Energy Consumption and Internal Distribution in Activated Sludge Wastewater Treatment Plants of Greece

The high-energy consumption of wastewater treatment plants (WWTPs) is a crucial issue for municipalities worldwide. Most WWTPs in Greece operate as extended aeration plants, which results in high operational costs due to high energy needs. The present study investigated the energy requirements of 17 activated sludge WWTPs in Greece, serving between 1100–56,000 inhabitants (population equivalent, PE), with average daily incoming flowrates between 300–27,300 m3/d. The daily wastewater production per inhabitant was found to lie between 0.052 m3/PE·d and 0.426 m3/PE·d, with average volume of 0.217 ± 0.114 m3/PE·d. The electric energy consumption per volume unit (EQ (kWh/m3)) was between 0.128–2.280 kWh/m3 (average 0.903 ± 0.509 kWh/m3) following a near logarithmic descending correlation with the average incoming flowrate (Qav) (EQ = −0.294lnQav + 3.1891; R2 = 0.5337). A similar relationship was found between the daily electric energy requirements for wastewater treatment per inhabitant (EPE (kWh/PE·d)) as a function of PE, which varied from 0.041–0.407 kWh/PE·d (average 0.167 ± 0.101 kWh/PE·d)) (EPE = −0.073ln(PE) + 0.8425; R2 = 0.6989). Similarly, the daily energy cost per inhabitant (E€/PE (€/PE·d)) as a function of PE and the electric energy cost per wastewater volume unit (E€/V (€/m3)) as a function of average daily flow (Qav) were found to follow near logarithmic trends (E€/PE = −0.013ln(PE) + 0.1473; R2 = 0.6388, and E€/V = −0.052lnQav + 0.5151; R2 = 0.6359), respectively), with E€/PE varying between 0.005–0.073 €/PE·d (average 0.024 ± 0.019 €/PE·d) and E€/V between 0.012–0.291 €/m3 (average 0.111 ± 0.077 €/m3). Finally, it was calculated that, in an average WWTP, the aeration process is the main energy sink, consuming about 67.2% of the total electric energy supply to the plant. The large variation of energy requirements per inlet volume unit and per inhabitant served, indicate that there is large ground for improving the performance of the WWTPs, with respect to energy consumption.

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Structure and indicators of electric energy consumption in dairy wastewater treatment plant

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.146599 ◽

2021 ◽

pp. 146599

Author(s):

Radosław Żyłka ◽

Beata Karolinczak ◽

Wojciech Dąbrowski

Keyword(s):

Wastewater Treatment ◽

Energy Consumption ◽

Wastewater Treatment Plant ◽

Treatment Plant ◽

Electric Energy ◽

Dairy Wastewater ◽

Electric Energy Consumption

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Modeling of Electric Energy Consumption during Dairy Wastewater Treatment Plant Operation

Energies ◽

10.3390/en13153769 ◽

2020 ◽

Vol 13 (15) ◽

pp. 3769 ◽

Cited By ~ 1

Author(s):

Radosław Żyłka ◽

Wojciech Dąbrowski ◽

Paweł Malinowski ◽

Beata Karolinczak

Keyword(s):

Wastewater Treatment ◽

Energy Consumption ◽

Air Temperature ◽

Biological Treatment ◽

Municipal Wastewater ◽

Treatment Plant ◽

Electric Energy ◽

Dairy Wastewater ◽

Organic Load ◽

Electric Energy Consumption

The intensification of biological wastewater treatment requires the high usage of electric energy, mainly for aeration processes. Publications on energy consumption have been mostly related to municipal wastewater treatment plants (WWTPs). The aim of the research was to elaborate on models for the estimation of energy consumption during dairy WWTP operation. These models can be used for the optimization of electric energy consumption. The research was conducted in a dairy WWTP, operating with dissolved air flotation (DAF) and an activated sludge system. Energy consumption was measured with the help of three-phase network parameter transducers and a supervisory control and data acquisition (SCADA) system. The obtained models provided accurate predictions of DAF, biological treatment, and the overall WWTP energy consumption using chemical oxygen demand (COD), sewage flow, and air temperature. Using the energy consumption of the biological treatment as an independent variable, as well as air temperature, it is possible to estimate the variability of the total electric energy consumption. During the summer period, an increase in the organic load (expressed as COD) discharged into the biological treatment causes higher electric energy consumption in the whole dairy WWTP. Hence, it is recommended to increase the efficiency of the removal of organic pollutants in the DAF process. An application for the estimation of energy consumption was created.

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Application and Evaluation of Energy Conservation Technologies in Wastewater Treatment Plants

Applied Sciences ◽

10.3390/app9214501 ◽

2019 ◽

Vol 9 (21) ◽

pp. 4501 ◽

Cited By ~ 2

Author(s):

Yongteng Sun ◽

Ming Lu ◽

Yongjun Sun ◽

Zuguo Chen ◽

Hao Duan ◽

...

