Page 87 - Solid Waste Analysis and Minimization a Systems Approach

RELATED RESEARCH 65

This research was very innovative and was the pioneer effort in rating environmental
performance of individual companies using mathematical analyses. A major drawback for
this study was that no significant variables were found to rate or predict solid waste gen-
eration performance of companies in each sector. The study found air and wastewater
emissions could be statistically evaluated using indicators, but not solid waste generation.
This research placed more emphasis on these variables over solid waste generation. As
mentioned, a serious drawback of this study was that no model was developed; the study
just identified the variables that are significant in evaluating environmental performance
(the core indices). This study solely analyzed data; it did not model the data.

2.10.5 PREDICTION METHODOLOGY FOR
WASTE GENERATION AND COMPOSITION

A study conducted in Europe developed a mathematical model to predict solid waste
generation for entire countries. The research is published in an article titled “Municipal
Solid Waste: A Prediction Methodology for Generation Rate and Composition in the
European Union and the United States of America” (Daskalopoulos, 1998). The research
conducted examines historical data from 1980 through 1993 to determine correlations
between United States and European Union MSW and indicator values. In this research
the significant parameters considered are population and the mean standard of living for
each country [as measured by gross domestic product (GDP)].
For this research, models were developed to express the relationship between GDP,
population, and MSW, in tons per year for the European Union and the United States.
The following equations were developed to describe the relationship for the European
and American cases:

Europe: MSW = 0.1292 GDP 0.4414 Population 0.4855

America: MSW = 4.08413 10 −3 GDP 0.458 Population 1.24075

The degree of accuracy of these models is determined by the reliability of the
published information, which has been provided by international organizations. The
models developed can be used to predict the future amount of the MSW generated
in a country, provided that gross domestic product and population forecasts are
available. Although this research studied waste generation for entire counties, the
indictors may also be significant for individual companies in terms of sales and
number of employees (instead of GDP and population). The model outputs for this
study were evaluated with the model outputs for this research. In particular the equa-
tions were linearized by taking the logs of both sides (Walpole and Myers, 1993).
The results of the linearized equation for America were compared to the results from
the model developed for this research. This method is discussed in Chap. 7; it involves
validating the system.
Contributions of this study were

■ Developed quantitative prediction models for solid waste generation.
■ Identified the variables that aid in the prediction of solid waste.