Remediation of nitrate-contaminated surface water using sulfur and limestone autotrophic denitrification processes

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:585783

Flere, J M; Zhang, T C ^[1]

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1. Univ. of Nebraska, Omaha, NE (United States). Dept. of Civil Engineering

The feasibility of using the sulfur/limestone autotrophic denitrification (SLAD) process as an in situ method for remediation of nitrate-contaminated surface water was investigated. Four bench-scale pond systems with working volumes of 21.4 liters each and hydraulic retention time (HRT) of 30 days were operated under mixed conditions. Under mixed (aerobic) conditions, with the addition of alkalinity to raise pH, NO{sub 3}{sup {minus}}-N removal in the SLAD ponds was 85--100%, while the control reactor showed negative removal. Sulfate production under mixed conditions was between 1,000--2,500 mg/l SO{sub 4}{sup 2{minus}}, which shows that 40--60 mg/l of SO{sub 4}{sup 2{minus}} is produced for every 1 mg/l of NO{sub 3}{sup {minus}}-N reduced. Although the system is very efficient in removing nitrates under simulated surface water conditions, the sulfate production makes the process questionable for use under aerobic conditions. However, batch experiments under anaerobic conditions demonstrate that system maybe very efficient in removing nitrate while not producing insufferable amounts of sulfates.

• OSTI ID: 585783
• Report Number(s): CONF-9705104--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
BACTERIA
BIODEGRADATION
IN-SITU PROCESSING
LIMESTONE
NITRATES
REMEDIAL ACTION
SULFATES
SURFACE WATERS