scholarly journals Effects of the chemical characteristics and concentration of inorganic suspended solids on nitrification in freshwater

2017 ◽  
Vol 76 (11) ◽  
pp. 3101-3113
Author(s):  
Quynh Nga Le ◽  
Chihiro Yoshimura ◽  
Manabu Fujii
Keyword(s):  
Clay Minerals ◽  
Rate Constants ◽  
Oxidation Rate ◽  
Suspended Solids ◽  
Nitrification Rate ◽  
Chemical Characteristics ◽  
Ammonium Oxidation ◽  
Nitrite Oxidation ◽  
Oxidation Rate Constant ◽  
Positive Effect

Abstract The effect of inorganic suspended solids (ISS) on nitrification in freshwater samples has been described inconsistently and remains unclear. This study therefore investigated the effects of the chemical characteristics and concentration of ISS on the nitrification rate by focusing on Nitrosomonas europaea and Nitrobacter winogradskyi as the two most dominant nitrification species in freshwater. Batch-wise experiments were conducted using three chemically well-characterized ISS (i.e. the clay minerals montmorillonite, sericite, and kaolinite in the concentration range 0–1,000 mg L−1). The results show that the ammonium oxidation rate constant (kNH4) was significantly affected by the ISS type, whereas changes in the ISS concentration had an insignificant effect on kNH4, except for kaolinite. The highest kNH4 was observed in samples containing sericite (kNH4, 0.067 L mg−1 day−1), followed by samples containing montmorillonite (kNH4, 0.044 L mg−1 day−1). The ammonium oxidation rate was low in the control and kaolinite samples. Nitrite oxidation was enhanced in the presence of all types of ISS. The rate constants of ISS-mediated nitrite oxidation (kNO2, 0.13–0.21 L mg−1 day−1) were not significantly different among the three types of ISS, but kNO2 was significantly affected by ISS concentration. Overall, our study indicated various effects of the ISS type and concentration on nitrification and, in particular, a notable positive effect of sericite.

scholarly journals The Effect of Stocking Density on Nitrification Rate in a Closed Recirculating Culture System

2007 ◽  
Vol 1 (2) ◽  
pp. 47 ◽  
Author(s):  
A.S. Sidik ◽  
, Sarwono ◽  
, Agustina
Keyword(s):  
Common Carp ◽  
Cyprinus Carpio ◽  
Oxidation Rate ◽  
Water System ◽  
Stocking Density ◽  
Nitrification Rate ◽  
Nitrite Oxidation ◽  
Common Carp Cyprinus Carpio ◽  
Carp Cyprinus Carpio ◽  
Recirculating Water System

<p>ABSTRACT</p><p>Nitrification rate in a closed recirculating water system with different stocking density of common carp (Cyprinus carpio L.) had been observed in the Laboratory of Aquaculture, Faculty of Fisheries and Marine Science, Mulawarman University.   Fish were cultivated  in rounded tanks with four level of stocking densities i.e. 10, 20, 30 and 40 fish/100 l in a closed recirculting water system, and fed on a commercial pellet given thrice a day at a quantity of 5% from the total body weight of fish per day.  The experiment was designed completely randomized with three replications. Nitrification rate was calculated stoichiometrically through the determination of  ammonia and nitrite oxidation rate. Results showed that in this experiment the ammonia and nitrite oxidation rate, and nitrification rate in a closed recirculating water system was increased with the increasing stocking density of fish.   On the contrary, the growth of fish was decreased with the increasing of stocking density.</p><p>Key words :  Nitrification rate, stocking density, recirculation system, common carp (Cyprinus carpio L.).</p><p> </p><p>ABSTRAK</p><p>Laju nitrifikasi dalam budidaya sistem resirkulasi air tertutup dengan padat penebaran ikan mas (Cyprinus carpio L.) yang berbeda telah diamati di Laboratorium Budidaya Perairan, Fakultas Perikanan dan Ilmu Kelautan Universitas Mulawarman.  Ikan dipelihara dalam tong plastik dengan empat tingkat padat penebaran, yaitu 10, 20, 30 dan 40 ekor/100 l, dan diberi makan pelet komersial tiga kali sehari dengan jumlah 5 % dari berat badan ikan per hari.  Penelitian ini dirancang secara acak lengkap dengan tiga ulangan.  Laju nitrifikasi dihitung secara stoikiometrik melalui penentuan laju oksidasi amoniak dan nitrit. Hasil penelitian menunjukkan bahwa laju oksidasi amoniak dan nitrit serta laju nitrifikasi dalam sistem resirkulasi air tertutup meningkat dengan meningkatnya padat penebaran.  Sebaliknya pertumbuhan ikan menurun dengan meningkatnya padat penebaran.</p><p>Kata kunci :  Laju nitrifikasi, padat penebaran, sistem resirkulasi, ikan mas (Cyprinus carpio L.).</p>

