Alternatives to automatic wastewater neutralization

Automatic wastewater treatment

Concentrated wastewater streams, such as ion-exchange regeneration effluent, may contain dissolved metals and other hazardous substances. They must be assessed and treated before discharge.

A treatment system may combine oxidation or reduction where appropriate, metal precipitation, adsorption, pH adjustment and solid-liquid separation. The process sequence depends on the contaminants and the discharge requirements.

Separated sludge and filter cake may still contain hazardous substances and require appropriate handling and disposal. Treated water must be checked against the applicable discharge criteria; filtration and neutralization alone do not establish that it is suitable for discharge.

An alternative: electrolytic metal recovery

The Metallyse system uses electrolysis to deposit dissolved metals on a cathode. A scraper collects the deposited metal for recovery. Potential applications include streams containing Cadmium, Cobalt, Copper, Gold, Iron, Lead, Manganese, Mercury, Molybdenum, Nickel, Palladium, Ruthenium, Silver, Tin and Zinc.

Suitability depends on the wastewater composition and operating conditions. Electrolytic recovery can reduce the metal load and the need for subsequent chemical treatment, but the remaining effluent must still be assessed. It does not automatically eliminate the need for neutralization or other treatment.

In some applications, evaporation may also be considered as an alternative treatment approach.