The Removal of Mercury and Mercurial Compounds From Wastewater
Over the past several decades, increasing attention has focused on wastewater reclamation. Legislative measures aimed at protecting the environment currently regulate wastewater composition. In addition, with greater demand for fixed natural water supplies, wastewater renovation has become more important. Potential reuses may include agricultural and industrial processes; wastewater may even find its way into potable supplies. The processes involved in wastewater reclamation are complex. A multitude of pollutants may be present in any given effluent. One contaminant which has long been recognized as a potential threat to human health is the metal, mercury. Within the environment, mercury may take a variety of forms. Perhaps the most toxic of these are the methylated mercurial compounds. Methylmercury and dimethylmercury can be created by anaerobic bacteria from inorganic mercurial sediments. They may then accumulate in the food chain. Mercury can be removed from wastewater by a number of different processes. Of the various methods, chemical precipitation, ion exchange, and biological remediation are perhaps the most important.
The first United States legislation addressing water pollution was enacted late in the 19th century. In 1886 and 1899, Congress passed laws designed to protect shipping from the dumping of solid wastes. It wasn't until the 20th century though, that the health effects of water pollution were recognized. The Public Health Service Act of 1912 contained a section on waterborne diseases. In addition, the Oil Pollution Act of 1924 protected aquatic life from oil discharges along coastal waters. Perhaps some of the most important water pollution legislation, however, was passed after the 1960s. The Water Quality Act of 1965, for example, set "water-quality standards for interstate waters." Then, one year later, the Clean Rivers R...