Conditions and technologies of biological wastewater treatment in Hungary

2012 ◽  
Vol 65 (9) ◽  
pp. 1676-1683 ◽  
Author(s):  
G. M. Tardy ◽  
V. Bakos ◽  
A. Jobbágy
Keyword(s):  
Wastewater Treatment ◽  
Carbon Source ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plants ◽  
Treatment Temperature ◽  
Low Carbon ◽  
Biological Phosphorus Removal ◽  
Wastewater Quality ◽  
Removal Technologies ◽  
Biological Nitrogen

A survey has been carried out involving 55 Hungarian wastewater treatment plants in order to evaluate the wastewater quality, the applied technologies and the resultant problems. Characteristically the treatment temperature is very wide-ranging from less than 10 °C to higher than 26 °C. Influent quality proved to be very variable regarding both the organic matter (typical COD concentration range 600–1,200 mg l−1) and the nitrogen content (typical NH4-N concentration range 40–80 mg l−1). As a consequence, significant differences have been found in the carbon availability for denitrification from site to site. Forty two percent of the influents proved to lack an appropriate carbon source. As a consequence of carbon deficiency as well as technologies designed and/or operated with non-efficient denitrification, rising sludge in the secondary clarifiers typically occurs especially in summer. In case studies, application of intermittent aeration, low DO reactors, biofilters and anammox processes have been evaluated, as different biological nitrogen removal technologies. With low carbon source availability, favoring denitrification over enhanced biological phosphorus removal has led to an improved nitrogen removal.

OPTIMIZING OPERATION OF WASTEWATER TREATMENT PLANTS BY OFFLINE AND ONLINE COMPUTER SIMULATION

1994 ◽  
Vol 30 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Ralf Otterpohl ◽  
Thomas Rolfs ◽  
Jörg Londong
Keyword(s):  
Computer Simulation ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Historical Analysis ◽  
Computer Work ◽  
Biological Phosphorus Removal ◽  
Wide Range

Computer simulation of activated sludge plant for nitrogen removal has become a reliable tool to predict the behaviour of the plant Models including biological phosphorus removal still require some practical experience but they should be available soon. This will offer an even wider range than today's work with nitrogen removal. One major benefit of computer simulation of wastewater treatment plants (WTP) is the optimization of operation. This can be done offline if hydrographs of a plant are collected and computer work is done with “historical” analysis. With online simulation the system is fed with hydrographs up to the actual time. Prognosis can be done from the moment of the computer work based on usual hydrographs. The work of the authors shows how accuratly a treatment plant can be described, when many parameters are measured and available as hydrographs. A very careful description of all details of the special plant is essential, requiring a flexible simulation tool. Based on the accurate simulation a wide range of operational decisions can be evaluated. It was possible to demonstrate that the overall efficiency in nitrogen removal and energy consumption of ml activated sludge plant can be improved.

scholarly journals Optimizing external carbon source addition in domestics wastewater treatment based on online sensoring data and a numerical model

2017 ◽  
Vol 75 (11) ◽  
pp. 2716-2725 ◽  
Author(s):  
Qibin Wang ◽  
Qiuwen Chen ◽  
Jing Chen
Keyword(s):  
Wastewater Treatment ◽  
Numerical Model ◽  
Carbon Source ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Fixed Dose ◽  
Carbon Addition ◽  
External Carbon Source ◽  
Wastewater Quality ◽  
Denitrification Reactor

The removal of total nitrogen in wastewater treatment plants (WWTPs) is often unsatisfactory for a variety of reasons. One possible measure to improve nitrogen removal is the addition of external carbon. However, the amount of carbon addition is directly related to WWTP operation costs, highlighting the importance of accurately determining the amount of external carbon required. The objective of this study was to obtain a low nitrate concentration in the anoxic zone of WWTPs efficiently and economically by optimizing the external carbon source dosage. Experiments were conducted using a pilot-scale pre-denitrification reactor at a Nanjing WWTP in China. External carbon source addition based on online monitoring of influent wastewater quality and a developed nitrification–denitrification numerical model was investigated. Results showed that carbon addition was reduced by 47.7% and aeration costs were reduced by 8.0% compared with those using a fixed-dose addition mode in the pilot reactor. The obtained technology was applied to the full-scale Jiangxinzhou WWTP in Nanjing with promising results.

scholarly journals Support vector machines for environmental informatics : application to biological nitrogen removal in wastewater treatment plants

