Premium
Evaluation of a Sulfur‐Thiobacillus denitrificans Nitrate Removal System
Author(s) -
Sikora L. J.,
Keeney D. R.
Publication year - 1976
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1976.00472425000500030016x
Subject(s) - effluent , denitrification , sulfur , chemistry , nitrate , sulfate , environmental chemistry , contamination , denitrifying bacteria , nuclear chemistry , environmental engineering , nitrogen , environmental science , ecology , biology , organic chemistry
An evaluation of sulfur‐ Thiobacillus denitrificans nitrate removal system as a means of denitrifying nitrified septic tank effluent was conducted. Duplicate 10 by 64 cm columns were filled with a 1/1 mixture (wt/wt) of elemental S (>2 mm) and dolomite chips (1 cm), and were pretreated by recycling an enrichment culture of T. denitrificans ATCC 23642 through the columns for 3 days. Continuous passage of the nitrified septic tank effluent (column influent) containing 40 µ g NO 3 − ‐N/ml through the columns resulted in nearly complete NO 3 − removal in 3.3 hours at steady‐state conditions (23C). Statistical analyses indicated that the denitrification kinetics closely resemble first order in the range of NO 3 − concentrations employed. Oxidation‐reduction potentials (Pt black electrodes) ranged from +160 to +300 mV. Analysis the gases produced showed that N 2 was present in highest concentration. Sulfate was the major S end product and was present at relatively high concentrations (90 µ g SO 4 2− ‐S/ml). A significant decrease in inorganic C occurred with depth in the columns while changes in organic C content were insignificant. A significant linear relationship was obtained between decreases in (NO 3 − + NO 2 − )‐N and production of S0 4 2− ‐S. Passage of column effluent through 10 by 60 cm Plainfield sand columns did not significantly decrease SO 4 2− levels. While use of this NO 3 − removal system appears promising, SO 4 2− contamination of the ground water may limit its applicability.