scholarly journals Effectiveness of Nitrification and Denitrification Processes in Biofilters Treating Wastewater from De-Icing Airport Runways

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 630 ◽  
Author(s):  
Joanna Rodziewicz ◽  
Kamila Ostrowska ◽  
Wojciech Janczukowicz ◽  
Artur Mielcarek
Keyword(s):  
Biofilm Reactors ◽  
Effective Removal ◽  
Carbon Compounds ◽  
Suspended Biomass ◽  
Nitrogen Ratio ◽  
Nitrification And Denitrification ◽  
Organic Carbon Loading ◽  
Light Expanded Clay Aggregates ◽  
Clay Aggregates

The basic factors determining the efficiency of the removal of nitrogen and carbon compounds from airport wastewater containing de-icing agents are low temperature and the C/N ratio (carbon to nitrogen ratio). Biofilm reactors (biofilters) create better conditions for nitrification and denitrification than suspended biomass reactors. The scope of the study included determination of the influence of the C/N ratio in the wastewater on nitrification, denitrification and organic compound removal in biofilm reactors depending on the temperature. The experiment was performed in 24 circular laboratory biofilters with LECA (Light Expanded Clay Aggregates) filling. The study was divided into three series differing in organic carbon loading. In each series, carried out at the same hydraulic retention time, biofilters were operated at 25, 8, 4 or 0 °C. The study showed the effective removal of nitrogen compounds across a very wide temperature range. The applied filling and properly selected operating parameters of the reactors resulted in effective simultaneous nitrification and denitrification. The highest efficiency of nitrogen removal at 0 °C (34.57 ± 4.54%) was obtained at the C/N ratio of 0.5 gC/gN. The efficiency of denitrification (the lowest at the temperature of 0 °C) increased as the temperature and C/N ratio increased in the wastewater.

Effect of Hydrogen Peroxide on soil Organic Matter

1931 ◽  
Vol 21 (2) ◽  
pp. 251-261 ◽  
Author(s):  
W. McLean
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Second Phase ◽  
Carbon And Nitrogen ◽  
Carbohydrate Complex ◽  
Carbon Compounds ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Two Phases

1. Six per cent. peroxide is found to be unsuitable as a reagent for the determination of the “degree of humification” of soil organic matter, as it oxidises not only compounds containing carbon and nitrogen but also a varying amount of a substance containing carbon but no nitrogen, this amount depending on the volume of reagent used and the total amount of carbon originally present in the quantity of soil employed.2. There are apparently two phases in the attack of peroxide on soil organic matter. In the first phase, material containing carbon and nitrogen is oxidised, whilst in the second phase the material oxidised consists solely of nitrogen-free carbon compounds.3. By the use of 3 per cent. peroxide (2 per cent, or less may be preferable for some soils) the attack on soil organic matter can be restricted to the first phase. The material thus oxidised appears to be built up by the association of a protein complex with a carbohydrate complex of high carbon content. Its carbon-nitrogen ratio is about 10:1.

Absolute configuration determination of some optically active multifunctional carbon compounds

1988 ◽  
Vol 29 (37) ◽  
pp. 4727-4730 ◽  
Author(s):  
Yoshio Takeuchi ◽  
Michiyo Nojiri ◽  
Toru Koizumi ◽  
Yoichi Iitaka
Keyword(s):  
Absolute Configuration ◽  
Optically Active ◽  
Carbon Compounds

scholarly journals Optimisation of pH, Temperature and Carbon Nitrogen Ratio for the Degradation of m-Chlorophenol by Pseudomonas putida CP1

1970 ◽  
Vol 23 (2) ◽  
pp. 159-161 ◽  
Author(s):  
ANM Fakhruddin ◽  
M Alamgir Hossain
Keyword(s):  
Chemical Oxygen Demand ◽  
Pseudomonas Putida ◽  
C:N Ratio ◽  
Oxygen Demand ◽  
Hydroxyl Group ◽  
Ph Optimum ◽  
Effective Removal ◽  
Carbon Nitrogen Ratio ◽  
Chlorine Substituent ◽  
Nitrogen Ratio

