SEARCH · PubMed Health

Results for “nitrogen uptake efficiency”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

PubMedDate not supplied

[Electrooptical properties of soil nitrogen-fixing bacterium Azospirillum brasilense: effect of copper ions].

The effects of copper ions on the uptake of some essential metals in the biomass and the electrooptical properties of cell suspensions of the nitrogen-fixing soil bacterium Azospirillum brasilense sp. 245 were studied. Copper cations were shown to be effectively taken up by the cell biomass from the culture medium. The addition of copper ions increased the rate of uptake of some other metals present in the culture medium. This was accompanied by changes in the electrooptical characteristics of cell suspension as measured within the orienting electric field frequency range of 10 to 10,000 kHz. The effects observed during short-term incubation of A. brasilense in the presence of copper cations were less significant than during long-term incubation. These results can be used for rapid screening of microbial cultures for enhanced efficiency of sorption and uptake of metals.

Azospirillum brasilense↗

PubMed2005

Effects of oxygen concentration on N-removal in an aerobic granular sludge reactor.

In order to optimise nitrogen removal in an aerobic granular sludge system, short- and long-term effects of decreased oxygen concentrations on the reactor performance were studied. Operation at decreased oxygen concentration is required to obtain efficient N-removal and low aeration energy requirement. A short-term oxygen reduction (from 100% to 50%, 40%, 20% or 10% of the saturation concentration) did not influence the acetate uptake rate. A lower aerobic acetate uptake at lower oxygen concentrations was obviously compensated by anoxic acetate uptake. Nitrogen removal was favoured by decreased oxygen concentrations, reaching a value of 34% for the lowest oxygen concentration tested. Long-term effects were evaluated at two oxygen saturation levels (100% and 40%). Nitrogen removal increased from 8% to 45% when the oxygen saturation was reduced to 40%. However, the granules started to disintegrate and biomass washout occurred. It was impossible to obtain stable granular sludge at this decreased oxygen concentration under applied conditions. A solution to obtain stable aerobic granular sludge at low oxygen concentrations is needed in order to make aerobic granular sludge reactors feasible in practice.

Acetates↗

PubMed2003

A model of dynamics of leaves and nitrogen in a plant canopy: an integration of canopy photosynthesis, leaf life span, and nitrogen use efficiency.

A model of dynamics of leaves and nitrogen is developed to predict the effect of environmental and ecophysiological factors on the structure and photosynthesis of a plant canopy. In the model, leaf area in the canopy increases by the production of new leaves, which is proportional to the canopy photosynthetic rate, with canopy nitrogen increasing with uptake of nitrogen from soil. Then the optimal leaf area index (LAI; leaf area per ground area) that maximizes canopy photosynthesis is calculated. If leaf area is produced in excess, old leaves are eliminated with their nitrogen as dead leaves. Consequently, a new canopy having an optimal LAI and an optimal amount of nitrogen is obtained. Repeating these processes gives canopy growth. The model provides predictions of optimal LAI, canopy photosynthetic rates, leaf life span, nitrogen use efficiency, and also the responses of these factors to changes in nitrogen and light availability. Canopies are predicted to have a larger LAI and a higher canopy photosynthetic rate at a steady state under higher nutrient and/or light availabilities. Effects of species characteristics, such as photosynthetic nitrogen use efficiency and leaf mass per area, are also evaluated. The model predicts many empirically observed patterns for ecophysiological traits across species.

Ecosystem↗

PubMed2003

Cyanobacterial H(2) production -- a comparative analysis.

Several unicellular and filamentous, nitrogen-fixing and non-nitrogen-fixing cyanobacterial strains have been investigated on the molecular and the physiological level in order to find the most efficient organisms for photobiological hydrogen production. These strains were screened for the presence or absence of hup and hox genes, and it was shown that they have different sets of genes involved in H(2) evolution. The uptake hydrogenase was identified in all N(2)-fixing cyanobacteria, and some of these strains also contained the bidirectional hydrogenase, whereas the non-nitrogen fixing strains only possessed the bidirectional enzyme. In N(2)-fixing strains, hydrogen was mainly produced by the nitrogenase as a by-product during the reduction of atmospheric nitrogen to ammonia. Therefore, hydrogen production was investigated both under non-nitrogen-fixing conditions and under nitrogen limitation. It was shown that the hydrogen uptake activity is linked to the nitrogenase activity, whereas the hydrogen evolution activity of the bidirectional hydrogenase is not dependent or even related to diazotrophic growth conditions. With regard to large-scale hydrogen evolution by N(2)-fixing cyanobacteria, hydrogen uptake-deficient mutants have to be used because of their inability to re-oxidize the hydrogen produced by the nitrogenase. On the other hand, fermentative H(2) production by the bidirectional hydrogenase should also be taken into account in further investigations of biological hydrogen production.

