WASTE MINIMISATION AND THE POWDER COATING INDUSTRY
3.1 Waste and Waste Management
CHAPTER 3
WASTE MINIMISATION AND THE POWDER
This shows that industrial waste is not the only kind of waste that needs to be managed.
Waste has been termed 'established' (also termed 'obvious'89and 'controlled'90) where the source is known and the quantity can usually be measured. Alternatively waste has been described as being 'less obvious'89 or 'uncontrolled.'90 In this case waste is often released, knowingly or unknowingly, directly into the environment and it is difficult to determine its origin.
There is extensive UK legislation which covers waste production and management. The UK Environmental Protection Act 199091 defines waste as being " any substance which constitutes a scrap material, effluent or any other surplus substance that arises from any process." This is consistent with definitions of waste given in points 1) and 3) above.
Point 2) is covered not only by the Environmental Protection Act but also by other pieces of legislation including The List of Wastes Regulations 2005.92 This document clearly and extensively defines hazardous waste in terms of its toxicity and concentration, and lists waste according to the relevant industrial sector that generates it. The UK Environment Agency has classified waste into the two types namely controlled and non- controlled waste. Controlled waste consists of household, industrial and commercial waste. This has also been termed municipal solid waste90 where the industrial waste comes from light industry. Non-controlled waste consists of agricultural waste and waste produced in mines and quarries.90 These are not normally sent through a treatment process prior to disposal but are discharged or disappear directly into the environment.
This has meant it has been very difficult to institute legislative control over the release of these wastes into the environment.
According to documentation published by the SA Department of Water Affairs and Forestry93 waste is defined as being "any undesirable or superfluous by-product, emission, residue or remainder of any process or activity, any matter, gaseous liquid or solid or any combination thereof." Although this definition is consistent with that given in point 1) above, this document does go on to give a detailed classification of hazardous waste. It defines hazardous waste as being any waste that can cause severe harm to public
health and the environment due to its inherent toxicological, chemical and physical characteristics. This definition is consistent with point 3) above. Such solid waste is usually uplifted by private contractors and can be disposed of in one of two ways, either in a hazardous waste landfill site or by incineration. Recently, incineration of hazardous waste has come under criticism both locally and internationally as the method releases heavy metals and other hazardous chemicals like dioxin into the atmosphere.93 Landfill sites are given a hazard rating on a four point scale (see Table 3.1) which differentiates among the fairly, moderately, very or extremely hazardous waste. This determines what type of landfill site in which the waste must be deposited at.
Table 3.1 Ratings of hazardous waste Hazard Rating
1 2 3 4
Risk Factor Extremely High
High Moderate
Low
Type of Landfill H:H H:H H:H or H:h
Landfill
There are two types of landfill sites that accept hazardous wastes which are H:H (High Hazardous) and H:h (Low Hazardous). The H:H landfills can accept wastes of all hazard ratings that are destined for landfill. However H:h landfills accept only wastes with hazard ratings 3 and 4. In Natal there are two low hazardous landfill sites and they are situated in Shongweni and Bulbul Drive in Durban. There are three high hazardous sites in SA: one in Holfontein, East London and Visserhok. Often hazardous waste has to be treated or encapsulated before disposal in a landfill site. This treatment is dependent upon the chemical composition of the waste.
The Department of Environment Affairs and Tourism94 in SA has begun to publish documentation along the lines of the UK concerning waste. In 1999 the National Waste Management Strategies and Action Plans South Africa were published. In the national waste management strategy, waste and waste management are very thoroughly defined and waste treatment is categorized under seven headings. This includes hazardous waste, both domestic and industrial and covered by points 1) and 2).
In the South African National Water Act of 199895 a water-borne waste is defined as being "any solid material or material that is suspended, dissolved or transported in water (including sediment) and which is spilled or deposited on land or into a water resource in such volume, composition or manner as to cause, or to be reasonably likely to cause, the water resource to be polluted.,,95
There is a general instruction under the National Environmental Management Act (NEMA) No.107 of 1998 not to damage the natural environment. It states ''that any individual that causes, has caused or may cause significant pollution or degradation of the environment must take reasonable measures to prevent this from occurring, continuing or recurring".96 This will apply to waste especially when it is hazardous.
There are many general definitions of waste in the literature. For example Manahan defines waste as being "all kinds of solids, semisolids, sludges, liquids, contaminated soils, sediments and other kinds of materials that are either wastes themselves or are contaminated by wastes.'>97 This definition agrees with that given in points I) and 3) above.
In the USA, the Resource Conservation and Recovery Act (RCRA) of 1988 covers hazardous wastes and solid wastes only. Italso requires that the company responsible for generating the waste must have a programme in place to reduce the volume, quantity and toxicity of the waste to a degree that becomes economically practicable. 98 Other forms of waste for example that are water or air-borne are dealt with in different pieces of legislation. The US Environment Protection Agency defines waste as being "any unwanted product arising from a process which should be discarded irrespective of their impact on the environment.',99 General waste refers to "any waste that does not fall within the definition of hazardous waste. It is waste that is unlikely to cause significant harm to the public or the environment, provided it is properly managed.',93 The treatment of this waste has been prioritized according to a waste management hierarchy (See Figure 3.1).
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Elimination
Minimisation or source reduction Reuse and recycling Treatment and disposal
Preferred option
Least preferred option Figure 3.1 The waste management hierarchy
Waste minimisation deals mainly with the first three levels of the hierarchy namely, elimination, minimization, and recycling and reuse. These are listed in order of decreasing sustainability as shown in Figure 3.1. Sustainability has been defined as
"existing and solving today's problems in a responsible and environmentally friendly manner without prejudicing the ability of future generations to exist or solve their own problems."106 The first option for sustainable waste management is elimination and this involves stopping waste from being formed in the first place. This has led to elimination and waste minimisation being called 'start of pipe' treatments.107108 Elimination produces 'zero waste'109 and the only output from the process is saleable products.102 However, elimination of all wastes is often unachievable in reality." This means that other waste management options from the waste hierarchy must be sought in order to reduce waste.
The second most preferred option in the hierarchy is waste minimisation. Such source reduction techniques have been employed not only to reduce the quantity of waste generated, but also to reduce the amount of toxic chemicals used and released into the environment.110 According to the EPA101, waste minimisation includes both source reduction and recycling.
The UK Environment Agency 111112 describes waste minimisation as being the efficient industrial use of natural resources by understanding and changing processes. This emphasizes the need for an in-depth understanding of the process in terms of inputs so that natural resources can be conserved. This definition given by the agency stresses that less hazardous inputs should be used instead of more toxic ones in the production
process. Adoption of these practices leads to a reduction in the amount of waste generated by the process.
Waste minimisation can be achieved through material changes {see points 1) and 3) below} or procedural changes {see points 2) and 4) below}.