scholarly journals Eco-Efficiency Assessment of Control Actions in Wastewater Treatment Plants

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 612
Author(s):  
Silvana Revollar ◽  
Montse Meneses ◽  
Ramón Vilanova ◽  
Pastora Vega ◽  
Mario Francisco
Keyword(s):  
Decision Making ◽  
Wastewater Treatment ◽  
Control Strategy ◽  
Energy Use ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Seasonal Effects ◽  
Effect Of Temperature ◽  
Seasonal Effect ◽  
Control Actions

This work explores the possibilities of improving the eco-efficiency of Wastewater Treatment Plants (WWTPs) introducing a plant-wide perspective in the formulation of the control strategy. Eco-efficiency goals are contemplated in the analysis of the appropriateness of control actions, considering the seasonal effects of temperature into the decision-making process. Plant-wide control strategy handles are the operation variables of the activated sludge process, the volume of the primary clarifier, and the temperature of the anaerobic digester. Performance is evaluated in terms of energy use, biogas production, effluent quality, emissions to air and soil, considering annual and bimestrial average values of indicators to capture seasonal effect of temperature. The result is a set of possible solutions, obtained from a multi-objective decision-making procedure, consisting on a sequence of control actions applied at different temporal windows that improve the eco-efficiency indicators of the plant. The results obtained when applying the different solutions make evident how the application of plant-wide control strategies is useful to improve performance indicators that represent individual goals, leading to trade-off solutions that describe WWTPs’ eco-efficiency.

scholarly journals A Review on Sonochemistry and Its Environmental Applications

Acoustics ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 766-775
Author(s):  
Başak Savun-Hekimoğlu
Keyword(s):  
Wastewater Treatment ◽  
Environmental Remediation ◽  
Energy Use ◽  
Advanced Oxidation Process ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Aqueous Media ◽  
Chemical Transformations ◽  
Water And Wastewater Treatment ◽  
Synthesis Of Nanoparticles

Sonochemistry is a significant contributor to green science as it includes: (i) the use of less toxic compounds and environmentally safe solvents, (ii) improvement of reaction conditions and selectivity, (iii) no toxic sludge generation, (iv) reduction in the energy use for chemical transformations, (v) reusability of materials. In water and wastewater treatment, ultrasound is used as an advanced oxidation process to eliminate refractory pollutants. Ultrasound is also used as a very effective sludge pretreatment technology in wastewater treatment plants to facilitate biogas production. Moreover, sonochemical synthesis of nanoparticles has recently attracted great attention as a greener protocol. This paper presents the main applications of ultrasound in environmental remediation and protection. The study also introduces mechanism for the degradation of pollutants from water via sonication in aqueous media and the principle factors affecting the cavitational effect.

scholarly journals Integrated Omic Analyses Provide Evidence that a “Candidatus Accumulibacter phosphatis” Strain Performs Denitrification under Microaerobic Conditions

mSystems ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Pamela Y. Camejo ◽  
Ben O. Oyserman ◽  
Katherine D. McMahon ◽  
Daniel R. Noguera
Keyword(s):  
Wastewater Treatment ◽  
Energy Use ◽  
Wastewater Treatment Plants ◽  
Cost Effective ◽  
Biological Nutrient Removal ◽  
Nitrogen And Phosphorus ◽  
Biological Removal ◽  
Cost Effective Alternative ◽  
Accumulibacter Phosphatis ◽  
Microaerobic Conditions

“CandidatusAccumulibacter phosphatis” is widely found in full-scale wastewater treatment plants, where it has been identified as the key organism for biological removal of phosphorus. Since aeration can account for 50% of the energy use during wastewater treatment, microaerobic conditions for wastewater treatment have emerged as a cost-effective alternative to conventional biological nutrient removal processes. Our report provides strong genomics-based evidence not only that “Ca. Accumulibacter phosphatis” is the main organism contributing to phosphorus removal under microaerobic conditions but also that this organism simultaneously respires nitrate and oxygen in this environment, consequently removing nitrogen and phosphorus from the wastewater. Such activity could be harnessed in innovative designs for cost-effective and energy-efficient optimization of wastewater treatment systems.

scholarly journals MBR-Assisted VFAs Production from Excess Sewage Sludge and Food Waste Slurry for Sustainable Wastewater Treatment

2020 ◽  
Vol 10 (8) ◽  
pp. 2921 ◽  
Author(s):  
Mohsen Parchami ◽  
Steven Wainaina ◽  
Amir Mahboubi ◽  
David I’Ons ◽  
Mohammad J. Taherzadeh
Keyword(s):  
Wastewater Treatment ◽  
Sewage Sludge ◽  
Food Waste ◽  
Volatile Fatty Acids ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Economic Assessment ◽  
Ph Control ◽  
Daily Basis ◽  
Solids Concentration