Biological Transport↗

PubMed1997

A cryptic proline permease in Salmonella typhimurium.

Wild-type Salmonella typhimurium expresses three proline transport systems: a high-affinity proline transport system encoded by the putP gene, and two glycine betaine transport systems with a lower affinity for proline encoded by the proP and proU genes. Although proline uptake by the ProP and ProU transport systems is sufficient to supplement a proline auxotroph, it is not efficient enough to allow proline utilization as a sole source of carbon or nitrogen. Thus, the PutP transport system is required for utilization of proline as a carbon or nitrogen source. In this study, an overexpression suppressor, designated proY, which allows proline utilization in a putP genetic background and does not require the function of any of the known proline transport systems, was cloned and characterized. The suppressor gene, designated proY, maps at 8 min on the S. typhimurium linkage map, distant from any of the other characterized proline transport genes. The DNA sequence of the proY gene predicts that it encodes a hydrophobic integral membrane protein, with strong similarity to a family of amino acid transporters. The suppressor phenotype requires either a multicopy done of the proY+ gene or both a single copy of the proY+ gene and a proZ mutation. These results indicate that the proY gene is the structural gene for a cryptic proline transporter that is silent unless overexpressed on a multicopy plasmid or activated by a proZ mutation.

Amino Acid Transport Systems↗

PubMed1981

Effect of growth rate and nutrient limitation on the transformability of Escherichia coli with plasmid deoxyribonucleic acid.

The observed transformation frequency by plasmid deoxyribonucleic acid of Escherichia coli grown in continuous culture was found to depend on both the steady-state growth rate and the type of nutrient used to limit growth. With carbon, nitrogen, or phosphorus limitation, the faster the growth rate, the higher the transformation frequency. The increase in transformation frequency associated with higher rates was shown to be due to more transformable cells in the population rather than an increased efficiency of deoxyribonucleic acid uptake. Growth rate had relatively little effect on the transformability of cells from sulfate- and Mg2+-limited chemostats, indicating that some factor other than the growth rate must influence the frequency of transformation. Regardless of the nutrient limitation or the growth rate, no transformants were obtained in the absence of CaCl2.

Calcium Chloride↗

PubMed2001

Development of a real-time control strategy with artificial neural network for automatic control of a continuous-flow sequencing batch reactor.

The purpose of this study is to develop a reliable and effective real-time control strategy by integrating artificial neural network (ANN) process models to perform automatic operation of a dynamic continuous-flow SBR system. The ANN process models, including ORP/pH simulation models and water quality ([NH4(+)-N] and [NOx(-)-N]) prediction models, can assist in real-time searching the ORP and pH control points and evaluating the operation performances of aerobic nitrification and anoxic denitrification operation phases. Since the major biological nitrogen removal mechanisms were controlled at nitrification (NH4(+)-N-->NO2(-)-N) and denitritification (NO2(-)-N-->N2) stages, as well as the phosphorus uptake and release could be completely controlled during aerobic and anoxic operation phases, the system operation performances under this ANN real-time control system revealed that both the aeration time and overall hydraulic retention time could be shortened to about 1.9-2.5 and 4.8-6.2 hrs/cycle respectively. The removal efficiencies of COD, ammonia nitrogen, total nitrogen, and phosphate were 98%, 98%, 97%, and 84% respectively, which were more effective and efficient than under conventional fixed-time control approach.

Ammonia↗

PubMed2004

Amino acid contents and transport in oilseed rape (Brassica napus L.) under different nitrogen conditions.

