Industrial Waste Dumps, Sampling and Analysis

Abstract

Abstract Industrial sites where residues and wastes such as slags, ashes, dust and sludges have been dumped are essential parts of the environment and of the economic structure. The amount of waste produced, distributed and deposited is constantly increasing. The wastes can contain hazardous components that pollute and endanger the environment, but they can also consist of valuable materials, which are a source of secondary raw materials. To assess the environmental risk caused by the waste, or to calculate the economic benefit of dumped material, a reliable knowledge of the waste composition is required. Waste management experience has regularly shown that conflicts and lawsuits are the result if the composition of the waste materials is difficult to determine reliably. Investigations carried out by different institutions and persons, or by the same personnel under varying conditions, will often have very different results. The measuring technology and the measuring methods cannot be the only reasons for that. Nowadays, it is possible to accurately determine chemical components in any natural concentration, and there is no problem in distinguishing the size and shape of particles down to the nanometer scale. The problems are created because the wastes are mixtures of particles and lumps which vary in size and shape as well as in chemical composition and physical properties. A waste dump with a varied production history and dumping conditions, with chemical reactions or physical changes occurring after dumping, will be heterogeneous as a rule. Therefore, the evaluation of any dump of industrial waste materials is quite difficult. To ensure that the results of evaluation are comparable, certain regulations of investigation must be followed. According to the delivery, the wastes are classified into material streams (stationary, moving or free falling), heaps delivered within containers and vehicles, and free‐standing heaps. As it is economically unjustifiable to investigate the entire waste dump, subsets of material (called samples) must be taken from the stream, the container or the heap in order to determine the measurements of interest. In doing this, rather a lot of errors can be made. Therefore, the errors that exist are frequently caused by unobjective sampling and improper handling of the sample material. However, a false estimation can also be made by evaluating reliable data using unsuitable statistical methods. The present contribution takes up this problem. An industrial waste dump and a contaminated site were chosen as examples, and proven sampling regulations were applied. The applicability of known statistical and geostatistical methods developed for homogeneous granular bulk solids and uniformly contaminated soils to the evaluation of extremely heterogeneous waste dumps and nonuniformly contaminated industrial sites is shown.