Contribution of P-bacteria in biological nutrient removal processes to overall effects on the environment

2001 ◽  
Vol 44 (1) ◽  
pp. 67-76 ◽  
Author(s):  
X. Hao ◽  
J. J. Heijnen ◽  
Y. Qian ◽  
M. C.M. van Loosdrecht
Keyword(s):  
Energy Consumption ◽  
Co2 Emissions ◽  
P Uptake ◽  
Biological Nutrient Removal ◽  
Net Energy ◽  
Positive Effects ◽  
Ch4 Production ◽  
Obligate Aerobic ◽  
Energy Consumption Simulation ◽  
P Removal

P-bacteria can combine denitrification and P-uptake. This category of P-bacteria is abbreviated DPB. Use of DPB in BNR processes, instead of obligate aerobic PAOs, reduces oxygen consumption. Moreover, less COD is needed for the nitrogen removal. Non-required COD can be removed by presettling and used for methanation. This leads to a lower sludge production. As a result, CO2 emissions are reduced owing to less net energy consumption. Simulation for a planned WWTP with the BCFS® process indicates that DPB can save 53-59% of required COD. The optimal ratios of COD/N and COD/P for simultaneous N and P removal are determined to be 3.9~4.5 and 32.2~35.2 at 12~20°C. 80-95% of particulate COD can be removed from the influent, thereby CH4 production is increased by 154-271%, and the total volume of reactors can be reduced by about 50% compared to a minimised process design. Less net energy consumption over the whole WWTP contributes to a net reduction of the total CO2 emissions up to 16-21%. The energy production from CH4 is excessive enough to balance the energy consumption from aeration, dewatering and incineration. It is concluded that contribution of P-bacteria to saving COD has overall positive effects on the environment.

Model based evaluation of plant improvement strategies for biological nutrient removal

1999 ◽  
Vol 39 (4) ◽  
pp. 45-53 ◽  
Author(s):  
H. M. van Veldhuizen ◽  
M. C. M. van Loosdrecht ◽  
F. A. Brandse
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
P Uptake ◽  
Biological Nutrient Removal ◽  
Adequate Description ◽  
Control Scheme ◽  
Detailed Simulation ◽  
High Fraction ◽  
Biokinetic Parameters ◽  
P Removal

An activated sludge model for biological N- and P-removal was developed, which describes anoxic and aerobic P-uptake based on bacterial metabolism. This model was tested in practice on two wastewater treatment plants, which are BCFS®-processes, which contain activated sludge with a high fraction of denitrifying P-removing bacteria (DPB's). The model appeared to be able to give an adequate description of the performance of these treatment plants under different conditions. If the process parameters are well defined almost no calibration of the biokinetic parameters was necessary. In the simulation of Dalfsen wwtp, which has a complex control scheme, it was possible to give an adequate simulation of the control actions and the concentration profiles in a rather simple way, showing that detailed simulation of these controllers was not necessary. With the calibrated model it was possible to analyse bottlenecks and give suggestions for upgrading of the concerned treatments plants. The simulation results were used in decisions on investments.

Difficulties and developments in biological nutrient removal technology and modelling

1999 ◽  
Vol 39 (6) ◽  
pp. 1-11 ◽  
Author(s):  
George A. Ekama ◽  
Mark C. Wentzel
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
P Uptake ◽  
Biological Nutrient Removal ◽  
Filamentous Bulking ◽  
Recent Developments ◽  
Removal Technology ◽  
Hydrolysis Of ◽  
Activated Sludge Systems ◽  
P Removal

