| 摘要 |
A waste water stream containing cyanide bearing compounds and heavy metals such as copper, silver, nickel, iron and the like is directed from a source after pH adjustment to a first tank containing adsorption material in the form of granular activated carbon. The waste water is oxygenated by compressed air. The cyanide bearing compounds and heavy metal are adsorbed onto the surface of the adsorption material which is pretreated to an initial pH in the range between about 8.5 to 11. The effluent from the first tank is pH adjusted by a pH controller which adds a caustic solution to the effluent to maintain a control point pH. The pH adjusted effluent is directed toward a second tank containing pretreated adsorption materials. The water stream free of cyanide and metal contaminants is directed to an effluent tank for safe discharge. Thereafter a stripping solution preferably containing sulfuric acid is circulated through the tank to remove the adsorbed metal for the adsorption material. The metal is carried by the stripping solution from the tank to an electrolytic metal recovery unit. The unit includes a cathode terminal and the stripping solution passes through a voltage potential resulting in electrolytic deposit of the heavy metal onto the cathode terminal. The stripping solution free of the heavy metal is returned to a tank for reuse in the adsorption process. The cathode terminal is removed from the metal recovery unit to allow recovery of the metal for reuse.
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