scholarly journals Nitrogen Removal in a Full-Scale Domestic Wastewater Treatment Plant with Activated Sludge and Trickling Filter

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Davood Nourmohammadi ◽  
Mir-Bager Esmaeeli ◽  
Hossein Akbarian ◽  
Mohammad Ghasemian
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Treated Wastewater ◽  
Trickling Filter ◽  
High Concentration ◽  
Nitrogen Gas

During the last decade, more stringent effluent requirements concerning the nutrients effluent values have been imposed by legislation and social concern. In this study, efficiency of total nitrogen removal in activated sludge and trickling filter processes (AS/TF) was investigated in Tehran North wastewater treatment plant. Biological system in this site was included, anoxic selector tank, aeration tank, final sedimentation, and trickling filter. A part of treated wastewater before chlorination was mixed with supernatant of dewatered sludge and fed to the trickling filter. Supernatant of dewatered sludge with high concentration of NH4-N was diluted by treated wastewater to provide complete nitrification in trickling filter Produced nitrate in trickling filter was arrived to the anoxic tank and converted to nitrogen gas by denitrification. According to the study result, low concentration of organic carbone and high concentration of NH4-N led to nitrification in TF, then nitrate denitrification to nitrogen gas occurred in selector area. NH4-N concentration decreased from 26.8 mg/L to 0.29 mg/L in TF, and NO3-N concentration increased from 8.8 mg/L to 27 mg/L in TF. Consequently, the total nitrogen decreased approximately to 50% in biological process. This efficiency has been observed in returned flow around 24% from final sedimentation into TF. It was concluded that, in comparison with biological nutrient removal processes, this process is very efficient and simple.

Operational Results of the Wolfsburg Wastewater Treatment Plant

1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Content ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Phosphate Removal ◽  
Total Nitrogen Content ◽  
Activated Sludge Process

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.

Rehabilitation and Upgrading of the Beni Suef City Wastewater Treatment Plant

1990 ◽  
Vol 22 (7-8) ◽  
pp. 131-138
Author(s):  
Ahmed Fadel
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Primary Treatment ◽  
High Rate ◽  
Shock Load ◽  
Economic Evaluations ◽  
Activated Sludge Process ◽  
Trickling Filter

Many of Egypt's cities have existing treatment plants under operation that have been constructed before 1970. Almost all of these treatment plants now need rehabilitation and upgrading to extend their services for a longer period. One of these plants is the Beni Suef City Wastewater Treatment Plant. The Beni Suef WWTP was constructed in 1956. It has primary treatment followed by secondary treatment employing intermediate rate trickling filters. The BOD, COD, and SS concentration levels are relatively high. They are approximately 800, 1100, and 600 mg/litre, respectively. The Beni Suef city required the determination of the level of work needed for the rehabilitation and upgrading of the existing 200 l/s plant and to extend its capacity to 440 l/s at year 2000 A description of the existing units, their deficiencies and operation problems, and the required rehabilitation are presented and discussed in this paper. Major problems facing the upgrading were the lack of space for expansion and the shortage of funds. It was, therefore, necessary to study several alternative solutions and methods of treatment. The choice of alternatives was from one of the following schemes: a) changing the filter medium, its mode of operation and increasing the number of units, b) changing the trickling filter to high rate and combining it with the activated sludge process, for operation by one of several possible combinations such as: trickling filter-solids contact, roughing filter-activated sludge, and trickling filter-activated sludge process, c) dividing the flow into two parts, the first part to be treated using the existing system and the second part to be treated by activated sludge process, and d) expanding the existing system by increasing the numbers of the different process units. The selection of the alternative was based on technical, operational and economic evaluations. The different alternatives were compared on the basis of system costs, shock load handling, treatment plant operation and predicted effluent quality. The flow schemes for the alternatives are presented. The methodology of selecting the best alternative is discussed. From the study it was concluded that the first alternative is the most reliable from the point of view of costs, handling shock load, and operation.

Intermittent feeding of wastewater in combination with alternating aeration for complete denitrification and control of filaments

2010 ◽  
Vol 61 (9) ◽  
pp. 2259-2266 ◽  
Author(s):  
Styliani Kantartzi ◽  
Paraschos Melidis ◽  
Alexander Aivasidis
Keyword(s):  
Wastewater Treatment ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Settling Tank ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Anoxic Conditions ◽  
Total Nitrogen Removal

In the present study, a laboratory scale system, consisting of a primary settling tank, a continuous stirred tank reactor and a clarifier were constructed and operated, using wastewater from the municipal wastewater treatment plant in Xanthi, Greece. The system operated under intermittent aeration in aerobic/anoxic conditions and feeding of the wastewater once in every cycle. The unit was inoculated with sludge, which originated from the recirculation stream of the local wastewater treatment plant. The wastewater was processed with hydraulic retention time (HRT) of 12 h, in which various experimental states were studied regarding the combination of aerobic and anoxic intervals. The wastewater was fed in limited time once in every cycle of aerobic/anoxic conditions at the beginning of the anoxic period. The two states that exhibited highest performance in nitrification and total nitrogen removal were, then, repeated with HRT of 10 h. The results show that, regarding the nitrification stage and the organic load removal, the intermittent system achieved optimum efficiency, with an overall removal of biological oxygen demand (BOD5) and ammonium nitrogen in the range of 93–96% and 91–95% respectively. As far as the total nitrogen removal is concerned, and if the stage of the denitrification is taken into account, the performance of the intermittent system surpassed other methods, as it is shown by the total Kjeldahl nitrogen (TKN) removal efficiency of 85–87%. These operating conditions suppressed the growth of filamentous organisms, a fact reflected at the SVI values, which were lower than 150 ml/g.