Filamentous bulking and the long sludge age required for nitrification are two important factors that limit the wastewater treatment capacity of biological nutrient removal (BNR) activated sludge systems. A growing body of observations from full-scale plants indicate support for the hypothesis that a significant stimulus for filamentous bulking in BNR systems in alternating anoxic-aerobic conditions with the presence of oxidized nitrogen at the transition from anoxic to aerobic. In the DEPHANOX system, nitrification takes place externally allowing sludge age and filamentous bulking to be reduced and increases treatment capacity. Anoxic P uptake is exploited in this system but it appears that this form of biological excess P removal (BEPR) is significantly reduced compared with aerobic P uptake in conventional BNR systems. Developments in the understanding of the BEPR processes of (i) phosphate accumulating organism (PAO) denitrification and anoxic P uptake, (ii) fermentation of influent readily biodegradable (RB)COD and (iii) anaerobic hydrolysis of slowly biodegradable (SB)COD are evaluated in relation to the IAWQ Activated Sludge Model (ASM) No.2. Recent developments in BEPR research do not yet allow a significant improvement to be made to ASM No. 2 that will increase its predictive power and reliability and therefore it remains essentially as a framework to guide further research.

Biological nitrogen and phosphorus removal in UCT-type MBR process

2009 ◽  
Vol 59 (11) ◽  
pp. 2093-2099 ◽  
Author(s):  
H. Lee ◽  
J. Han ◽  
Z. Yun
Keyword(s):  
Phosphorus Removal ◽  
P Uptake ◽  
Biological Nutrient Removal ◽  
Anoxic Zone ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Nitrate Inhibition ◽  
Biological Nitrogen ◽  
P Removal ◽  
Production Characteristics

A lab-scale UCT-type membrane bio-reactor (MBR) was operated for biological nitrogen (N) and phosphorus (P) removal simultaneously. In order to examine biological nutrient removal (BNR) characteristics of MBR, the lab unit was fed with a synthetic strong and weak wastewater. With strong wastewater, a simultaneous removal of N and P was achieved while application of weak wastewater resulted in a decrease of both N and P removal. Recycled nitrate due to the limited organic in weak wastewater operation probably caused a nitrate inhibition in anaerobic zone. In step feed modification with weak wastewater, both N and P removal capability recovered in the system, indicating that the allocation of COD for denitrification at anoxic zone was a key to increase the biological P removal. In addition, the analysis on the specific P uptake rate in anoxic zone demonstrated that denitrifying phosphorus accumulating organism (dPAO) played an important role to remove up to 40% of P along with N. The sludge production characteristics of UCT-type MBR were similar to ordinary activated sludge with BNR capability.

Comparison of aerobic and anoxic phosphorus uptake in ndbepr systems (uct and enbnras)

2002 ◽  
Vol 46 (4-5) ◽  
pp. 201-207 ◽  
Author(s):  
S.M. Vermande ◽  
S. Sötemann ◽  
G. Aguilera Soriano ◽  
M. Wentzel ◽  
J.M. Audic ◽  
...  
Keyword(s):  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Mass Fraction ◽  
Phosphorus Uptake ◽  
P Uptake ◽  
Biological Nutrient Removal ◽  
P Release ◽  
University Of Cape Town ◽  
The University ◽  
P Removal

Two Nitrification-Denitrification Biological Excess Phosphorus Removal (NDBEPR) systems have been operated for 8.5 months in order to compare their Biological Excess Phosphorus Removal (BEPR) performance. One of these systems, i.e. the University of Cape Town (UCT) system, exhibits mainly aerobic P uptake while the External Nitrification Biological Nutrient Removal Activated Sludge (ENBNRAS) system is characterised by high anoxic P uptake. It was observed that when operating with predominantly aerobic P uptake, the UCT system released more P than the ENBNRAS system, even though it had a lower anaerobic mass fraction. However, when the influent TKN/COD was high, i.e. >0.1, anoxic P uptake also occurred in the UCT system and P release dropped to lower levels than in the ENBNRAS. Accordingly, P uptake of the UCT system was 5 mg P/l influent higher than that of the ENBNRAS system, when it was predominantly aerobic, but 9 mg P/l influent lower when anoxic P uptake occurred. As a result, the UCT system achieved superior P removal when aerobic P uptake was predominant (23% higher), but when high influent TKN/COD promoted anoxic P uptake the P removal of the UCT system was poorer than that of the ENBNRAS system. This study clearly showed that anoxic P uptake is not beneficial to NDBEPR systems.

