Six years' practical experience with aerobic/anoxic deammonification in biofilm systems

2001 ◽  
Vol 44 (2-3) ◽  
pp. 39-48 ◽  
Author(s):  
A. Hippen ◽  
C. Helmer ◽  
S. Kunst ◽  
K.-H. Rosenwinkel ◽  
C. F. Seyfried
Keyword(s):  
Practical Experience ◽  
Pilot Scale ◽  
High Nitrogen ◽  
Industrial Plants ◽  
Carbon Demand ◽  
Operation Stability ◽  
Operation Results ◽  
Micro Organisms ◽  
Nitrogen Elimination ◽  
Nitrogen Contents

Nitrogen elimination through autotrophic micro-organisms is currently in the focus of research projects on the treatment of wastewater with high nitrogen contents, for instance to be able to develop and fix dimensioning parameters for purposeful application. In fact, several industrial plants have already shown for some years that the steady operation of nitrogen elimination without carbon demand is possible. Due to the low growth rates of the participating micro-organisms, these processes can be found in particular in biofilm systems, which also allow for the simultaneous running of the two basic processes. In the following, we will discuss on the basis of the operation results of industrial and pilot-scale plants the operation stability of the aerobic/anoxic deammonification, and explain which experiences are available in particular for conversion in biofilm systems.

One-stage deammonification: nitrogen elimination at low costs

2001 ◽  
Vol 1 (1) ◽  
pp. 71-80 ◽  
Author(s):  
C.F. Seyfried ◽  
A. Hippen ◽  
C. Helmer ◽  
S. Kunst ◽  
K-H Rosenwinkel
Keyword(s):  
Direct Conversion ◽  
High Nitrogen ◽  
Industrial Plants ◽  
Nitrogen Loads ◽  
Operation Results ◽  
Micro Organisms ◽  
Biological Nitrogen ◽  
Nitrogen Elimination ◽  
Nitrogen Contents ◽  
Elementary Nitrogen

Biological nitrogen elimination used to purify wastewater with high nitrogen contents can become a major cost factor, in particular when the wastewater in question contains only little amounts of biologically degradable carbon compounds. The use of new biological conversion methods and the application of compact operation technology, however, does allow us to save operation and investment costs. Currently, the focus of scientific interest is on deammonification, that is the direct conversion of ammonia into elementary nitrogen by autotrophic micro-organisms, because in contrast to conventional nitrification/denitrification this method requires considerably smaller amounts not only of carbon, but also of oxygen. Moreover, the use of compact biofilm technology makes it possible to considerably reduce the reaction tank volume. In the following we will present the operation results of both industrial plants and laboratory-scale units for the treatment of wastewater with high nitrogen loads, results which unequivocally show the favourable cost-effectiveness of the mentioned method combination and thus the economic viability inherent in the purposeful industrial utilisation of this technology.

Degradation of Oil by Land Disposal

1987 ◽  
Vol 19 (8) ◽  
pp. 99-105 ◽  
Author(s):  
G. Tesan ◽  
D. Barbosa
Keyword(s):  
Nutrient Availability ◽  
Filter Cake ◽  
Test Procedure ◽  
Pilot Scale ◽  
Effluent Treatment ◽  
Biological Degradation ◽  
Chemical Fertilizers ◽  
Land Disposal ◽  
Micro Organisms

The work presented consists of a test procedure applied at a pilot scale using soil as a biological degradation agent. The experiments described were carried out with oily residues considered as wastes difficult to degrade by other means. The tests were applied to filter cake with activated clay containing 40% oil and oily residues from re-refining of lubricants to give white oils and vaseline. The effect of the amount of moisture is evaluated using a mechanical stirrer to improve the interaction between the wastes and microorganisms. The following are also evaluated: nutrient availability; incorporation of micro-organisms into the soil; introduction of chemical fertilizers; and, injections of sludge from effluent treatment plants.