Oilseed rape (Brassica napus L.) needs very high nitrogen fertilizer inputs. Significant amounts of this nitrogen are lost during early leaf shedding and are a source of environmental and economic concern. The objective of this study was to investigate whether the remobilization of leaf amino acids could be limiting for nitrogen use efficiency. Therefore, amino acid concentrations were analyzed in subcellular compartments of leaf mesophyll cells of plants grown under low (0.5 mM NO3-) and high (4 mM NO3-) nitrogen supply. With high nitrogen supply, young leaves showed an elevated amino acid content, mainly in vacuoles. In old leaves, however, subcellular concentrations were similar under high and low nitrogen conditions, showing that the excess nitrogen had been exported during leaf development. The phloem sap contained up to 650 mM amino acids, more than four times as much than the cytosol of mesophyll cells, indicating a very efficient phloem-loading process. Three amino acid permeases, BnAAP1, BnAAP2, and BnAAP6, were identified and characterized. BnAAP1 and BnAAP6 mediated uptake of neutral and acidic amino acids into Xenopus laevis oocytes at the actual apoplastic substrate concentrations. All three transporters were expressed in leaves and the expression was still detectable during leaf senescence, with BnAAP1 and BnAAP2 mRNA levels increasing from mature to old leaves. We conclude that phloem loading of amino acids is not limiting for nitrogen remobilization from senescing leaves in oilseed rape.

Amino Acid Transport Systems↗

PubMed1988

Protein metabolism in the rumen of silage-fed steers: effect of fishmeal supplementation.

1. Ryegrass (Lolium perenne cv. Cropper) silage was given to four Friesian steers (initial live weight (LW) 172 kg) alone or with a fishmeal supplement (150 g fresh weight/kg silage dry matter (DM)) in a balanced two-period change-over design. The dietary components were the same as those used in a recent experiment by Gill et al. (1987). All diets were offered hourly at 24 g DM/kg LW. 2. Fishmeal supplementation increased dietary nitrogen intake (P less than 0.01) and significantly increased the flow of total N (P less than 0.01), non-ammonia N (NAN) (P less than 0.01) and amino acids (P less than 0.05) at the duodenum. The increased supply of NAN to the duodenum was due largely (67%) to increased flow of undergraded dietary protein. 3. Microbial protein production was estimated simultaneously with 15N, diaminopimelic acid (DAPA) and a novel technique using L-[4,5-3H]leucine. Estimates varied with the marker and source of microbial isolate but mean values indicated that microbial N flow was significantly increased by fishmeal supplementation (P less than 0.05). The use of L-[4,5-3H]leucine as a microbial marker is justified and its possible advantages over other markers are discussed. 4. The efficiency of microbial protein synthesis was significantly increased from 30.8 g N/kg organic matter apparently digested in the rumen (OMADR) to 54.3 g N/kg OMADR by fishmeal supplementation (P less than 0.01). However, this indicates that relatively high efficiencies can be achieved with unsupplemented high quality silage supplied continuously. Rumen degradable N (RDN) supply was significantly increased by fishmeal supplementation (P less than 0.05) but apparent efficiency of capture of RDN by rumen microbes was not significantly increased. 5. Attempts were made to investigate the source of N utilized by the microbes on the two diets by intrarumen infusions of (15NH4)2SO4 and L-[4,5-3H]leucine but these were confounded by rumen-mixing problems. Findings obtained suggest that a lower proportion of microbial N may have been derived from rumen ammonia when the silage was supplemented with fishmeal but no differences in the extent of direct incorporation of leucine into microbial protein were observed. This could indicate an increase in microbial peptide uptake on the fishmeal-supplemented diet. However, evidence was also obtained suggesting that the improvement in microbial protein synthetic efficiency with supplementary fishmeal was also due to the provision of a more continuous supply of nitrogenous substrates for microbial growth, as a result of hourly feeding.(ABSTRACT TRUNCATED AT 400 WORDS)

Animal Feed↗

PubMed2005

The impact of influent nutrient ratios and biochemical reactions on oxygen transfer in an EBPR process--a theoretical explanation.

