scholarly journals Microalgal growth, nitrogen uptake and storage, and dissolved oxygen production in a polyculture based-open pond fed with municipal wastewater in northern Sweden

Chemosphere ◽  
2021 ◽  
Vol 276 ◽  
pp. 130122
Author(s):  
Sandra Lage ◽  
Andrea Toffolo ◽  
Francesco G. Gentili
Keyword(s):  
Dissolved Oxygen ◽  
Nitrogen Uptake ◽  
Municipal Wastewater ◽  
Northern Sweden ◽  
Oxygen Production ◽  
Open Pond ◽  
And Storage

Cobalt pyrophosphate (Co2P2O7) derived from an Open-Framework Cobalt Phosphite: A Durable Electroactive Material for Electrochemical Energy Conversion and Storage Application

2021 ◽  
Author(s):  
Jogendra Nath Behera ◽  
Abhisek Padhy ◽  
Aneeya K Samantara
Keyword(s):  
Energy Conversion ◽  
Water Splitting ◽  
Oxygen Production ◽  
Electroactive Material ◽  
Open Framework ◽  
Energy Conversion And Storage ◽  
Energy Conversion Systems ◽  
And Storage ◽  
Cobalt Pyrophosphate ◽  
Electrochemical Energy

Water splitting is an assuring method of qualitative as well as quantitative oxygen production to support future energy conversion systems and strictly depends on the nature of the electrocatalyst. Likewise,...

Municipal wastewater characteristics at Irtah pumping station in the Tulkarem city

2000 ◽  
Vol 42 (1-2) ◽  
pp. 337-340 ◽  
Author(s):  
H.Q. Shaheen
Keyword(s):  
Dissolved Oxygen ◽  
Suspended Solids ◽  
Municipal Wastewater ◽  
Total Suspended Solids ◽  
Ammonia Nitrogen ◽  
Total Kjeldahl Nitrogen ◽  
Pumping Station ◽  
Kjeldahl Nitrogen ◽  
Sodium And Potassium ◽  
Mixed Samples

Wastewater flow samples were collected at 2-hour intervals for one week during the month of October 1998 at the Irtah wastewater pumping station in the Tulkarem city. The station collects about 32% of the wastewater of the Tulkarem city and 25% of the Tulkarem camp. The samples were mixed on 24-hour basis and tested for the pollution parameters BOD5, COD, total suspended solids, orthophosphate, total Kjeldahl nitrogen, ammonia nitrogen, nitrate, calcium, sodium and potassium. At the 2-hour intervals the wastewater flow was tested for conductivity, temperature, pH, and dissolved oxygen. The variation of the strength of these parameters and its relation to the flow values are observed and evaluated. The produced organic strength versus the flow and the 24-hour mixed samples are presented and commented upon.

scholarly journals Influence of dissolved oxygen on nitrification kinetics in a circulating bed reactor

1998 ◽  
Vol 37 (4-5) ◽  
pp. 189-193 ◽  
Author(s):  
V. Lazarova ◽  
R. Nogueira ◽  
J. Manem ◽  
L. Melo
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Municipal Wastewater ◽  
Ammonia Concentration ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Laboratory Scale ◽  
Nitrification Rate ◽  
Nitrification Kinetics ◽  
Laboratory Scale Reactor

The influence of dissolved oxygen concentration in nitrification kinetics was studied in a new biofilm reactor, the circulating bed reactor (CBR). The study was carried out partly at laboratory scale with synthetic water containing inorganic carbon and nitrogen compounds, and partly at pilot scale for secondary and tertiary nitrification of municipal wastewater. The experimental results showed that either the ammonia or the oxygen concentration could be limiting for the nitrification rate. The transition from ammonia to oxygen limiting conditions occurred for an oxygen to ammonia concentration ratio of about 1.5 - 2 gO2/gN-NH4+ for both laboratory- and pilot-scale reactors. The nitrification kinetics of the laboratory-scale reactor was close to a half order function of the oxygen concentration, when oxygen was the rate limiting substrate.

scholarly journals Enhancing Nitrate Removal from Waters with Low Organic Carbon Concentration Using a Bioelectrochemical System—A Pilot-Scale Study

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 516 ◽  
Author(s):  
Rauno Lust ◽  
Jaak Nerut ◽  
Kuno Kasak ◽  
Ülo Mander
Keyword(s):  
Organic Carbon ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Power Efficiency ◽  
Municipal Wastewater ◽  
Nitrate Removal ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Dissolved Oxygen Concentration ◽  
Organic Carbon Concentration