Characteristics of Dynamic Recrystallization during Hot Deformation for High Nitrogen Stainless Steels

2012 ◽  
Vol 715-716 ◽  
pp. 115-121
Author(s):  
Hai Wen Luo ◽  
Xu Dong Fang ◽  
Rui Zhen Wang ◽  
Zhan Yin Diao
Keyword(s):  
Dynamic Recrystallization ◽  
Stainless Steels ◽  
Hot Deformation ◽  
Strain Rates ◽  
Peak Strain ◽  
High Nitrogen ◽  
Flow Curves ◽  
Grain Sizes ◽  
Nitrogen Contents ◽  
High Nitrogen Stainless Steel

Dynamic recrystallization was studied for the stainless steels with nitrogen contents of 0.56% to 1.08% during hot deformation at temperatures of 900~1200 with strain rates ranging from 0.003 to 42 s-1. It was found that flow stress could increase remarkably with increasing nitrogen content. Flow curves during the deformation by 0.1~42/s at temperatures of 900~1200°C show a single peak, indicating the occurrence of dynamic recrystallization during deformation. The peak strain seems to decrease with increasing N content, suggesting that higher content of N facilitates dynamic recrystallization. The quenched microstructures were analyzed by optical microscopy, EBSD and TEM. The recrystallized grain sizes on the quenched specimens were measured and its dependence on temperature and strain rate was analyzed. At high temperature, continuously dynamically recrystallized microstructures were observed; whilst at low temperature, necklace-like partially recrystallized microstructures were found. Key words: High nitrogen stainless steel; dynamic recrystallization; stress-strain curves

La corrosion par piqûres d'aciers inoxydables austéno-ferritiques dans l'eau de mer synthétique

1996 ◽  
Vol 84 ◽  
pp. 23-30
Author(s):  
I. Trigui ◽  
H. Sidhom ◽  
C. Braham ◽  
J. Lédion
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Sea Water ◽  
Phase Behaviour ◽  
High Nitrogen ◽  
Electrochemical Tests ◽  
Analysis Techniques ◽  
Pitting Corrosion Resistance ◽  
Nitrogen Contents ◽  
Image Analysis Techniques

Duplex stainless steels crevice and pitting corrosion resistance in synthetic sea water is studied. Conventional electrochemical tests and image analysis techniques are used. Three commercial steels are examined. The forged material has the best behaviour, whereas cast materials, in spite of their high nitrogen contents, have a lower corrosion resistance. Micrographic studies show a good correlation between pittings distribution and inclusions distribution and reveal that gamma phase behaviour is more affected by inclusions. The metallurgic purity of products seems to be the most important parameter in this type of corrosion. Consequently, the PREN index is questionable in pitting corrosion grading of these steels because it does not take into acount the inclusions effect.

Tensile Fracture of the Welded Joints of Austenitic High-Nitrogen 05Kh22AG16N8M Steel with Various Nitrogen Contents

2021 ◽  
Vol 2021 (10) ◽  
pp. 1299-1303
Author(s):  
V. M. Blinov ◽  
E. I. Lukin ◽  
E. V. Blinov ◽  
M. A. Samoilova
Keyword(s):  
Welded Joints ◽  
Tensile Fracture ◽  
High Nitrogen ◽  
Nitrogen Contents

Use of immobilised bacteria for the wastewater treatment – examples from the sugar industry

2006 ◽  
Vol 53 (3) ◽  
pp. 9-15 ◽  
Author(s):  
H.-J. Jördening ◽  
K. Hausmann ◽  
B. Demuth ◽  
M. Zastrutzki
Keyword(s):  
Wastewater Treatment ◽  
High Performance ◽  
Sugar Industry ◽  
Pilot Scale ◽  
Fluidized Bed Reactors ◽  
Reactor Volume ◽  
High Performance Systems ◽  
Pilot Scale Reactor ◽  
Nitrogen Elimination ◽  
Hydrolysis Of