Role of copepod-dominated meiofauna in the nitrification process of a cold marine mesocosm

1999 ◽  
Vol 56 (9) ◽  
pp. 1639-1648 ◽  
Author(s):  
Serge Parent ◽  
Antoine Morin
Keyword(s):  
Ammonia Oxidation ◽  
Nitrifying Bacteria ◽  
Nitrification Rate ◽  
Nitrite Oxidation ◽  
Sand Filters ◽  
Large Populations ◽  
Negative Effect ◽  
The Relationship ◽  
Positive Effect

Large populations of copepod-dominated meiofauna are found in the sand filters of the St. Lawrence marine mesocosm at the Montreal Biodome. Experiments were conducted in heterotrophic microcosms to quantify how populations of micro- and meiofaunal organisms affect ammonia oxidation (nitrition) and nitrite oxidation (nitration) using apparent nitrition rate (ANiR) and apparent nitration rate (ANaR) as proxies. ANiR and ANaR were not related to ciliate density. Meiofauna had no effect on ANiR, but a significant relationship between ANaR and meiofaunal biomass was observed, which varied with the particulate organic nitrogen (PON) content of the sediment. The relationship was negative at low PON and positive at high PON. These results suggest a direct negative action by predation on nitrifying bacteria and an indirect positive action by reducing competitors through grazing of heterotroph bacteria. The negative effect of 1 g meiofauna·m-2 at low PON (-20% of ANaR0, i.e., ANaR without meiofauna) is much smaller than its positive effect at high PON (+172 to +571% of ANaR0). Copepod-dominated meiofaunal biomasses less than 0.16 g·m-2 increase two to five times the nitrification rate in heterotrophic habitats rich in PON.

Single-disc investigations on nitrogen removal of higher loads in sequencing batch and continuously operated RDR systems

2000 ◽  
Vol 41 (4-5) ◽  
pp. 77-84 ◽  
Author(s):  
J. Lindemann ◽  
U. Wiesmann
Keyword(s):  
Nitrogen Removal ◽  
Oxidation Rate ◽  
C:N Ratio ◽  
Treatment Phase ◽  
Synthetic Wastewater ◽  
Ammonium Oxidation ◽  
Nitrite Oxidation ◽  
Rotating Disc ◽  
Hydraulic Residence Time ◽  
First Results

Nitrification of ammonium-rich synthetic wastewater was studied in a continuously operated rotating disc reactor (RDR) with additional aeration. For a wastewater with 500 mg L−1 NH4−N a nearly complete oxidation to nitrate could be demonstrated for a hydraulic residence time of 27 h (HRT). The reactor was nearly completely mixed. Nevertheless, the biofilm covering the first discs was remarkably thicker than that of the last discs. In order to study the bioactivity of selected discs, single-disc reactors were used. The determined ammonium oxidation rate was nearly independent of the thickness and location of the disc. In contrast, the nitrite oxidation rate increased from the first to the last discs. Some results from experiments on nitrogen removal in sequencing batch single-disc reactors (SBSDR) are discussed. The SBSDR was operated with 2 phases, a partially submerged phase for nitrification and a completely submerged anoxic phase in which acetate was added for denitrification. It was advantageous to operate without additional aeration and thus produce more nitrite and saving carbon and energy. First results of the treatment of a synthetic wastewater with a C:N ratio of 1 in a 5-phase SBBR process providing 2 nitrification, 2 anoxic and a final aerobic post-treatment phase showed average specific rates.

Application of magnetic enhanced bio-effect on nitrification: a comparative study of magnetic and non-magnetic carriers

2013 ◽  
Vol 67 (6) ◽  
pp. 1280-1287 ◽  
Author(s):  
Chuang Yao ◽  
Heng-Yi Lei ◽  
Qiang Yu ◽  
Shu-Ping Li ◽  
Hua-Liang Li ◽  
...  
Keyword(s):  
Oxidation Rate ◽  
Magnetic Carrier ◽  
Ammonium Oxidation ◽  
Nitrite Oxidation ◽  
Surface Magnetic Field ◽  
Biofilm Reactors ◽  
Rate Analysis ◽  
Magnetic Carriers ◽  
N Concentration ◽  
Time Required

A novel magnetic carrier with surface magnetic field of 4 mT was developed for studying the magnetic enhanced bio-effect on nitrification. The bio-effect on nitrificaton induced by the magnetic carrier was studied by comparing the performance of sequencing batch biofilm reactors filled with magnetic (MC) and non-magnetic (NMC) carriers. The result showed that the bioreactor with MC had better performance for nitrification than bioreactor with NMC. During the biofilm culturing period, the time required for nitrification formation in biofilm of the MC reactor was 25% less than that for the NMC reactor. The results also showed that the ammonium oxidation rate of the MC reactor was 1.6-fold faster than that in the NMC reactor at high influent NH4-N concentration, while nitrite oxidation rate was always accelerated regardless of influent NH4-N concentration. The specific oxygen uptake rate analysis revealed that ammonia and nitrite oxidation activities in biofilm of the MC reactor were 1.65 and 1.98 times greater than those of the NMC reactor, respectively.

