This page has only limited features, please log in for full access.

Prof. Dimitris Vayenas
Department of Chemical Engineering, University of Patras, University Campus, GR-26504 Rio, Patras, Greece

Basic Info


Research Keywords & Expertise

0 Potable Water Treatment
0 Decentralized wastewater treatment systems
0 Agro-industrial and industrial wastewater treatment
0 Application of microalgae for wastewater treatment and biodiesel production
0 Modeling of biological processes

Fingerprints

Agro-industrial and industrial wastewater treatment
Potable Water Treatment

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Journal article
Published: 16 July 2021 in Journal of Environmental Management
Reads 0
Downloads 0

A novel pilot-scale hydrodynamic cavitation (HC) reactor was used to decolorize industrial-grade dye solutions and printing ink wastewater (PIW). The effect of the orifice plate geometry (1 hole plate of 1 mm and 2 mm in diameter, 31 holes of 1 mm and 2 mm in diameter, 62 holes of 1 mm and 2 mm in diameter), inlet pressure (4, 5 bar), initial dye concentration (0.3 and 0.6 OD), and the synergistic effect of HC and hydrogen peroxide concentration (0.0, 0.5, 1.0, 2.0 g/L) were investigated. The results showed that the highest color removal was obtained using 31 holes orifice plate of 2 mm holes’ diameter, at 4 bar inlet pressure. Furthermore, although HC could not degrade completely all the industrial-grade dyes, efficiency was enhanced in the presence of H2O2. The optimum concentration of hydrogen peroxide was 1.0 g/L regardless of the initial concentration of the dyes studied. Under optimum operating conditions, color removal reached up to 68% for black, 39% for red, 43% for yellow, 55% for green, and 51% for cyan dye, while color removal in the PIW reached only 15%. The black dye solution presented almost 100% COD removal, while 38%, 25%, 67%, and 78% COD removal values were obtained for the red, yellow, cyan and green dyes, respectively. 55% COD removal was recorded from the PIW. Concerning cavitation yields, black, red, yellow, green, cyan dye yields reached 2.5E(-7), 1.1E(-7), 1.5E(-7), 2.0E(-7), 1.7E(-7) OD⋅L/J, respectively, while PIW yield was 6.3E(-8) OD⋅L/J. The present study demonstrates that HC combined with green oxidants such as hydrogen peroxide could be an alternative treatment approach for real industrial wastewater streams. However, a combination with a post-treatment method should be applied to maximize both color and COD removal.

ACS Style

Charikleia Zampeta; Kleio Bertaki; Irene-Eva Triantaphyllidou; Zacharias Frontistis; Dimitris V. Vayenas. Treatment of real industrial-grade dye solutions and printing ink wastewater using a novel pilot-scale hydrodynamic cavitation reactor. Journal of Environmental Management 2021, 297, 113301 .

AMA Style

Charikleia Zampeta, Kleio Bertaki, Irene-Eva Triantaphyllidou, Zacharias Frontistis, Dimitris V. Vayenas. Treatment of real industrial-grade dye solutions and printing ink wastewater using a novel pilot-scale hydrodynamic cavitation reactor. Journal of Environmental Management. 2021; 297 ():113301.

Chicago/Turabian Style

Charikleia Zampeta; Kleio Bertaki; Irene-Eva Triantaphyllidou; Zacharias Frontistis; Dimitris V. Vayenas. 2021. "Treatment of real industrial-grade dye solutions and printing ink wastewater using a novel pilot-scale hydrodynamic cavitation reactor." Journal of Environmental Management 297, no. : 113301.

Editorial
Published: 31 March 2021 in Water
Reads 0
Downloads 0

Food processing consumes high volumes of water, making agro-industries the third biggest industrial user of water after oil refineries, primary metals and chemicals industries

ACS Style

Christos Akratos; Athanasia Tekerlekopoulou; Dimitrios Vayenas. Agro-Industrial Wastewater Treatment with Decentralized Biological Treatment Methods. Water 2021, 13, 953 .

AMA Style

Christos Akratos, Athanasia Tekerlekopoulou, Dimitrios Vayenas. Agro-Industrial Wastewater Treatment with Decentralized Biological Treatment Methods. Water. 2021; 13 (7):953.

Chicago/Turabian Style

Christos Akratos; Athanasia Tekerlekopoulou; Dimitrios Vayenas. 2021. "Agro-Industrial Wastewater Treatment with Decentralized Biological Treatment Methods." Water 13, no. 7: 953.

