Occurrence and enrichment of ‘bacterial sherpas’: climb to sustainability in wastewater treatment

2015 ◽  
Vol 72 (9) ◽  
pp. 1481-1487
Author(s):  
M. Arnaldos ◽  
K. R. Pagilla
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Initial Response ◽  
Biological Processes ◽  
Sufficient Time ◽  
Treatment Stage ◽  
Removal Processes ◽  
Biological Nitrogen ◽  
Insight Into ◽  
Low Do

The paper presents research on hemoglobin (Hb)-expressing bacteria in biological wastewater treatment systems. The outcome(s) will greatly reduce the aeration needs of wastewater treatment plants (WWTPs) and provide insight into emerging biological nitrogen removal processes using low dissolved oxygen (DO) conditions. In anthropogenic terms, the bacteria that express Hb could be considered as ‘bacterial sherpas’ that can function under low DO conditions. Hitherto, this functionality of bacteria has not been realized due to the initial response of the aerobic treatment stage: namely, morphology change by bacteria to filamentous forms to overcome oxygen mass transfer limitations causing bulking/foaming and nitrification inhibition. There is evidence, however, of the potential expression of Hb proteins by activated sludge (AS) bacteria. First, bacteria known to possess genes coding Hb proteins have been isolated from AS systems. Secondly, there is evidence that WWTPs are able to operate their biological processes at low DO without sludge bulking or incomplete nitrification. Our research has focused on nitrifying systems and has shown that this is due to prolonged operation at low DO conditions (0.1 mg O2/L), which allows sufficient time for bacterial acclimation. Additionally, it has been shown that enhanced Hb expression is linked to acclimation to low DO conditions.

Upgrading Wastewater Treatment Plants for Biological Nutrient Removal

1990 ◽  
Vol 22 (7-8) ◽  
pp. 53-60 ◽  
Author(s):  
B. Rabinowitz ◽  
T. D. Vassos ◽  
R. N. Dawson ◽  
W. K. Oldham
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Design Flow ◽  
Biological Nutrient Removal ◽  
Nitrogen And Phosphorus ◽  
Conventional Activated Sludge ◽  
Recent Developments ◽  
Removal Technology ◽  
Biological Nitrogen

A brief review of recent developments in biological nitrogen and phosphorus removal technology is presented. Guidelines are outlined of how current understanding of these two removal mechanisms can be applied in the upgrading of existing wastewater treatment plants for biological nutrient removal. A case history dealing with the upgrading of the conventional activated sludge process located at Penticton, British Columbia, to a biological nutrient removal facility with a design flow of 18,200 m3/day (4.0 IMGD) is presented as a design example. Process components requiring major modification were the headworks, bioreactors and sludge handling facilities.

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.

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.

scholarly journals Application of Ultrasound waves for Sludge Dewatering

2015 ◽  
Vol 9 (4) ◽  
pp. 6-9
Author(s):  
Farshad Golbabaei Kootenaei ◽  
Naser Mehrdadi ◽  
Gholamreza Nabi Bidhendi ◽  
Hasan Amini Rad
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Ease Of Use ◽  
Biological Processes ◽  
Complex Materials ◽  
Sludge Dewatering ◽  
Ultrasound Waves ◽  
Secondary Pollution ◽  
Increase Rate

Because of increase in application of biological processes in wastewater treatment plants the amount of sludge produced by them is increasing rapidly. Therefore finding new sludge reduction technologies in wastewater treatment plants is very important. Nowadays ultrasound waves have an increase rate of application in full scale in wastewater industry. The most important advantages of ultrasound waves are such as: No sludge production, ease of use, increasing the biogas production, contributing to dewatering, no secondary pollution and degradation of complex materials into simpler substances. In this research, different applications of ultrasound waves in wastewater and sludge treatment and improving dewaterabilty of sludge is investigated.DOI: http://dx.doi.org/10.3126/ijls.v9i4.12680

Reductions in greenhouse gas (GHG) generation and energy consumption in wastewater treatment plants

2013 ◽  
Vol 67 (5) ◽  
pp. 1159-1164 ◽  
Author(s):  
L. Yerushalmi ◽  
O. Ashrafi ◽  
F. Haghighat
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Greenhouse Gas ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Anaerobic Digester ◽  
Biological Processes ◽  
Ghg Emission ◽  
Physical Chemical ◽  
Co2 Equivalent

