Household wastes are not normally regarded as hazardous, since they consist almost entirely of materials, which have been handled by individuals before being discarded. However, such wastes can be extremely variable in their composition, depending to a large extent on the lifestyle of the generator.
For example, it can be expected that in the countries where almost everything bought is associated with wrapping materials, the packaging waste very often comprises a significant part of household waste. There will also be foodstuffs adhering to it or unusable material derived from foods preparation, such as vegetable peelings, meat scrapes and bones, which make it unattractive for recycling. Also present in waste collected from households are such items as batteries and other electrical components, some of which may contain mercury, containers in which are present residues of oils, paints, pool chemicals, caustic materials, sterilizing agents, bleaches, medicines, etc. Although these constitute a small portion of wastes collected from households, they are particularly problematic due to their hazardous characteristic, variability in chemistry and associated high recovery costs. There may be in addition, aerosol canisters, caustic materials, sterilizing agents, bleaches, medicines, disposable baby’s nappies or diapers, animal faeces and its associated litter along with discarded foodstuffs which rapidly degrade and become offensive by virtue of their smell. Such wastes are attractive to vermin, flies and scavenging animals and birds.
For all these reasons there is a need to control and give special consideration to household wastes and carry out practices, which demonstrate environmentally sound management. Such wastes could also be generated in offices, commercial establishments, hotels, etc.
Approximately 80% of the weight of car tyres and 75% of truck tyres is rubber compound. Tyres contain about 1.5% by weight of elements or compounds listed in Annex 1 of the Basel Convention. These are encased in the rubber compound or present as an alloying element.
These technical guidelines provide general guidance on specially engineered landfills used for the wastes which exhibit one or more hazardous characteristics. The technical guidelines also discuss the landfilling of other wastes, as defined in the Basel Convention, e.g. collected from households, to provide a more comprehensive picture on environmental and health problems arising from landfills. In addition to the requirements for establishing new landfills, the technical guidelines also consider the critical issue of existing or abandoned landfill sites which require strict control, monitoring and often remedial measures. They provide general guidance as to which hazardous wastes would be suitable for landfilling.
Landfill is by far the most commonly practised waste disposal method in the majority of countries. It is the descriptor used for the placement of wastes into or onto the ground and, in many cases because of the nature of the materials involved, equates to long-term storage.
As a result of serious environmental and health problems experienced with historic and abandoned dump sites and the very high costs associated with clean-up measures at contaminated sites, many countries have introduced the "specially engineered landfill concept", the wastes for which are only consigned to sites selected for their containment properties, these being natural, augmented by or provided directly by liners, the overall engineering being such as to ensure as far as possible the isolation of wastes from the environment. Such landfills are considered a final resort option only to be used after every effort has been made to reduce, mitigate or eliminate the hazards posed by such wastes.
Incineration is a high temperature, thermal treatment process in which hazardous wastes are converted into gases and essentially incombustible solid residue.
A high level of technical competence is required in designing, operating and monitoring an incineration facility. It is an integrated activity involving a number of process operations (feed reception, control and preparation - actual combustion stage - treatment of combustion products, waste gases and
residues). The options available within these process operations can be combined in various ways to meet the technical needs of a wide range of circumstances. Thermal treatments are of three main kinds: incineration; pyrolysis; other thermal processes (i.e. thermal oxidation). Thermal oxidation or process is by far the most used method for the treatment of hazardous wastes and is the subject matter of these draft technical guidelines.
The processing of used and waste oils has been practised for many years, with organised recycling of engine lubricating oil from vehicle fleets being well established by the 1930s. Certain waste oils streams arising on oil refinery sites have been fed into so called "crude ponds" and as part of material which was accumulated in these have been recycled.
In the context of these guidelines used oil means any semi-solid or liquid used product consisting totally or partially of mineral oil or synthesised hydrocarbons (synthetic oils), oily residues from tanks, oil-water mixtures and emulsions. These arising from industrial and non industrial sources where they have been used for lubricating, hydraulic, heat transfer, electrical insulating (dielectric) or other purposes and whose original characteristics have
changed during use thereby rendering them unsuitable for further use for the purpose for which they were originally intended.
The Guidelines seek to provide concise information to help competent and other authorities better understand the scope and nature of biological and physico-chemical processes.
In most countries, nowadays, used lead-acid batteries are returned for lead recycling. However, considering that a normal battery also contains sulfuric acid and several kinds of plastics, the recycling process may be a potentially dangerous process if not properly controlled.
These technical guidelines are, therefore, meant to provide guidance to countries which are planning to improve their capacity in order to manage the used lead-acid battery wastes.
The disposal of wastes originating from health-care establishments (public and private) can have an effect on human health and well-being, the environment (air, water, soil, animals, plants, landscape) and issues relating to public security and order.
Nevertheless, experience has proven that wastes originating from health-care establishments, when properly managed, generally pose no greater risks than that of properly treated municipal or industrial wastes. This also pertains to the disposal of biomedical and health-care wastes, in contrast to occasional public perception.
The guidelines provide information for the proper treatment of wastes from health-care establishments (public and private). The information provided takes due consideration of the waste management requirements of disposal and recovery measures as well as hygiene requirements. In addition to ecological aspects, the information and recommendations should be economically feasible and easy to undertake. It and also makes allowances for technical progress.
The present technical guidelines are principally intended to provide guidance, to countries which are building their capacity to manage waste in an environmentally sound and efficient manner, in their development of procedures or strategies for recycling metals and metal compounds, and to encourage further recycling of metals in an environmentally sound manner.
Some waste will contain metals and metal compounds in forms and amounts sufficient for recycling and reclamation to be considered in preference to disposal, and in that case such recycling and reclamation is to be preferred.
These guidelines focus mainly on the recycling and reclamation of metals and metal compounds that are listed in Annex I to the Basel Convention as categories of wastes to be controlled. Those categories include the following metals and their compounds: antimony (Sb), arsenic (As), beryllium (Be), cadmium (Cd), lead (Pb), mercury (Hg), selenium (Se), tellurium (Te) and thallium (Tl). They also include compounds of copper, zinc and hexavalent chromium, but not the metals themselves. These metals and metal compounds may be referred to as Annex I metals and metal compounds or, more simply, as Annex I metals. Materials that contain them are controlled under the Basel Convention if they fall within the Convention’s definition of waste, unless they do not possess any of the hazardous characteristics listed in Annex III to the Convention.