What is a Source Reduction?

The reduction of waste at source is an established waste minimization technique. It is the most effective technique which should always be considered first. This approach to waste management considers the internal flow of resources, materials and waste through the production chain in three key areas: resource inputs, the manufacturing process and product marketing

Reuse

It refers to the reuse of discarded items without any additional processing. Examples include reusing plastic supermarket carrier bags, partly worn and reusing automobile parts. Reusing a product extends the lifetime of the material used and therefore reduces the waste quantity requiring treatment and disposal.

Recycling

Recycling is the collection, segregation, cleaning up and processing of waste materials to produce a marketable material or product. Recycling can take place within the manufacturing process such as in the paper industry where surplus pulp fibres, mill off cuts and damaged paper rolls are recycled back into the pulping process. Alternatively, recycling takes place at the post- consumer stage, where paper can be collected separately or segregated from the refuse and then re-enter the paper-making process.

Recovery

Waste recovery should only be considered after all other waste reduction options have been instituted. Waste recovery incorporates reclamation of organic substances, metals and other inorganic materials. It also includes oil re-refining and the use of waste principally as a fuel or other means to generate energy. Table 9.1 gives some examples of energy that can be recovered from various waste treatment and disposal techniques.

Treatment

Waste treatment covers any method, technique or process that changes the physical, chemical or biological character of waste. The objectives of waste treatment are as follows:

1. Neutralization of waste

2. Making the waste less hazardous, non-toxic, manageable, and recoverable

3. Reduction of volume of waste.

The waste cam is treated by applying physical, chemical and biological processes and operations. Most of the waste treatment methods may result in transfer of a waste from one form to another resulting in a continuing problem. For example, scrubbing of contaminated gas stream produces contaminated liquid stream. Biological treatment of sewage and industrial effluents produces solid sludge. Judicious choice of a treatment process can result in effective reuse of a waste material. The anaerobic treatment of high-strength organic waste (aqueous form) produces methane, which can be used as fuel (energy recovery).

Disposal

Disposal is the discharge, deposition, injection, spilling or placing of waste into or on land and water or into the air.

To summarize, the strategy of waste minimization should aim at source reduction first followed by reuse, recycling, treatment and disposal.

Cleaner production

Cleaner production is about minimizing the ecological impacts of our commercial and industrial activity, while maximizing the benefits gained from any raw material or resource we consume. Cleaner production aims to:

1. Minimize the creation of wastes and environmental contaminants.

2. Reduce overall cost and add market advantage.

3. increase resource-use efficiency and utilization

4. Benefit the environment.

5. Encourage a sustainable society.

Other aims of cleaner production may extend to involve the full life cycle costs of products, including their ultimate disposal by consumers after use, and any environmental impacts associated with their use.

Cleaner production approach may involve:

1. Modifying product to reduce its environmental impact.

2. Substituting raw material inputs with less toxic alternatives.

3. changing production processes and technologies used

4. resource recovery, re-use, and recycling

5. good administration and procedures to minimise the risks of spills or leaks

6. The goal of any cleaner production initiatives should be to:

7. Conserve raw materials, energy and water.

8. Reduce the toxicity and amount of wastes and pollutants being created.