Keyword(s):

Wastewater Treatment ◽

Energy Consumption ◽

Energy Conservation ◽

Energy Saving ◽

Wastewater Treatment Plants ◽

System Optimization ◽

High Energy ◽

Green Energy ◽

Application Process ◽

Conservation Technologies

High energy consumption is an important issue affecting the operation and development of wastewater treatment plants (WWTPs). This paper seeks energy-saving opportunities from three aspects: energy application, process optimization, and performance evaluation. Moreover, effective energy-saving can be achieved from the perspective of energy supply and recovery by using green energy technologies, including wastewater and sludge energy recovery technologies. System optimization and control is used to reduce unnecessary energy consumption in operation. Reasonable indexes and methods can help researchers evaluate the application value of energy-saving technology. Some demonstration WWTPs even can achieve energy self-sufficiency by using these energy conservation technologies. Besides, this paper introduces the challenges faced by the wastewater treatment industry and some emerging energy-saving technologies. The work can give engineers some suggestions about reducing energy consumption from comprehensive perspectives.

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Benchmarking of energy consumption in municipal wastewater treatment plants – a survey of over 200 plants in Italy

Water Science & Technology ◽

10.2166/wst.2018.035 ◽

2018 ◽

Vol 77 (9) ◽

pp. 2242-2252 ◽

Cited By ~ 17

Author(s):

M. Vaccari ◽

P. Foladori ◽

S. Nembrini ◽

F. Vitali

Keyword(s):

Wastewater Treatment ◽

Energy Consumption ◽

Municipal Wastewater ◽

Energy Savings ◽

Wastewater Treatment Plants ◽

Specific Energy Consumption ◽

Oxygen Demand ◽

Energy Performance ◽

High Energy ◽

Municipal Wastewater Treatment

Abstract One of the largest surveys in Europe about energy consumption in Italian wastewater treatment plants (WWTPs) is presented, based on 241 WWTPs and a total population equivalent (PE) of more than 9,000,000 PE. The study contributes towards standardised resilient data and benchmarking and to identify potentials for energy savings. In the energy benchmark, three indicators were used: specific energy consumption expressed per population equivalents (kWh PE−1 year−1), per cubic meter (kWh/m3), and per unit of chemical oxygen demand (COD) removed (kWh/kgCOD). The indicator kWh/m3, even though widely applied, resulted in a biased benchmark, because highly influenced by stormwater and infiltrations. Plants with combined networks (often used in Europe) showed an apparent better energy performance. Conversely, the indicator kWh PE−1 year−1 resulted in a more meaningful definition of a benchmark. High energy efficiency was associated with: (i) large capacity of the plant, (ii) higher COD concentration in wastewater, (iii) separate sewer systems, (iv) capacity utilisation over 80%, and (v) high organic loads, but without overloading. The 25th percentile was proposed as a benchmark for four size classes: 23 kWh PE−1 y−1 for large plants > 100,000 PE; 42 kWh PE−1 y−1 for capacity 10,000 < PE < 100,000, 48 kWh PE−1 y−1 for capacity 2,000 < PE < 10,000 and 76 kWh PE−1 y−1 for small plants < 2,000 PE.

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CONSUMO E CUSTO DE ENERGIA ELÉTRICA NA CULTURA DE CITROS IRRIGADO POR GOTEJAMENTO E MICROASPERSÃO, COM TRÊS LÂMINAS DE ÁGUA.

Irriga ◽

10.15809/irriga.2010v15n1p75 ◽

2010 ◽

Vol 15 (1) ◽

pp. 75-89 ◽

Cited By ~ 1

Author(s):

Humberto Vinicius Vescove ◽

Jose Eduardo Pitelli Turco

Keyword(s):

