Advanced nitrogen elimination by encapsulated nitrifiers

2003 ◽  
Vol 48 (8) ◽  
pp. 19-26 ◽  
Author(s):  
M. Sievers ◽  
K.-D. Vorlop ◽  
J. Hahne ◽  
M. Schlieker ◽  
S. Schäfer
Keyword(s):  
Hydraulic Retention Time ◽  
Carbon Sources ◽  
Oxygen Demand ◽  
Reaction Rates ◽  
Substantial Contribution ◽  
Reaction Volume ◽  
Nitrification Process ◽  
Soluble Chemical Oxygen Demand ◽  
Nitrogen Elimination ◽  
Denitrification Process

By introducing a mixed population of nitrifiers encapsulated in gel lens beads a more selective nitrification process was found in treatment of settled sewage in lab scale at a hydraulic retention time (HRT) of about 30 to 60 minutes. The reaction rates for oxidation of soluble chemical oxygen demand (SCOD) were found to vary between 25 to 150 mg/L·h while nitrification takes place around 50 mg nitrogen per hour and litre reaction volume. However, based on this SCOD removal in the nitrification step, a consequent post-denitrification process without nitrate recycle and dosage of external carbon sources has been proven to reach substantial nitrate elimination of up to 20 mg nitrogen per litre at COD/N-ratios of approx. 6 in settled sewage. At such COD/N-ratios, suitable nitrogen elimination seems to be possible, because the bioflocs of settled sewage, produced so far by SCOD oxidation and entrapment of particulate COD, are passing through the nitrification process having a substantial contribution to the denitrification rate additionally to the remaining SCOD.

Nitrogen elimination from sludge treatment reject water – comparison of the steam-stripping and denitrification processes

1994 ◽  
Vol 30 (6) ◽  
pp. 41-51 ◽  
Author(s):  
Burkhard Teichgräber ◽  
Andreas Stein
Keyword(s):  
Organic Nitrogen ◽  
Hydraulic Retention Time ◽  
Surface Load ◽  
Operational Experience ◽  
Sludge Treatment ◽  
Reject Water ◽  
Total Treatment ◽  
Treatment Facilities ◽  
Nitrogen Elimination ◽  
Denitrification Process

Steam stripping and nitrification/denitrification for the elimination of nitrogen from sludge treatment reject water from the Central Sludge Treatment Facilities (CSTF) of the Emschergenossenschaft in Bottrop were tested in half-scale pilot plants. More than 90% efficiency could be achieved with both systems; the nitrification/denitrification process also removed organic nitrogen. Operational experience has shown that full scale application of both systems is possible. The design surface load of the stripping column has been evaluated as 10 m3/(m2*h) and the steam/water ratio as 0.12 t/m3. The nitrification/denitrification process can be designed for 0.07 kgN/(kg MLSS*d) and 1.4 days hydraulic retention time. Total treatment costs are estimated to be between 5 and 7.5 DM/kg N.

scholarly journals Biodegradation of main carbon sources in vinasse stillage by a mixed culture of bacteria: influence of temperature and pH of the medium

2018 ◽  
Vol 78 (4) ◽  
pp. 764-775 ◽  
Author(s):  
Agnieszka Ryznar-Luty ◽  
Edmund Cibis ◽  
Krzysztof Lutosławski
Keyword(s):  
Mixed Culture ◽  
Organic Pollutants ◽  
Carbon Sources ◽  
Oxygen Demand ◽  
Aerobic Biodegradation ◽  
Medium Ph ◽  
Initial Ph ◽  
Fourth Series ◽  
Soluble Chemical Oxygen Demand ◽  
Available Carbon

Abstract The aim of the study was to examine how temperature and the pH influence the progress and efficiency of an aerobic biodegradation process, where major organic pollutants are removed from beet molasses vinasse by a mixed culture of Bacillus bacteria. It was conducted in an aerated bioreactor with a stirring system in four experimental series, each composed of five processes run at temperatures of 27, 36, 45, 54 and 63 °C. In the first and second series, medium pH was not controlled, the initial pH amounted to 6.5 and 8.0, respectively. In the third and fourth series, medium pH was controlled at 6.5 and 8.0, respectively. Under optimal conditions, the pollution load of the vinasse stillage expressed as soluble chemical oxygen demand was removed with an 88.73% efficiency. The bacterial culture assimilated all organic pollutants simultaneously, but the rate of assimilation was different. An exception was the process of betaine assimilation, which intensified only when readily available carbon sources were depleted in the medium. Synthesis and assimilation of organic acids were observed in all experiments. Advantages of the proposed method include: possibility of its use at high temperatures, and no necessity for medium pH adjustment during the process.

