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.

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.

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.

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

2013 ◽  
Vol 8 (1) ◽  
pp. 68-74
Keyword(s):  
Wastewater Treatment ◽  
Carbon Source ◽  
Kinetic Parameters ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Biological Processes ◽  
Process Kinetics ◽  
Half Saturation Constant

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.

Nutrient Removal in Small Wastewater Treatment Plants

1990 ◽  
Vol 22 (3-4) ◽  
pp. 211-216
Author(s):  
Niels Skov Olesen
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Wastewater Treatment Plants ◽  
Ferrous Sulphate ◽  
Practical Solution ◽  
Sensitive Technique ◽  
Pumping Station ◽  
Denitrification Reactor

In some areas of Denmark nutrient removal is required even for very small wastewater plants, that is down to 500 pe (pe = person equivalents). The goal for the removal is 80% removal of nitrogen and 90% removal of phosphorus, or in terms of concentrations: 8 mg nitrogen/l and 1.2 mg phosphorus/l. The inlet concentrations are typically 40 mg N/l and 10 mg P/l. The paper presents the results from two such plants with a capacity of 800 pe. Phosphorus removal is made by simultaneous precipitation with ferrous sulphate. Nitrogen removal is carried out using the recirculation method. Both plants were originally rotor aerated oxidation ditches. They have been extended with a denitrification reactor and a recirculation pumping station. At present both plants have been in activity for about 3 years and with satisfactory results. Average concentrations of nitrogen (summer) and phosphorus is 7 mg/l and 0.9 mg/l respectively. Nitrogen removal seems to be a practical solution on these small plants. It is,though, sensitive to temperature and highly oxidized rain water. Phosphorus removal seems to be an easily run and relatively non-sensitive technique at least when using simultaneous precipitation.

Ammonia removal in a pilot-scale WSP complex in Northeast Brazil

1996 ◽  
Vol 33 (7) ◽  
pp. 165-171 ◽  
Author(s):  
J. Soares ◽  
S. A. Silva ◽  
R. de Oliveira ◽  
A. L. C. Araujo ◽  
D. D. Mara ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Surface Waters ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Ammonia Removal ◽  
Northeast Brazil ◽  
Environmental Legislation ◽  
Aerobic Conditions ◽  
High Degree

Ammonia removal was monitored in a waste stabilisation pond complex comprising ponds of different geometries and depths under two different operational regimes. It was found that a high degree of ammonia removal commenced in the secondary maturation ponds, with the highest removals occurring in the shallowest ponds as a consequence of improved aerobic conditions. The tertiary maturation ponds produced effluents with mean ammonia concentrations of &lt; 5 mg N/l, the maximum permitted recommended by Brazilian environmental legislation for the discharge of effluents of wastewater treatment plants into surface waters. Ammonia removal in the secondary facultative and maturation ponds could be modelled using equations based on the volatilization mechanism proposed by Middlebrooks et al. (1982).

Small wastewater treatment plants in Flanders (Belgium): standard approach and experiences with constructed reed beds

2000 ◽  
Vol 41 (1) ◽  
pp. 57-63 ◽  
Author(s):  
S. Vandaele ◽  
C. Thoeye ◽  
B. Van Eygen ◽  
G. De Gueldre
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Surface Flow ◽  
Limiting Factor ◽  
Vertical Flow ◽  
Reed Beds ◽  
Reed Bed

In Flanders (Belgium) an estimated 15% of the population will never be connected to a central wastewater treatment plant (WWTP). Small WWTPs can be a valuable option. Aquafin bases the decision to build SWWTPs on a drainage area study. To realise an accelerated construction the process choice is made accordingly to a standard matrix, which represents the different technologies in function of the size and the effluent consents. A pilot scale constructed two-stage reed bed is used to optimise the concept of the reed beds. The concept consists of a primary clarifier, two parallel vertical flow reed beds followed by a sub-surface flow reed bed. The removal efficiency of organic pollutants is high (COD: 89%, BOD: 98%). Phosphorus removal is high at the start-up but diminishes throughout the testing period (from 100% to 71% retention after 7 months). Nitrogen removal amounts to 53% on average. Nitrification is complete in summer. Denitrification appears to be the limiting factor. In autumn leakage of nitrogen is assumed. Removal efficiency of pathogens amounts to almost 99%. Clogging forms a substantial constraint of the vertical flow reed bed. Problems appear to be related with presettlement, feed interval and geotextile.

scholarly journals Simultaneous Denitrification and Bio-Methanol Production for Sustainable Operation of Biogas Plants

2019 ◽  
Vol 11 (23) ◽  
pp. 6658 ◽  
Author(s):  
I-Tae Kim
Keyword(s):  
Wastewater Treatment ◽  
Carbon Source ◽  
Food Waste ◽  
Treatment Process ◽  
Wastewater Treatment Plants ◽  
Treatment Efficiency ◽  
Wastewater Treatment Process ◽  
Methanol Production ◽  
Sustainable Operation ◽  
Biogas Plants

This study was conducted to secure the sustainability of biogas plants for generating resources from food waste (FW) leachates, which are prohibited from marine dumping and have been obligated to be completely treated on land since 2013 in South Korea. The aim of this study is to reduce the nitrogen load of the treatment process while producing bio-methanol using digested FW leachate diverted into wastewater treatment plants. By using biogas in conditions where methylobacter (M. marinus 88.2%) with strong tolerance to highly chlorinated FW leachate dominated, 3.82 mM of methanol production and 56.1% of total nitrogen (TN) removal were possible. Therefore, the proposed method can contribute to improving the treatment efficiency by accommodating twice the current carried-in FW leachate amount based on TN or by significantly reducing the nitrogen load in the subsequent wastewater treatment process. Moreover, the produced methanol can be an effective alternative for carbon source supply for denitrification in the subsequent process.

Ozonation of wastewater sludge for reduction and recycling

2002 ◽  
Vol 46 (10) ◽  
pp. 71-77 ◽  
Author(s):  
K.-H. Ahn ◽  
K.Y. Park ◽  
S.K. Maeng ◽  
J.H. Hwang ◽  
J.W. Lee ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Economic Assessment ◽  
Pilot Scale ◽  
Wastewater Sludge ◽  
Ozone Treatment ◽  
Sludge Treatment ◽  
Micro Particles ◽  
Belt Press ◽  
Treatment And Disposal

An ozone treatment system was introduced as an alternative method for municipal sludge treatment and disposal. A pilot-scale facility was built to investigate the feasibility of the ozonation for sludge reduction and recycle. The system consists of three main parts; advanced wastewater treatment, sludge ozone treatment and belt press dewatering. Ozonation of wastewater sludge resulted in mass reduction by mineralization as well as volume reduction by improvement of dewatering characteristics. The supernatant of the ozonated sludge, consisting of solubilized organics and micro-particles, proved to be an effective carbon source for denitrification. A simple economic assessment reveals that the ozonation process can be more economical than incineration for sludge treatment and disposal at small- and medium-sized wastewater treatment plants.

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