Stabilization of source-separated urine by biological nitrification process: treatment performance and nitrite accumulation

2012 ◽  
Vol 66 (7) ◽  
pp. 1491-1497 ◽  
Author(s):  
F. Y. Sun ◽  
W. Y. Dong ◽  
M. F. Shao ◽  
J. Li ◽  
L. Y. Peng
Keyword(s):  
Ammonia Oxidation ◽  
Great Influence ◽  
High Strength ◽  
Ammonia Concentration ◽  
Nitrite Accumulation ◽  
Batch Reactors ◽  
Ammonia Content ◽  
Free Nitrous Acid ◽  
Nitrification Process ◽  
Solids Retention

A laboratory study on nitrification of high-strength source-separated urine was conducted by means of sequencing batch reactors (SBR) and membrane bioreactors (MBR). The highest influent ammonia concentration for SBR and MBR reached more than 2,400 and 1,000 mg N/L, while the maximum pH was about 9 and 8.9, respectively. The ammonia oxidizing efficiency in both SBRs and MBRs was around 50%, which was restrained mainly by the deficiency of alkalinity in bulks. Meanwhile, the nitrite accumulation did also dominate in these two systems, and the major factor to inhibit the nitrite oxidization was thought to be the high free ammonia and free nitrous acid content in bulks. Hence, an ammonia nitrite solution was achieved with concentration ratio of 1:1; after that ammonia oxidation was restrained owing to the deficiency of alkalinity in urine. The temperature and influent ammonia content have no great influence on the nitrification process in both kinds of bioreactors. The nitrification can be progressed under a solids retention time (SRT) longer than 30 d; however, termination of ammonia oxidization was observed as the SRT fell below 20 d. The nitrifier biomass showed an excellent settleability, such that the suspended solids (SS) in effluent was of a low average, about 60 mg/L. This study on the stabilization of human urine will be useful to understand the process of urine separation from source.

Effect of long-term idle periods on the performance of sequencing batch reactors

2000 ◽  
Vol 41 (1) ◽  
pp. 105-113 ◽  
Author(s):  
E. Morgenroth ◽  
A. Obermayer ◽  
E. Arnold ◽  
A. Brühl ◽  
M. Wagner ◽  
...  
Keyword(s):  
Ammonia Oxidation ◽  
Heterotrophic Bacteria ◽  
Batch Reactor ◽  
Effective Control ◽  
Nitrite Accumulation ◽  
Gene Probe ◽  
Minor Effect ◽  
Batch Reactors ◽  
A Minor

Sludge storage can be used as an effective control handle to adjust plant capacity to large influent variations. The sequencing batch reactor (SBR) technology is well suited for temporary sludge storage because reactors can easily be switched off individually and operated in an idle mode. In this study experimental results on the effect of long term (weeks) idle periods on nitrogen removal are presented. The SBRs were operated with idle times ranging from 6 to 20 days. Batch experiments were performed where sludge was stored without the addition of any substrate for 7 weeks. In the SBRs, repeated long-term idle phases had only a minor effect on ammonia oxidation. The nitrite oxidation process was more sensitive to long idle phases resulting in temporary nitrite accumulation in the SBRs. Quantitative gene probe analyses demonstrated that the decay of ammonia oxidizers was slower than the decay of nitrite oxidizers which in turn decayed slower than heterotrophic bacteria.

Nitrite accumulation in the treatment of wastewaters with high ammonia concentration

2003 ◽  
Vol 48 (3) ◽  
pp. 135-141 ◽  
Author(s):  
W. Yang ◽  
J. Vollertsen ◽  
T. Hvitved-Jacobsen
Keyword(s):  
Nitrous Acid ◽  
Ammonia Oxidation ◽  
Ammonia Concentration ◽  
Pilot Scale ◽  
Nitrite Accumulation ◽  
Operational Parameters ◽  
Treatment Unit ◽  
Operational Conditions ◽  
Reject Water ◽  
Oxidation Rates

Different operational parameters of the nitritation process were investigated in both jar tests and pilot scale Sequencing Batch Reactors (SBRs). In the laboratory study, 100-1,200 mg N l-1 of ammonia was used. The pH and temperature were varied. Batch experiments were done on municipal sludge, pectin industrial sludge and sludge from a reject water treatment unit. Ammonia oxidation was observed with relative nitrite accumulations from 2% to 100% and ammonia oxidation rates from 0.01 to 0.58 g N g VSS-1 d-1. The nitritation process and relative nitrite accumulation were highly affected by pH, temperature and the sludge type. pH 8.0-8.5 and temperature 30°C were found favourable for the nitritation. Pilot SBR systems for treating reject water achieved 100% of nitrite accumulation under the operational conditions of pH 7.5-8.0, temperature 30°C and dissolved oxygen (DO) 1.0 mg l-1. Six months of operation revealed that pH regulations were essential to avoid the inhibitions by either free ammonia or nitrous acid. At an unionized ammonia concentration of approximately 20 mg NH3-N l-1, half of the normal nitritation ability still remained. Total inhibition occurred when the concentration of nitrous acid reached 3.0 mg HNO2-N l-1. However, both types of inhibitions were reversible in the SBR with a proper operation control. Stable and controllable nitritation could be achieved in pilot scale.