Effect of Acclimation Strategy on the Biological Nitrification in the Saline Wastewater

2011 ◽  
Vol 183-185 ◽  
pp. 522-526 ◽  
Author(s):  
Ling Ling Li ◽  
Bo Yang ◽  
Peng Zhou
Keyword(s):  
Oxidation Rate ◽  
Nitrifying Bacteria ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonium Oxidation ◽  
Salt Tolerant ◽  
Nitrite Oxidation ◽  
Saline Wastewater ◽  
Nacl Concentration ◽  
Nitrite Oxidizing Bacteria ◽  
Fresh Culture

During the process of cultivation of salt-tolerant nitrifying bacteria, the increase in NaCl concentrations was carried out in two different manners. The NaCl concentration in reactor A was increased by increment of 5 g/L, while the NaCl concentration in reactor B was increased by increment of 2.5 g/L. The impacts of NaCl content on the fresh culture and two acclimated cultures were investigated, which focused upon the changes of the specific ammonium oxidation rate (SAOR) and specific nitrite oxidation rate (SNOR). The results indicated that fresh nitrifiers were severely inhibited by high salinity. At NaCl concentration of 25 g/L, ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) completely lost the nitrification capability. After 46 days of acclimation, the nitrifying bacteria could be adapted to the saline wastewater. The average SAOR and SNOR in reactor B were slightly higher than those in reactor A, which meant that low increment in salt concentration may be in favor of the development of salt-tolerant nitrifiers. But the two NaCl increasing approaches did not affect the SAOR and SNOR too much. Salt-tolerant nitrifiers could be well developed with the two acclimation manners.

scholarly journals Nitrification in the oligotrophic Atlantic Ocean

2021 ◽  
Author(s):  
Darren R. Clark ◽  
Andrew P. Rees ◽  
Charrisa Ferrera ◽  
Lisa Al-Moosawi ◽  
Paul J. Somerfield ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Oxidation Rate ◽  
Inorganic Nitrogen ◽  
Mesoscale Eddy ◽  
Data Availability ◽  
Nitrification Rate ◽  
Ammonium Oxidation ◽  
Short Term ◽  
Data Variability ◽  
Subsequent Degradation

Abstract. The recycling of scarce nutrient resources in the sunlit open ocean is crucial to ecosystem function. Ammonium oxidation, the first stage of the nitrification process, directs ammonium derived from organic matter decomposition towards the regeneration nitrate, an important resource for photosynthetic primary producers. However, the technical challenge of making nitrification rate measurements in oligotrophic conditions combined with the remote nature of these marine systems means that data availability, and the understanding that provides, is limited. This study reports rate measurements of ammonium oxidation over a 13, 000 km transect within the photic zone of the Atlantic Ocean. These measurements, at relatively fine resolution (order 300 km), permit the examination of interactions with environmental conditions that may warrant explicit development and inclusion in model descriptions. At all locations we report measurable rates with significant variability between and within Atlantic provinces. This adds to evidence that nitrification is an important component of pelagic nitrogen cycling which modifies the inorganic nitrogen inventory of the sunlit ocean. Particular features of interest included a significant hemispheric difference in ammonium oxidation rate and elevated rates associated with mesoscale eddy features. Statistical analysis of potential links between ammonium oxidation rate and routinely measured ecosystem variables indicated significant correlative structure, explaining ~65 % of the data variability. Differences between sampling depths were of the same magnitude or greater than horizontally resolved differences along the transect length, identifying distinct biogeochemical niches between depth horizons. Principle component analysis demonstrated that the best overall match between ammonium oxidation rate and environmental variables involved a combination of chlorophyll-a concentration, the duration of the light phase and silicate concentration (which we argue to be a short-term tracer of physical instability). Results allude to an association between ammonium oxidation and potentially short-term product(s) of photosynthetic activity and subsequent degradation. Approximately 35 % of data variability was not explained, which may include descriptions of DOM pool dynamics.

