The Classification Of Solid Waste Environmental Sciences Essay

Waste management which has always formed part of the human society consists of waste prevention, reuse, recycling of materials, composting, energy recovery and final disposal. The mushrooming of the world’s population, increasing industrialization, improving quality of life, and developments in technology have all resulted in an increase in both the quantity and the different types of solid wastes generated by industries, households and other activities (UNEP,1991). The problems of dealing with large amount of waste materials arise specially in developing countries where these changes have not been met by developments in waste-management technologies (Wilson & Balkau, 1990). Domestic solid waste has become a health and environmental hazard in many developing countries as a result of careless handling and a failure to make arrangement for appropriate solid waste collection techniques. It is a common belief that improving solid waste management (SWM) implies making waste collection and disposal systems more efficient, raising residents’ awareness and enforcing SWM laws and regulations (Obeng.P.A; Donkor.A.E& Mensah.A; 2009).

2.1 Definition of solid waste

Solid waste can be defined as “a different types of solid materials and also some liquids in cans, that are disposed as being spent, useless, worthless or in excess” (Nemerow.L.N, Gardy.A.J.F, Sullivan.P and Salvato.A.J; 2009)

2.2 Classification of solid waste

The classification of solid waste is based on the content, moisture and heating value. An example of classification is as follows:

Garbage refers to the biodegradable solid waste constituents, obtained during the preparation or storage of food (meat, fruits, and vegetables). These wastes water content of about 70% and a heating value of around 6ooooookg (Rao,1991)

Rubbish refers to non-putrecible solid waste constituents either combustible (paper, wood, scrap) or non-combustible (metals, glasses ceramics). These wastes contain about 25% of water and the heating value of the waste is around 15000000kg (Rao, 1991).

Solid waste can be further classified based on the source of the solid waste:

Domestic waste

Commercial waste

Institutional waste

Industrial waste

Agricultural waste

2.3 Sources and Types of solid wastes

Table 1.0 below shows different source & types of solid wastes produced

Sources

Typical locations where wastes are generated

Types of solid wastes

Municipal wastes (domestic, commercial, institutional)

Residential, open areas (street)

Food wastes, rubbish, paper

Industrial wastes

Factory wastes

Organic wastes from food processing, metallic sludges

Agricultural wastes

Forestry wastes

Crop residues, animal manure

Mining & Quarrying wastes

Mining minerals

Rock, topsoil

Energy generation wastes

Thermal power plants

Fly ash

Source: Peavy, Rowe & Tchobanoglous (1985)

Since, domestic waste, commercial waste and institutional wastes are collected and transported by similar authorities, that is the municipal council or district council, they are usually group together and called Municipal Solid Waste (MSW).

2.4 What is solid waste management?

Solid waste management is considered as a serious matter in different parts of the world. The unexpected increase of waste production emphasizes on the necessity of a right balance in the various technological facilities for the collection and treatment of waste, taking into consideration the existing regulations, economic constraints, environmental issues and also public acceptance, (Caputo.C.A, Pelagagge.M.P and Scacchia.F; 2002).

Solid waste management can be defined as “the technical measures that will ensure respective executions of the functions of collection, transport, processing, treatment and disposal of solid waste”. The global concern about environmental health suggests that wastes be managed in an efficient manner and disposed of in an acceptable way, in order to reduce and or where possible get rid of its potential dangers that are posed to human beings and the environment as a whole, (Robinson 1986).

2.5 The need for municipal solid waste management

The need for municipal solid waste management arose since the effects of solid waste in the environment outweigh the benefits. The following illustrate some examples of improper solid waste management.

Public Health Problems and Diseases

The uncontrolled fermentation of garbage provides the food source and habitat for bacterial growth. Furthermore, there is proliferation of insects, flies, mosquitoes and some birds which act as passive vectors in the transmission of some infectious diseases.

Aesthetic consideration

Dumping of solid waste everywhere and failure to collect those wastes in a proper way, not only provide rooms for the growth and spreading of mosquitoes and insects, but also give rise to strong odour and lead to an unsightly and unpleasant environment.

Air Pollution

Uncontrolled and incomplete combustion of solid waste materials can result in a number of unwanted air pollutants including particulate matter, smoke, sulphur dioxide and other noxious gases from the burning of plastic materials.

Thus by analyzing the few health hazards and environmental impacts of solid waste, we conclude that a safe and environmentally and economically sustainable solid waste management plan is indispensable.

2.6 General solid waste management in Mauritius

In Mauritius, it is the local authorities which consist of five municipalities for urban areas and four district councils for rural regions, private sectors such as Securiclean, Maxiclean, Atics among others, and the Ministry of Local Government which carry out waste collection. The Chief Health Inspector in all the five municipalities controls the operation of collection, disposal and street cleaning. The officer is also responsible for transport allocation and operation, including control of drivers, except in Port-Louis where transport and drivers are on the establishment of the City Engineer’s department.

There exist a similar structure in the three district councils concerning the management and operational transport. However since the labour force is small, employees from the government are supplemented to perform the work.

The frequency of collection regarding domestic refuse varies from twice a week to once monthly between local authorities. The collection of commercial or trade waste in urban and rural areas is treated as a main concern and a daily service is provided.

With respect to storage, some municipalities have provided plastic bins and plastic bags to the residents. This has facilitated the collection process. All waste collected by the district and municipal council and the private contractors are disposed of directly to a dump site or to a transfer station where the waste is processed and compacted before dumping. (Source: http://localgovernment.gov.mu)