Energy Consumption ◽

Energy Cost ◽

Citrus Sinensis ◽

Irrigation System ◽

Electric Energy ◽

Sprinkler Irrigation ◽

Electric Energy Consumption ◽

Group A ◽

Group B ◽

Water Depths

O objetivo deste trabalho foi analisar o consumo, custo de energia elétrica, e resultado econômico em citros (Citrus sinensis) irrigado. Os tratamentos constaram de sistemas de irrigação do tipo gotejamento, com uma e duas linhas laterais de distribuição de água, microaspersão e um tratamento sem irrigação. Para cada sistema foram utilizadas três lâminas de água; 100%, 75% e 50% da Etc (evapotranspiração da cultura). Foi estudado o custo da energia elétrica para dois grupos tarifários, Grupo A e Grupo B. Para o grupo A foram determinado os dispêndios com a energia para tarifas Estrutura Binômia Convencional e Horo-Sazonal (verde e azul), além, da tarifa especial para irrigante noturno. Os preços do kWh dos sistemas tarifários foram obtidos no site CPFL (Companhia Paulista de Força e Luz). A melhor relação entre o consumo de energia elétrica por ha (kWh.ha-1) pela produtividade (t.ha-1) foi observado nos tratamentos irrigados com 50% da Etc. O sistema tarifário horo sazonal verde/azul Grupo A irrigante noturno teve o menor custo de energia. Os tratamentos irrigados com lâmina de 50% apresentaram maiores produtividade em relação à lâmina de 100% da Etc. O maior retorno econômico ocorreu nos tratamentos irrigados com 50% da Etc. UNITERMOS: sistemas de irrigação, lâminas de irrigação, sistemas tarifários de energia. VESCOVE, H. V.; TURCO, J. E. P. ELETRIC ENERGY CONSUMPTION AND COST IN CITRUS CROP IRRIGATED BY DUP AND MICROSPRINKLER IRRIGATION UNDER THREE WATER DEPTHS. 2 ABSTRACT The objective of this work was to analyze the consumption, electric energy cost, and economic results of irrigated citrus (Citrus sinensis). The treatments consisted of a dripping irrigation system with one and two lateral distribution lines, a micro sprinkler irrigation system and a treatment without irrigation. For each irrigation system, three water depths were used: 100%, 75% and 50% of Etc (citrus evapotranspiration). The electric energy cost for two tariff groups, Group A and Group B, was studied. For Group A, the expenses with energy were determined for the Conventional Binomial Structure tariff, the Hour-seasonal tariff (green and blue) and the special tariff for nocturnal irrigation. The kWh cost for the tariff systems were obtained from the website of CPFL (São Paulo State Power and Light Company, Brazil). The best relation between the electric energy consumption (kWh.ha-1) and productivity (t.ha-1) occurred in the treatment irrigated with 50% of the Etc. The irrigated treatments increased productivity. The biggest productivity was observed in the irrigation treatments with 50% of the Etc when compared to the ones with 100% of the Etc. The blue and green Hour-seasonal tariff system of Group A (nocturnal irrigation) was the best option. A biggest economic turnover occurred in the treatments irrigated with 50% of the Etc. KEYWORDS: irrigation systems, irrigation depths, tariff systems of energy.

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The Experience and the Results of Operating Small Wastewater Treatment Plants

Water Science & Technology ◽

10.2166/wst.1990.0211 ◽

1990 ◽

Vol 22 (3-4) ◽

pp. 267-273

Author(s):

Mitja Rismal

Keyword(s):

Waste Water ◽

Wastewater Treatment ◽

Energy Consumption ◽

Water Treatment ◽

Activated Sludge ◽

Wastewater Treatment Plants ◽

Waste Water Treatment ◽

Water Jet ◽

Rotating Discs ◽

Water Treatment Plants

About 15 years of experience gained from operating 7 small waste water treatment plants between 150-500 p.e. and 6 plants of 2000-3000 p.e. capacity are described. All of the plants involved are low-loaded activated sludge plants with water jet aeration generated by screw or propeller pumps which both proved to be efficient in aeration while secure and simple in operation. In comparison with other types of small treatment plants in our country (rotating discs and bubble aeration activated sludge plants), they proved to be reliable and simple in operation and produce an effluent of good quality. The energy consumption and the necessary flow velocites in aeration tanks are computed and measured.

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Optimization of Electrical Energy Consumption and Level Reliability of Water Supply System

Jurnal Teknologi ◽

10.11113/jt.v72.3883 ◽

2015 ◽

Vol 72 (2) ◽

Author(s):

Mohd Ismail Jusoh ◽

Folorunso Taliha Abiodun ◽

Fatimah Sham Ismail ◽

Sohailah Shafie

Keyword(s):

Energy Consumption ◽

Water Supply ◽

Electric Energy ◽

Electrical Energy ◽

High Energy ◽

Supply System ◽

Water Supply System ◽

Operational Cost ◽

Electric Energy Consumption ◽

Optimized Model

Generally, high operational cost is associated with all water supply system. This is as a result of the high amount of electric energy consumption ascribed to the system due to its components. The water supply system of the Mara-Japan Industrial Institute (MJII), Beranang, Selangor is one of such system that suffers this challenge of high operational cost. In this paper we have applied the use of an Adaptive Weighted Sum Genetic Algorithm to optimize the system operations such that it minimizes the high energy consumption as well as ensuring the overall reliability of the water level in the reservoir. The results obtained from the optimized model of the system show a promising and a significant reduction to the tune of 34.97% in the amount of energy consumed as compared with that of normal operations.

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