Fan Dongqin, M.S.M. Jetten * and M.C.M Vanrecht **
Department of Bioengineering, School of Applied Science, Delft University, Netherlands. Technology, Julianalaan 67, Delft, Netherlands
2828 (e-mail: mcmvanloosdrecht @ tnw.tudelft.nl)
* Current address: Department of Microbiology, University. Nijmegen, Netherlands 6525 ED lens Nijmegen's
Netherlands
** correspondent
Abstract Ammonium treatment of rich wastewater, such as sewage sludge biogas digesters, can be significantly
When the new improvement process is introduced, biotechnology is introduced. In this paper, combined with partial
nitrification process (nitrification? ) and anoxic ammonia oxidation (anaerobic ammonia oxidation? ) process treatment
evaluation of ammonia-rich influent. In the process of this merger, the recycling of sludge < P > wine from sewage treatment plant Rotterdam Dokhaven was studied. Salon process operation has been stable for more than 2
For many years, continuous aeration was carried out in ten liters of CSTR, with HRT as one day. Ammonia water was converted into 53% and nitrite only in sludge liquor < P >. No nitrate formation was observed during the test. The
salon process of effluent is very suitable as an anaerobic ammonia oxidation reactor with influent. In the process of anaerobic ammonium oxidation
, it is operated as SBR process of granular sludge. More than 8% of ammonia is converted into 1.2 kgN/m3 of natural gas load per day. Planctomycete-like bacteria are the main anaerobic ammonia oxidation reactor in mixed society, and only a small proportion of the population is oxidized by aerobic ammonia. This shows that ammonia-oxidizing bacteria did not < P > accumulate in SBR process during sewage salon. During the test, it is shown that the combined Sharon anaerobic ammonia oxidation system can work stably and the long-term process is ready for full implementation.
partial nitrification of key words; Nitrite; Aerobic and anaerobic ammonia oxidation; Sludge wine; Salon
Anaerobic Ammonia Oxidation
Introduction
Ammonia is one of the most important components of wastewater, which has been removed
and can be discharged from hospital. This is mainly to realize the complete oxidation of < P > nitrate, and the subsequent reduction of nitrate to < P > sacrificed COD under the condition of two-gas hypoxia. Using oxygen (air) to oxidize < P > ammonium in wastewater requires a lot of energy. In addition, a large amount of wastewater with COD as < P > is often limited, which makes it necessary to buy methanol in the form of COD.
Due to the age required for long-term sludge nitrification, large reactors (area requirements)
are necessary. Some of these limitations may bypass two processes of applying new biotechnologies recently developed: partially nitrated ammonia
rapidly increasing nitrified nitrite and denitrified nitrite, and using ammonia water
as an electron donor in natural gas. In this way, nitrogen is removed with minimum COD and energy.
A denitrification process rarely uses energy and COD
A basic process in Figure 1 proposes the concept of Salon anaerobic ammonia oxidation, which has been partially
implemented in a sewage treatment plant in Dokhaven, Rotterdam, the Netherlands, and is depicted. That
sludge circulating water usually contains 15% of the total load of the factory and only 1% of the hydraulic load. Ammonia water (1-1.5 gNH4 nitrogen/liter) is used as an electron donor in sludge wine by deleting < P > part of ammonium oxide as nitrite, and the nitrite as denitrified ammonium < P > after. These processes, which are essential for these two systems, have recently been
Water Science and Technology: No.1, Vol.44, pp.153-16? Nuremberg Press 21
153
In our Development Department: Salon and Anaerobic Ammonia Oxidation Process (Fan Lei Hutt
and Jetten 1998). In this way, the required nitrogen removal of oxygen is reduced by < P > 6%, there is no required chemical oxygen demand, the sludge output is marginalized, and the net carbon dioxide emission is greatly reduced < P >.
ammonia oxidation has no biomass energy retention
Sharon process (Hellinga et al. , 1997, 1999) without any biological reservation.
this means that sludge age (broadcast and television) is equal to hydraulic retention time (HRT). In
such a system, the effluent concentration only depends on the growth rate (1/SRT) of
bacteria, and the independent influent concentration. During the
salon operation, when the temperature exceeds 25℃, the rapidly growing ammonium oxidizers
are selected. However, these organisms have low affinity ammonium (affinity constant
2-4 mgNH4 nitrogen/liter). In practice, this will lead to the application of microorganisms to wastewater with relatively high ammonium concentration (? 5-1 mg/L). Therefore, Sharon
process is the key to treat wastewater with high concentration of ammonium ("5mg/L) rather than effluent quality.
