ABSTRACT
The dumping of materials, bankrupt and abandoned manufacturing plants, insufficient methods for waste storage, treatment, and disposal facilities have contributed to the contamination of many sites as indicated in previous chapters. Chemical waste categories include organic liquids such as solvents from dry cleaning, oils including lubricating oils, automotive oils, hydraulic oils, fuel oils, and organic sludges/solids and organic aqueous wastes and wastewaters. Most soil contamination is the result of accidental spills and leaks, generation of chemical waste leachates and sludges from cleaning of equipment, residues left in used containers and outdated materials and indiscriminant dumping. Smaller generators of chemical contaminants include improperly managed landfills, automobile service establishments, maintenance shops, and photographic film processors. Household wastes including pesticides, paints, cleaning, and automotive products may also contribute significantly as sources of organic chemicals (LaGrega et al., 2010). The more common heavy metals include lead (Pb), cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), iron (Fe), mercury (Hg), and zinc (Zn).
