Kinetic Model of Sequencing Batch Activated Sludge Process for Municipal Wastewater Treatment

1991 ◽  
Vol 23 (4-6) ◽  
pp. 1097-1106 ◽  
Author(s):  
H. Nakazawa ◽  
K. Tanaka
Keyword(s):  
Wastewater Treatment ◽  
Kinetic Model ◽  
Activated Sludge ◽  
Mathematical Models ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Operational Conditions ◽  
Aeration Time

Mathematical models based on the kinetic aspect of the sequencing batch activated sludge process were developed to explain the characteristics of the process treating municipal wastewater. These models are a steady-state model dealing with the overall relationship between biomass concentrations in a reactor and operational conditions of the process, and a kinetic model dealing with the behaviors of biomass and substrate in a reactor within one cycle time of the process. Applying these mathematical models for the results of pilot-scale experiments for municipal wastewater treatment, reasonable parameters' values were obtained and the effects of operating strategies including the aeration time ratio and the solids retention time became clear for the process performance.

scholarly journals Loofah Sponges as Bio-Carriers in a Pilot-Scale Integrated Fixed-Film Activated Sludge System for Municipal Wastewater Treatment

2020 ◽  
Vol 12 (11) ◽  
pp. 4758
Author(s):  
Huyen T.T. Dang ◽  
Cuong V. Dinh ◽  
Khai M. Nguyen ◽  
Nga T.H. Tran ◽  
Thuy T. Pham ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Agricultural Product ◽  
Aeration Tank ◽  
Municipal Wastewater Treatment ◽  
Treatment Processes ◽  
Fixed Film ◽  
The Cost

Fixed-film biofilm reactors are considered one of the most effective wastewater treatment processes, however, the cost of their plastic bio-carriers makes them less attractive for application in developing countries. This study evaluated loofah sponges, an eco-friendly renewable agricultural product, as bio-carriers in a pilot-scale integrated fixed-film activated sludge (IFAS) system for the treatment of municipal wastewater. Tests showed that pristine loofah sponges disintegrated within two weeks resulting in a decrease in the treatment efficiencies. Accordingly, loofah sponges were modified by coating them with CaCO3 and polymer. IFAS pilot tests using the modified loofah sponges achieved 83% organic removal and 71% total nitrogen removal and met Vietnam’s wastewater effluent discharge standards. The system achieved considerably high levels of nitrification and it was not limited by the loading rate or dissolved oxygen levels. Cell concentrations in the carriers were twenty to forty times higher than those within the aeration tank. Through 16S-rRNA sequencing, the major micro-organism types identified were Kluyvera cryocrescens, Exiguobacterium indicum, Bacillus tropicus, Aeromonas hydrophila, Enterobacter cloacae, and Pseudomonas turukhanskensis. This study demonstrated that although modified loofah sponges are effective renewable bio-carriers for municipal wastewater treatment, longer-term testing is recommended.

The limits and ultimate possibilities of technology of the activated sludge process

2008 ◽  
Vol 58 (8) ◽  
pp. 1671-1677 ◽  
Author(s):  
A. F. van Nieuwenhuijzen ◽  
A. G. N. van Bentem ◽  
A. Buunnen ◽  
B. A. Reitsma ◽  
C. A. Uijterlinde
Keyword(s):  
Wastewater Treatment ◽  
The Netherlands ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Method ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Nitrogen And Phosphorus ◽  
Activated Sludge Processes

The (low loaded) biological nutrient removing activated sludge process is the generally accepted and applied municipal wastewater treatment method in the Netherlands. The hydraulical and biological flexibility, robustness and cost efficiency of the process for advanced removal of nutrients like nitrogen and phosphorus without (too much) chemicals results in a wide application of the activated sludge process within Dutch waterboards. Presumably, wastewater treatment plants will have to contribute to the improvement of the quality of the receiving surface waters by producing cleaner effluent. In this perspective, the Dutch research organisation STOWA initiated a research project entitled “The Boundaries of the Activated Sludge Process” to investigate the possibilities and limitations of activated sludge processes to improve the effluent quality. It is concluded that the activated sludge process as applied and operated at WWTP's in the Netherlands has the potential to perform even better than the current effluent discharge standards (10 mg Ntotal/l and 1 mg Ptotal/l). Reaching the B-quality effluent (<5mg Ntotal/l and <0.3 mg Ptotal/l) will be possible at almost all WWTPs without major adjustments under the conditions that:   the sludge load is below 0.06 kg BOD/kg TSS.d   the internal recirculation is above 20   the BOD/N ratio of the influent is above 3. Complying with the A-quality effluent (<2.2 Ntotal/l and <0.15 mg Ptotal/l) seems to be difficult (but not impossible) and requires more attention and insight into the activated sludge process. Optimisation measures to reach the A-quality effluent are more thorough and are mostly only achievable by additional construction works (addition of activated sludge volume, increasing recirculation capacity, etc.). It is furthermore concluded that the static HSA-results are comparable to the dynamic ASM-results. So, for fast determinations of the limits of technology of different activated sludge processes static modelling seems to by sufficient.

