |
| Abstract | This work is a continuity of the ongoing study of sweeping air pervaporation or air
perstripping for the treatment of VOCs found in numerous industrial wastewater. A
thorough literature survey on different models, influencing parameters, membranes, modules
and module geometries was performed in order to investigate the results of the experiments
in the light of the latest concepts.
In order to study the behavior of pervaporation and its underlying kinetics, laboratory
scale experiments were performed, with dense silicone-polyethersulfone, commercial
composite capillary membranes. Basically optimization of flux with respect to the air flow
rate, responses to different initial feed concentration of VOCs, performance of different flow
modes ( cocurrent and cross flow) and the effect of presence of an additional interfering
compound (1, 1, 1 trichloroethane) on the flux of a targeted volatile organic compound
(trichloroethylene) were the focus of the study.
Optimization of flux with respect to air flow rate could be clearly identified and the
effect of excess air flow on flux production was found to have either no impact or negative
impact, depending upon the flow mode chosen.
Out of the parameters that vitally influence flux production, initial feed concentration
was found to be one of predominant one and it was found that the membrane strains to
handle low feed concentration of the VOCs. Water flux was found to be heavily influenced
by organic flux and decreased with the increase of the organic flux.
Cross flow mode was found to be better than the cocurrent flow mode in almost all
respects. However the difference was marked in case of low concentration of organic
compounds which is the usual case with actual wastewater. Also at higher air flow rates the
performance of the cross flow mode improved unlike cocurrent flow mode.
The effect of the addition of another organic compound of almost same nature, was
found to be positive and flux of both the compounds improved due to the better swelling
of the membrane.
Prediction of flux by Solution-Diffusion model was reasonably good, while Resistance-in-Series model showed that for VOCs, resistance at the liquid-membrane interface was the
rate limiting step. Models for binary compounds failed to predict flux upto expectations and
indicated that modifications are required.
Lastly perstripping combined with the state-of-art post treatment technologies has
been proposed to complete the treatment train of VOCs. |
| Year | 1994 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Visvanathan, C. ;
|
| Examination Committee(s) | Mora, Jean-Claude ;
Chongrak Polprasert ;Reutergardh, Lars
|
| Scholarship Donor(s) | Swedish International Development Authority (SIDA) |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1994 |