| 摘要 |
The nickel content of a waste water stream, such as a stream of grey water that is separated in the decanting operation of a partial oxidation process or blow-down water from a gas quench cooling and/or scrubbing operation is reduced to below 1 mg/l to produce an environmentally upgraded water stream. In the process, the dilute waste water stream containing nickel impurities at a temperature in the range of about 60 DEG to 220 DEG F. is mixed with a water soluble material selected from the group consisting of formaldehyde, ionizable polysulfide salt, and hydrogen peroxide; and with dimethyl glyoxime. The pH is adjusted to a value in the range of over 7 to 11 by the addition of a base material and a water insoluble nickel precipitate forms. The precipitate and other insoluble matter are separated from the water by means of at least one conventional solids-liquid separator, and a stream of upgraded water is produced. At least a portion of the upgraded water stream may be recycled to the gas quench cooling and/or scrubbing operation. The nickel content of the upgraded water stream has been reduced to conform with environmental regulations. Further, build-up of nickel in the recycle circulating water system and the formation of troublesome nickel carbonyl are prevented.
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