In this investigation, a laboratory-scale enhanced biological phosphorus removal (EBPR) process was operated under controlled conditions to study the impact of varying the influent ratio of chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and total phosphorus (TP), and the consequential biochemical reactions on oxygen transfer parameters. The data showed that the experiment with high influent phosphorus relative to nitrogen (COD/TP = 51 and TKN/TP = 3.1) achieved higher alpha and oxygen transfer efficiency (OTE(f)). On the other hand, the experiment with high influent nitrogen relative to phosphorus (TKN/TP = 14.7 and COD/TP = 129) resulted in approximately 50% reduction in alpha and OTE(f) under similar organic loading. This suggested that the intracellular carbon storage and the enhanced biological P removal phenomenon associated with the phosphorus-accumulating organisms (PAOs) had a positive influence on OTE(f) in the high phosphorus experiment compared to an active population of nitrifying and denitrifying organisms in the high nitrogen experiment. The intracellular carbon storage by the glycogen-accumulating organisms also appeared to have had a positive effect on oxygen transfer efficiency, although to a lesser extent in comparison to the PAOs. It was also found that oxygen uptake rate (OUR) was not a good indicator of the measured alpha and OTE(f), because it was a combined effect of several biochemical reactions, each having a varying degree of influence. It is difficult to underestimate the crucial role of flocs in mass transfer of oxygen, because microorganisms associated with flocs carry out the biochemical reactions. It seems that the combination of influent characteristics and biochemical reactions in each experiment produced a unique biomass quality (determined by the biomass N to P ratio), ultimately affecting the mass transfer of oxygen. A theoretical explanation for the observed oxygen transfer efficiency under the process conditions is also proposed in this article.

Bacteria, Aerobic↗

PubMedDate not supplied

Supramolecular gene delivery vectors showing enhanced transgene expression and good biocompatibility.

Soluble supramolecular inclusion complexes were formed by threading alpha-cyclodextrin (alpha-CD) molecules over poly(ethylene glycol) (PEG) and poly(epsilon-caprolactone) (PCL) chains of ternary block copolymers of PEG, PCL and polyethylenimine (PEI). Characteristic shifts of PCL absorptions in FTIR, (1)H NMR and UV spectra strongly suggest that alpha-CD is threaded over PEG and PCL blocks. Due to the reduced hydrophobic interaction between PCL blocks, the resulting supramolecular complexes displayed a dramatically increased solubility, in comparison with the ternary block copolymers. Their ability to complex DNA was almost as efficient as that of branched PEI 25 kDa, as shown in the ethidium bromide fluorescence quenching experiments. Resulting DNA polyplexes displayed a size of around 200 nm and a neutral surface charge. Microscopy studies in 3T3 fibroblasts revealed an efficient cellular uptake. Transfection efficiencies of inclusion complexes were in the same order of magnitude as PEI. In contrast to PEI a 100x lower toxicity was observed by MTT-assay, allowing the administration of nitrogen-to-phosphate ratios of up to 20. These new gene delivery systems merit further characterization under in vivo conditions.

Animals↗

PubMed2006

Effects of Cd2+ on K+, Ca2+ and N uptake in two halophytes Sesuvium portulacastrum and Mesembryanthemum crystallinum: consequences on growth.

One of the limits of Cd2+-phytoextraction is the high toxicity of this metal to plants. Growth restriction, chlorosis and necrosis are usually accompanied with a large disturbance of the uptake of essential elements. This work aims to study the effects of cadmium (Cd2+) on potassium (K+), calcium (Ca2+) and nitrogen (N) acquisition, and their consequences on growth in two halophytes species: Sesuvium portulacastrum and Mesembryanthemum crystallinum. Seedlings were grown for 30 days in split-root conditions. One half of the root system was immersed in complete nutrient solution (Basal medium (B)) supplemented with 100 microM Cd2+, and the other half was immersed in a Cd2+-free medium, containing all nutrients (B/Cd plants) or deprived of potassium ((B-K)/Cd) or calcium ((B-Ca)/Cd) or nitrogen ((B-N)/Cd). Using this approach, we demonstrated that K+ and Ca2+ uptake was impaired in roots exposed to Cd2+. Concerning N, we noticed no indication of uptake inhibition by Cd2+. However, restriction of K+ uptake by roots was compensated by an increase in the K+-use efficiency, so that growth was not inhibited. Calcium uptake was strongly limited by Cd2. This inhibition was accompanied by a reduction in growth of ((B-Ca)/Cd) plants. Thus, we conclude that Cd2+ limits growth of both halophytes through restriction imposed on Ca2+ uptake. We suggest that the increase of Ca2+ availability in soils could improve the growth of both species in the presence of Cd2+. This would be essential for improving their utility for extraction of this metal by from salty contaminated soils.

Aizoaceae↗

PubMed2001

The role of nitrogen-efficient cultivars in sustainable agriculture.

