Chapter 5 Mineral constituents
Résumé
This chapter presents the complexometric method for the simultaneous determination of copper (Cu), iron (Fe), mercury (Hg) in water and wastewater. . Metallic constituents come from natural origin (ore) or more frequently from anthropogenic pollution. N and P compounds are probably the most important inorganic nonmetallic constituents with regard to their environmental effects such as eutrophication of surface water (lakes and rivers). Some of them are directly considered as nutrients (nitrate or phosphate), while others are nutrients precursors (ammonia, organic nitrogen, and organic phosphorous). The presence of the reduced compounds in surface water is due to natural organic matter and, in major part, to discharges coming from biological wastewater treatment plants for the ammoniacal form. These reduced compounds increase the oxygen demand, resulting in the formation of final stable products as nitrate and are toxic for fish in rivers. Oxidized forms can also be toxic for human beings, through tap water.