scholarly journals Comparison of Ammonium-oxidizing Bacterial Community Changes in Sludges from a Sewage and a Marine Fish Market Wastewater Treatment Plant During Enrichment Cultivation Under High Saline Conditions

2021 ◽  
Vol 43 (1) ◽  
pp. 79-87
Author(s):  
Jeongmi Kim ◽  
Jaecheul Yu ◽  
Soyeon Jeong ◽  
Yeonju Kim ◽  
Hyokwan Bae ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Ammonia Oxidation ◽  
Batch Reactor ◽  
Bacterial Species ◽  
Treatment Plant ◽  
High Strength ◽  
Wastewater Sludge ◽  
Nitrite Accumulation ◽  
High Concentration ◽  
Fish Market

Objectives:It is important to enrich and cultivate ammonia oxidation bacteria (AOB) in order to successfully treat nitrogen in high saline wastewater using a deammonification process. Two different inocula, a sewage sludge and a fish-market wastewater sludge, were cultivated to enrich AOB and compared the changes of microbial community.<br/>Methods:A sequential batch reactor (SBR) inoculated with the sewage sludge (PN1) enriched AOB under high-strength ammonium condition (500-3,000 mg NH4<sup>+</sup>-N/L) and then the salt concentration in the medium was gradually increased up to 20 g-NaCl/L. The other SBR seeded with the fish market wastewater sludge (PN2) was operated to enrich AOB directly under 20 g NaCl/L without any acclimation step.<br/>Results and Discussion:Both PN1 and PN2 successfully showed more than 60% of the nitrite accumulation efficiency at a high saline concentration of 20 g NaCl/L. At the level of the phylum, Proteobacteria containing nitrifying microorganisms became dominant in both PN1 and PN2. However, the most dominant bacterial species in PN1 and PN2 were Nitrosomonas eutropha (60.7%) and N. halophila (20.2%), respectively.<br/>Conclusions:Although different results of the most abundant AOB were shown in both sewage sludge and fish-market wastewater sludge conditions, nitritation was successfully developed even with wastewater containing high salinity. Therefore, in this study, both sludges can be applied for inoculation to the PN process for efficiently treating wastewater with high concentration of ammonium and saline.

Phase separation in sol gel-derived ceramic films of silica-zirconia, alumina-zirconia, and titania-zirconia system

1994 ◽  
Vol 52 ◽  
pp. 646-647
Author(s):  
J. Tong ◽  
L. Eyring
Keyword(s):  
Fracture Toughness ◽  
Phase Separation ◽  
Sol Gel ◽  
Great Influence ◽  
High Strength ◽  
Chemical Durability ◽  
Separation Method ◽  
Toughening Mechanism ◽  
Ceramic Films ◽  
Zirconia Toughened Alumina

There is increasing interest in composites containing zirconia because of their high strength, fracture toughness, and its great influence on the chemical durability in glass. For the zirconia-silica system, monolithic glasses, fibers and coatings have been obtained. There is currently a great interest in designing zirconia-toughened alumina including exploration of the processing methods and the toughening mechanism.The possibility of forming nanocrystal composites by a phase separation method has been investigated in three systems: zirconia-alumina, zirconia-silica and zirconia-titania using HREM. The morphological observations initially suggest that the formation of nanocrystal composites by a phase separation method is possible in the zirconia-alumina and zirconia-silica systems, but impossible in the zirconia-titania system. The separation-produced grain size in silica-zirconia system is around 5 nm and is more uniform than that in the alumina-zirconia system in which the sizes of the small polyhedron grains are around 10 nm. In the titania-zirconia system, there is no obvious separation as was observed in die alumina-zirconia and silica-zirconia system.

scholarly journals Nitrification Process in a Nuclear Wastewater with High Load of Nitrogen, Uranium and Organic Matter under ORP Controlled

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1607
Author(s):  
Mariano Venturini ◽  
Ariana Rossen ◽  
Patricia Silva Paulo
Keyword(s):  
Ammonia Oxidation ◽  
High Load ◽  
Nuclear Fuels ◽  
Monod Model ◽  
Nernst Equation ◽  
Nitrification Process ◽  
Real Wastewater ◽  
High Concentrations ◽  
Wastewater Samples ◽  
Very High