The sludge digestion wastewater from Salon process is at 3-4 degrees Celsius
with no microbial biomass, so the dilution rate can be set at such an interest rate
The growth rate of ammonium nitrate oxidizer is not fast enough to stay in the reactor, while nitrite oxidizing bacteria
are being washed out. Sharon has been
digesting wastewater in the operating laboratory (2-liter reactor) for more than 2 years. This is directly expanded to full scale (18 cubic meters)
where it is going as expected (Mulder, etc. , 21).
The biomass of mixed microbial community was investigated in Salon
Molecular ecological technology (Logemann et al. , 1998). Total DNA extraction
from biological samples and primers used for PCR amplification, with universal bacteria. The PCR products of
were used to construct a gene bank. The analysis showed that the dominant clone (69%) was a very similar nitrifying Alcaligenes. This is the quality < P > and quantitative confirmation of two independent microscopic methods. The presence of
about 5-7% ammonia-oxidizing bacteria indicates the use of targeted fluorescent oligonucleotide probes (NEU653) with 16 counties rRNA genes.
Alcaligenes nitrifying has been described in literature as a fast-growing nitrifying bacterium that can
increase the concentration of ammonium and nitrate at a high level. American Fan Dongqin et al. 154
fig. 1 ammonia is generated in the salon process of Dokhaven
in Rotterdam, a sewage treatment plant, Nitrite mixture
When Sharon reactor is used to provide feed, only 5%
ammonium needs to be converted into nitrite:
ammonium sulfate < p p>++HCO3
-+.75 oxygen → .5 ammonium sulfate
+.5 nitrogen dioxide
-+carbon dioxide+1.5 water. Increasing the base is necessary because anaerobic digestion caused by sludge
wine will generally contain enough alkalinity (sodium bicarbonate in the form of
) to make up for the acid produced if only 5% of ammonium nitrate is
oxidized.
Salon, which may produce 5:5 mixed ammonium and nitrite, has been evaluating the extensive laboratory system, and sludge wine
comes from Rotterdam as the influent of sewage treatment plant. The results (Figure 1, Table 1) show that in fact < P > a stable transformation is possible. The ammonium oxide is 53%, and the nitrite is under the load of 1.2kg nitrogen < P > per cubic meter per day, without any necessary pH control. The
of ammonia-oxidizing bacteria can tolerate high concentration of nitrite (".5g nitrogen dioxide/L, at pH 7).
it can be sensitive to the process of ammonium/nitrite ratio
it is affected by the changing reaction pH value between 6.5 and 7.5. In this way, the accuracy is < P >, which can be obtained in the process of fully denitrifying anaerobic ammonia oxidation. During the experiment
, the possibility of several successful tests (first stage 3 and 5) was evaluated
The required ammonium/nitrite ratio was set by using the control method of pH value
Fan Dongqin et al.
155
Table 1 The conversion Sharon reactor is under test. The water inflow is the
parameter of centrate's sludge-digesting centrifuge in Dokhaven, Rotterdam (hydraulic retention time = radio and television = 1 day)
period of steady-state operation of the unit (24 four)
influent ammonia nitrogen kg/ m3 1.18 .14 1.17 .25
influent nitrogen oxide kg/m3 < M3 .55 .1.6 .2
wastewater nitrogen dioxide kg/m3 .6 .1.55 .2
wastewater nitrate nitrogen kg/m3
pH 6.7 .36.8 1.2
NH4-N conversion% 53 4. Hydraulic residence time and radio and television people
both sides of the day. Period 1: Start-up period, period 2,4 and 6 run stably withot pH control, and period 3
5 test period, evaluate the pH value pair conversion affecting the reactor. (1) Ammonia-nitrogen; ? : NH4-N output; ? Nitrogen dioxide nitrogen comes out)
water comes out. Under the principle of this control, the use of chemostat system: the sewage with constant dilution < P > interest rate substrate concentration will not change. It has been shown that ammonia, while
then ammonium
+ is the active substrate (Hellinga et al. , 1999). If the pH value increases, the ammonium level will be reduced by continuously < P > ammonia content. That is, by increasing the quantity of pH value < P >, the ammonium in wastewater drops rapidly. The results show that there is a < P > during the 3rd and 5th days, and a slight change in pH value has led to a large number of changes in the ammonium/nitrite ratio.
