CLEANER
PRODUCTION
CASE STUDY
THE WORLD'S BEST SHOCK ABSORBERS
MONROE
AUSTRALIA PTY LTD
SUMMARY
The company implemented a major waste minimisation strategy that enables them to process
liquid waste, reduce water usage, chemical and waste disposal costs.The new equipment, a Microsep
industrial wastewater treatment plant, treats wastewater to remove emulsified fats and oils, grease,
heavy metals and all forms of suspended, colloidal and some dissolved solids. Mains water usage
was reduced by over 10 ML per annum and wastewater discharge to sewer was reduced by 50%.
The new technology has brought a saving of $250,000 per annum with a payback period of 2 years.
CASE STUDY CASE STUDY CASE STUDY CASE STUDY
MONROE
AUSTRALIA PTY LTD
Business Profile
Monroe Australia is a leading manufacturer of shock absorbers and strut suspension units for the automotive
industry.The company had a turnover of over $100 million in 1998 and has 450 employees. A significant
percentage of the company’s total production is exported to Asia, North America and Europe.
Financial assistance provided
An interest free loan of $50,000 for purchasing the new equipment was provided by the EPA’s
Cleaner Industries Demonstration Scheme.
Measures implemented
Major waste minimisation strategy; Microsep wastewater treatment plant and ancillary equipment;
reverse osmosis pure water generation unit; water recycling.
Cleaner production motivators
The need to identify and focus on: reducing all forms of waste generation; conserving water;
generating and maintaining a healthy environment for employees and surrounding community.
TRADITIONAL APPROACH
An inherent part of the process of manufacturing shock absorbers and strut suspension units
for motor vehicles involves various chemicals that contribute to the liquid waste stream.
CLEANER PRODUCTION INITIATIVES
Benefits recommended and implemented
Installation of Microsep wastewater treatment plant and ancillary equipment
Installation of reverse osmosis pure water generation unit
Installations of water recycling pumps and pipework
The Microsep unit is a combination of chemical reactor and clarifier within a single plant able to treat many
forms of liquid waste.The plant pretreats chemicals when necessary, then allows the resultant solids
including gelatinous precipitates, oils and grease to rapidly settle out.The plant can also filter previously
unfilterable solids for disposal.
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CASE STUDY
CASE STUDY
CASE STUDY
CASE STUDY CASE
WASTE MANAGEMENT
The process
1) Waste directly to sewer
generating waste
From two sources: as rinse water from the hard chromium electroplating process and from the metal
pretreatment process before the finished product is painted.Total discharge flow was 45 kL per day.
2) Waste treated for disposal
Oily water waste streams comprising metal turning, cutting and grinding lubricants and coolants from
the machining centres with a daily volume of 10,000 L.
Regular removal and replacement of chemical solutions required average daily volume of 2000 L.
Waste stream
In 1994 this processing used over 70 ML of water and generated almost 15 ML of liquid waste.
Excess water cost in 1994 was $50,358 with wastewater streams of 52 ML.
12 ML per annum of purified water was generated for process requirements.
Water in all forms—clean, treated or contaminated—represented a significant volume and cost burden
on the company’s operation.
Waste
composition
The effluent contained a mixture of amines, olamines, amides, surfactants and wetting agents (generally
organic in nature), refined mineral oils and synthetic machining and grinding fluids; plus a high content
of heavy metals such as chromium, zinc, copper, aluminium; and oil and grease, and iron.
Cost of disposal
Total costs for disposal of non-sewerable liquid waste in 1995: approx $403,000.
Mains water
Electroclean
rinse
Chemical Machining Cooling Domestic
processing coolants/ towers
lubricants
tanks
Process
solutions
Oily
water
Bulk
Bulkwater
rinse
Bulk
Microsep
plant
waste
water
treatment
Sludge
Process flow diagram—water
treatment and recycling
Filter
press
Cake
Landfill
VICr
removal
Top up
chrome
solution
Clean
water
Top up
phosphate
Clean
water
storage
Post
chrome
rinse area
Water
purification
unit
Stage 3
rinse
paint shop
Pure
water
Bulk
storage
Stage 5 paint
shop rinse
Rectifier
cooling
water
Air scrubbers
Horticulture
Excess
water
Direct
sewer
discharge
Non-sewerable wastewater streams are blended with rinse water (directed to the sewer traditionally) to provide a
homogenous feed to the Microsep facility.The products from this processing step are sludge and clean water.The
sludge is then fed to a filter press to yield approx 7 t dry cake in 7–10 days, and further clean water.The clean water
is used directly instead of mains water, for rectifier cooling and overflow rinses in the paint shop and chromium plating
areas. Excess clean water is drained into the sewer and is the only water discharged in the process.
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BENEFITS
ENVIRONMENTAL
Water usage
• Mains water usage reduced by over 10 ML per annum
• Direct discharge of wastewater reduced by 50% from 10.8 ML per annum to 5.4 ML per annum
• Mains water consumption reduced by reusing treated water.
Liquid waste
• All liquid waste processed on site.
• Reduced environmental impact by generating cleaner wastewater for direct sewer discharge.The quality of
the wastewater has improved significantly and with volume reduction has reduced the load on municipal
sewage. Solid contaminant loadings are up to 20 times lower than the traditional discharge levels.The levels
of contaminants per discharge are well below the limits set in SA for trade waste. In terms of loading all
contaminants especially chromium, oil and grease, zinc and total suspended solids (TSS) were reduced substantially.
Chromium content was reduced by 96.3%.TSS figures after Microsep treatment are below 10 ppm.
• Elimination of acid and alkali use for regeneration of resins used in de-ionised water production.
Solid waste
• Substantial reduction of extracted solids/sludge volume, previously disposed at a landfill.
ECONOMIC
Investment
• $530,000 (includes EPA contribution)
Productivity
• The plant is cost effective and saves space.
• Land usage savings.
Savings,
outcomes
Material resource savings
$ per annum
Generated savings:
• Savings on mains water usage
9,011
• Savings on liquid waste transport and treatment off-site 289,988
• Chemical costs of pure water generation
36,000
Operating costs:
• Microsep processing costs (water treatment)
75,000
• Landfill costs (cake disposal)
9,360
• Total savings
Payback period
• 2.12 years.
BENEFITS RECOMMENDED AND BEING CONSIDERED
As chemical analyses show suitable results, dry cake has the potential to be
mixed with garden soil as a rich source of nutrients.
WHERE TO FIND ADDITIONAL INFORMATION
Mr B Bond
Principal contact officer
Monroe Australia Pty Ltd
1326 South Road
Clovelly Park SA 5042
Ph: (08) 8374 5222
250,639