Effect of the addition of organic carbon sources on nitrous oxide emission in anaerobic-aerobic (low dissolved oxygen) sequencing batch reactors

This study investigated the effect of organic carbon source on ammonia oxidizing community in single sludge laboratory scale sequencing batch reactors (SBR). Two sequencing batch reactors performing simultaneous carbon oxidation and nitrification were operated. Operationally and functionally, these two reactors were identical, except that one reactor was fed peptone and sodium acetate, and the other was fed glucose and sodium acetate as external organic carbon sources. The peptone-fed reactor had 98.1±1.84% COD removal and 97.3±6.69% NH3-N oxidation. The glucose-fed reactor had 99.1±1.29% COD removal and 99.4±0.76% NH3-N oxidation. The reactor fed with peptone, a complex organic carbon source comprised of enzymatic digests of animal proteins, had greater diversity in both the heterotrophic bacterial community and the ammonia oxidizing bacteria community than in the reactor fed with glucose, a simple sugar as evidenced by automated ribosomal intergenic spacer analysis (ARISA) and terminal restriction fragment length polymorphism (TRFLP) experiments respectively.

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Assimilation of various organic carbon sources by Haematococcus strains

Acta Agronomica Hungarica ◽

10.1556/aagr.57.2009.2.14 ◽

2009 ◽

Vol 57 (2) ◽

pp. 231-237

Author(s):

M. Zych ◽

A. Stolarczyk ◽

K. Maca ◽

A. Banaś ◽

K. Termińska-Pabis ◽

...

Keyword(s):

Organic Carbon ◽

Organic Compounds ◽

Present Experiment ◽

Carbon Sources ◽

Growth Conditions ◽

Mixotrophic Growth ◽

Naturally Occurring ◽

Organic Carbon Sources ◽

Secondary Carotenoids ◽

Colour Changes

Differences in the assimilation of individual organic compounds (5 mM sugars and L-asparagine) under mixotrophic growth conditions were described for three naturally occurring Haematococcus strains.The effects of assimilation were measured by the growth intensity and size of algal cells, and the effect of colour changes in the cultures was observed. Some compounds caused the cell colouration to change from green to yellow, being the result of chlorophyll disappearance and the accumulation of yellow secondary carotenoids. In the present experiment none of the cultures turned red, thus excluding the intense accumulation of the commercially interesting carotenoid, astaxanthin.

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Effect of magnetic field on biomass properties and their role in biodegradation under condition of low dissolved oxygen

Applied Water Science ◽

10.1007/s13201-021-01439-9 ◽

2021 ◽

Vol 11 (7) ◽

Author(s):

Nur Syamimi Zaidi ◽

Johan Sohaili ◽

Khalida Muda ◽

Mika Sillanpää ◽

Norelyza Hussein

Keyword(s):

Magnetic Field ◽

Dissolved Oxygen ◽

Biomass Concentration ◽

Aerobic Bacteria ◽

Batch Reactors ◽

Sequencing Batch Reactors ◽

Great Chance ◽

Sludge Bulking ◽

The Magnetic Field ◽

High Biomass Concentration

AbstractLow condition of dissolved oxygen (DO) is commonly associated with sludge bulking problem that was able to disrupt the efficiency of wastewater treatment performances. Relatively, very little attention was paid to the possibility of applying magnetic field in controlling the bulking problem. Hence, this study aims to investigate the performance of magnetic field on biomass properties and its effect on biodegradation under low condition of DO. Two continuous laboratory-scale sequencing batch reactors—Reactor A (SBRA) and Reactor B (SBRB)—were setup. SBRA was equipped with the magnetic device to exhibit magnetic field of 88 mT, while SBRB acted as a control system. The results showed that the biomass concentration in SBRA was higher compared to SBRB. High biomass concentration in SBRA resulted to better settleability with mean SVI of less than 30 mL/g. SBRA also showed consistently high removal performances of organic and inorganic contents compared to SBRB. These observations confirmed that the magnetic field was able to enhance the biomass properties, which further enhance the biodegradation ability of the aerobic bacteria under low DO condition. This also indicates that under the sludge bulking circumstances, the use of magnetic field stands a great chance in maintaining high biodegradation of the treatment system.

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