Nitrification and denitrifying phosphorus removal in an upright continuous flow reactor

2016 ◽  
Vol 73 (9) ◽  
pp. 2093-2100 ◽  
Author(s):  
Maryam Reza ◽  
Manuel Alvarez Cuenca
Keyword(s):  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Continuous Flow ◽  
Flow Reactor ◽  
Oxygen Demand ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Denitrifying Phosphorus Removal ◽  
Continuous Flow Reactor ◽  
Activated Sludge Processes

Simultaneous nitrification and denitrifying phosphorus removal was achieved in a single-sludge continuous flow bioreactor. The upright bioreactor was aligned with a biomass fermenter (BF) and operated continuously for over 350 days. This study revealed that unknown bacteria of the Saprospiraceae class may have been responsible for the successful nutrient removal in this bioreactor. The successive anoxic–aerobic stages of the bioreactor with upright alignment along with a 60 L BF created a unique ecosystem for the growth of nitrifier, denitrifiers, phosphorus accumulating organisms and denitrifying phosphorus accumulating organisms. Furthermore, total nitrogen to chemical oxygen demand (COD) ratio and total phosphorus to COD ratio of 0.6 and 0.034, respectively, confirmed the comparative advantages of this advanced nutrient removal process relative to both sequencing batch reactors and activated sludge processes. The process yielded 95% nitrogen removal and over 90% phosphorus removal efficiencies.

scholarly journals Continuous flow synthesis of ZSM-5 zeolite on the order of seconds

2016 ◽  
Vol 113 (50) ◽  
pp. 14267-14271 ◽  
Author(s):  
Zhendong Liu ◽  
Kotatsu Okabe ◽  
Chokkalingam Anand ◽  
Yasuo Yonezawa ◽  
Jie Zhu ◽  
...  
Keyword(s):  
Mass Production ◽  
Continuous Flow ◽  
Flow Reactor ◽  
Hot Water ◽  
Batch Reactors ◽  
Pressurized Water ◽  
Synthetic Process ◽  
Free System ◽  
Continuous Flow Reactor ◽  
Heating Medium

The hydrothermal synthesis of zeolites carried out in batch reactors takes a time so long (typically, on the order of days) that the crystallization of zeolites has long been believed to be very slow in nature. We herein present a synthetic process for ZSM-5, an industrially important zeolite, on the order of seconds in a continuous flow reactor using pressurized hot water as a heating medium. Direct mixing of a well-tuned precursor (90 °C) with the pressurized water preheated to extremely high temperature (370 °C) in the millimeter-sized continuous flow reactor resulted in immediate heating to high temperatures (240–300 °C); consequently, the crystallization of ZSM-5 in a seed-free system proceeded to completion within tens of or even several seconds. These results indicate that the crystallization of zeolites can complete in a period on the order of seconds. The subtle design combining a continuous flow reactor with pressurized hot water can greatly facilitate the mass production of zeolites in the future.

Comparison of Biocenoses from Continuous and Sequencing Batch Reactors

1992 ◽  
Vol 25 (6) ◽  
pp. 239-249 ◽  
Author(s):  
J. Wanner
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Continuous Flow ◽  
Sequencing Batch Reactor ◽  
Flow System ◽  
Batch Reactor ◽  
Continuous Reactor ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Filamentous Microorganisms

Sequencing batch reactors (SBR) are often used for research on nutrient removal systems. A model anaerobic-oxic SBR was compared with a compartmentalized continuous-flow system. The levels of COD, phosphorus, and nitrogen removal in both systems were comparable but the biocenoses differed significantly. The SVI values of activated sludge from the continuous reactor ranged between 100 and 200 ml/g although no significant occurrence of filamentous microorganisms was observed. The sequencing batch reactor produced activated sludge with the SVIs below 100 ml/g and with high settling velocities. Filamentous microorganisms were frequently observed in the biocenosis of the SBR. The differences in settling properties and filamentous growth in both reactors are discussed and explained.