ANFIS Based Effluent pH Quality Prediction Model for an Activated Sludge Process

2013 ◽  
Vol 845 ◽  
pp. 538-542 ◽  
Author(s):  
Muhammad Sani Gaya ◽  
Norhaliza Abdul Wahab ◽  
Yahya M. Sam ◽  
Sharatul Izah Samsuddin
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Ph Value ◽  
Treatment Plant ◽  
Quality Prediction ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Anfis Model ◽  
Inference System

Activated sludge process is the most efficient technique used for municipal wastewater treatment plants. However, a pH value outside the limit of 6-9 could inhibit the activities of microorganisms responsible for treating the wastewater, and low pH value may cause damage to the treatment system. Therefore, prediction of pH value is essential for smooth and trouble-free operation of the process. This paper presents an adaptive neuro-fuzzy inference system (ANFIS) model for effluent pH quality prediction in the process. For comparison, artificial neural network is used. The model validation is achieved through use of full-scale data from the domestic wastewater treatment plant in Kuala Lumpur, Malaysia. Simulation results indicate that the ANFIS model predictions were highly accurate having the root mean square error (RMSE) of 0.18250, mean absolute percentage deviation (MAPD) of 9.482% and the correlation coefficient (R) of 0.72706. The proposed model is efficient and valuable tool for the activated sludge wastewater treatment process.

scholarly journals Unwanted mainstream nitritation-denitritation causing massive N2O emissions in a continuous activated sludge process

2021 ◽  
Author(s):  
A. Kuokkanen ◽  
K. Blomberg ◽  
A. Mikola ◽  
M. Heinonen
Keyword(s):  
Nitrous Oxide ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Activated Sludge Processes

Abstract Nitrous oxide emissions can contribute significantly to the carbon footprint of municipal wastewater treatment plants even though emissions from conventional nitrogen removal processes are assumed to be moderate. An increased risk for high emissions can occur in connection with process disturbances and nitrite (NO2−) accumulation. This work describes the findings at a large municipal wastewater treatment plant where the levels of NO2− in the activated sludge process effluent were spontaneously and strongly increased on several activated sludge lines which was suspected to be due to shortcut nitrogen removal that stabilized for several months. The high NO2− levels were linked to a dramatic increase in nitrous oxide (N2O) emissions. As much as over 20% of the daily influent nitrogen load was emitted as N2O. These observations indicate that highly increased NO2− levels can occur in conventional activated sludge processes and result in high nitrous oxide emissions. They also raise questions concerning the risk of increased greenhouse gas (GHG) emissions of the nitritation-denitritation processes – although the uncontrolled nature of the event described here must be taken into consideration – and underline the importance of continuous monitoring and control of N2O emissions.

scholarly journals Polyhydroxyalkanoate (PHA) production from sludge and municipal wastewater treatment

2013 ◽  
Vol 69 (1) ◽  
pp. 177-184 ◽  
Author(s):  
F. Morgan-Sagastume ◽  
F. Valentino ◽  
M. Hjort ◽  
D. Cirne ◽  
L. Karabegovic ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Storage Capacity ◽  
Waste Treatment ◽  
Pilot Scale ◽  
Municipal Wastewater Treatment ◽  
Solid Waste Treatment ◽  
Pha Production ◽  
Eu Project

Polyhydroxyalkanoates (PHAs) are biodegradable polyesters with comparable properties to some petroleum-based polyolefins. PHA production can be achieved in open, mixed microbial cultures and thereby coupled to wastewater and solid residual treatment. In this context, waste organic matter is utilised as a carbon source in activated sludge biological treatment for biopolymer synthesis. Within the EU project Routes, the feasibility of PHA production has been evaluated in processes for sludge treatment and volatile fatty acid (VFA) production and municipal wastewater treatment. This PHA production process is being investigated in four units: (i) wastewater treatment with enrichment and production of a functional biomass sustaining PHA storage capacity, (ii) acidogenic fermentation of sludge for VFA production, (iii) PHA accumulation from VFA-rich streams, and (iv) PHA recovery and characterisation. Laboratory- and pilot-scale studies demonstrated the feasibility of municipal wastewater and solid waste treatment alongside production of PHA-rich biomass. The PHA storage capacity of biomass selected under feast–famine with municipal wastewater has been increased up to 34% (g PHA g VSS−1) in batch accumulations with acetate during 20 h. VFAs obtained from waste activated sludge fermentation were found to be a suitable feedstock for PHA production.

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