To improve nitrogen (N) efficiency in agriculture, integrated N management strategies that take into consideration improved fertilizer, soil, and crop management practices are necessary. This paper reports results of field experiments in which maize (Zea mays L.) and oilseed rape (Brassica napus L.) cultivars were compared with respect to their agronomic N efficiency (yield at a given N supply), N uptake efficiency (N accumulation at a given N supply), and N utilization efficiency (dry matter yield per unit N taken up by the plant). Under conditions of high N supply, significant differences among maize cultivars were found in shoot N uptake, soil nitrate depletion during the growing season, and the related losses of nitrate through leaching after the growing season. Experiments under conditions of reduced N supply indicated a considerable genotypic variation in reproductive yield formation of both maize and oilseed rape. High agronomic efficiency was achieved by a combination of high uptake and utilization efficiency (maize), or exclusively by high uptake efficiency (rape). N-efficient cultivars of both crops were characterized by maintenance of a relatively high N-uptake activity during the reproductive growth phase. In rape this trait was linked with leaf area and photosynthetic activity of leaves. We conclude that growing of N-efficient cultivars may serve as an important element of integrated nutrient management strategies in both low- and high-input agriculture.

Agriculture↗

PubMed1991

Exposure to fumes in typical New Zealand welding operations.

Sixteen welders, welding under typical New Zealand conditions, had ambient air within their welding helmets sampled and analysed for ozone, nitrogen oxides, fluoride, carbon monoxide, aluminium, chromium, iron, nickel, zinc and total dust. Postshift urinary metals were also analysed, and a respiratory questionnaire completed for each welder. Levels above the New Zealand Workplace Exposure Standard (WES) were found for nitrogen dioxide in four welders (two TIG, one MMA and one plasma cutter), and for total chromium in one plasma cutter, who also had a nickel level of 24% of the WES. Dust levels were highest in the plasma cutters, with one reaching 8.67 mg/m3 (WES = 5 mg/m3). Urinary levels however did not indicate excessive short or long term uptake. Where efficient fume extraction was in use, levels of air contaminants were lower than with natural ventilation. Respiratory symptoms were reported by 67% of welders, 38% meeting criteria for chronic bronchitis (relative risk = 2.0). Smoking welders reported more symptoms than nonsmoking welders.

Adult↗

PubMed2026

Silicon-mediated alleviation of mercury toxicity requires coordinated regulation of antioxidant defense, metal homeostasis, and nodule function in mung bean.

Mercury (Hg) contamination and accumulation in agricultural soil represent a major hazardous environmental concern, posing serious threats to living organisms, including plants. Silicon (Si) has been widely recognized to mitigate heavy metal (loid) toxicity; however, the underlying mechanism of Si-mediated mitigation of Hg-stress in mung bean remains unclear. In this study, we addressed this research gap by thoroughly examining the potential effects of Si supplementation on Hg-stressed mung bean plants, with particular emphasis on investigating the possible effects of Si on plant biomass, nodulation traits, antioxidant defense, and expression of metal-transporter and detoxification genes. Our findings demonstrated that Hg stress significantly impaired plant growth by inducing oxidative stress and reducing biological nitrogen fixation efficiency whereas Si application significantly alleviated the Hg-induced toxicity. Specifically, Si increased shoot dry biomass by +113% (2.13-fold), root dry biomass by +60% (1.60-fold), nodule number by +152% (2.52-fold), and nodule dry weight by +273% (3.73-fold) under Hg stress compared to Hg treated plants only. Furthermore, Si enhanced antioxidant defense system, restricted the uptake and accumulation of Hg in different plant tissues, and regulated the expression of genes related to metal transport and detoxification, contributing to improved nodulation and nitrogen fixation under Hg stress. Overall, our findings demonstrate that Si application mitigates the Hg-induced toxicity in mung bean plants by enhancing antioxidant defense, improving nitrogen fixation, regulation of genes involved in metal transport and detoxification, and limiting Hg accumulation.

Vigna radiata↗

PubMed1997

Hepatic amino acid and protein metabolism in non-anorectic, moderately cachectic tumor-bearing rats.

