Field evaluation of arsenic and selenium removal by iron coprecipitation: Final report

Technical Report · Fri May 01 04:00:00 EDT 1987

OSTI ID:6572023

Merrill, D T; Manzione, M A; Petersen, J J; Parker, D S

The priority trace elements arsenic and selenium were removed from ash pond effluent by iron coprecipitation in a field study at the Carolina Power and Light Company's Roxboro Station. The study's broad objectives were to verify previously-derived laboratory results, confirm the technology's technical and economic feasibility, and develop information that could be used to make preliminary designs and cost estimates for full-scale treatment plants. The technology was tested at pilot scale in a continuous-flow system under field conditions. A chemical coagulation system was used of the kind typically employed for municipal and industrial water treatment. Arsenic was strongly removed (90% and above) with moderate iron dosages (14 mg/l to 28 mg/l Fe). Selenium removals were lower (56 to 80%) under comparable chemical conditions. Arsenic and selenium removals were strongly affected by solution pH. Testing indicated that process sludges can be gravity thickened, then dewatered with filter presses to 25 to 35% solids. Dewatered pilot sludges were determined to be not hazardous, as defined by Extraction Procedure (EP) toxicity test criteria. Costs to treat wastes similar to Roxboro ash pond effluent are estimated to be $345/million gallons (9.1 cents/cu m). However, costs will be different for plants that have wastewaters that differ in composition and volume from Roxboro ash pond effluent, or plants that have different treatment goals. Examples are provided to illustrate methods that can be used to make preliminary designs and cost estimates for different treatment scenarios. 30 refs., 62 figs., 29 tabs.

• Research Organization: Brown and Caldwell, Pleasant Hill, CA (USA); Electric Power Research Inst., Palo Alto, CA (USA)
• OSTI ID: 6572023
• Report Number(s): EPRI-CS-5187; ON: TI87920419
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010800* -- Coal
Lignite
& Peat-- Waste Management
ARSENIC
CONTROL
COPRECIPITATION
COST
DATA
ELEMENTS
EXPERIMENTAL DATA
FOSSIL-FUEL POWER PLANTS
HYDROGEN COMPOUNDS
INFORMATION
IRON
LIQUID WASTES
METALS
NUMERICAL DATA
OXYGEN COMPOUNDS
POLLUTION CONTROL
POWER PLANTS
PRECIPITATION
REMOVAL
SELENIUM
SEMIMETALS
SEPARATION PROCESSES
THERMAL POWER PLANTS
TRACE AMOUNTS
TRANSITION ELEMENTS
WASTE WATER
WASTES
WATER
WATER TREATMENT