Metalworkers clean up their waste
This article describes how using methods such as chemical precipitation, filtration, and ion exchange, metal parts manufacturers are reducing the pollutants in their wastewater so it can be reused or safely discharged. Metalworking manufacturer are recovering useful materials, lowering their disposal costs, and reducing pollution by treating their wastewater with methods such as chemical precipitation and ion exchange so that it can be reused or safely discharged. They are also reducing wastes by recycling metalworking coolants. The major wastewater treatment technologies identified by the Environmental Protection Agency are chemical precipitation, or adding flocculants to bind waste particles together; membrane ultrafiltration and reverse osmosis, in which waste is trapped when the water passes through a membrane; and ion exchange, in which specially formulated resins capture dissolved metal salts. Other treatment techniques cited by Elwood Forsht, chief of the chemicals and metals branch at the EPA, include electrowinning, which uses electrolysis to concentrate metallic ions in wastewater, and coolant recycling, a method that removes metal particles by centrifugal force and kills bacteria by pasteurization. Many metalworking operations create wastewater, including drilling, welding, soldering, surface finishing, electroplating, acid treatment, anodizing, assembly, and machining. Companies use wastewater treatment technologies to recycle their wastewater or clean it so that it meets EPA standards and can be discharged into a municipal waste system, thus avoiding high disposal costs.
- OSTI ID:
- 7001367
- Journal Information:
- Mechanical Engineering; (United States), Vol. 116:10; ISSN 0025-6501
- Country of Publication:
- United States
- Language:
- English
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54 ENVIRONMENTAL SCIENCES
METAL INDUSTRY
MATERIALS RECOVERY
WASTE WATER
WATER TREATMENT
WATER TREATMENT PLANTS
HYDROGEN COMPOUNDS
INDUSTRY
LIQUID WASTES
MANAGEMENT
OXYGEN COMPOUNDS
PROCESSING
WASTE MANAGEMENT
WASTE PROCESSING
WASTES
WATER
320305* - Energy Conservation
Consumption
& Utilization- Industrial & Agricultural Processes- Industrial Waste Management
540220 - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)