Page 69 - Materials Chemistry, Second Edition

Ch002-P373623.qxd 3/22/07 5:27 PM Page 50
Sustainable Industrial Design and Waste Management
50
CP opportunity assessment
Cleaner production opportunities were identified by means of an industrial
or cleaner production audit. The audit findings were as follows:

• Different solid wastes stored haphazardly in open areas and on roads,
constituting a fire risk and negatively impacting the aesthetic value
of the premises.
• Milk was wasted due to overflow during the filling for storage and ser-
vice tanks.
• Milk leakages in the milk packaging and refrigeration units.
• Oils used in vehicle maintenance facilities were drained to factory
sewers leading to drain blockage and foul odors.
• Excessive consumption of heavy oil in the boiler house due to poorly
tuned boilers.

CP techniques implemented
• Good housekeeping was applied to the plant as a whole; improve-
ments include the following:
– Factory drainage, sewers and manholes were maintained and
upgraded to eliminate blockage and overflow problems.
– Plant roadways were paved to allow better traffic flow of factory
vehicles.
– Waste management: Application of an effective solid waste man-
agement system was shown in the following:
◆ Garbage and packing wastes are trucked out and disposed of.
◆ Solid wastes such as scrap iron and metal objects are sold in
auctions.
• Onsite recycling: Oil, grease and lubricants are now collected instead
of being disposed of to the sewer with the following benefits:
– Approximately 0.75 tons of oil are accumulated monthly and sold
at $50/ton.
– Reduction of the pollutants in wastewater.
– Prevention of serious blockage of sewers.
• Equipment/Process modification:
– Since the boilers were consuming much heavy oil, the ratio of air
to heavy oil intake was optimized to increase the efficiency of the
boilers.
– The refrigeration room was upgraded to prevent spoilage and
loss.
– The packaging unit was relocated to prevent handling losses.
– 50% of whey reused at the cheese packing stage in place of fresh
water.
– Milk storage tanks were equipped with level sensors and stop-
cocks to prevent overflow particularly during the receiving stage.