Mercury containing wastewater mainly comes from non-ferrous metal smelting plants, chemical plants, agricultural and pharmaceutical plants, paper mills, dyestuff factories and instrument factories of thermal equipment.
The methods of removing inorganic mercury from wastewater include sulfide precipitation, chemical condensation, activated carbon adsorption, metal reduction, ion exchange and microbiological methods.
Generally alkaline mercurial wastewater is treated by chemical condensation or sulfide precipitation.
Partial acid mercury containing wastewater can be treated by metal reduction.
Low concentration of waste water containing mercury available activated carbon adsorption method, chemical coagulation method or activated sludge method process, organic mercury wastewater more difficult, often organic mercury oxidation for inorganic mercury first, and then for processing.
The toxicity of various mercury compounds varies greatly.
Elemental mercury is basically nontoxic;
Hg in inorganic mercury is a highly toxic substance.
Methyl mercury is easily absorbed into the body, is not easily degraded, and is excreted slowly, especially in the brain.
The most virulent diseases, such as minamata disease, are caused by methylmercury poisoning.