To produce nuclear fuels, it is necessary to convert uranium′s ore into UO2-ceramic grade, using several quantities of kerosene, methanol, nitric acid, ammonia, and, in low level, tributyl phosphate (TBP). Thus, the effluent generated by nuclear industries is one of the most toxic since it contains high concentrations of dangerous compounds. This paper explores biological parameters on real nuclear wastewater by the Monod model in an ORP controlled predicting the specific ammonia oxidation. Thermodynamic parameters were established using the Nernst equation to monitor Oxiders/Reductors relationship to obtain a correlation of these parameters to controlling and monitoring; that would allow technical operators to have better control of the nitrification process. The real nuclear effluent is formed by a mixture of two different lines of discharges, one composed of a high load of nitrogen, around 11,000 mg/L (N-NH4+-N-NO3−) and 600 mg/L Uranium, a second one, proceeds from uranium purification, containing TBP and COD that have to be removed. Bioprocesses were operated on real wastewater samples over 120 days under controlled ORP, as described by Nernst equations, which proved to be a robust tool to operate nitrification for larger periods with a very high load of nitrogen, uranium, and COD.

Evaluation of hybrid processes for nitrification by comparing MBBR/AS and IFAS configurations

2007 ◽  
Vol 55 (8-9) ◽  
pp. 43-49 ◽  
Author(s):  
E. Germain ◽  
L. Bancroft ◽  
A. Dawson ◽  
C. Hinrichs ◽  
L. Fricker ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Biofilm Reactor ◽  
Nitrite Accumulation ◽  
Removal Rates ◽  
Solids Retention ◽  
Different Temperatures ◽  
Suspended Biomass ◽  
The Media ◽  
Population Counts ◽  
Ammonia Oxidising Bacteria

An integrated fixed-film activated sludge (IFAS) pilot plant and a moving bed biofilm reactor coupled with an activated sludge process (MBBR/AS) were operated under different temperatures, carbon loadings and solids retention times (SRTs). These two types of hybrid systems were compared, focusing on the nitrification capacity and the nitrifiers population of the media and suspended biomass alongside other process performances such as carbonaceous and total nitrogen (TN) removal rates. At high temperatures and loadings rates, both processes were fully nitrifying and achieved similarly high carbonaceous removal rates. However, under these conditions, the IFAS configuration performed better in terms of TN removal. Lower temperatures and carbon loadings led to lower carbonaceous removal rates for the MBBR/AS configuration, whereas the IFAS configuration was not affected. However, the nitrification capacity of the IFAS process decreased significantly under these conditions and the MBBR/AS process was more robust in terms of nitrification. Ammonia oxidising bacteria (AOB) and nitrite oxidising bacteria (NOB) population counts accurately reflected the changes in nitrification capacity. However, significantly less NOBs than AOBs were observed, without noticeable nitrite accumulation, suggesting that the characterisation method used was not as sensitive for NOBs and/or that the NOBs had a higher activity than the AOBs.

Investigation of Amorphous/Crystalline State in Cu-Hf-Al Alloys

2010 ◽  
Vol 649 ◽  
pp. 87-92
Author(s):  
E. Nagy ◽  
Viktória Rontó ◽  
Jenő Sólyom ◽  
András Roósz
Keyword(s):  
Amorphous Alloys ◽  
Great Influence ◽  
Amorphous State ◽  
High Strength ◽  
Al Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Different Shapes ◽  
Important Purpose

Cu-Hf-Al alloys are considered to be relatively new ones among Cu-based bulk amorphous alloys. Cu-Hf-Al alloys have high strength in amorphous state and this property makes many applications feasible for the industry. During the production of amorphous alloys the most important purpose is to produce them in the biggest diameter to make them suitable for a wide range of applications. The circumstances of the production process have a great influence on the developing structure. In the present work solidification of Cu-Hf-Al alloys were investigated. The alloys were cast into different shapes with different Al contents with special regard to the appearance of the amorphous/crystalline structure. The appearance and the structure of crystalline phases were determined by X-ray diffraction and X-ray, DSC and metallographic measurements were used to investigate the developing structure.