This work focuses on the implementation of high performance systems to the wastewater treatment of sugar factories. For this purpose, systems with immobilised bacteria were studied. For the hydrolysis of organic matter and denitrification, fluidized bed reactors were used. The nitrification was studied with an airlift reactor system. Both hydrolysis and nitrogen elimination were investigated on laboratory and pilot scales in sugar factories. Although with porous materials higher biomass concentrations are attainable for the hydrolysis (up to 55 kg/m3), for economical reasons sand was used (22.5 kg/m3) for the pilot scale-study. With a pilot-scale reactor (volume 1 m3) the maximum sucrose conversion rate achieved with sand in the first campaign was 52 kg/(m3 d). For the nitrogen elimination on the pilot scale, a system with denitrification and nitrification was combined. The highest performance for the nitrification (reactor volume: 0.68 m3) with pumice as support material was 1.2 kg NH4-N/(m3 d), limiting the whole system. The denitrification rate (reactor volume: 0.12 m3) was four times higher (3.5–5 kg NO3-N/(m3 d). Rules of the modelling of the system are discussed.

Large Scale Anaerobic-Aerobic Treatment of Complex Industrial Waste Water Using Biofilm Reactors

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1427-1436 ◽  
Author(s):  
J. J. Heijnen ◽  
A. Mulder ◽  
R. Weltevrede ◽  
J. Hols ◽  
H. L. J. M. van Leeuwen
Keyword(s):  
Industrial Wastewater ◽  
Large Scale ◽  
Pilot Scale ◽  
Rate Process ◽  
Practical Application ◽  
Industrial Waste Water ◽  
Biofilm Reactors ◽  
Micro Organisms ◽  
Production Problems ◽  
Air Lift

Warm concentrated industrial wastewaters are preferably treated in an anaerobic reactor for reasons of energy generation and low surplus sludge production. Problems to be solved in the practical application concern a low growth rate of the micro-organisms, their low settling rate process instability, and the need for after-treatment of the noxious anaerobic effluent which often contains NH4+ and HS−. The use of biomass immobilized on small suspended carriers (< 0.5 mm) has proven to be a suitable mean to overcome most of these problems. Results are presented on–pilot and full-scale pretreatment of industrial wastewater in an anaerobic 2-stage fluidized bed reactor for CH.-production.–laboratory and pilot scale post-treatment of the anaerobic effluent, which contains NH4+. and HS2− in an aerobic air-lift suspension reactor for the production of NO3− and SO4−.

Comparison of nitrogen elimination rates of different constructed wetland designs

2011 ◽  
Vol 64 (5) ◽  
pp. 1122-1129 ◽  
Author(s):  
Eriona Canga ◽  
Sara Dal Santo ◽  
Alexander Pressl ◽  
Maurizio Borin ◽  
Guenter Langergraber
Keyword(s):  
Constructed Wetland ◽  
Elimination Rate ◽  
Domestic Wastewater ◽  
High Strength ◽  
Pilot Scale ◽  
Synthetic Wastewater ◽  
Main Layer ◽  
Average Value ◽  
In Series ◽  
Nitrogen Elimination

In this paper the nitrogen elimination rates of different constructed wetland (CW) designs reported in literature are compared with those obtained for outdoor and indoor 2-stage vertical flow (VF) systems. The outdoor system is located about 150 km west of Vienna. Both stages are planted with Phragmites australis and the system has been operated for 4 years continuously. During this period the average value of the nitrogen elimination rate was 3.30 g N m−2 d−1. The indoor system comprises three parallel operated 2-stage VF systems and is located in the technical lab hall at BOKU University. The design of the indoor system resembles the outdoor system. However, there are a few differences: (1) the indoor systems are not planted, and (2) different filter media have been used for the main layer of the first stages. With the indoor system the highest nitrogen elimination rate achieved was 2.24 g N m−2 d−1 for the system with zeolite and impounded drainage layer. Similar results have been found in France for treating raw wastewater with VF and horizontal flow (HF) beds in series with nitrogen elimination rates of 1.89 and 2.82 g N m−2 d−1 for differently designed HF beds. The highest nitrogen elimination rates of 15.9 g N m−2 d−1 reported were for pilot-scale VF CWs treating high-strength synthetic wastewater (total nitrogen of 305 mg L−1 in the influent) in Thailand. It has been shown that the outdoor two-stage VF CW system has one of the highest nitrogen elimination rates of CWs treating domestic wastewater.

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