Greenhouse gas (GHG) emission and energy consumption by on-site and off-site sources were estimated in two different wastewater treatment plants that used physical–chemical or biological processes for the removal of contaminants, and an anaerobic digester for sludge treatment. Physical–chemical treatment processes were used in the treatment plant of a locomotive repair factory that processed wastewater at 842 kg chemical oxygen demand per day. Approximately 80% of the total GHG emission was related to fossil fuel consumption for energy production. The emission of GHG was reduced by 14.5% with the recovery of biogas that was generated in the anaerobic digester and its further use as an energy source, replacing fossil fuels. The examined biological treatment system used three alternative process designs for the treatment of effluents from pulp and paper mills that processed wastewater at 2,000 kg biochemical oxygen demand per day. The three designs used aerobic, anaerobic, or hybrid aerobic/anaerobic biological processes for the removal of carbonaceous contaminants, and nitrification/denitrification processes for nitrogen removal. Without the recovery and use of biogas, the aerobic, anaerobic, and hybrid treatment systems generated 3,346, 6,554 and 7,056 kg CO2-equivalent/day, respectively, while the generated GHG was reduced to 3,152, 6,051, and 6,541 kg CO2-equivalent/day with biogas recovery. The recovery and use of biogas was shown to satisfy and exceed the energy needs of the three examined treatment plants. The reduction of operating temperature of the anaerobic digester and anaerobic reactor by 10°C reduced energy demands of the treatment plants by 35.1, 70.6 and 62.9% in the three examined treatment systems, respectively.

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.

scholarly journals Experimental study on using commercial membranes for treatment of wastewater generated by collagen production

2019 ◽  
pp. 50-55
Author(s):  
Mirela Alina Constantin ◽  
Lucian Alexandru Constantin ◽  
Ion Viorel Patroescu ◽  
Gheorghe Batrinescu
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
The Other ◽  
Treated Wastewater ◽  
Biological Processes ◽  
Wastewater Discharge ◽  
Organic Loading ◽  
Membrane Processes ◽  
Collagen Production ◽  
Valuable Compounds

Collagen production is generating wastewater with high organic loading. This type of wastewater is still containing valuable compounds that can be reused in other applications. In order to investigate the possibility to recover and reuse these compounds the membrane based processes were investigated. Four types of commercial available membranes were characterised and then used to recover the proteins. The results proved that membrane based processes represent a viable alternative to treatment of wastewater generated by collagen production facilities when recovery of valuable compounds is envisaged. It has to be stressed that on the other hand only membrane processes do not assure too reach the quality norms imposed by the legislation for treated wastewater discharge into sewerage systems or natural receivers. Therefore, when proteins recovery and reuse is wanted, the membrane processes represent only the first step of wastewater treatment and should be followed by biological processes in order to obtain the organic loading quality indicators required for wastewater treatment plants discharges.

scholarly journals Implementing Cost-effective Co-treatment of Domestic and Food-industrial Wastewater by Novel Methods for Estimating Industrial Load

2020 ◽  
Vol 64 (4) ◽  
pp. 505-513
Author(s):  
Vince Bakos ◽  
Péter Szombathy ◽  
József Simon ◽  
Andrea Jobbágy
Keyword(s):  
Carbon Source ◽  
Wastewater Treatment Plants ◽  
Screening Method ◽  
Domestic Wastewater ◽  
Cost Effective ◽  
Flexible System ◽  
Additional Constant ◽  
Bioreactor System ◽  
Biological Nitrogen ◽  
Low Do

Detection and characterization of hidden industrial inflows causing high fluctuations of the inlet load, is a challenging issue pushing plant operators for a cost-effective solution at regional wastewater treatment plants (WWTPs). On the other hand, carbon source of food industrial origin may have a good use at WWTPs facing otherwise inlet carbon source deficiency.In a case study of a regional domestic WWTP receiving seasonally organic carbon-rich discharge from a fruit juice factory, a new method combining on-site measurements and mathematical modelling was developed and successfully applied for estimating the quality and quantity of both industrial influent load and incoming domestic wastewater streams properly. The originally un-staged bioreactor system operated at low dissolved oxygen (low DO) concentration was unable to meet effluent nitrogen requirements with an additional constant risk of encouraging filament growth. A novel screening method based on special sampling campaigns for estimating carbon availability and C:N ratios of influent wastewater streams coming separately from the large catchment area, was developed and applied. Staging of the previously low DO basins into a flexible system containing non-aerated selectors proved to be efficient for enhancing both biological nitrogen removal and sculpturing appropriately settling biomass.

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