Faculty Opinions recommendation of Complete nitrification by Nitrospira bacteria.

2016 ◽  
Author(s):  
Dietmar Pieper
Keyword(s):  
Complete Nitrification

scholarly journals Design and function of a nitrogen and sediment removal system in a recirculating aquaculture system optimized for aquaponics

2020 ◽  
Vol 26 (2) ◽  
pp. 190494-0
Author(s):  
Siriwanee Supajaruwong ◽  
Penpicha Satanwat ◽  
Wiboonluk Pungrasmi ◽  
Sorawit Powtongsook
Keyword(s):  
Utilization Efficiency ◽  
Plant Production ◽  
Nutrient Concentrations ◽  
Recirculating Aquaculture System ◽  
Plant Weight ◽  
Recirculating Aquaculture ◽  
Nutrient Utilization Efficiency ◽  
Aquaculture System ◽  
Filtration Unit ◽  
Complete Nitrification

Aquaponic systems (APSs) are based upon the sustainable utilization of nitrogen and phosphorus from a recirculating aquaculture system (RAS) as the nutrient source for plant production. Since the proper management of nitrogen and suspended solids are important for nutrient utilization efficiency, their optimization was evaluated. The RAS integrated with filtration unit and nitrifying biofilter provided complete nitrification without solid accumulation. Under the optimal treatment condition for 16 d, the treated water was low in ammonia (0 mg-N/L) and high in nitrate (> 6 mg-N/L) concentrations, which was appropriate for use in the cultivation of lettuce (Lactuca sativa). The RAS was then incorporated with hydroponics at a 5:1 fish: plant weight ratio. Moreover, the simplified APS was compared with a typical APS system that incorporated filtration unit and nitrifying biofilter. The natural growth of nitrifying microorganisms in the simplified APS could perform complete nitrification after 20 d of operation giving low ammonia and nitrite concentrations. The nutrient removal efficiency of the simplified APS resembled the typical system. During the aquaponics, the hydroponic unit in the aquaculture system was sufficient to control the nutrient concentrations within the appropriate levels for fish cultivation, i.e. nitrate (< 20 mg-N/L) and phosphate (< 3 mg-P/L).

scholarly journals Low-Dissolved-Oxygen Nitrifying Systems Exploit Ammonia-Oxidizing Bacteria with Unusually High Yields

2011 ◽  
Vol 77 (21) ◽  
pp. 7787-7796 ◽  
Author(s):  
Micol Bellucci ◽  
Irina D. Ofiţeru ◽  
David W. Graham ◽  
Ian M. Head ◽  
Thomas P. Curtis
Keyword(s):  
Wastewater Treatment ◽  
Dissolved Oxygen ◽  
Ammonia Oxidation ◽  
Rrna Gene ◽  
Airflow Rate ◽  
Ammonia Oxidizing Bacteria ◽  
Oxidation Rates ◽  
Operational Costs ◽  
Complete Nitrification ◽  
Low Do

ABSTRACTIn wastewater treatment plants, nitrifying systems are usually operated with elevated levels of aeration to avoid nitrification failures. This approach contributes significantly to operational costs and the carbon footprint of nitrifying wastewater treatment processes. In this study, we tested the effect of aeration rate on nitrification by correlating ammonia oxidation rates with the structure of the ammonia-oxidizing bacterial (AOB) community and AOB abundance in four parallel continuous-flow reactors operated for 43 days. Two of the reactors were supplied with a constant airflow rate of 0.1 liter/min, while in the other two units the airflow rate was fixed at 4 liters/min. Complete nitrification was achieved in all configurations, though the dissolved oxygen (DO) concentration was only 0.5 ± 0.3 mg/liter in the low-aeration units. The data suggest that efficient performance in the low-DO units resulted from elevated AOB levels in the reactors and/or putative development of a mixotrophic AOB community. Denaturing gel electrophoresis and cloning of AOB 16S rRNA gene fragments followed by sequencing revealed that the AOB community in the low-DO systems was a subset of the community in the high-DO systems. However, in both configurations the dominant species belonged to theNitrosomonas oligotrophalineage. Overall, the results demonstrated that complete nitrification can be achieved at low aeration in lab-scale reactors. If these findings could be extended to full-scale plants, it would be possible to minimize the operational costs and greenhouse gas emissions without risk of nitrification failure.

