CYANIDE DEGRADATION BY WATER HYACINTHS, EICHORNIA-CRASSIPES (MART) SOLMS

Cyanide degradation by water hyacinths, Eichornia crassipes (Mart.) So lms, in solutions containing 3-300 mg/l cyanide was investigated in ba tch tests. Water hyacinth was more efficient to remove free cyanide in the first 8 hours, compared to cyanide controls, free of plant. Gold mill synthetic effluents containing free cyanide (9 to 20 mg/l), thioc yanate (14 to 23 mg/l), and metallocyanides (iron, copper and zinc) wa s fed to a continuous lab. scale unit (6 l/h) to confirm the ability o f water hyacinth to degrade free cyanide and that it can remove zinc a nd small amounts of iron. However, copper and thiocyanate remained unt ouched in the solution. According to the results, water hyacinth is on ly suitable to be used in conjunction with other cyanide wastewater tr eatments.