Survey of cyanide generation in effluent of different part of stainless steel manufacturing

Cyanide is extremely toxic, and if taken, may cause acute effects in human as weakness, nausea, coma and ultimately to death. Iron-steel mill is one of the important source of cyanide. It appears as hydrogen cyanide in coke and blast furnace wastewaters. For humane and environmental urgency, it is needed an instant treatment. The purpose of this experimental research is to pinpoint and determine the polluting sources and discharges to atmosphere and nature. Then, the samples were collected from of coke plant, inlet and outlet of wastewater lagoons and taken to lab tests. The experiments were carried out in three continuous months and two stages; treated and untreated wastewaters. The results showed the fact that the cyanide content in the industrial influent of lagoon is lower than contained in coke plant discharge or the blast furnace. For this reason, a separate treatment line is proposed for any one of them. Eventually, it was found that the amounts of cyanide is much more than the limit to discharge to groundwaters or agricultural purposes. Moreover, there is possibility of leakage of wastewater to groundwaters and a need to be treated, primarily, before entering to the biological pond.