Suspended carrier technology allows upgrading high-rate activated sludge plants for nitrogen removal via process intensification

2000 ◽  
Vol 41 (4-5) ◽  
pp. 5-12 ◽  
Author(s):  
E.v. Münch ◽  
K. Barr ◽  
S. Watts ◽  
J. Keller
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Residence Time ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Pilot Plant ◽  
Treatment Plant ◽  
Carbon Removal ◽  
Suspended Carrier ◽  
Plastic Media

The Oxley Creek wastewater treatment plant is a conventional 185,000 EP BOD removal activated sludge plant that is to be upgraded for nitrogen removal to protect its receiving water bodies, the Brisbane River and Moreton Bay. Suspended carrier technology is one possible way of upgrading this activated sludge wastewater treatment plant for nitrogen removal. Freely moving plastic media is added to the aeration zone, providing a growth platform for nitrifying bacteria and increasing the effective solids residence time (SRT). This paper presents the results from operating a pilot plant for 7 months at the Oxley Creek WWTP in Brisbane, Australia. Natrix Major 12/12 plastic media, developed by ANOX (Lund, Sweden), was trialed in the pilot plant. The pilot plant was operated with a mixed liquor suspended solids concentration of 1220 mg/L and a total hydraulic residence time of 5.4 hours, similar to the operating conditions in the full-scale Stage 1&2 works at the Oxley Creek WWTP. The plastic carriers were suspended in the last third of the bioreactor volume, which was aerated to a DO setpoint of 4.0 mg/L. The first third of the bioreactor volume was made anoxic and the second third served for carbon removal, being aerated to a DO setpoint of 0.5 mg/L. The results from the pilot plant indicate that an average effluent total inorganic nitrogen concentration (ammonia-N plus NOx−N) of less than 12 mg/L is possible. However, the effluent ammonia concentrations from the pilot plant showed large weekly fluctuations due to the intermittent operation of the sludge dewatering centrifuge returning significant ammonia loads to the plant on three days of the week. Optimising denitrification was carried out by lowering the DO concentration in the influent and in the carbon removal reactor. The results from the pilot plant study show that the Oxley Creek WWTP could be upgraded for nitrogen removal without additional tankage, using suspended carrier technology.

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.

A Wastewater Treatment Plant Composed of UASB Reactors, Activated Sludge with DAF and UV Disinfection, in Series

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
J. R. Campos ◽  
M.A.P. Reali ◽  
R. Rossetto ◽  
J. Sampaio
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Treated Wastewater ◽  
Second Step ◽  
Uv Disinfection ◽  
Treatment Level ◽  
Preliminary Treatment ◽  
Uasb Reactors

This paper focuses the Piçarrão wastewater treatment plant (WWTP) located in Brazil; including its project, construction and operation, related to its first step, with working capacity until 2010 (208.785 inhabitants). The conception of the second step is also presented. This WWTP, based on the water quality of the receiving river, was designed to reach a secondary treatment level in the first step, and a tertiary treatment level in the second step. In the first step, preliminary treatment, UASB reactors, activated sludge with dissolved air flotation (DAF) and post-aeration were implanted. For the second step, denitrification, coagulation applying ferric chloride and UV disinfection should be included. In the second step, one of the UASB modules will be adapted to operate as an anoxic reactor for denitrification. The process/operation flow diagram resulted in a low complexity and relatively low cost treatment plant: USD$ 120.9 per inhabitant for implantation, and USD$ 219.05 per 1000m3 of treated wastewater. Average results for this first period of operation are: BOD5.20°C removal in the UASB reactors: 72.0%, global BOD5.20°C removal in the system: 91.4%; effluent turbidity: (11±5)NTU; total suspended solids in the effluent: (16±8)mg.L-1; fecal coliform removal ≥4 log and dewatered sludge production: 12.3 ton.d-1.