Ammonia recovery from high strength agro industry effluents

2002 ◽  
Vol 45 (12) ◽  
pp. 189-196 ◽  
Author(s):  
M. Altinbas ◽  
I. Ozturk ◽  
A.F. Aydin
Keyword(s):  
Experimental Studies ◽  
Ammonium Phosphate ◽  
High Strength ◽  
Stoichiometric Ratio ◽  
Ammonia Content ◽  
Magnesium Ammonium Phosphate ◽  
Fenton’S Oxidation ◽  
Ammonia Recovery ◽  
Fenton's Oxidation ◽  
Opium Alkaloid

The aim of the study was to investigate ammonia recovery from high strength agro industry effluents involving significant amounts of ammonia, by applying magnesium ammonium phosphate (MAP) precipitation technology. Two types of industrial effluents have been tested in the study. The first plant was an opium alkaloid processing industry and the second one was a baker`s yeast industry. High chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and unacceptable dark brown color characterized effluents from both industries. Effluents from the biologically treated opium alkaloid and baker's yeast industries were both applied at the stoichiometric ratio (Mg:NH4:PO4 =1:1:1) and above the stoichiometric ratio (Mg:NH4:PO4 =1.1:1:1.1) to MAP precipitation. NH4 removals of 61-80% were achieved at the pH of 9.2 at the stoichiometric ratio, whereas 83% NH4 removal was obtained at the pH of 9.2 above the stoichiometric ratio. Experimental studies performed on both anaerobically and/or aerobically treated baker`s yeast and opium alkaloid industry effluents have clearly indicated that MAP precipitation was an appropriate treatment option for NH4 removal or struvite recovery from high ammonia content agro industry effluents. Additional ammonia recovery studies were conducted on ozonated and Fenton's oxidation applied effluents and these have also indicated that the amounts of struvite and the quality of MAP precipitate was increased significantly. In this framework, MAP sludge recovered from combined biological and Fenton's oxidation treatment effluents were considered as a more valuable slow release fertilizer for agricultural use.

New Developments in Complete Nitrogen Removal with Biological Aerated Filters

1990 ◽  
Vol 22 (1-2) ◽  
pp. 273-280 ◽  
Author(s):  
Frank Rogalla ◽  
Marie-Marguerite Bourbigot
Keyword(s):  
Large Scale ◽  
Ammonia Oxidation ◽  
Bacterial Degradation ◽  
Operational Parameters ◽  
Design Data ◽  
New Developments ◽  
Hydraulic Conditions ◽  
Solids Retention ◽  
Extensive Pilot ◽  
Pilot Tests

Biological aerated filters combine bacterial degradation of pollution by fixed biomass with physical filtration in a single reactor.Several full-size plants with the BIOCARBONE process have established the compactness, ease of operation and high removal rates achievable with this advanced treatment system. Based on large-scale industrial experiences, a new biofilter design offering simplified operation and increased performance is presented. Design data for carbon and nutrient removal were collected during extensive pilot tests. Hydraulic conditions and pollution loadings were varied in order to optimize the biological and operational parameters of the filter. Carbon and ammonia oxidation as well as denitrification and suspended solids retention could be achieved with an overall hydraulic retention time of two hours.

Effect of organic compounds on nitrite accumulation during the nitrification process for coking wastewater

2010 ◽  
Vol 62 (9) ◽  
pp. 2096-2105 ◽  
Author(s):  
H. B. Li ◽  
H. B. Cao ◽  
Y. P. Li ◽  
Y. Zhang ◽  
H. R. Liu
Keyword(s):  
Organic Compounds ◽  
Ammonia Oxidation ◽  
Industrial Effluents ◽  
Reaction Rates ◽  
Inhibitory Effect ◽  
Nitrite Accumulation ◽  
Coking Wastewater ◽  
Batch Bioreactor ◽  
The Difference ◽  
High Concentrations

Coking wastewater is one of the most toxic industrial effluents since it contains high concentrations of ammonia and toxic organic compounds. Nitrification might be upset by the inhibitory effect of organic compounds during the biological treatment of the wastewater. In this study, shortcut nitrification was obtained in a sequencing batch bioreactor (SBR) and the inhibitory effect of organic compounds on the nitrification was examined when temperature was 30±1°C, pH was 7.0–8.5, and dissolved oxygen concentration was 2.0–3.0 mg L−1. The inhibitory effect of organic compounds was presumed to be one of the main factors to obtain satisfactory nitrite accumulation. The effect of organic compounds on nitrification was examined in the SBR with initial inhibitor concentrations ranging from 0 to 80 mg L−1, including phenol, pyrocatechol, resorcin, benzene, quinoline, pyridine and indole. The inhibitory effect became stronger with the increase in the concentration, and it was presumed to take place through a direct mechanism resulting from biological toxicity of the inhibitor itself. Furthermore, the inhibitory effect on ammonia oxidation was slighter than that on nitrite oxidation, and the nitrite accumulation ratio during the nitrification was determined by the difference between the reaction rates of above two processes.

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