NCM initiated its Chemicals Cleaner Production Project, the aim of which is to minimize waste creation.

Problem Overview:

Industrial production, particularly chemical processes, results in significant amounts of chemical and solid waste that must be treated, stored, and when appropriate, discarded.

Industrial pollution and waste management remains one of the greatest obstacles to protecting the global environment and achieving sustainable development.

Background:

In its efforts to reduce the amount of solid waste from chemical processing in industrial production, Nowra Chemical Manufacturers (NCM) of Australia launched an effective solid waste treatment program.

The traditional "wash down process" previously used by NCM introduced chemicals into the waste stream, where they were diluted and mixed to produce vast quantities of sludge. The sludge was subsequently collected in a tank and required further dilution before being discharged down the drain to the sewer. The remaining sludge was then shoveled into large filter bags, left to drain for weeks and then disposed at a local licensed waste disposal area. Costing more than $60,000 this process posed several problems. First it produced a large quantity of solid waste (sludge) to handle manually; second, many man-hours were spent in supervising and administering handling of solid waste; and finally, large areas of factory space were reserved to store filter bags.

NCM is an Australian owned private company, which, for over 20 years, has been responsible for the production of 200 specialty chemicals including various detergents, cleaning products, and disinfectants. The production capabilities of NCM include: 1) manufacturing and distributing cleaning compounds including swimming pool chemicals, floor polishes and sealers; 2) decanting and distributing bulk chemicals such as Sodium Hypochlorite, and liquid Aluminum Sulphate; and, contracting manufactured special chemical products such as surfactants and flocculants. NCM's Cleaner Production Project is well within the scope of its environmental and economic performance; it is well known for its incorporation of environmental policy and standards in company goals and has shown great commitment to targeting issues such as energy management, waste reduction and material recycling.

NCM's Cleaner Production strategy can be broken down into six steps: 1) Initial visit of the site by Dames & Moore and Energetics consultants to review site processes and identify specific cleaner production opportunities with potential to becoming projects; 2) Follow-up site visits to identify specific cleaner production opportunities with the potential of becoming projects; 3) Cost-Benefit analysis of each prospective project; 4) Selection of the appropriate project to be implemented on the site; 5) Implementing the selected project and monitoring benefits of the project 6) Reviewing implemented project to evaluate its efficiency, benefits and effectiveness.

Following the review of site processes and the cost-benefit analysis of identified cleaner production strategies, the consultants and NCM's managers agreed on an initiative to reduce solid waste production. The strategy was employed to improve process operation by categorizing and separating effluent streams of different products in order to prevent sludge formation. This was accomplished by first conducting product mixing trials, which determined which chemicals would react to form sludge and investigated the viability of separating the effluent stream. The second step was to install pipes that directed specific products from specific groups to the appropriate handling system. And, the third and final step involved training personnel in installing piping system; increasing environmental awareness; reviewing cleaning procedures; and introducing new effluent handling processes to ensure correct connection of the correct effluent pipes.

The mixing trial involved 41 products that were: consistently produced by NCM; produced in significant quantities; potentially enter the waste water system; thought to be most reactive; and/or representative of a number of other similar products. These 41 chemicals were used in test solutions by mixing them with water. Each sample was subsequently mixed with samples of every other solution. In total, 780 tests were carried out with all major product samples, and any reaction noted. Based on the tests, it was concluded that: when wastewater containing anions (detergent-type chemicals) were mixed together, no sludge is produced; when wastewater containing nonions (detergents and products which do not ionise) are mixed together, no sludge is produced; and, when other products (disinfectants, emulsions and oils) are mixed together, sludge is produced. Thus, sludge is produced when nonions are mixed with anions, when anions are mixed with other products, and when nonions are mixed with other products.

The results of the test also confirmed that stream separation was feasible, and would reduce solid waste. Thus, new pipelines were installed to facilitate segregation of anion, nonion, and other products into three separate tanks. Color coding was used to ensure that pipes designated to a specific product were not connected with other effluent streams, and scheduled release of effluent tanks also prevented mixing downstream from the site which would result in sludge formation. Personnel were then trained in the system's installation, operation and maintenance.

While the program has proved to be largely effective, there were several obstacles in its implementation. The first was its delay in installation; the second was an exceeding budget: it was determined that additional pumps would be required which offset the initial budget; the third was buckling of the new holding tank due to external water pressures from the clay ground. Finally, implementation of the project is largely dependent on technical expertise; therefore, the availability of specialized personnel and/or consultants in tailoring the program to a different site may also prove to be a constraining factor in replicating this project.

Status:

The Clean Production strategy is a proven success story in reducing the amount of sludge produced as well as the number of man-handling hours spent managing the waste. Monitoring these parameters demonstrated that NCM was able to cut its production of sludge by 66%. The amount of sludge being disposed to landfill has decreased by approximately 16.5 tons/yr., to approximately 8.5 tons/yr. The greatest saving from this program was improving the overall efficiency of operations by reducing personnel time committed to sludge handling; the hours spent handling sludge were reduced from approximately 780 hours/yr to 260 hours/yr.

Follow-up:

Evaluation and fine-tuning of this project has been continuous since its implementation. Due to the cleaner production strategy, the company has increased productivity, cost savings, minimized negative environmental effects, and improved its public image in the market community. The program has demonstrated that it is often more simple and effective to treat the source of the problem rather than the end product, and, when applied to even a small industry, can assist in its development.

Submitted by:

Clare Parker, Horizon Intern
Former address:
United Nations Environment Programme
2 UN Plaza
Rm. DC2-803
New York, NY, 10017

Information Date: 1997-01-01
Information Source: EnviroNET Australia Cleaner Production Case Studies Directory