Increased nitrogen removal in existing volumes at Sundet wastewater treatment plant, Växjö

2014 ◽  
Vol 9 (2) ◽  
pp. 215-224 ◽  
Author(s):  
Anneli Andersson Chan ◽  
Niklas Johansson ◽  
Magnus Christensson
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Full Scale ◽  
Biofilm Reactor ◽  
Main Stream ◽  
Ammonium Oxidation ◽  
N Removal

Many wastewater treatment plants need to improve their nitrogen removal due to stricter requirements and increasing loads. This often means larger bioreactor volumes, which can be very expensive and is sometimes impossible if space is limited. Therefore, there is a need for compact hybrid solutions that can increase capacity within existing volumes. Two full-scale demonstration projects using moving bed biofilm reactor (MBBR) technology has proven to be an efficient way to treat nitrogen in existing volumes at Sundet wastewater treatment plant in Växjö. Increased nitrification and denitrification capacity in parts of the main stream were demonstrated through the Hybas™ process, a combination of MBBR and activated sludge using the integrated fixed-film activated sludge technology. The ANITA™ Mox process, using autotrophic N-removal through anaerobic ammonium oxidation (anammox), provided high nitrogen removal for the sludge liquor. Data collected on-site for over a year are analyzed and compared with the performance of conventional treatment systems. These two full-scale demonstration projects have been a successful learning experience in identifying and correcting both process and operational issues, which may not have arisen at pilot scale. The set objectives in terms of nitrogen removal were met for both processes and design modifications have been identified that will improve future operation at Sundet WWTP.

Internal recycle to improve denitrification in a step feed anoxic/aerobic activated sludge system

2009 ◽  
Vol 60 (7) ◽  
pp. 1661-1668 ◽  
Author(s):  
C. A. Boyle ◽  
C. J. McKenzie ◽  
S. Morgan
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Treatment Plant ◽  
Anoxic Zone ◽  
Activated Sludge System ◽  
Low Load ◽  
Aerobic Zone ◽  
Wastewater Treatment Plant Effluent

During periods of low load (weekends and holidays) the Mangere wastewater treatment plant effluent has breached the summer consent conditions for total nitrogen. The purpose of this research was to determine if an internal recycle would improve nitrogen removal in the anoxic/aerobic activated sludge reactors sufficient to meet the summer resource consent standard. The recycle returned nitrate rich mixed liquor from the downstream aerobic zone back to the initial anoxic zone, thus potentially improving denitrification. A full scale trial showed that installation of the internal recycle on each RC would have satisfied the resource consent for total nitrogen in most cases over the three summer resource consent periods since the upgrade. However, further modifications of the internal recycle would be required to ensure that consent conditions were satisfied at all times and to improve the consistency of the results.

scholarly journals Nitrification Processes in Tehran Wastewater Treatment Plant

2011 ◽  
Vol 2011 ◽  
pp. 1-9
Author(s):  
S. A. Sadrnejad
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Primary Treatment ◽  
High Rate ◽  
Trickling Filter ◽  
Combined System ◽  
Conventional Activated Sludge ◽  
Balance Analysis

A wastewater treatment plant is designed to daily treat 450000 m3 of wastewater collected from the city of Tehran. The wastewater treatment plant is located at the south of Shahr-Ray in southern Tehran with the area of 110 hectares. The treatment plant effluent will be transferred to Varamin agricultural lands to be used for the irrigation of crops. A conventional activated sludge for carbon removal and a high-rate trickling filter for nitrification of ammonia to nitrate are designed and constructed. The treatment plant consists of inlet pumping station, primary treatment, primary sedimentation tanks, selector and aeration tanks, trickling filter, and sludge treatment units. A mass balance analysis method which is a new approach for optimum design is used to achieve cost saving for the construction of south Tehran wastewater treatment plant. The comparison between combined system of activated sludge with trickling filter and an activated sludge alone shows that the combined system is 20% less costly and more efficient for the treatment of Tehran wastewater, the system has low volume demand, maximum biogas yeild, and low process control and is less variable to pH and chemical effects and highly energy-efficient.

Monitoring cations to predict and improve activated sludge settling and dewatering properties of industrial wastewaters

1998 ◽  
Vol 38 (3) ◽  
pp. 119-126 ◽  
Author(s):  
Sudhir N. Murthy ◽  
John T. Novak ◽  
Robert D. De Haas
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Divalent Cations ◽  
Treatment Plant ◽  
Field Tests ◽  
Ammonium Ion ◽  
Ammonium Ions ◽  
High Concentration ◽  
The Impact

Laboratory and field tests were conducted on activated sludge from an industrial wastewater treatment plant in order to monitor the settling and dewatering properties and to assess the impact cations may have on these properties. The influent to the wastewater treatment plant contained a high concentration of sodium ions and a low concentration of divalent cations. The sludge exhibited poor settling and dewatering properties. Initial laboratory results indicated an improvement in settling and dewatering properties through the addition of calcium and magnesium. After addition of magnesium during field trials, floc density and settling properties improved considerably. In addition, residual ammonium ions in the mixed liquor appeared to interact with the activated sludge flocs to influence their dewatering properties. It was observed that an increase in ammonium ion in the soluble sludge fraction was related to deterioration in the dewatering properties. During these trials, the ammonium ions demonstrated a greater influence on dewatering properties than did the magnesium ions. The tests conducted at the treatment plant revealed that complex interactions between cations and sludge influenced the settling and dewatering properties in a manner that depended on ratios and concentrations of monovalent and divalent cations in the activated sludge feed and solution.

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