Waste Definition and Classification

Sri SuhartiniPostgraduate student in The University of Queensland


There are many definitions of waste. According to McBean, et al. (1995), “Waste is a material that is cheaper to throw away than to use”. Furthermore, the Western Australian Government Department of Environmental Protection (2001) defines, “Wastes are (i) any substance that is discarded, emitted, or deposited in the environment in such volume, constituency or manner as to cause an alteration in the environment; (ii) any discarded, rejected, unwanted, surplus or abandoned substance; and (iii) any otherwise discarded, rejected, unwanted, surplus or abandoned substance intended for sale or for recycling, reprocessing, recovery, or purification by a separate operation from that which produced the substance.”

In addition, the types of wastes vary depending on their physical characteristics, components, and effects. According to Cutarao (2006), wastes, based on their physical characteristics, can be divided into “Solid wastes which are domestic, commercial and industrial wastes especially common as co-disposal of wastes (e.g. plastics, styrofoam, containers, bottles, cans, papers, scrap iron, and other trash; and liquid wastes which are in liquid form (e.g. domestic washings, chemicals, oils, wastewater from ponds, manufacturing industries, and other sources).” From their components, wastes can be characterized into two groups, “bio-degradable which can be degraded (e.g. paper, wood, fruits and others) and non-biodegradable which cannot be degraded (e.g. plastics, bottles, old machines, cans, styrofoam containers, and others).” Based on their effects on human and environment, wastes can be classified as “hazardous wastes, which are dangerous for commercially, industrially, agriculturally, or economically use, and non hazardous wastes, which are secure for commercially, industrially, agriculturally, or economically use.”


Numerous literatures define and divide solid wastes into different categories. Gottinger (1991, 3) defines solid wastes as “any garbage, refuse, sludge from a waste treatment plant, or air pollution control facility, and other discarded material resulting from industrial, commercial, mining and agricultural operations, and community activities.” Similarly, Tchobanoglous, et al. (1993, 3), add that solid wastes are all the wastes produced by human and animal activities which are solid and are discharged as unwanted.

It is clear that the solid waste quantity and composition (or component) is different in all societies, both in developing countries (e.g. Indonesia) and developed countries (e.g. Australia). Wahono, and Sahwan (1998), for example, state that the major compositions of solid wastes in major Indonesian cities (e.g. Jakarta, Bandung, and Semarang) are organic materials. This is supported by Tchobanoglous, et al. (1993) who mention that the distribution of components of residential municipal solid waste is typically different among countries, whereas developing countries produce more organic wastes than developed countries. Similarly, in companies or industries, the major composition of solid wastes is paper and paperboard wastes.

Clearly, there are many factors affecting the differences on solid waste composition. According to Bilitewski, et al. (1996, 3), these differences are caused by many factors, such as “level of consumption, production and packaging; standard of living; type of residence (yard space; degree of self-sufficiency); local conditions; and type and capacity of waste and recyclables containers.” Additionally, Rhyner, et al. (1995) add that the changes in product design, packaging materials, and buying habits have also changed the waste composition. This is also supported by Gupta, et al. (1998, 101) who found that the waste composition are depend on many factor such as “food habits, cultural tradition, lifestyles, climate and income etc”, which are found across all country around the world.

Obviously, solid wastes resources in all communities’ levels in developing countries (e. g. Indonesia) are quite similar with developed countries (e.g. Australia). In general, sources of solid wastes in a community are defined as “residential, commercial, institutional, industrial, and municipal services” (Tchobanoglous, et al. 1993, 40 and McBean, et al. 1995, 8) and “agricultural, construction and demolition, and treatment and plant sites which are depending on land use and zoning.” (Tchobanoglous, et al. 1993, 40) (see Table 2). Based on this figure, wastes resources in all level of society are generally similar, whereas wastes generation are relatively varied among these resources. For instance, in developed country, such as Australia, wastes are generated from agricultural (e.g. rice husks, macadamia shells, animal slurries, bagasse from sugar cane and timber mill residues), commercial and industrial, and household (BCSE 2005, 3).
Therefore, the main constituents of solid wastes are similar all over the world. However the quantity, the density and the proportion of these wastes generally vary among industries, countries, and communities, depending on the economic development level, geographic location, technology, and social conditions. These differences will lead to different approach on handling these waste problems.

References

Bilitewski, B., G. Hardtle, K. Marek, A. Weissbach, and H. Boeddicker. (1996), Waste Management, Springer, Berlin.

Gottinger, H. W. (1991), Economic Models and Applications of Solid Waste Management, Gordon and Breach Science Publisher, New York.

Gupta, S., and T. G. Lizon. 2004. Technical assistance (co-financed by the Canadian cooperation fund on climate change) to the Republic of Indonesia for the gas generation from waste project. Asian Development Bank. Retrieved September 9, 2006, from http://www.asiandevbank.org/Documents/TARs/INO/tar-ino-36557.pdf

McBean, E. A., F. A. Rovers, and G. J. Farquhar. (1995), Solid Waste Landfill Engineering and Design, Prentice Hall HTR, New Jersey.

Rhyner, C. R., L. J. Schwartz, R. B. Wenger, and M. G. Kohrell. (1995), Waste Management and Resource Recovery, Lewis Publishers, New York.

Tchobanoglous, G., H. Theisen, and S. Vigil. (1993), Integrated Solid Waste Management: Engineering Principles and Management Issues, McGraw-Hill, Inc, New York.

Wahono, S. and F. L. Sahwan. (1998). Indonesia: Solid waste composting trends and projects. BioCycle, 39, 64-68. Retrieved September 9, 2006, from Proquest Academic Research Library Database.