FATE AND EFFECTS OF CYANIDE DURING WASTE-WATER TREATMENT PROCESSES

This paper presents a literature review on the fate and effects of cya nide and its species during wastewater treatment at conventional sewag e treatment works. Initially, the chemistry, speciation and associated toxicities of cyanide are considered, after which the sources of cyan ide to wastewaters are reviewed. The susceptibility of cyanide species present in wastewater to stripping to the atmosphere, adsorption to p articulate material, chemical transformations and biological degradati on during primary treatment and activated sludge treatment is discusse d. The possible adverse effects of cyanide on biological sewage treatm ent processes are considered to assess whether there are any threshold effect levels.