scholarly journals A two-stage soil infiltration system incorporated with heterotrophic denitrification (TSISHD) for urban runoff treatment

2015 ◽  
Vol 47 (1) ◽  
pp. 128-136
Author(s):  
Lizhu Hou ◽  
Xue Xu ◽  
Yiran Song ◽  
Chuanping Feng
Keyword(s):  
Carbon Sources ◽  
Oxygen Demand ◽  
Urban Runoff ◽  
Quality Standard ◽  
Soil Infiltration ◽  
Class V ◽  
National Quality ◽  
Removal Efficiencies ◽  
Denitrification Process ◽  
Heterotrophic Denitrification

To enhance denitrification performance of soil infiltration, a soil infiltration system incorporated with heterotrophic denitrification (TSISHD) for urban runoff treatment was developed. Sawdust and grass powders were added in the anaerobic stage (ANS) to provide organic carbon sources for the denitrification process, and the reduction environment was improved by iron addition in the ANS. Aerobic respiration and nitrification primarily occurred in the upper aerobic stage (AES), which removed 86.68% of the chemical oxygen demand (COD) and 91.80% of the NH+4-N. Moreover, heterotrophic denitrification occurred in the bottom ANS when added sawdust and grass powders were used as a carbon source. Overall, the TSISHD showed remarkable removal efficiencies of 88.29%, 82.50%, 92.05%, and 78.10% for COD, NO−3-N, NH+4-N, and total phosphorus, respectively, and the corresponding effluent concentrations met the national quality standard of China for class V surface water. The removal efficiencies were significantly higher than those of the previous soil infiltration systems without inoculated microbes. The developed system has the potential to treat urban runoff.

scholarly journals Nitrogen-removal efficiency in an upflow partially packed biological aerated filter (BAF) without backwashing process

2011 ◽  
Vol 1 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Pramanik Biplob ◽  
Suja Fatihah ◽  
Zain Shahrom ◽  
ElShafie Ahmed
Keyword(s):  
Dissolved Oxygen ◽  
Removal Efficiency ◽  
Hydraulic Retention Time ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Nitrogen Loading ◽  
Biological Aerated Filter ◽  
Biological Phenomena ◽  
Nitrification Process ◽  
Aerated Filter

An upflow, partially packed biological aerated filter (BAF) reactor was used to remove nitrogen in the form of ammonia ions by a nitrification process that involves physical, chemical and biological phenomena governed by a variety of parameters such as dissolved oxygen concentration, pH and alkalinity. Dissolved oxygen (DO) and pH were shown to have effects on the nitrification process in this study. Three C:N ratios i.e., 10, 4 and 1 were compared during this study by varying the nitrogen loading while the carbon loading was kept constant at 0.405 ± 0.015 kg chemical oxygen demand m−3 d−1. The removal efficiencies of ammonia linearly increase with a rise of the initial concentration of ammonia-nitrogen. The results of the 115 days' operation of the BAF system showed that its overall NH3-N performance was good, where a removal efficiency of 87.0 ± 2.9%, 89.2 ± 1.38% and 91.1 ± 0.7% and COD removal of 87.6 ± 2.9%, 86.4 ± 2.1% and 89.5 ± 2.6% were achieved for the C:N ratios of 10, 4 and 1, respectively on average, over 6 h hydraulic retention time (HRT). No clogging occurred throughout the period although backwashing was eliminated. It was concluded that the BAF system proposed in this study removed nitrogen by the nitrification process extremely well.