Assessments of groundwater aquifers made around the world show that in many cases, nitrate concentrations exceed the safe drinking water threshold. This study assessed how bioelectrochemical systems could be used to enhance nitrate removal from waters with low organic carbon concentrations. A two-chamber microbial electrosynthesis cell (MES) was constructed and operated for 45 days with inoculum that was taken from a municipal wastewater treatment plant. A study showed that MES can be used to enhance nitrate removal efficiency from 3.66% day−1 in a control reactor to 8.54% day−1 in the MES reactor, if a cathode is able to act as an electron donor for autotrophic denitrifying bacteria or there is reducing oxygen in a cathodic chamber to favor denitrification. In the MES, greenhouse gas emissions were also lower compared to the control. Nitrous oxide average fluxes were −639.59 and −9.15 µg N m−2 h−1 for the MES and control, respectively, and the average carbon dioxide fluxes were −5.28 and 43.80 mg C m−2 h−1, respectively. The current density correlated significantly with the dissolved oxygen concentration, indicating that it is essential to keep the dissolved oxygen concentration in the cathode chamber as low as possible, not only to suppress oxygen’s inhibiting effect on denitrification but also to achieve better power efficiency.

Transformation of Azo Dye AO-7 by Wastewater Biofilms

1992 ◽  
Vol 26 (3-4) ◽  
pp. 627-636 ◽  
Author(s):  
C. Harmer ◽  
P. Bishop
Keyword(s):  
Dissolved Oxygen ◽  
Azo Dye ◽  
Municipal Wastewater ◽  
Bond Cleavage ◽  
Biofilm Reactor ◽  
Cod Removal ◽  
Bulk Phase ◽  
Acid Orange 7 ◽  
Low Dissolved Oxygen ◽  
The Impact

Azo dyes are common contaminants in wastewater. Many are poorly removed by most typical municipal treatment processes. Those which are partially degraded may form toxic intermediates, particularly under anaerobic conditions. Acid Orange 7 (AO-7) is a simple azo dye which is biotransformable. In this study, bulk-phase factors affecting azo bond cleavage of AO-7 in a synthetic municipal wastewater were investigated using lab-scale, rotating drum biofilm reactors. A series of statistically designed experiments were used to characterize the response of the pseudo-steady state biofilms. A variety of microorganisms from the activated sludge seed for the biofilm were found to be capable of transforming the AO-7. Biofilm removals of AO-7 ranged from 18 to 97%. Two maxima of AO-7 transformation rates were found-one at high bulk-phase dissolved oxygen and low COD removal flux, and another at low dissolved oxygen and high COD flux. No 1-amino 2-naphthol intermediate was detected. The sulfanilic acid intermediate was present at low dissolved oxygen levels. Suspended-phase COD removal was inhibited by AO-7, but the effect was not detected in the biofilm reactor system. AO-7 transformation and biological nitrification interact, but the impact is small.

Effect of static magnetic field on the oxygen production of Scenedesmus obliquus cultivated in municipal wastewater

2015 ◽  
Vol 86 ◽  
pp. 132-138 ◽  
Author(s):  
Renjie Tu ◽  
Wenbiao Jin ◽  
Tingting Xi ◽  
Qian Yang ◽  
Song-Fang Han ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Municipal Wastewater ◽  
Scenedesmus Obliquus ◽  
Oxygen Production

A Study on the Fish Pond Oxygenase System Driven by Wind Turbine

2014 ◽  
Vol 875-877 ◽  
pp. 1666-1670
Author(s):  
Zi Jie Chien ◽  
Hung Pin Cho ◽  
Ching Song Jwo ◽  
Sih Li Chen ◽  
Chao Chun Chien ◽  
...  
Keyword(s):  
Wind Speed ◽  
Power Consumption ◽  
Dissolved Oxygen ◽  
Wind Turbine ◽  
Wind Power ◽  
Power Supply ◽  
Reciprocating Compressor ◽  
Oxygen Production ◽  
Horizontal Axis Wind Turbine ◽  
Rotating Speed

This study developed an oxygenase system with horizontal-axis wind turbine driving the oxygenation device by belt pulley for aquaculture, and verified the feasibility of the system in conditions of Taiwan’s average wind speed. The experimental system is consisted of a horizontal wind turbine, a reciprocating compressor, and water channels. At the first stage of the experiment, the reciprocating compressor oxygenase system was measured according to the power supply standards in terms of power consumption, air displacement and oxygen production, in case of various rotating speeds and the compliance with aquaculture standards. At the second stage of the experiment, the wind turbine was used to directly drive the reciprocating compressor oxygenase system. According to the experimental results, regarding the test of the compressor oxygenase system, when power supply rotating speed is 406.7 rpm, power consumption is 234.5 W and the oxygen production is 7.48mg/L, which is above the level of amount of dissolved oxygen of aquaculture at 5.5mg/L. In case of driving the oxygenation device by wind power, when wind speed is 5.06 m/s and the wind turbine rotating speed is 140 rpm, the average dissolved oxygen in the water is 5.9 mg/L, which meets the aquaculture standards. Even in case of unstable wind speed, good oxygen production effects can be achieved. Moreover, the system is directly driven by wind power and does not require electric power.

