scholarly journals Modeling light and temperature influence on ammonium removal by Scenedesmus sp. under outdoor conditions

2016 ◽  
Vol 74 (8) ◽  
pp. 1964-1970 ◽  
Author(s):  
Ana Ruiz-Martínez ◽  
Joaquin Serralta ◽  
Aurora Seco ◽  
Jose Ferrer
Keyword(s):  
Mathematical Model ◽  
Light Intensity ◽  
Flat Plate ◽  
Membrane Bioreactor ◽  
Removal Rate ◽  
Ammonium Concentration ◽  
Temperature Influence ◽  
Ammonium Removal ◽  
Maximum Light ◽  
Flat Plate Photobioreactor

The ammonium removal rate of the microalga Scenedesmus sp. was studied under outdoor conditions. Microalgae were grown in a 500 L flat-plate photobioreactor and fed with the effluent of a submerged anaerobic membrane bioreactor. Temperature ranged between 9.5 °C and 32.5 °C and maximum light intensity was 1,860 μmol·m−2·s−1. A maximum specific ammonium removal rate of 3.71 mg NH4+-N·g TSS−1·h−1 was measured (at 22.6 °C and with a light intensity of 1,734 μmol·m−2·s−1). A mathematical model considering the influence of ammonium concentration, light and temperature was validated. The model successfully reproduced the observed values of ammonium removal rate obtained and it is thus presented as a useful tool for plant operation.

scholarly journals Ammonium removal by a novel heterotrophic nitrifying and aerobic denitrifying bacterium Pseudomonas stutzeri KTB from wastewater

2015 ◽  
Vol 50 (3) ◽  
pp. 219-227 ◽  
Author(s):  
Maohong Zhou ◽  
Hairen Ye ◽  
Xiaowei Zhao
Keyword(s):  
Nitrogen Removal ◽  
Removal Rate ◽  
Pseudomonas Stutzeri ◽  
Culture Conditions ◽  
Aerobic Denitrification ◽  
Ammonium Concentration ◽  
Logarithmic Phase ◽  
Ammonium Removal ◽  
Removal Ratio ◽  
Initial Ph

The effects of culture conditions on a newly isolated Pseudomonas stutzeri KTB's ability to simultaneously perform heterotrophic nitrification and aerobic denitrification were investigated to determine its potential of application in nitrogen removal from wastewater. The results from experiments in the presence of 10 mmol/L of ammonium were as follows: succinate was the preferred carbon source, and the optimum C/N ratio, temperature, and initial pH were 10, 30 °C, and 7–8, respectively. Nitrogen removal took place not only in the logarithmic phase but also in the stationary phase. Under the optimum conditions, the nitrogen removal rate increased as the ammonium concentration elevated, until it was as high as 60 mmol/L. Meanwhile, the maximum specific growth rate decreased. The highest nitrogen removal rate of 0.977 mmol/L/h was observed at 60 mmol/L of ammonium and the maximum removal ratio of 85.6% at 40 mmol/L when the bacterial treatment for 48 h was completed. The strain was vulnerable to even higher ammonium loads. When incubated in anaerobically digested hennery wastewater containing 43.85 mmol/L of ammonium and 2.32 mmol/L of nitrate, the removal ratio and rate reached 82.4% and 0.397 mmol/L/h, respectively. The strain might be a great candidate for ammonium removal from wastewater.

Completely Autotrophic Nitrogen-Removal for Treatment of High Ammonia Leachate

2010 ◽  
Vol 113-116 ◽  
pp. 662-665
Author(s):  
Wen De Tian ◽  
Kyoung Jin An ◽  
Zhi Wei Li
Keyword(s):  
Nitrogen Removal ◽  
Removal Rate ◽  
Optimal Operation ◽  
Ammonium Concentration ◽  
Operation Condition ◽  
Partial Nitritation ◽  
Ammonium Removal ◽  
High Ammonia ◽  
Anammox Process ◽  
Autotrophic Nitrogen Removal

This study focused on the feasibility of autotrophic nitrogen removal to treat high ammonia leachate, using combined partial Nitritation and Anammox process. In partial nitritation reactor, the optimal operation condition was found with influent ammonium concentration of 1200 mg/L, DO about 3 mg/L, HRT 3 days and temperature about 31°C at the ratio of NO2-N / NH4-N effluent kept at 1.1, which is a prerequisite for the application of Anammox. In Anammox reactor, more than 85% ammonium is removed at HRT 8 days, temperature 28±1°C, and pH 8. The removal rate of nitrogen and COD in combined partial Nitritation and Anammox process are 90% and 74%, respectively. Thus, a combined process of partial nitritation and a subsequent Anammox could be an alternative solution for ammonium removal for leachate.

