Release of nitrous oxide (N2O) from denitrifying activated sludge caused by H2S-containing wastewater: quantification and application of a new mathematical model

1998 ◽  
Vol 38 (1) ◽  
pp. 237-246 ◽  
Author(s):  
Barbara Schönharting ◽  
Ruxandra Rehner ◽  
Jörg W. Metzger ◽  
Karlheinz Krauth ◽  
Manfred Rizzi
Keyword(s):  
Mathematical Model ◽  
Nitrous Oxide ◽  
Hydrogen Sulfide ◽  
Activated Sludge ◽  
Sulfide Concentration ◽  
Oxide Reduction ◽  
Strong Inhibition ◽  
Wide Range ◽  
Nitrous Oxide Reduction ◽  
Denitrification Process

A new mathematical model is presented which describes the denitrification process by dynamic material balance equations. In this approach the kinetic rate expressions of the single denitrification steps and the observed strong inhibition of nitrate on nitrite and nitrous oxide reduction are based exclusively on fundamental enzyme kinetics. This allows a prediction of the denitrification process in a wide range of wastewater-relevant nitrate concentrations. The model was successfully applied to the description of the kinetic behavior of a standardized denitrifying activated sludge system. Furthermore the experimentally investigated influence of hydrogen sulfide was quantified by extending the model with a non-competitive inhibition mechanism involving all steps of the denitrification process. The inhibitory effect was related to the free membrane-permeable hydrogen sulfide concentration. This means that the extent of its inhibition depends additionally on the pH-value. Even very low hydrogen sulfide concentrations lead to a strong inhibition of nitrous oxide reduction and therefore to a high release of nitrous oxide from wastewater treatment plants.

Sulfide alleviation of acetylene inhibition of nitrous oxide reduction by Flexibacter Canadensis

1992 ◽  
Vol 38 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Alison M. Jones ◽  
Roger Knowles
Keyword(s):  
Nitrous Oxide ◽  
Pseudomonas Stutzeri ◽  
Sulfide Concentration ◽  
Oxide Reduction ◽  
Acetylene Inhibition ◽  
Experimental Conditions ◽  
Nitrous Oxide Reduction ◽  
Pure Cultures ◽  
Dissolved Sulfide ◽  
Key Words Denitrification

The role of sulfide in the relief of acetylene inhibition of nitrous oxide reduction by Flexibacter canadensis was studied. In this organism, the reversal of acetylene inhibition of nitrous oxide reduction is correlated with a 90% decrease in the dissolved sulfide concentration. The fate of this sulfide is not known, since there was no concomitant increase in acid-soluble sulfide and volatile sulfur compounds were not detectable by flame photometric gas chromatography. Of the other sulfur-containing compounds tested (sulfate, sulfite, thiosulfate, cysteine, methionine, dithionite, dithionate, and glutathione), only cysteine relieved the acetylene block of nitrous oxide reduction by F. canadensis. Under similar experimental conditions, other denitrifiers tested (Azospirillum brasilense, Pseudomonas stutzeri, and a Flavobacterium isolate) failed to reduce nitrous oxide in the presence of sulfide and an inhibitory concentration of acetylene. It is concluded that both biological and abiological factors contribute to the sulfide relief of acetylene inhibition of nitrous oxide by pure cultures of F. canadensis. Key words: denitrification, nitrous oxide, acetylene, sulfide, Flexibacter canadensis.

Micromolar sulfide concentrations alleviate acetylene blockage of nitrous oxide reduction by denitrifying Pseudomonas fluorescens

1987 ◽  
Vol 33 (11) ◽  
pp. 1001-1005 ◽  
Author(s):  
Jan Sørensen ◽  
Lone K. Rasmussen ◽  
Isao Koike
Keyword(s):  
Nitrous Oxide ◽  
Pseudomonas Fluorescens ◽  
Prolonged Exposure ◽  
Transition Period ◽  
Complete Inhibition ◽  
Sulfide Concentration ◽  
Resting Cells ◽  
Oxide Reduction ◽  
Nitrous Oxide Reduction ◽  
Acetylene Blockage

The influence of low sulfide concentrations on nitrous oxide (N2O) reduction by resting cells of denitrifying Pseudomonas fluorescens was studied. Nitrous oxide reduction was inhibited by sulfide with an apparent Ki value of 1 μM. The inhibition was immediate and was readily alleviated by a short treatment of the cells with O2. In the absence of sulfide, addition of acetylene (0.2 kPa C2H2 or more) caused an immediate and complete inhibition of N2O reduction. However, when the sulfide concentration was higher than 2 μM, addition of C2H2 (range of 0.7–13 kPa tested) gave incomplete inhibition of the N2O reduction. Complete inhibition was in this case only obtained after prolonged exposure to the C2H2. The transition period with incomplete C2H2 blockage was shortest (about 20 min) for relatively high C2H2 applications (about 10 kPa). Incomplete C2H2 blockage was seen only when sulfide was added to the cell suspensions before C2H2. The data may relate to the low efficacy of the "acetylene blockage technique" when the assay is applied to [Formula: see text]-deficient and reducing environments.

High Temperature Hydrogen Sulfide Corrosion★

CORROSION ◽  
1956 ◽  
Vol 12 (1) ◽  
pp. 22-32 ◽  
Author(s):  
E. B. BACKENSTO ◽  
R. D. DREW ◽  
C. C. STAPLEFORD
Keyword(s):  
Hydrogen Sulfide ◽  
High Temperature ◽  
Carbon Steel ◽  
Carbon Steels ◽  
Effect Of Temperature ◽  
Sulfide Concentration ◽  
Wide Range ◽  
Sulfide Corrosion ◽  
Hydrogen Sulfide Corrosion ◽  
Hydrogen Sulfide Concentration

Abstract High temperature hydrogen sulfide corrosion of carbon steel and low chrome alloys has become a serious problem in the petroleum industry in connection with the increasing use of high pressure hydrogenation and dehydrogenation processes for upgrading petroleum fractions. The effect of temperature, pressure and hydrogen sulfide concentration on the corrosion rate of a wide range of commonly used carbon steels and alloys has been determined in laboratory tests. It has been established that the low chrome alloys (up to 5 percent chromium) which have been used to combat sulfur corrosion in fractionation and cracking equipment, show little or no advanage over carbon steel in resisting attack by hydrogen sulfide. Of the conventional alloy steels tested, only the 18-8 chrome nickel and higher alloys have shown good resistance to this type of corrosion over a wide range of pressure, temperature and hydrogen sulfide concentration. It was found that aluminum coated steels also showed very good corrosion resistance. Three methods were proposed for minimizing hydrogen sulfide corrosion: (1) Reduction of hydrogen sulfide in process streams, (2) Use of chrome-nickel alloys, and (3) Protection of metals by aluminum coating.

scholarly journals Beyond denitrification: the role of microbial diversity in controlling nitrous oxide reduction and soil nitrous oxide emissions

2021 ◽  
Author(s):  
Jun Shan ◽  
Robert A. Sanford ◽  
Joanne Chee‐Sanford ◽  
Sean Khan Ooi ◽  
Frank E. Löffler ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Microbial Diversity ◽  
Nitrous Oxide Emissions ◽  
Oxide Reduction ◽  
Nitrous Oxide Reduction
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