2021 ◽  
Author(s):  
Yinghui Yang
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
Weather Conditions ◽  
Support Vector ◽  
Biological Nitrogen Removal ◽  
Complex Nature ◽  
Generalized Regression Neural Network ◽  
Biological Nitrogen

In order to meet the more stringent environmental regulations, the adaptive and optimal control strategies should be investigated for the biological nitrogen removal (BNR) processes in wastewater treatment plants. Because of the complex nature of the microbial metabolism involved, the conventional mechanistic models for nitrogen removal are difficult to formulate and the existing ones are still uncertain to some extent. Alternatively, the machine learning methods have been investigated as black-box modelling techniques. A new approach, Support Vector Machine (SVM) was proposed to be used to model the biological nitrogen removal processes in this thesis. Specifically, LS-SVM, a simplified formulation of SVM, was applied to predict the concentration of nitrate & nitrite (NO). The simulation results indicate that the proposed method has better generalization performance in comparison with generalized regression neural network, especially under weather conditions that are quite different from the training weather conditions.

Model and Sensor Based Optimization of Nitrogen Removal at Klagshamn Wastewater Treatment Plant

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1315-1323 ◽  
Author(s):  
H. Aspegren ◽  
B. Andersson ◽  
U. Nyberg ◽  
J. la C. Jansen
Keyword(s):  
Wastewater Treatment ◽  
Carbon Source ◽  
Activated Sludge ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
On Line ◽  
Ammonia Sensors

Optimization of wastewater treatment plants with extensive phosphorus and nitrogen removal is complicated. The Klagshamn wastewater treatment plant in Sweden is operated with pre-precipitation of phosphorus with ferric chloride and denitrification with methanol as carbon source. An activated sludge process, operated with pre-precipitation and denitrification with external carbon source in a compartmentalized plant, requires only small tank volumes but increases the need for proper operation and optimization. On-line nitrogen, ammonia, and TOC sensors are used for a day-to-day control and optimization while mathematical modelling is used for long term strategic planning. The on-line measurements are further used as the basis for the modelling. TOC and ammonia sensors at the influent clearly identify typical and extreme loading variations and nitrate measurements in the activated sludge tanks and the effluent shows the dynamics of the processes. These measurements provide a basis for model calibration. In combination low residuals of nitrogen, phosphorus and organic matter can be achieved.

scholarly journals Effect of COD:N ratio on biological nitrogen removal using full-scale step-feed in municipal wastewater treatment plants

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Supaporn Phanwilai ◽  
Pongsak Noophan ◽  
Chi-Wang Li ◽  
Kwang-Ho Choo
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Biological Nitrogen Removal ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plants ◽  
Scale Step ◽  
Biological Nitrogen

Abstract This study investigated the effect of low and high chemical oxygen demand (COD):N ratios on biological nitrogen removal and microbial distributions in full-scale step-feed (SF) municipal wastewater treatment plants (WWTPs) in Thailand (SF1) and Taiwan (SF2). The SF1 WWTP had a low COD:N (4:1) ratio, a long solids retention time (SRT) (> 60 d), and low dissolved oxygen (DO) conditions (0.2 mg L− 1 in anoxic tank and 0.9 mg L− 1 in aerobic tank). The total nitrogen (TN) removal efficiency was 48%. The SF2 WWTP had a high COD:N (10:1) ratio, a short SRT (7 d), and high DO (0.6 mg L− 1 in anoxic tank and 1.8 mg L− 1 in aerobic tank). The TN removal efficiency was 61%. The nitrification and denitrification rates from these two plants were inadequate. Using a quantitative polymerase chain reaction (qPCR) technique, the populations of ammonium oxidizing bacteria (AOB) and ammonium oxidizing archaea were quantified. Measurement of ammonia monooxygenase (amoA) gene abundances identified these AOB: Nitrosomonas sp., Nitrosospira sp., Nitrosoccus sp. and Zoogloea sp. Higher amounts of the archaeal-amoA gene were found with long SRT, lower DO and COD:N ratios. Abundance of Nitrobacter sp. was slightly higher than Nitrospira sp. at the SF1, while abundance of Nitrobacter sp. was two orders of magnitude greater than Nitrospira sp. at the SF2. More denitrifying bacteria were of the nirS-type than the nirK-type, especially at higher COD:N ratio. Most bacteria belong to the phyla Acidobacteria, Actinobacteria Bacteroidetes, Chloroflexi, Proteobacteria. The results from this work showed that insufficient carbon sources at the SF1 and high DO concentration in anoxic tank of SF2 adversely affected nitrogen removal efficiencies. In further research work, advanced techniques on the next generation sequencing with different variable regions should be recommended in full-scale WWTPs.