The significant amount of excess sewage sludge (ESS) generated on a daily basis by wastewater treatment plants (WWTPs) is mainly subjected to biogas production, as for other organic waste streams such as food waste slurry (FWS). However, these organic wastes can be further valorized by production of volatile fatty acids (VFAs) that have various applications such as the application as an external carbon source for the denitrification stage at a WWTP. In this study, an immersed membrane bioreactor set-up was proposed for the stable production and in situ recovery of clarified VFAs from ESS and FWS. The VFAs yields from ESS and FWS reached 0.38 and 0.34 gVFA/gVSadded, respectively, during a three-month operation period without pH control. The average flux during the stable VFAs production phase with the ESS was 5.53 L/m2/h while 16.18 L/m2/h was attained with FWS. Moreover, minimal flux deterioration was observed even during operation at maximum suspended solids concentration of 32 g/L, implying that the membrane bioreactors could potentially guarantee the required volumetric productivities. In addition, the techno-economic assessment of retrofitting the membrane-assisted VFAs production process in an actual WWTP estimated savings of up to 140 €/h for replacing 300 kg/h of methanol with VFAs.

Carbon footprints of Scandinavian wastewater treatment plants

2013 ◽  
Vol 68 (4) ◽  
pp. 887-893 ◽  
Author(s):  
D. J. I. Gustavsson ◽  
S. Tumlin
Keyword(s):  
Wastewater Treatment ◽  
Carbon Footprint ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Municipal Wastewater Treatment ◽  
Carbon Footprints ◽  
Fossil Carbon

This study estimates the carbon footprints of 16 municipal wastewater treatment plants (WWTPs), all situated in Scandinavian countries, by using a simple model. The carbon footprint calculations were based on operational data, literature emission factors (efs) and measurements of greenhouse gas emissions at some of the studied WWTPs. No carbon neutral WWTPs were found. The carbon footprints ranged between 7 and 108 kg CO2e P.E.−1 year−1. Generally, the major positive contributors to the carbon footprint were direct emissions of nitrous oxide from wastewater treatment. Whether heat pumps for effluents have high coefficient of performance or not is extremely important for the carbon footprint. The choice of efs largely influenced the carbon footprint. Increased biogas production, efficient biogas usage, and decreased addition of external fossil carbon source for denitrification are important activities to decrease the carbon footprint of a WWTP.

scholarly journals Influence of the Presence of Long Chain Fatty Acids (Lcfas) in the Sewage on the Growth of M. Parvicella in Activated Sludge Wastewater Treatment Plants

2013 ◽  
Vol 8 (1) ◽  
pp. 82-88
Keyword(s):  
Fatty Acids ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Effect Of Temperature ◽  
Long Chain Fatty Acids ◽  
Filamentous Microorganism ◽  
Total Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids

Foaming and bulking problems in activated sludge treatment plants are associated to the presence of a variety of filamentous bacteria. However, it has been observed that M. parvicella is the most frequent filamentous microorganism causing sludge bulking and foaming, especially in treatment plants involving nutrients removal. High sludge retention time, low DO, low temperature, presence of anoxic, anaerobic, and intermittently aerated zones, are the most commonly cited conditions associated with its growth. Substrate composition is another significant factor, as it has been found that slowly degradable organic material may favour the growth of M. parvicella. If has also been suggested that M. parvicella may preferably store long chain fatty acids (LCFAs) under anaerobic conditions and subsequently use it for growth. The paper presents the results of an investigation conducted at the wastewater treatment plant of Ioannina, aiming to establish a cause-effect relationship between the presence of LCFAs and the abundance of M. parvicella. This investigation is a part of a wider study sponsored by the Greek Secretariat for Research, under the PENED programme. The duration of the investigation covers 8 months, from January 2004 to August 2004. During this period samples were taken from the sewage collection network and wastewater treatment plant of Ioannina and analysed for, among other parameters, LCFAs and total fatty acids while samples of the mixed liquor and the foam in the biological reactors were microscopically analysed in order to determine the presence and amount of various types of filamentous bacteria. Two main conclusions were drawn. The first is related to the effect of temperature on the growth of M. parvicella, indicating that the growth of this specific filamentous bacterium is favoured by low temperatures (generally below 20 oC), while higher temperatures cause the practical elimination of M. parvicella, irrespectively of other factors. This conclusion verifies previous studies in pilot units and full scale plants. The second conclusion is that during winter periods there seems to be a positive correlation, between the presence of fatty acids and more specifically LCFAs and the amount of M. parvicella.

Sign in / Sign up

Export Citation Format

Share Document