Enhancement of biomass concentration in activated sludge systems

1995 ◽  
Vol 32 (7) ◽  
pp. 151-157
Author(s):  
R. Plaβ ◽  
I. Sekoulov
Keyword(s):  
Activated Sludge ◽  
Waste Water Treatment ◽  
Stable Process ◽  
Biomass Concentration ◽  
Air Bubbles ◽  
Volume Loading ◽  
Secondary Clarifier ◽  
Additional Charge ◽  
Complete Nitrification ◽  
Activated Sludge Systems

By installation of lamella in the activated sludge tank an increase of biomass concentration in the activated sludge tank can be achieved without additional charge of the secondary clarifier. Integrated packages of lamella which are installed in the discharge of the activated sludge tank at an angle of 60° effect a partial sedimentation and so a MLSS-preseparation. The MLSS in the activated sludge tank (influent of the lamella construction) was 6.5 g/l, the MLSS in the influent to the final clarifier (effluent of the lamella) was 3.1 g/l. That means that the lamella increased the MLSS concentration in the activated sludge tank by a factor of two. Despite a volume loading of 1.24 kg BOD5/(kg MLSS • d) a complete nitrification could be obtained. For ensuring a stable process and a balanced concentration of the biomass in the influent of the secondary clarifier, the preseparation of solids in the lamella is controlled by addition of air bubbles. By the enhancement of biomass concentration using this preseparation device, the extension of waste water treatment plants can be carried out with lower investment costs.

scholarly journals Complete nitrification by a single microorganism

Nature ◽  
2015 ◽  
Vol 528 (7583) ◽  
pp. 555-559 ◽  
Author(s):  
Maartje A. H. J. van Kessel ◽  
Daan R. Speth ◽  
Mads Albertsen ◽  
Per H. Nielsen ◽  
Huub J. M. Op den Camp ◽  
...  
Keyword(s):  
Complete Nitrification

Upgrading a Municipal Activated Sludge Plant for High-Rate Biological Nutrient Removal

1990 ◽  
Vol 22 (7-8) ◽  
pp. 21-33 ◽  
Author(s):  
Clifford W. Randall ◽  
David Waltrip ◽  
Milind V. Wable
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Growing Season ◽  
High Rate ◽  
Biological Nutrient Removal ◽  
Minimal Cost ◽  
Winter Conditions ◽  
Warm Weather ◽  
Nutrient Discharge ◽  
Complete Nitrification

A full-scale activated sludge plant was modified for high-rate BNR operation at minimal cost. Three different processes (A/0+, A2/0+ and UCT) were studied at BSRTs varying from 4 to 14 days and HRTs of 2 to 6 hours. Onset of BPR was almost immediate without addition of special seed. Good phosphorus removal was obtained with all three processes except for periods of extremely high influent flows or high nitrate recycle to the anaerobic zone. However, because of high process phosphorus loadings resulting from high influent concentrations and sludge processing recycles, effluent TP concentrations were typically in excess of 2 mg/L. Nitrogen removal was excellent when nitrification could be maintained and nitrate recycle was sufficiently high. All processes yielded excellent nitrogen removals during warm weather, but complete nitrification could not be maintained during winter conditions. Implementation of a statewide phosphate detergent ban resulted in a 40 per cent decrease in the influent wastewater concentrations. Following the ban, the UCT process was shown to be capable of consistently meeting the Virginia nutrient discharge standards of 10 mg/L TN and 2 mg/L TP during the growing season.

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