Aromatic pollutants like m-chlorophenol is toxic to the environment and chlorophenol containing a metachlorine are more persistent under aerobic conditions than compounds lacking a chlorine substituent in positions meta to hydroxyl group. Therefore, it should be removed effectively from the environment. In order to increase the degradative activity, the optimum conditions for m-chlorophenol degradation by Pseudomonas putida CP1, some physicochemical conditions like pH, temperature and carbon nitrogen ratio for the growth and degradation of most persistent monochlorophenol, m-chlorophenol by the organism was optimised. The pH optimum for m-chlorophenol degradation by the bacterium was between pH 6.5 and 7.0 and the temperature optimum was 30°C for removal activity. Carbon : nitrogen (C:N) ratio of 3:1 was found best for effective removal of chemical oxygen demand (COD) and m-chlorophenol by the bacterium. Keywords: m-Chlorophenol degradation, Pseudomonas putida CP1, Chemical oxygen demand (COD)DOI: http://dx.doi.org/10.3329/bjm.v23i2.884  Bangladesh J Microbiol, Volume 23, Number 2, December 2006, pp 159-161

Biofilm development during the start-up of a sulfate-reducing down-flow fluidized bed reactor at different COD/SO42− ratios and HRT

2011 ◽  
Vol 64 (4) ◽  
pp. 910-916 ◽  
Author(s):  
E. Z. Piña-Salazar ◽  
F. J. Cervantes ◽  
M. Meraz ◽  
L. B. Celis
Keyword(s):  
Fluidized Bed ◽  
Granular Sludge ◽  
Fluidized Bed Reactor ◽  
Sulfate Reducing ◽  
Sulfate Removal ◽  
Start Up ◽  
Effective Removal ◽  
Suspended Biomass ◽  
High Sulfate ◽  
Biofilm Development

In sulfate-reducing reactors, it has been reported that the sulfate removal efficiency increases when the COD/SO42− ratio is increased. The start-up of a down-flow fluidized bed reactor constitutes an important step to establish a microbial community in the biofilm able to survive under the operational bioreactor conditions in order to achieve effective removal of both sulfate and organic matter. In this work the influence of COD/SO42− ratio and HRT in the development of a biofilm during reactor start-up (35 days) was studied. The reactor was inoculated with 1.6 g VSS/L of granular sludge, ground low density polyethylene was used as support material; the feed consisted of mineral medium at pH 5.5 containing 1 g COD/L (acetate:lactate, 70:30) and sodium sulfate. Four experiments were conducted at HRT of 1 or 2 days and COD/SO42− ratio of 0.67 or 2.5. The results obtained indicated that a COD/SO42− ratio of 2.5 and HRT 2 days allowed high sulfate and COD removal (66.1 and 69.8%, respectively), whereas maximum amount of attached biomass (1.9 g SVI/L support) and highest sulfate reducing biofilm activity (10.1 g COD-H2S/g VSS-d) was achieved at HRT of 1 day and at COD/sulfate ratios of 0.67 and 2.5, respectively, which suggests that suspended biomass also played a key role in the performance of the reactors.

scholarly journals Determination of kinetic coefficients for treating synthetic oily wastewater in suspended growth batch fed reactor

2021 ◽  
Author(s):  
P. Sanghamitra ◽  
Debabrata Mazumder ◽  
Somnath Mukherjee
Keyword(s):  
Real Life ◽  
Oily Wastewater ◽  
Efficient Design ◽  
Oil And Grease ◽  
Property A ◽  
Kinetic Coefficients ◽  
Suspended Growth ◽  
Suspended Biomass ◽  
High Level

Abstract Discharge of oily wastewater imparts serious threat to the environment because of high level concentration of COD, BOD as well as oil and grease and it is difficult to treat such wastewater due to its inherent toxic and inhibitory property. A treatability study of oily wastewater (carrying petroleum) has been performed in the present work using a batch suspended growth reactor. The experiment was conducted using acclimatized suspended biomass in laboratory environment and the kinetic coefficients were determined which are immensely important for design of such reactor. The oil removal efficiency was observed to be in the range of 62.84–85.45% corresponding to average MLSS concentration range of 1,797–3,668 mg/L. Haldane kinetic model was found to be the best fitted for the biodegradation of oily wastewater with acclimatised microorganisms in the present investigation. The kinetic co-efficients including Ks, Y, kd, k and ki were calculated from the experimental data and the values were compared with published results cited by various scientists. The derived kinetic coefficients values are to be useful for understanding the dynamics of substrate utilisation with production of biomass and efficient design of biological systems and also for pilot plant investigation with real life wastewater of similar nature.