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

2005 ◽  
Vol 52 (10-11) ◽  
pp. 569-578 ◽  
Author(s):  
J. Lee ◽  
J. Kim ◽  
C. Lee ◽  
Z. Yun ◽  
E. Choi
Keyword(s):  
P Uptake ◽  
Biological Nutrient Removal ◽  
Biological Aerated Filter ◽  
Biological Phosphorus Removal ◽  
Nitrogen And Phosphorus ◽  
Suspended Growth ◽  
Oxic Zone ◽  
Aerated Filter ◽  
Biological Phosphorus ◽  
P Removal

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°C.

Acidogenic Activity: Process of Carbon Source Generation for Biological Nutrient Removal

1999 ◽  
Vol 40 (8) ◽  
pp. 25-32
Author(s):  
E. Rustrian ◽  
J. P. Delgenes ◽  
N. Bernet ◽  
R. Moletta
Keyword(s):  
Anaerobic Digestion ◽  
Carbon Source ◽  
Batch Reactor ◽  
P Uptake ◽  
Synthetic Wastewater ◽  
Biological Nutrient Removal ◽  
Methanogenic Activity ◽  
Operational Conditions ◽  
Acidogenic Reactor ◽  
P Removal

In this study, a sequencing batch reactor (SBR) connected with a two step anaerobic digestion system is proposed in order to investigate the possibility of simultaneous C, N and P removal from wastewater. The system was studied using synthetic wastewater. In this system, the effluent of nitrate from the SBR reactor is added to the acidogenic reactor influent. Nitrate elimination and VFA production are then achieved together in the acidogenic reactor. The performances of three lab-scale reactors, operated for C, N and P biological removal are analyzed. The removals of TOC, TN and TP-PO4 were greater than 96%, 75% and 86%, respectively. The results show that the combination of anaerobic digestion in two step-SBR treatment is effective for simultaneous C, N and P removal. The benefits from this process are the saving of carbon source for denitrification and phosphorus removal. Reactor arrangement made possible the existence of zones where the different bacterial populations involved could coexist. Complete denitrification occurs in acidogenic reactor and hence the methanogenic activity is not reduced nor inhibited by N-NO3 presence, allowing greater TOC removal. A stable P-release and P-uptake took place after coupling of the three reactors. Furthermore, a fast settling, compact sludge is generated in the SBR with the operational conditions applied.

scholarly journals Energy consumption, economic development and environmental degradation nexus for Nigeria

2021 ◽  
Vol 8 (4) ◽  
pp. 463-473
Author(s):  
David Ashibi Ushie ◽  
Esther Ranmilowo Aderinto
Keyword(s):  
Economic Development ◽  
Energy Consumption ◽  
Co2 Emissions ◽  
Environmental Degradation ◽  
Ecological Footprint ◽  
Environmental Indicators ◽  
Pollutant Emissions ◽  
Positive Effects ◽  
Long Run ◽  
Short Run

This study tests the existence of the Environmental Kuznets Curve (EKC) hypothesis for Nigeria using two environmental indicators vis-à-vis ecological footprint and carbon dioxide emissions. Data was sourced from World Development Indicators (WDI) and the Global Footprint Network for the period spanning from 1981 to 2019.The Auto Regressive Distributed Lag (ARDL) method was employed. It was observed that short-run and long-run relationships exist among the variables. Findings revealed that in the short and long run, energy consumption has positive effects on CO2 emissions in Nigeria. However, for ecological footprint, only energy consumption in the three lagged period has a positive relationship with EFP in the short run without any significant effect being observed in the long run. Similarly, an inverted U-shaped environmental degradation-economic development relationship was established in the study which validated the EKC hypothesized inverted U-shape for CO2 emissions. However, for EFP, there was no evidence of the EKC. As such, the shape of the EKC curve is subject to the environmental indicators employed. The study therefore recommends an increase in the use of alternative sources of energy that are relatively free from pollutant emissions as an alternative and viable option for Nigeria.

