275

The Disposal of Municipal Solid

Wastes

11

11.1 The Nature of Wastes in General

Wastes are unwanted materials or outcomes resulting
from a particular human activity. The fact that a
material or outcome is a waste in a particular activity
does not render that material or outcome totally
unwanted for all other activities. Indeed what is waste
under one condition may be the corner stone of activity
in another. Thus molasses is a waste material in sugar
manufacture, but it is a major input in the manufacture
of many fermentation products such as antibiotics.
Similarly, farm trash such as corn cobs, wastes from

corn growing, may be the basis for improving soil

qualities through composting.

Wastes differ in nature and weight according to the

activities which generate them. Thus wastes by weight

were highest in construction and manufacturing, fol-

lowed by mining and by municipal activities, agricul-

ture in the European Union (EU) in 2002. (Anonymous

2005 ).

The nature of the wastes generated in any society or

country clearly relates to the economic activity of that

society. Thus, although wastes from construction and

manufacturing are expected to be heavier by their

Abstract

The publication of Rachel Carson’s Silent Spring (1962) stimulated eventual

worldwide interest in the environment, leading to the founding of the United

Nations Environmental Programme (UNEP) and the inauguration of national

environmental ministries, agencies or laws world-wide.

Solid wastes management involves waste reduction, reuse and recycling, com-

posting, incineration with or without energy recovery, and landfilling.

Modern incinerators scrub the flue gases of incineration to reduce the harmful

components. Newer methods of treating wastes include plasma arc gasification, in

which waste is treated at very high temperatures and pressures, melting the waste

into a nontoxic dross and yielding a fuel, syngas, for generating electricity.

Pyrolysis operates at about 430°C. Supercritical water oxidation (SCWO) is the

destruction technology for organic compounds and toxic materials at very high

temperature and pressure, converting them to carbon dioxide, hydrogen to water,

and chlorine atoms to chloride ion.

Keywords

Municipal solid wastes • Environment and development • Waste management

• Incineration • Landfills • Plasma gasification • Composts • Energy from waste


• Recycling • Reuse • Supercritical water oxidation • Pyrolysis

N. Okafor, Environmental Microbiology of Aquatic and Waste Systems,
DOI 10.1007/978-94-007-1460-1_11, © Springer Science+Business Media B.V. 2011