Isolation, Identification and Characterization of Heterotrophic Nitrifying Bacteria from Surface Water

2013 ◽  
Vol 726-731 ◽  
pp. 406-411 ◽  
Author(s):  
Duo Ying Zhang ◽  
Wei Guang Li ◽  
Wen Qin ◽  
Xiao Fei Huang
Keyword(s):  
Drinking Water ◽  
Heterotrophic Bacteria ◽  
Removal Rate ◽  
Drinking Water Treatment ◽  
Nitrifying Bacteria ◽  
Ammonium Concentration ◽  
N Accumulation ◽  
Songhua River ◽  
Ammonium Removal ◽  
Heterotrophic Nitrifying Bacteria

For reducing ammonium concentration and guaranteeing safe drinking water, three heterotrophic bacteria were isolated from the Songhua River, which were SFA6, SFA7 and SFA11. When the initial ammonium concentration was about 130 mg/L, the ammonium removal rate of the strains SFA7, SFA6 and SFA 11 were 1.54 mg NH4+/L/h, 1.20 mg NH4+/L/h and 1.27 mg NH4+/L/h respectively at 8 °C. The 16S rDNA sequence results revealed that the strain SFA6 wasBacillus subtilis, SFA7 wasPseudomonas putida, and SFA11 showed similarity toPseudomonas nitroreducens. The biochemical characteristics of SFA6 were quite different from that of SFA7 and SFA11. After 48 h degradation, the NH4+-N (about 5 mg/L) was consumed to 0.23±0.15 mg/L, 0.37±0.20 mg/Land 0.58±0.17 mg/L by the strains SFA6, SFA7 and SFA11, with little NO3--N and NO2--N accumulation. Above all, the strains SFA6, SFA7 and SFA11 could be used in drinking water treatment at 8 °C. The strain SFA6 showed the highest ammonium removal efficiency.

Temperature Influence on Performance of Oxidation Ponds

1991 ◽  
Vol 24 (5) ◽  
pp. 85-96 ◽  
Author(s):  
Qingliang Zhao ◽  
Zijie Zhang
Keyword(s):  
Mathematical Model ◽  
Temperature Influence ◽  
Field Scale ◽  
Experiment Data ◽  
Computer Technique ◽  
Oxidation Pond ◽  
Optimum Model ◽  
Oxidation Ponds ◽  
The Mathematical Model ◽  
The Relationship

By means of simulated tests of a laboratory–scale oxidation pond model, the relationship between BOD5 and temperature fluctuation was researched. Mathematical modelling for the pond's performance and K1determination were systematically described. The calculation of T–K1–CeCe/Ci) was complex but the problem was solved by utilizing computer technique in the paper, and the mathematical model which could best simulate experiment data was developed. On the basis of experiment results,the concept of plug–ratio–coefficient is also presented. Finally the optimum model recommended here was verified with the field–scale pond data.

scholarly journals Simulation of the laser-material interaction of ultrashort pulse laser processing of silicon nitride workpieces and the key factors in the ablation process

2021 ◽  
Author(s):  
Babak Soltani ◽  
Faramarz Hojati ◽  
Amir Daneshi ◽  
Bahman Azarhoushang
Keyword(s):  
Mathematical Model ◽  
Laser Ablation ◽  
Pulse Laser ◽  
Ultrashort Pulse ◽  
Laser Processing ◽  
Laser Power ◽  
Removal Rate ◽  
Ultrashort Pulse Laser ◽  
Laser Material ◽  
Material Interaction

AbstractUnderstanding the laser ablation mechanism is highly essential to find the effect of different laser parameters on the quality of the laser ablation. A mathematical model was developed in the current investigation to calculate the material removal rate and ablation depth. Laser cuts were created on the workpiece with different laser scan speeds from 1 to 10 mm s−1 by an ultrashort pulse laser with a wavelength of about 1000 nm. The calculated depths of laser cuts were validated via practical experiments. The variation of the laser power intensity on the workpiece’s surface during laser radiation was also calculated. The mathematical model has determined the laser-material interaction mechanism for different laser intensities. The practical sublimation temperature and ablated material temperature during laser processing are other data that the model calculates. The results show that in laser power intensities (IL) higher than 1.5 × 109 W cm−2, the laser-material interaction is multiphoton ionisation with no effects of thermal reaction, while in lower values of IL, there are effects of thermal damages and HAZ adjacent to the laser cut. The angle of incidence is an essential factor in altering incident IL on the surface of the workpiece during laser processing, which changes with increasing depth of the laser cut.

Parameter Optimization for Vibration Flow Field of Polystyrene Melts via RBF Neural Networks Combined with SALS

2012 ◽  
Vol 602-604 ◽  
pp. 757-761
Author(s):  
Guang Ming Xian ◽  
Jing Ping Qu ◽  
Bi Qing Zeng
Keyword(s):  
Light Intensity ◽  
Flow Field ◽  
Polymer Melts ◽  
Scattered Light ◽  
Projection Area ◽  
Rbf Neural Networks ◽  
Maximum Light ◽  
Before And After ◽  
Small Angle Light Scattering ◽  
Slit Die

This work aims at developing an accurate measurement of characterization flow field of polymer melts by small-angle light scattering (SALS). In this article we propose a new method, based on radial basis function neural network (RBFNN) for predicting the optimum vibration field parameters. A laser light passes through polymer melts in the visual slit die. The results reported in this study were obtained with polystyrene (PS) with rotation speed at 20 rpm. In order to capture the scattered light, a polarizer and an analyzer are placed before and after the polymer melts. RBFNN inputs consist of frequency and amplitude, which are used as input parameters to predict the maximum light intensity projection area. RBFNN predicts that the optimum value of frequency, amplitude are 15.86 Hz and 0.20mm, respectively. And the maximum light intensity projection area is predicted to be 9260 pixels.

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