Monroe Australia Pty Ltd

Summary

Traditional approach

Cleaner production initiatives

Waste management

Benefits

Benefits recommended and being considered

Where to find additional information

October 1997

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.

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.

Waste management

The process generating waste	Waste directly to sewer 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. 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.
Waste composition	Water in all forms—clean, treated or contaminated—represented a significant volume and cost burden on the company's operation. 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.

Process flow diagram - water treatment and recycling

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.

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. 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 10ppm. Elimination of acid and alkali use for regeneration of resins used in de-ionised water production. Substantial reduction of extracted solids/ sludge volume, previously disposed at a landfill. $530,000 (includes EPA contribution) The plant is cost effective and saves space. Land usage savings.
Liquid waste	Energy consumption minimised by more direct heat process. Heat not lost to surrounding air and far less heat energy lost through top of oven. Incorporated closed powder coating process uses 100% of the powder; no waste. Number of rejects from incorrectly cured steel reduced significantly. By recoiling automatically strip remains free of dust and dirt so not contaminated when painted; no accumulation of waste.
Solid waste	Fully enclosed water cooling process recycles 100% of water used; water wastage reduced substantially.
Economic
Investment	Unipower heating equipment $38,600 Reel to reel press $7,500 Pneumatic steel guillotine $16,500 Water cooling plant for induction oven $3,200 Installation cost $6,000 Total $64,300 (includes EPA contribution)
Productivity	Efficiency of process significantly increased. Production increased from 2 to 3.6 runs per 8 hr working day; a net increase in productivity of 80%. Potential exists for increasing speed of line to 2.5 m per min which would further increase productivity. The press and the computerised cutting machine can accommodate increased line speed giving 40% extra capacity. Approx 1 hr of labour per day is saved by elimination of manual rerolling of protective strip.
Savings, outcomes	Material resource savings Generated savings:	$ per annum
	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	250,639
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

Phone: (+61 8) 8374 5222

This page was last modified 21-04-2006