scholarly journals Determination of kinetic parameters in a pilot scale BNR system treating municipal wastewater

2013 ◽  
Vol 8 (1) ◽  
pp. 68-74

Kinetics for the biological processes of nitrification, denitrification and carbon oxidation were studied in the aerobic and anoxic phases of a pilot scale Biological Nutrient Removal (BNR) plant treating municipal wastewater. The configuration of the treating system is based on the combination of the UCT (University of Cape Town) design and the step feeding process in a cascade denitrification. In order to study the process kinetics and to obtain reliable values for the investigated kinetic parameters batch experiments were performed. For this purpose, continuous feeding of the treating system was interrupted for a given period of time and the pilot plant was turned into a batch mode of operation. Thereafter, addition of NO3 --N and NH4 +-N into the anoxic and aerobic compartments of the treating plant, respectively, followed, whereas adequate initial concentration of a carbon source (municipal wastewater or synthetic substrate) was ensured in the mixed liquor. Experimental data indicated that the examined biological processes followed saturation kinetics. The maximum specific denitrification rate, qDN,max , was found to obtain values, depending on the type of the carbon source, between 0,045 and 0,390 gNO3 --N/(gXHET·d), whereas the extremely low value of the half saturation constant for the denitrification process (Km,NO3-N << 1mgN/l) indicated its description by zero order kinetics. The maximum specific nitrification rate, qN,max, was determined to vary in a narrow frame, between 1,28 and 1,60 gNH4 +- N/(gXAO·d). The half saturation constant for the nitrification process, Km,NH4-N, was estimated graphically at 3,1 – 6,1 gNH4 +-N l-1, corresponding to 62 – 122 μgNH3-N l-1. These values are considered to be in good agreement with the literature. The determination of kinetic parameters can be considered as a useful tool for the process design, operation and improvement of wastewater treatment plants. Furthermore, the study of the biological process kinetics contributes to the better understanding and outline of the complicated biological processes that contemporarily take place within the various phases of BNR wastewater treatment plants.

2017 ◽  
Vol 75 (11) ◽  
pp. 2716-2725 ◽  
Author(s):  
Qibin Wang ◽  
Qiuwen Chen ◽  
Jing Chen

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.


Chemosphere ◽  
2007 ◽  
Vol 66 (8) ◽  
pp. 1535-1544 ◽  
Author(s):  
Mar Esperanza ◽  
Makram T. Suidan ◽  
Ruth Marfil-Vega ◽  
Cristina Gonzalez ◽  
George A. Sorial ◽  
...  

2018 ◽  
Vol 45 ◽  
pp. 00113 ◽  
Author(s):  
Józef Trela ◽  
Elżbieta Płaza

The article presents new trends in the treatment of municipal wastewater in Sweden caused by the constantly increasing requirements for discharging pollutants into Baltic Sea waters. The development of new technologies for nitrogen removal, pharmaceutical residues removal and the possibility of using membrane processes in wastewater treatment is presented. The state of research on innovative wastewater treatment processes at the level of pilot-scale tests and their implementation in full technical scale has been described. These technologies can allow the application of new, economical and environmentally friendly wastewater treatment processes based on biological, chemical and physical methods. Swedish wastewater treatment plants are preparing to meet the new conditions required for discharged wastewater with a value of 6 mg N/L for total nitrogen and 0.2 mg P/L for total phosphorus. This requires large investments in the reconstruction of municipal wastewater treatment plants and the introduction of new treatment processes.


2016 ◽  
Vol 74 (2) ◽  
pp. 438-447 ◽  
Author(s):  
J. Väänänen ◽  
M. Cimbritz ◽  
J. la Cour Jansen

Primary and chemically enhanced primary wastewater treatment with microsieving (disc or drum filtration) was studied at the large pilot scale at seven municipal wastewater treatment plants in Europe. Without chemical dosing, the reduction of suspended solids (SS) was (on average) 50% (20–65%). By introducing chemically enhanced primary treatment and dosing with cationic polymer only, SS removal could be controlled and increased to &gt;80%. A maximum SS removal of &gt;90% was achieved with a chemical dosing of &gt;0.007 mg polymer/mg influent SS and 20 mg Al3+/L or 30 mg Fe3+/L. When comparing sieve pore sizes of 30–40 μm with 100 μm, the effluent SS was comparable, indicating that the larger sieve pore size could be used due to the higher loading capacity for the solids. Phosphorus removal was adjusted with the coagulant dose, and a removal of 95–97% was achieved. Moreover, microsieving offers favourable conditions for automated dosing control due to the low retention time in the filter.


Author(s):  
T. Gehring ◽  
E. Deineko ◽  
I. Hobus ◽  
G. Kolisch ◽  
M. Lübken ◽  
...  

Abstract The uncertainty associated with the determination of load parameters, which is a key step in the design of wastewater treatment plants (WWTPs), was investigated on basis on data sets from 58 WWTPs. A further analysed aspect was the organic load variations associated with variable sewage temperatures. Data from 26 WWTPs with a high inflow sampling frequency was used to simulate scenarios to investigate the effect of lower sampling frequencies through a Monte Carlo approach. The calculation of 85-percentile values for chemical oxygen demand (COD) loadings based on only 26 samples per year is associated with a variability of up to ±18%. Approximately 90 samples per year will be necessary to reduce this uncertainty for estimation of COD loadings below 10%. Hence, a low sampling frequency can potentially lead to under- or overestimation of design parameters. Through an analogous approach, it was possible to identify uncertainties of ±11% in COD loading when weekly average data was used with 4 samples per week. Finally, a tendency of lower COD input loads with increasing temperatures was identified, with a reduction of about 1% of the average loading per degree Celsius.


2011 ◽  
Vol 63 (1) ◽  
pp. 57-65 ◽  
Author(s):  
J. M. Choubert ◽  
S. Martin Ruel ◽  
M. Esperanza ◽  
H. Budzinski ◽  
C. Miège ◽  
...  

The next challenge of wastewater treatment is to reliably remove micro-pollutants at the microgram per litre range in order to meet the environmental quality standards set by new regulations like the Water Framework Directive. The present work assessed the efficiency of different types of primary, secondary and tertiary processes for the removal of more than 100 priority substances and other relevant emerging pollutants through on-site mass balances over 19 municipal wastewater treatment lines. Secondary biological processes proved to be in average 30% more efficient than primary settling processes. The activated sludge (AS) process led to a significant reduction of pollution loads (more than 50% removal for 70% of the substances detected). Biofilm processes led to equivalent removal efficiencies compared to AS, except for some pharmaceuticals. The membrane bioreactor (MBR) process allowed to upgrade removal efficiencies of some substances only partially degraded during conventional AS processes. Preliminary tertiary processes like tertiary settling and sand filtration could achieve significant removal for adsorbable substances. Advanced tertiary processes, like ozonation, activated carbon and reverse osmosis were all very efficient (close to 100%) to complete the removal of polar pesticides and pharmaceuticals; less polar substances being better retained by reverse osmosis.


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