Acetate and ethanol as potential enhancers of low temperature denitrification in soil contaminated by fur farms: a pilot-scale study.
Ethanol and acetate were examined as potential candidates to enhance denitrification at low temperature in soils contaminated by fur farms. Five pilot-scale sand and gravel columns with a top layer of soil from a fur farm were set up and fed with nitrate-containing water (influent concentration of 100 and 200 mg L(-1)) for 459 days at 6+/-2 degrees C. Two of the columns also received acetate and two other ethanol while one received no additional C-substrate. During the experiment, various C:N-ratios were tested to find the most optimal concentration of the added C-substrates, and effluent concentrations of nitrate, nitrite, and TOC were monitored. At the end of the experiments, soils in the columns were unpacked and the soils were used to measure a pattern of enzyme activities and the rates of denitrification in microcosms. The fur farm contaminated soil appeared to harbour a good intrinsic potential for denitrification, which could be greatly enhanced by the introduction of ethanol or acetate. Consequently, in the C-substrate-fed columns, 95-100% of the influent nitrate was removed after an acclimatization period of some weeks. Ethanol with C:N-ratio of ca. 6 at the nitrate level 200 mg L(-1) proved to be the most promising candidate to be used in field trials.
Martin
Derek
D
Finnish Environment Institute, P.O. Box 140, FI-00251 Helsinki, Finland.
Salminen
Jani M
JM
Niemi
R Maarit
RM
Heiskanen
Ilse M
IM
Valve
Matti J
MJ
Hellstén
Pasi P
PP
Nystén
Taina H
TH
D000085:Acetates / Q000737:chemistry; D000818:Animals; D000829:Animals, Domestic; D003080:Cold Temperature; D000431:Ethanol / Q000737:chemistry; D009566:Nitrates / Q000302:isolation & purification*; D009573:Nitrites / Q000302:isolation & purification; D012989:Soil Pollutants / Q000302:isolation & purification*
D000085:Acetates; D009566:Nitrates; D009573:Nitrites; D012989:Soil Pollutants; D000431:Ethanol