Effects of the DO of Nitrification Return Flow on the Nitrogen Removal of A/A-MBR Combined Process

2012 ◽  
Vol 174-177 ◽  
pp. 58-63 ◽  
Author(s):  
Xiao Ying Zheng ◽  
Wei Chen ◽  
Ji Li ◽  
Yu Jie He ◽  
Xi Huang ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Treatment Plant ◽  
Denitrification Rate ◽  
Effective Control ◽  
Return Flow ◽  
Stable Operation ◽  
Combined Process

In this study, the traditional A/A/O process was combined with MBR to create the A/A-MBR combined process. A 2.0 m3/h pilot scale study on the combined process was carried out. The influence mechanism of dissolved oxygen (DO) in the return flow on the A/A-MBR combined process was analyzed and the suitable dissolved oxygen concentration in MBR was further optimized. The results show that the combined process has the characteristics of rapid start and stable operation. Its COD, NH4+-N, TN and TP removals were 82.1%~92.4%, 93.0~98.3%, 48.4~70.7% and 93.8~97.9%, respectively. The return flow with high concentration of DO in MBR seriously affected the denitrification rate. The DO concentration of return flow increased gradually from 2.0 mg/L to 5.0 mg/L, the denitrification rate continuously decreased, the denitrification rate in the first stage decreased from 2.52 mg NO3--N/(gVSS•h) to 0.34mg NO3--N/(gVSS•h). When the DO of nitrification return liquid ascended to 5 mg/L, the denitrification ability of activated sludge was severely inhibited, and its denitrification activity was even lost. DO were controlled between 4.0±0.5 mg/L by adjusting the aeration rate in the MBR, effluent TN could be stably maintained between 10.82-13.94 mg/L with 62.6% average removal rate. The effluent COD, NH4+-N, TN and TP stably qualified to t criteria of the first level A of China’ s "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant" (GB18918-2002). If the effective control of membrane fouling could be ensured, the DO in the MBR was controlled as much as possible fewer than 4.0 mg/L. This could decrease the inhibition of denitrification by high DO from the return flow and insure that effluent TN achieved the discharge standard.

scholarly journals Thickening and Storage of Sewage Sludge Contribute to the Degradation of LAS and EOX and the Humification of Organic Matter

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 933
Author(s):  
Ali Khakbaz ◽  
Daniele Goi ◽  
Carlo Bravo ◽  
Marco Contin
Keyword(s):  
Organic Matter ◽  
Sewage Sludge ◽  
Humic Substances ◽  
Municipal Wastewater ◽  
Biological Activities ◽  
Land Application ◽  
Organic Matter Quality ◽  
Organic C ◽  
And Storage

Land application of sewage sludge on agricultural soils can be sustainable only if pollutant contents and organic matter quality meet the requirements imposed by minimization of environmental risks. This study investigated the degradation of linear alkylbenzene sulfonates (LAS) and extractable organic halogens (EOX) and the formation of humic substances (HS) during the thickening and storage phases of sewage sludge treatment. Changes in spectroscopic properties (UV-Vis, FT-IR, and excitation-emission matrix (EEM) fluorescence) of HS were also evaluated to assess the occurrence of biological activities during these curing phases of sewage sludge (SS). Humic acids (HA), fulvic acids (FA), EOX, and LAS were extracted from sewage sludge sampled from four municipal wastewater treatment plants of different size and treatment sequence, before and after 90 days of aerobic or anaerobic storage. During storage, the loss of organic C in the SS ranged from almost null to 31%. No significant changes of FA were registered, whereas HA increased in almost all samples, up to 30%. The amount of humic substances synthesized during storage correlated with the percentage of C lost. Spectroscopic changes of FA and HA showed an increase in their aromaticity, with a corresponding decrease in the aliphatic contribution. These changes show the improved agronomical quality of SS. LAS decreased during storage up to 30%, surprisingly more under anaerobic than aerobic conditions, whereas EOX decreased significantly in all samples, even up to 81%. In conclusion, although storage may be normally considered not influencing the quality of SS, their organic matter quality improved and contamination decreased during 90 days of storage, whatever the conditions of oxygen availability applied.

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