Oxidation of (1-hydroxybenzyl)ferrocene and its derivatives substituted in phenyl ring with bis(triphenylsilyl) chromate

1982 ◽  
Vol 47 (12) ◽  
pp. 3375-3380 ◽  
Author(s):  
Jaroslav Holeček ◽  
Karel Handlíř ◽  
Milan Nádvorník ◽  
Milan Vlček
Keyword(s):  
Linear Dependence ◽  
Rate Constants ◽  
Oxidation Rate ◽  
Phenyl Ring ◽  
Equilibrium Constants ◽  
Aprotic Solvents ◽  
Protonation Equilibrium ◽  
Oxidation Of Alcohols ◽  
Hammett Σ Constants ◽  
Sulphuric Acid Medium

Kinetics have been studied of oxidation of (1-hydroxybenzyl)ferrocenes substituted in phenyl ring with bis(triphenylsilyl) chromate in benzene solutions as well as protonation of these alcohols in sulphuric acid medium. Logarithms of the oxidation rate constants (kobs, 20-40 °C) and those of the protonation equilibrium constants (KR+, 25 °C) show linear dependence on the Hammett σ constants, the ρ constant values being -0.86 to -0.40 and -2.50, respectively. These negative values suggest that the both processes are influenced by the same effects and confirm the mechanism proposed earlier for oxidation of alcohols with ferrocenyl substituent by action of bis(triphenylsilyl) chromate in aprotic solvents.

scholarly journals Structure–activity relationship for the estimation of OH-oxidation rate constants of carbonyl compounds in the aqueous phase

2013 ◽  
Vol 13 (23) ◽  
pp. 11625-11641 ◽  
Author(s):  
J.-F. Doussin ◽  
A. Monod
Keyword(s):  
Aqueous Phase ◽  
Rate Constants ◽  
Oxidation Rate ◽  
Carbonyl Compounds ◽  
Estimation Method ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Oh Radicals ◽  
Structure Activity ◽  
Polyfunctional Compounds

Abstract. In the atmosphere, one important class of reactions occurs in the aqueous phase in which organic compounds are known to undergo oxidation towards a number of radicals, among which OH radicals are the most reactive oxidants. In 2008, Monod and Doussin have proposed a new structure–activity relationship (SAR) to calculate OH-oxidation rate constants in the aqueous phase. This estimation method is based on the group-additivity principle and was until now limited to alkanes, alcohols, acids, bases and related polyfunctional compounds. In this work, the initial SAR is extended to carbonyl compounds, including aldehydes, ketones, dicarbonyls, hydroxy carbonyls, acidic carbonyls, their conjugated bases, and the hydrated form of all these compounds. To do so, only five descriptors have been added and none of the previously attributed descriptors were modified. This extension leads now to a SAR which is based on a database of 102 distinct compounds for which 252 experimental kinetic rate constants have been gathered and reviewed. The efficiency of this updated SAR is such that 58% of the rate constants could be calculated within ±20% of the experimental data and 76% within ±40% (respectively 41 and 72% for the carbonyl compounds alone).

Temporal variation in maximum cell-specific nitrification rate

2010 ◽  
Vol 61 (8) ◽  
pp. 2069-2073 ◽  
Author(s):  
M. Fujita ◽  
K. Tsuji ◽  
A. Akashi
Keyword(s):  
Ammonia Oxidation ◽  
Thermal Power ◽  
Nitrification Rate ◽  
Nitrite Oxidation ◽  
Cell Numbers ◽  
Oxidation Rates ◽  
Batch Tests ◽  
Nitrogen Loads ◽  
Clone Analysis ◽  
Maximum Cell

The cell numbers of ammonia-oxidising bacteria (AOBs), Nitrospira and Nitrobacter in activated sludge used to treat wastewater from a thermal power plant in Japan were examined for nine months using a real-time PCR quantification technique. AOB cell numbers ranged 2.8 × 1010–2.3 × 1011 cell/L. The amoA clone analysis showed that the only Nitrosomonas halophila was responsible for ammonia oxidation over the period. Nitrospira were in the range of 2.6 × 109–2.4 × 1010 cell/L and Nitrobacter were less than 1% as common as Nitrospira. Meanwhile, maximum nitrification rates, maximum ammonia- and nitrite-oxidation rates obtained from aerobic batch tests, ranged 0.5–1.3 mmol-N/L h and 1.0–2.5 mmol-N/L h, respectively. No clear correlations were observed between the cell numbers of AOBs or Nitrospira and their maximum rates, because the maximum cell-specific ammonia- and nitrite-oxidation rates varied remarkably over the ranges of 1.1–11.9 and 2.4–21.6 fmol-N/cell h, respectively. To explore the factors controlling maximum cell-specific nitrification rates, the relationship to influent nitrogen loads per AOB or Nitrospira cell numbers was investigated. Fairly good correlations were obtained. Considering the effluent ammonia and nitrite concentrations were zero and only Nitrosomonas halophila had a role in ammonia oxidation over the period, we conclude that the amount of nitrogen oxidised per AOB or Nitrospira cell numbers likely controls maximum cell-specific ammonia- or nitrite-oxidation rates, respectively.

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