scholarly journals Energy consumption and CO2 emission reductions trough refurbishment of residential buildings’ roofs by applying the green roof system: Case study

2018 ◽  
Vol 22 (Suppl. 4) ◽  
pp. 1217-1229 ◽  
Author(s):  
Katarina Djordjevic ◽  
Olja Joksimovic ◽  
Milica Jovanovic-Popovic
Keyword(s):  
Energy Consumption ◽  
Co2 Emissions ◽  
Energy Savings ◽  
Residential Buildings ◽  
Structural Characteristics ◽  
Green Roof ◽  
Green Roofs ◽  
Noticeable Effect ◽  
Roof System ◽  
Positive Effects

Climate changes which we are experiencing at the moment are affecting the entire globe. Serbia, as a developing country, is in the process of defining its own energy strategy and priorities when it comes to the problem of increased energy consumption in its building stock. Research shows that residential sector consumes the largest quantity of energy. CO2 emissions present another big problem which is in a direct correlation with energy consumption. Green roofs have multiple positive effects on buildings and their surroundings which make them a desirable option for retrofitting roofs. The aim of this paper is to investigate thermal properties of chosen green roof system and its potential to positively influence energy consumption for heating buildings and therefore CO2 emissions trough refurbishing existing old flat roofs. New Belgrade was chosen for this research for its unique urban characteristics - existence of large number of similar or identical buildings, which have same structural characteristics and similar surroundings. For the purpose of this paper, blocks 45 and 70 were chosen. Results of this research are applicable on all of the 132 buildings found at this location, which have total roof area of 90990m2. By calculating energy quantity needed for heating the building with the existing roof and two hypothetical models, which have green roof, it was possible to quantify energy savings, which are in a direct correlation with CO2 emissions. A control roof was introduced in order to examine if the proposed green roof possesses better characteristics than a traditional solution, most commonly used in Serbia. Apart from energy savings, overall impact of the green roof on the CO2 reduction per building was calculated. By multiplying these results, we drew the conclusion that a project such as greening roofs of existing residential buildings in blocks 45 and 70 would have a noticeable effect on both the energy savings and CO2 emissions.

ANALISIS DETERMINAN KUALITAS LINGKUNGAN PERIODE 1999-2013

2016 ◽  
Vol 21 (1) ◽  
pp. 9-20
Author(s):  
Ersalina Tang
Keyword(s):  
Foreign Direct Investment ◽  
Energy Consumption ◽  
Gross Domestic Product ◽  
Co2 Emissions ◽  
Direct Investment ◽  
Meat Consumption ◽  
Domestic Product ◽  
World Data ◽  
The World ◽  
The Impact

The purpose of this study is to analyze the impact of Foreign Direct Investment, Gross Domestic Product, Energy Consumption, Electric Consumption, and Meat Consumption on CO2 emissions of 41 countries in the world using panel data from 1999 to 2013. After analyzing 41 countries in the world data, furthermore 17 countries in Asia was analyzed with the same period. This study utilized quantitative approach with Ordinary Least Square (OLS) regression method. The results of 41 countries in the world data indicates that Foreign Direct Investment, Gross Domestic Product, Energy Consumption, and Meat Consumption significantlyaffect Environmental Qualities which measured by CO2 emissions. Whilst the results of 17 countries in Asia data implies that Foreign Direct Investment, Energy Consumption, and Electric Consumption significantlyaffect Environmental Qualities. However, Gross Domestic Product and Meat Consumption does not affect Environmental Qualities.

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