Production of Biogas from Anaerobic Co-Digestion of Oil Palm Mesocarp Fibre and Cattle Manure: In Batch

2015 ◽  
Vol 735 ◽  
pp. 200-204
Author(s):  
Ain Zubaidah Mohd Sabri ◽  
Hazwani Samsudin ◽  
Syahrul Syazwan Yaacob ◽  
Muhamad Ali Muhammad Yuzir
Keyword(s):  
Oil Palm ◽  
Hydraulic Retention Time ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Cattle Manure ◽  
Ph Values ◽  
High Nutrient ◽  
Soluble Chemical Oxygen Demand ◽  
Scale Experiment ◽  
Main Substrate

There is a rising demand for energy crops and animal manures in biogas production.This research focused at anaerobic co-digestion of oil palm mesocarp fibre (OPMF) and cattle manure (CM) for biogas production.OPMF is considered as lignocellulosic biomass and acting as the main substrate of the digestion.CM contains high nutrient which could lead to higher biogas production.A batch scale experiment was carried out in mesophilic condition at 37°C.Main parameters involved are pH, soluble chemical oxygen demand (COD) and volume biogas production.The obtained pH values of the samples are between 6.5 and 7.5.This anaerobic co-digestion gave 76% of COD removal on day 30.The observed volume of biogas that produced was between 90 to 130mL.The system was run for two different hydraulic retention time (HRT).The HRTs are 15 and 30 days.Co-digestion of two different organic matters gave good biogas production in comparison to normal single digestion.

Designing Experiments for Model Identification of the Nitrification Process

1991 ◽  
Vol 24 (6) ◽  
pp. 9-16 ◽  
Author(s):  
P. J. Ossenbruggen ◽  
H. Spanjers ◽  
H. Aspegren ◽  
A. Klapwijk
Keyword(s):  
Mechanistic Model ◽  
Nonlinear Differential Equations ◽  
Model Identification ◽  
Reaction Rates ◽  
Variable Coefficients ◽  
Model Specification ◽  
First Order ◽  
Interactive Behavior ◽  
Batch Tests ◽  
Nitrification Process

A series of batch tests were performed to study the competition for oxygen by Nitrosomonas and Nitrobacter in the nitrification of ammonia in activated sludge. Oxygen uptake rate (OUR) and dynamic (compartment) models describing the process are proposed and tested. The OUR model is described by a Monod relationship and the biogradation process by a set of first order nonlinear differential equations with variable coefficients. The results show a mechanistic model and ten reaction rates are sufficient to capture the interactive behavior of the nitrification process. Methods for model specification, calibrating, and testing the model and the design of additional experiments are described.

scholarly journals The Start-Up of Continuous Biohydrogen Production from Cheese Whey: Comparison of Inoculum Pretreatment Methods and Reactors with Moving and Fixed Polyurethane Carriers

2021 ◽  
Vol 11 (2) ◽  
pp. 510
Author(s):  
Elza R. Mikheeva ◽  
Inna V. Katraeva ◽  
Andrey A. Kovalev ◽  
Dmitriy A. Kovalev ◽  
Alla N. Nozhevnikova ◽  
...  
Keyword(s):  
Cheese Whey ◽  
Hydraulic Retention Time ◽  
Continuous Production ◽  
Oxygen Demand ◽  
Organic Load ◽  
Anaerobic Sludge ◽  
Acid Pretreatment ◽  
Methanogenic Activity ◽  
Start Up ◽  
Load Rate

This article presents the results of the start-up of continuous production of biohydrogen from cheese whey (CW) in an anaerobic filter (AF) and anaerobic fluidized bed (AFB) with a polyurethane carrier. Heat and acid pretreatments were used for the inactivation of hydrogen-scavengers in the inoculum (mesophilic and thermophilic anaerobic sludge). Acid pretreatment was effective for thermophilic anaerobic sludge to suppress methanogenic activity, and heat treatment was effective for mesophilic anaerobic sludge. Maximum specific yields of hydrogen, namely 178 mL/g chemical oxygen demand (COD) and 149 mL/g COD for AFB and AF, respectively, were obtained at the hydraulic retention time (HRT) of 4.5 days and organic load rate (OLR) of 6.61 kg COD/(m3 day). At the same time, the maximum hydrogen production rates of 1.28 and 1.9 NL/(L day) for AF and AFB, respectively, were obtained at the HRT of 2.02 days and OLR of 14.88 kg COD/(m3 day). At the phylum level, the dominant taxa were Firmicutes (65% in AF and 60% in AFB), and at the genus level, Lactobacillus (40% in AF and 43% in AFB) and Bifidobacterium (24% in AF and 30% in AFB).

scholarly journals Modelization of Nutrient Removal Processes at a Large WWTP Using a Modified ASM2d Model