Uncontrolled conversion is already a total "9% available", so it is doubtful
whether it is economically worthwhile to additionally clear the pH control.
in the process of anaerobic ammonia oxidation
in the process of anaerobic ammonia oxidation, it is a process, in which ammonium dihydrogen is converted into nitrite under anoxic conditions
as an electron donor:
ammonium sulfate
+nitrogen dioxide
- → nitrogen+2 water (2)
The anaerobic ammonia oxidation catalytic reaction of this bacterium is autotrophic, which means that. , 1998). In the process of anaerobic ammonia oxidation, it was found that there was a spirit of experimental factory installation < P >, Jin (Mulder et al. In 1992, 1995). The process of biological properties can
show that the activity of anaerobic ammonia oxidation is inactivated by gamma ray irradiation,
heating the sludge of experimental plant or incubating various inhibitors (Jetten et al. , 1998).
Cells reversibly inhibit oxygen concentration as low as .5% air saturation
( Strous et al. In 1997, Jetten et al. , 1998). In addition, it has been pointed out that nitrite < P > is the preferred electron acceptor process.
Bacteria are responsible for the sequencing batch reactor with rich processes
Ammonium, nitrite and sodium bicarbonate in the synthetic medium (Strous et al. ,
1998, 1999). The growth rate (doubling time 11 days) and growth rate (.11 Jin Shi/
gNH4-n) of organisms are very low. Obvious advantages of anaerobic ammonia oxidation process, so < P > low sludge production. However, the use of an effective system, such as the biomass retention
SBR system, will be necessary to maintain all the biomass in the anaerobic ammonium oxidation reactor and < P > will need to produce enough biomass as long as the start-up time. Specific height is the highest
nitrogen consumption rate (.82 nephritis/gVSS.day), very high affinity ammonia and
nitrite (statement ".1 mg? /L) and particle growth keep high-efficiency biomass energy, and
make it possible to design a very compact device.
Previous studies have shown that some nitrifying species can also
ammoxidation and nitrite as electron acceptors. The reaction rate is less than .8 nephritis/gVSS.day under the condition of hypoxia or oxygen limitation
(Bok et al. , 1995; Jetten
et al. , 1999; Yi, Verstraete, 1998; Schmidt, Bok, 1997; Schmidt, Bok, 1998; Zart,
Bok, 1998). Our culture with anaerobic ammonia oxidation activity is much higher than this ratio.
In addition, our culture is dominant by 7% or more, which is a typical microorganism.
The results show that members with three attributes are in the same order
planctomycetes: the bud of cell division, the
present cell wall with internal cell fragments, and the membrane with dyslipidemia
(Strous et al. , 1999). The tentative name
Brocadia Anammoxidans based on 16S RNA analysis has proposed the anaerobic ammonia oxidation
process as a responsible organism.
Recently, a large amount of nitrogen loss (Table 2) has been reported in several sewage treatment systems (Helmer and Art, 1998; Hippen and so on. , 1996; Siegrist et al. In 1998, schmid and other
bases. , 2). With very high nitrogen load and limited air supply, a large amount of < P > ammonia loses gaseous nitrogen compounds. Under such system conditions, Fan Dongqin and others in the United States may be in advance. 156
Weil can * * * survive in these two nitrifying and anaerobic ammonia oxidizing bacteria
(schmid et al. , 2). With the help of specific hybridization probes, it is determined that < P > anaerobic.