Nitrogen removal in multi-stage wastewater treatment plants by using a modified post-denitrification system

1998 ◽  
Vol 37 (9) ◽  
pp. 151-158
Author(s):  
Dieter Schreff ◽  
Peter A. Wilderer
Keyword(s):  
Wastewater Treatment ◽  
Carbon Source ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Feeding Rates ◽  
Multi Stage ◽  
Stage System ◽  
Set Up

Systems in which denitrification follows nitrification (post-denitrification) copy the natural sequence of nitrogen removal. The disadvantage of post-denitrification, however, is that an external carbon source must be added to the denitrification reactor. In the concept discussed in this paper, excess sludge from a high loaded activated sludge plant is used as carbon source and as source of denitrifiers in a three-stage system. The sludge is fed into a anoxic reactor placed in between the nitrification reactor (e.g., trickling filter) and the final clarifier. Two different operation methods were investigated at a pilot-scale system set up at the Ingolstadt wastewater treatment plant. Low nitrate effluent values were obtained at high sludge feeding rates, but at the expense of a significant increase in turbidity and NH4-N effluent concentrations. This problem could be solved by a reduction of the sludge feeding rate and by applying intermittent feeling. The effluent turbidity was kept at an acceptable level, but denitrification was relatively slow in progress. To achieve both low effluent turbidity and low nitrate discharge, a combination of pre- and post-denitrification is recommended.

Enhanced denitrification with methanol at WWTP Zürich-Werdhölzli

1996 ◽  
Vol 33 (12) ◽  
pp. 117-126 ◽  
Author(s):  
I. Purtschert ◽  
H. Siegrist ◽  
W. Gujer
Keyword(s):  
Wastewater Treatment ◽  
Carbon Source ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Yield Coefficient ◽  
Adaptation Period ◽  
Municipal Wastewater Treatment

In coordination with the EU-guidelines the large wastewater treatment plants in Switzerland have to be extended with enhanced nitrogen removal. Due to the existing plant configuration, the low COD/N ratio and dilute wastewater, denitrification supported by an external carbon source instead of extending the plant may be an interesting and cost effective solution for municipal wastewater treatment. At the wastewater treatment plant Zürich-Werdhölzli different experiments were performed with methanol addition to predenitrification from March to July 1994. The aim of this work was to evaluate the use of methanol as an alternative to plant extension to achieve a higher nitrogen removal efficiency. Therefore, two parallel denitrifying lanes were investigated, one served for methanol addition experiments and the other as a control. The effect of oxygen input into the anoxic zone due to influent, return sludge and mixing was investigated, too. The results show that nitrogen removal efficiency can be substantially increased as compared to the reference lane. The adaptation period for methanol degradation was only a few days and the process was relatively stable. Based on total nitrogen in the inflow, the average denitrification was 55% with methanol addition and 35% without methanol. The yield coefficient YCOD was 0.4 g CODX g−1 CODMe. Due to the small net growth rate of the methanol degraders the denitrification capacity is relatively low and nitrate peak loads cannot be fully denitrified. Hence, methanol as a carbon source requires more or less constant dosing. To prevent nitrate limitation, methanol addition should be controlled by the anoxic nitrate concentrations.

scholarly journals ASSESMENT OF NITRIFICATION AND DENITRIFICATION RATE IN BIOLOGICAL NITROGEN REMOVAL FROM WASTEWATER

2007 ◽  
Vol 15 (2) ◽  
pp. 77-84 ◽  
Author(s):  
Giedrė Vabolienė ◽  
Algirdas Bronislovas Matuzevičius
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Biological Treatment ◽  
Treatment Plant ◽  
Denitrification Rate ◽  
Biological Nitrogen Removal ◽  
Nitrification And Denitrification ◽  
Removal Technologies ◽  
Biological Nitrogen

Biological nitrogen removal from wastewater is based on nitrification and denitrification processes in biological treatment plants with activated sludge. Slowed growth of nitrification bacteria is one of basic problems in biological nitrogen removal from wasterwater. Using biological nitrogen removal technologies at changing nitrification and denitrification rate, it is very important to evaluate properly aeration and reduced aeration duration and to estimate nitrification and denitrification rate. To this purpose an investigation was carried out at Utena Wastewater Treatment Plant. Nitrification and denitrification rate was estimated during five experiments in aeration tanks when the duration of aeration and reduced aeration was from 120 to 180 min. Nitrification and denitrification rate at a different aeration regime and impact of aeration regime on biological nitrogen removal was estimated in the work.

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