ABSTRACT
Manufactured gas plants, also referred to as town gas plants, produced large quantities of tar and related by-products. Although there are some similarities among these sites, the sites often vary significantly in the specific types and quantities of wastes present, depending upon the types of processes used (coal, water, or oil gas) and the era in which the plant was operational. Polynuclear aromatic hydrocarbons (PAH’s) are components of all kinds of tars, and tars are a by-product of all of these plants. The physical and chemical characteristics of these tars vary, however, according to the process employed. 1 , 2 Oxide wastes from purifier boxes may contain ferrocyanide and varying amounts of arsenic, chromium, copper, lead, nickel, and zinc (all of which appear on the Environmental Protection Agency priority pollutants list). Lamp black, clinker, cinders, and ash may also be present.