2018 ◽  
Vol 15 (12) ◽  
pp. 2817 ◽  
Author(s):  
Jakub Drewnowski ◽  
Jacek Makinia ◽  
Lukasz Kopec ◽  
Francisco-Jesus Fernandez-Morales
Keyword(s):  
Nutrient Removal ◽  
Carbon Sources ◽  
Oxygen Demand ◽  
Full Scale ◽  
Biological Nutrient Removal ◽  
Organic Substrates ◽  
Modified Model ◽  
Rate Limiting Step ◽  
Uptake Rates ◽  
Rate Limiting

The biodegradation of particulate substrates starts by a hydrolytic stage. Hydrolysis is a slow reaction and usually becomes the rate limiting step of the organic substrates biodegradation. The objective of this work was to evaluate a novel hydrolysis concept based on a modification of the activated sludge model (ASM2d) and to compare it with the original ASM2d model. The hydrolysis concept was developed in order to accurately predict the use of internal carbon sources in enhanced biological nutrient removal (BNR) processes at a full scale facility located in northern Poland. Both hydrolysis concepts were compared based on the accuracy of their predictions for the main processes taking place at a full-scale facility. From the comparison, it was observed that the modified ASM2d model presented similar predictions to those of the original ASM2d model on the behavior of chemical oxygen demand (COD), NH4-N, NO3-N, and PO4-P. However, the modified model proposed in this work yield better predictions of the oxygen uptake rate (OUR) (up to 5.6 and 5.7%) as well as in the phosphate release and uptake rates.

Anaerobic co-digestion of winery waste and waste activated sludge: assessment of process feasibility

2013 ◽  
Vol 69 (2) ◽  
pp. 269-277 ◽  
Author(s):  
C. Da Ros ◽  
C. Cavinato ◽  
F. Cecchi ◽  
D. Bolzonella
Keyword(s):  
Activated Sludge ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Waste Activated Sludge ◽  
Organic Loading ◽  
Operational Conditions ◽  
Loading Rates ◽  
Thermophilic Conditions ◽  
Soluble Chemical Oxygen Demand

In this study the anaerobic co-digestion of wine lees together with waste activated sludge in mesophilic and thermophilic conditions was tested at pilot scale. Three organic loading rates (OLRs 2.8, 3.3 and 4.5 kgCOD/m3d) and hydraulic retention times (HRTs 21, 19 and 16 days) were applied to the reactors, in order to evaluate the best operational conditions for the maximization of the biogas yields. The addition of lee to sludge determined a higher biogas production: the best yield obtained was 0.40 Nm3biogas/kgCODfed. Because of the high presence of soluble chemical oxygen demand (COD) and polyphenols in wine lees, the best results in terms of yields and process stability were obtained when applying the lowest of the three organic loading rates tested together with mesophilic conditions.

Two-stage entrapped mixed microbial cell process for simultaneous removal of organics and nitrogen for rural domestic sewage application

2004 ◽  
Vol 49 (5-6) ◽  
pp. 281-288 ◽  
Author(s):  
S.J. Kim ◽  
P.Y. Yang
Keyword(s):  
Removal Efficiency ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Microbial Cell ◽  
Two Stage ◽  
Rate Limiting Step ◽  
Soluble Chemical Oxygen Demand ◽  
Removal Efficiencies ◽  
Entrapped Mixed Microbial Cell

A two-stage entrapped mixed microbial cell (2SEMMC) process which separates nitrification and denitrification phases by the installation of the anoxic and oxic EMMC reactors packed with EMMC carriers was operated with 6, 4, 3, and 2 hours of hydraulic retention time (HRT) using simulated domestic wastewater. The activated sludge was immobilized using cellulose acetate for the EMMC carriers. Similar soluble chemical oxygen demand (SCOD) removal efficiencies of 90-97% were observed for all HRTs (SCOD loading rate of 0.84-2.30 g/L/d) applied. In order to achieve more than 80 % of TN removal efficiency, the HRT should be maintained higher than 4 hours (less than 0.24 g/L/d of TN loading rate). Denitrification was a rate-limiting step which controlled overall TN removal efficiency at TN loading rate of 0.15-0.31 g/L/d although nitrification efficiencies achieved 97-99 %. The effluent TSS of less than 25 mg/L in the 2SEMMC process was maintained at the SCOD loading rate of less than 1.23 g/L/d with back-washing intervals of 5 and 10 days in the anoxic and oxic EMMC reactors, respectively. The minimum HRT of 4 hours is required for high removal efficiencies of organics (average 95.6 %) and nitrogen (average 80.5 %) in the 2SEMMC process with 3 times of recirculation ratio.

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