BACKGROUND/AIMS: Cancer cachexia is characterized by loss of lean body mass. Under this condition peripheral proteins are broken down and transferred to visceral organs and the tumor. The liver is the principal organ in the regulation of protein and amino acid metabolism, but liver amino acid kinetics in cancer are unclear. Therefore, we examined the effects of increasing tumor loads on hepatic protein turnover and amino acid handling. METHODS: A MCA-induced sarcoma was implanted subcutaneously in Lewis rats (200-225 g). Rats were studied when the tumor was 5-15% or 15-30% of body weight. Control rats were sham implanted. Under anesthesia, a primed constant infusion of para-aminohippuric acid and L-[3, 4-3H]-valine was given to calculate hepatic substrate fluxes and protein turnover. Serum alpha 2-macroglobulin concentration was measured to determine the acute phase response. RESULTS: Carcass weight decreased approximately 10% in large-tumor-bearing rats (p < 0.001). Liver wet weight increased from 5.5 +/- 0.1 (g) to 5.9 +/- 0.2 in the small-tumor-bearing group and 7.3 +/- 0.3 (p < 0.001) in the large-tumor-bearing group, with minimal changes in water content. Serum alpha 2-macroglobulin concentration, essential and gluconeogenic amino acid uptake by the liver increased in large-tumor-bearing animals. This contrasted with reduced liver ammonia uptake and unchanged urea production in tumor-bearing rats. In the small-tumor-bearing group liver protein synthesis increased, whereas protein breakdown remained unchanged. In the large-tumor-bearing group protein synthesis also increased, but protein breakdown decreased to zero. CONCLUSIONS: The study shows that in tumor-bearing rats, liver uptake of essential and gluconeogenic amino acids increases without significant increases in urea or glucose production. Synthesis of both structural and export proteins, e.g. acute phase proteins, increases suggesting that the liver becomes a more efficient nitrogen-sparing and active protein-synthesizing organ during the growth of a malignant tumor.

Amino Acids↗

PubMed2004

High-rate nitrification at low pH in suspended- and attached-biomass reactors.

This article reports on high-rate nitrification at low pH in biofilm and suspended-biomass reactors by known chemolithotrophic bacteria. In the biofilm reactor, at low pH (4.3 +/- 0.1) and low bulk ammonium concentrations (9.3 +/- 3.3 mg.liter(-1)), a very high nitrification rate of 5.6 g of N oxidized.liter(-1).day(-1) was achieved. The specific nitrification rate (0.55 g of N.g of biomass(-1).day(-1)) was similar to values reported for nitrifying reactors at optimal pH. In the suspended-biomass reactor, the average pH was significantly lower than that in the biofilm reactor (pH 3.8 +/- 0.3), and values as low as pH 3.2 were found. In addition, measurements in the suspended-biomass reactor, using isotope-labeled ammonium (15N), showed that in spite of the very low pH, biomass growth occurred with a yield of 0.1 g of biomass.g of N oxidized(-1). Fluorescence in situ hybridization using existing rRNA-targeted oligonucleotide probes showed that the nitrifying bacteria were from the monophyletic genus Nitrosomonas, suggesting that autotrophic nitrification at low pH is more widespread than previously thought. The results presented in this paper clearly show that autotrophic nitrifying bacteria have the ability to nitrify at a high rate at low pH and in the presence of only a negligible free ammonia concentration, suggesting the presence of an efficient ammonium uptake system and the means to cope with low pH.

Bacteria↗

PubMed2005

Biological phosphorus and nitrogen removal with biological aerated filter using denitrifying phosphorus accumulating organism.

In order to accomplish the biological nutrient removal with a weak sewage at low temperature, a hybrid process consisted of anoxic denitrifying phosphorus accumulating organism (dPAO) and nitrifying biological aerated filter (BAF) was studied in both lab and field pilot plants with weak sewage. The biofilm BAF was used as a post-nitrification process that provided sufficient nitrate to suspended growth dPAO. The anoxic/BAF configuration could remove nitrogen and phosphorus appreciably compared to other BNR systems. The enhanced biological phosphorus removal (EBPR) was mainly occurred in anoxic zone of suspended growth reactor. It has been found that P removal efficiency of dPAO was enhanced with an addition of a short oxic zone in suspended reactors compared to that of without oxic zone. However, the degree of aerobic P uptake in oxic zone was far lower than anoxic P uptake. The operating results of field plant indicated that dPAO/BAF configuration successfully reduced the adverse temperature effects at lower than 15 degrees C.

Bacteria, Aerobic↗