| Author | Dodangoda, K. D. G. P. |
| Call Number | AIT Thesis no.EV-92-25 |
| Subject(s) | Tanning--Waste disposal
Sewage--Purification--Chromium removal
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Leather shavings generated, when the thiclrn ess of the pre tanned hides and
sl<ins is corrected either manually with a double handled lrnife or by machines in
the chrome-tanned leather processing, are toxic wastes, high in chromium content
(about 3%). Generation of solid wastes in the tanning industry is estimated to be
1 million tons per year throughout the world. The bigger pieces of trimmings are
utilized for the production of artificial l eather. However, most of them are just
disposed of in environmentally unsound manner in spite of the growing
environmental awareness.
Chromium can be extracted from the leather shavings and recycl ed in the
tanning process, leaving two kinds of byproducts; protein and protein residue. The
former can be used as industrial glue or animal feed, while the latter can be
utilized as organic fertilizer for non-edible crops.
The experiments utilizing calcium oxide as the all<ali and the leather
shavings from the Kwang Hah Lee Tannery was carried out in order to demonstrate
the viability of recovery of chromium and protein from leather shavings in smallscale tanneries. For this purpose, pilot-scale digeste r was designed based on the
bench scale experimental data, and fabricated in the workshop of the AIT Physical
Plant.
From four pilot-scale experimental runs of which two were made in AIT and
the rest performed in the tannery, it was verified that prolonged digestion does
not increase the concentration of protein obtained while enhancing the
concentration of chromium in t he protein recovered. Further these revealed that
the particle size of l eather shavings has a profound effect on digestion of leather
shavings.
Results of the pilot-scale experiments indicate that the recovery of chromium
and protein from leather shavings is technically feasible and viable on small scale
applications provided the separation of chromium from protein is controlled
carefully. |
| Year | 1992 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-92-25 |
| Type | Thesis |
| 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 (EEM) |
| Chairperson(s) | Zhuang, Ya-Hui |
| Examination Committee(s) | Chongrak Polprasert;Nagarur, N. |
| Scholarship Donor(s) | Canadian International De velopment Agency |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1992 |
