TECHNOLOGY
ALTERNATIVES FOR DYES AND DYE INTERMEDIARY INDUSTRY IN INDIA
DYES AND
DYE INTERMEDIARY INDUSTRY
Dyes and Dye
Intermediates industry is an important sector of the Indian Chemical Industry.
This sector has grown at a very fast pace after independence and nearly
half of its production is being exported today. A remarkable feature of
the Indian dyestuff industry is the co-existence of units in the small,
medium and large sectors, actively involved in the manufacture of dyestuffs
and their intermediates. The pollution that accompanies this industry in
its nature and extents, particularly, because of the non-biodegradable
nature of the dyes as well as due to the presence of acid/alkali/toxic
metals/carcinogenic aromatic amines in the effluents. In addition to effluent,
gaseous emissions such as SO2, Nox, NH3 & HCI
and solid wastes in the form of iron sludge, gypsum and sludge from treatment
facilities are generated.
The available
pollution control systems and the requirements are tabulated below :
|
Technologies/Current
Practices
|
Requirements
|
| Effluent treatment
comprising primary (physico-chemical) and secondary (biological) systems
are in practice. Some of the units have also provided tertiary treatment
and incinerators for non biodegradable waste. |
Possibilities
for adaptation of cleaner process options for reducing the water consumption
and effluent generation; better management practices for segregation and
reuse/recycle of the treated effluent; effective utilisation of raw materials;
improvement in efficiency of process; and recovery of by-products.
The effluent
generated from manufacturing of some of the dyes and intermediates such
as H-acid is not biodegradable, which requires process change. |
| Gaseous emissions
such as SOx, NOx, HCI and NH3 are generally scrubbed. |
Properly designed
scrubber with recovery reuse of scrubbed liquid is required. |
| Gypsum, iron
sludge and sludge from ETP are generated as solid waste. The gypsum and
iron sludge can be used in the cement and pigment industries. The sludge
is either disposed off on land/secured landfill or sent to other user industries. |
Cleaner process
technologies e.g. catalytic hydrogenation, use of spent acid after nitration
for acidification of fusion mass, which can eliminate generation of iron
and gypsum sludge. |
SOURCE :
CENTRAL POLLUTION CONTROL BOARD
DATE: 28TH
NOVEMBER, 2000
KEYWORDS:
TECHNOLOGY
ALTERNATIVES, ALTERNATIVE TECHNOLOGIES, BEST PRACTICES, INDIAN INDUSTRY,
TECHNOLOGY TIPS, POLLUTION CONTROL, CENTRAL POLLUTION CONTROL BOARD, CPCB,
TECHNOLOGY OPTIONS, DYES AND DYE INTERMEDIARY INDUSTRY, DYES AND DYE INTERMEDIARY |