scholarly journals A III B VI PHOTOVOLTAIC RECEPTORS FOR EXPERIMENTAL DETERMINATION OF CARBON COMPOUNDS IN ATMOSPHERE

2016 ◽  
Vol 19 (3) ◽  
Author(s):  
IULIANA CARAMAN ◽  
IGOR EVTODIEV ◽  
OXANA RACOVEŢ ◽  
MARIUS STAMATE
Keyword(s):  
Electric Fields ◽  
Full Range ◽  
Absorption Bands ◽  
Gaseous State ◽  
Wide Range ◽  
Carbon Compounds ◽  
Strong Electric Fields ◽  
Qualitative Measurements ◽  
Semiconductor Type

<p><span lang="EN-US">This paper examines the prospects of using semiconductor layered A<span class="apple-converted-space"> </span><sup>III</sup><span class="apple-converted-space"> </span>B<span class="apple-converted-space"> </span><sup>VI</sup><span class="apple-converted-space"> type -</span> photovoltaic cells<span class="apple-converted-space"> </span>and the photoresis<span class="apple-converted-space">tors</span> as receptors<span class="apple-converted-space"> </span>for quantitative and qualitative measurements of carbon oxides. Carbon compounds in gaseous state form absorption bands of<span class="apple-converted-space"> </span>electromagnetic<span class="apple-converted-space"> </span>radiation in a wide range of spectrum (200 ÷ 100 000) cm<sup>-1</sup>.<span class="apple-converted-space"> </span>The light absorbed<span class="apple-converted-space"> </span>or emitted<span class="apple-converted-space"> </span>in these bands <span class="apple-converted-space">at the</span> excitations with ionizing radiation (X, γ) or strong electric fields contain direct information about the<span class="apple-converted-space"> </span>concentration of these molecules.  The frequencies that<span class="apple-converted-space"> </span>correspond to maxima of these bands are characteristic parameters of absorbing molecules. Fundamental absorption bands of CO, CO<span class="apple-converted-space"> </span><sub>2</sub> and NC have the edge of band at the border of ultraviolet-vacuum, while the emission bands <em>d</em> cover their full range of wave numbers from 45000 cm<sup>-1 </sup>to 10000 cm<sup>-1</sup>. Two types of radiation receptors from lamellar semiconductor type A<sup>III</sup>B<sup>VI</sup><span class="apple-converted-space"> </span>photosensitive in this spectral range are studied.</span></p>

Tertiary nitrification in pure oxygen moving bed biofilm reactors

2000 ◽  
Vol 41 (4-5) ◽  
pp. 361-368 ◽  
Author(s):  
L. Bonomo ◽  
G. Pastorelli ◽  
E. Quinto ◽  
G. Rinaldi
Keyword(s):  
Municipal Wastewater ◽  
Treatment Plant ◽  
Ammonia Nitrogen ◽  
Pure Oxygen ◽  
Secondary Effluent ◽  
Municipal Wastewater Treatment ◽  
Typical Application ◽  
Moving Bed ◽  
Biofilm Reactors ◽  
Nitrogen Ratio

Two bench-scale reactors, fed with the secondary effluent of a municipal wastewater treatment plant (WWTP), were used in order to study tertiary nitrification in pure oxygen moving bed biofilm reactors (PO-MBBRs) with patented KMT® media as biofilm carriers. The process allowed to measure very high nitrification rates, both in ammonia limiting conditions (up to 7 gN m−2 d−1; oxygen-to-ammonia nitrogen ratio higher than 3–4 mgO2 (mgN)−1) and in oxygen limiting conditions (up to 8 gN m−2 d−1; oxygen-to-ammonia nitrogen ratio lower than 1–2 mgO2 (mgN)−1). Since the process proved flexible and reliable, it is suitable for full-scale application to municipal WWTPs. Typical application could regard, but is not limited to, tertiary nitrification of secondary effluent from existing high-purity oxygen activated sludge systems designed to achieve only organic carbon removal.

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