Continuous flow electrocoagulation in the treatment of wastewater from dairy industries

2015 ◽  
Vol 73 (6) ◽  
pp. 1418-1425 ◽  
Author(s):  
Toni L. Benazzi ◽  
Marco Di Luccio ◽  
Rogério M. Dallago ◽  
Juliana Steffens ◽  
Rúbia Mores ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Flow Reactor ◽  
Oxygen Demand ◽  
Primary Treatment ◽  
Electrochemical Treatment ◽  
Dairy Wastewater ◽  
Hydraulic Residence Time ◽  
Microbial Decomposition ◽  
Continuous Flow Reactor ◽  
A Current

Dairy industry wastewater contains high levels of organic matter, consisting mainly of fat, protein and products of their partial microbial decomposition. In the present study, the use of continuous electrocoagulation is proposed for the primary treatment of dairy wastewater. The electrochemical treatment was carried out in a continuous flow cell with aluminum electrodes. The influence of the voltage, the distance between the electrodes and the hydraulic residence time (HRT) on the process performance was assessed, by measuring the removal of color, turbidity, total organic carbon (TOC) and chemical oxygen demand (COD). The optimum voltage, distance between the electrodes and HRT were 10 V, 1 cm and 90 min, respectively, yielding a current density of 13.3 A.m−2. Under these conditions, removal of color, turbidity, TOC and COD were 94%, 93%, 65% and 69%, respectively, after a steady state was reached in the continuous flow reactor.

scholarly journals N2O Reduction During Denitrifying Phosphorus Removal With Propionate as Carbon Source

2021 ◽  
Author(s):  
Li Cong ◽  
Qian Wang ◽  
Wenlin Jia
Keyword(s):  
Carbon Source ◽  
Phosphorus Removal ◽  
Dominant Factor ◽  
Nitrite Accumulation ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
N2o Reduction ◽  
Denitrifying Phosphorus Removal ◽  
Factors Affecting ◽  
Mixed Carbon Source

Abstract Denitrifying phosphorus removal was realized in sequencing batch reactors using different carbons sources (acetate, propionate, and a mixture of acetate/propionate). Nutrient removal and N2O production were investigated, and the factors affecting N2O production were explored. Nitrogen removal was 40.6% lower when propionate was used as the carbon source instead of acetate, while phosphorus removal was not significantly different. N2O production was greatly reduced when propionate was used as the carbon source instead of acetate. The emission factor in the propionate system was only 0.43%, while those in the acetate and mixed-carbon source system were 16.3% and 1.9%, respectively. Compared to the propionate system, ordinary heterotrophic organisms (i.e., glycogen-accumulating organisms) were enriched in the acetate system, explaining the higher N2O production in the acetate system. The lower nitrite accumulation in the propionate system compared to the acetate system was the dominant factor leading to the lower N2O production.

Nutrient removal, microbial community and sludge settlement in anaerobic/aerobic sequencing batch reactors without enhanced biological phosphorus removal

2010 ◽  
Vol 61 (10) ◽  
pp. 2433-2441
Author(s):  
Guangxue Wu ◽  
Michael Rodgers
Keyword(s):  
Microbial Community ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Significant Proportion ◽  
Volume Index ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Biological Phosphorus

Nutrient removal, microbial community and sludge settlement were examined in two 3-litre laboratory-scale anaerobic/aerobic sequencing batch reactors (SBRs). One SBR was operated at 10°C and the other SBR at 20°C. Different from conventional enhanced biological phosphorus removal, most of the soluble sodium acetate was removed in the aerobic phase and no organic carbon uptake or biological phosphorus release occurred in the anaerobic phase. In this type of anaerobic/aerobic SBR, the phosphorus removal and sludge settlement seemed to be unstable, and the dominant microorganism was Zoogloea sp. Although no excess biological phosphorus removal occurred, extracellular phosphorus precipitation contributed a significant proportion to total phosphorus removed. Sludge volume index decreased with increasing phosphorus contents in the biomass under all conditions. The functions of extracellular polymeric substances in sludge settlement and phosphorus removal depended on the environmental conditions applied.

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