Journal article
Published: 10 February 2021 in Journal of Environmental Management
Reads 0
Downloads 0

Electrocoagulation (EC) with an aluminum electrode arrangement as anode-cathode was applied to denitrify groundwater and electrooxidation (EO) was examined as a post-treatment step to remove the produced by-products. Initially, EC experiments were performed under batch operating mode using artificially-polluted tap water to investigate the effects of initial pH (5.5, 7.5, 8.5), initial NO3−-N concentration (25, 35, 45, 55 mg L−1) and applied current density (10, 20 mA cm−2) on process efficiency. The effect of initial solution pH on ammonium cation concentration was also investigated as their generation (as a by-product) is the main drawback preventing wide-scale application of these treatment processes. Experimental results revealed high nitrate removal percentages (up to 96.3%) for initial pH 7.5 and all initial concentrations and current densities, while the final ammonium concentrations ranged between 5.3 and 9.2 mg NH4+-N L−1 (for initial NO3−-N of 25 mg L−1). Therefore, EO was examined to oxidize the ammonium cations to nitrogen gas on iridium oxide coated titanium electrodes (IrO2/Ti) anode surface. The effects of cathode material (aluminum, stainless steel), total current density and anode surface area (3.3–30 mA cm−2 and 12–36 cm2, respectively) were investigated, and lead to NH4+-N percentage removals of between 25% (10 mA cm−2, 12 cm2) and 100% (30 mA cm−2, 24 cm2) for an initial NH4+-N concentration of 10 mg L−1. The optimum EC (20 mA cm−2, natural initial pH 7.5–7.8) and EO parameters (30 mA cm−2, 24 cm2 surface area anode, Al cathode) were combined into a hybrid system to treat two real nitrate-polluted groundwaters with initial NO3−-N concentrations of 25 and 75 mg L−1. Results revealed that the proposed hybrid treatment system can be used to efficiently remove nitrate from groundwaters.

ACS Style

Andreas K. Benekos; Maria Tsigara; Stergios Zacharakis; Irene-Eva Triantaphyllidou; Athanasia G. Tekerlekopoulou; Alexandros Katsaounis; Dimitris V. Vayenas. Combined electrocoagulation and electrochemical oxidation treatment for groundwater denitrification. Journal of Environmental Management 2021, 285, 112068 .

AMA Style

Andreas K. Benekos, Maria Tsigara, Stergios Zacharakis, Irene-Eva Triantaphyllidou, Athanasia G. Tekerlekopoulou, Alexandros Katsaounis, Dimitris V. Vayenas. Combined electrocoagulation and electrochemical oxidation treatment for groundwater denitrification. Journal of Environmental Management. 2021; 285 ():112068.

Chicago/Turabian Style

Andreas K. Benekos; Maria Tsigara; Stergios Zacharakis; Irene-Eva Triantaphyllidou; Athanasia G. Tekerlekopoulou; Alexandros Katsaounis; Dimitris V. Vayenas. 2021. "Combined electrocoagulation and electrochemical oxidation treatment for groundwater denitrification." Journal of Environmental Management 285, no. : 112068.

Journal article
Published: 27 December 2020 in Applied Sciences
Reads 0
Downloads 0

Algal/cyanobacterial biofilm photobioreactors provide an alternative technology to conventional photosynthetic systems for wastewater treatment based on high biomass production and easy biomass harvesting at low cost. This study introduces a novel cyanobacteria-based biofilm photobioreactor and assesses its performance in post-treatment of brewery wastewater and biomass production. Two different supporting materials (glass/polyurethane) were tested to investigate the effect of surface hydrophobicity on biomass attachment and overall reactor performance. The reactor exhibited high removal efficiency (over 65%) of the wastewater’s pollutants (chemical oxygen demand, nitrate, nitrite, ammonium, orthophosphate, and total Kjeldahl nitrogen), while biomass per reactor surface reached 13.1 and 12.8 g·m−2 corresponding to 406 and 392 mg·L−1 for glass and polyurethane, respectively, after 15 days of cultivation. The hydrophilic glass surface favored initial biomass adhesion, although eventually both materials yielded complete biomass attachment, highlighting that cell-to-cell interactions are the dominant adhesion mechanism in mature biofilms. It was also found that the biofilm accumulated up to 61% of its dry weight in carbohydrates at the end of cultivation, thus making the produced biomass a suitable feedstock for bioethanol production.

ACS Style

Konstantinos P. Papadopoulos; Christina N. Economou; Athanasia G. Tekerlekopoulou; Dimitris V. Vayenas. A Cyanobacteria-Based Biofilm System for Advanced Brewery Wastewater Treatment. Applied Sciences 2020, 11, 174 .

AMA Style

Konstantinos P. Papadopoulos, Christina N. Economou, Athanasia G. Tekerlekopoulou, Dimitris V. Vayenas. A Cyanobacteria-Based Biofilm System for Advanced Brewery Wastewater Treatment. Applied Sciences. 2020; 11 (1):174.

Chicago/Turabian Style

Konstantinos P. Papadopoulos; Christina N. Economou; Athanasia G. Tekerlekopoulou; Dimitris V. Vayenas. 2020. "A Cyanobacteria-Based Biofilm System for Advanced Brewery Wastewater Treatment." Applied Sciences 11, no. 1: 174.

Journal article
Published: 11 January 2020 in Molecules
Reads 0
Downloads 0

Various pretreatment methods, such as thermal, alkaline and acid, were applied on grass lawn (GL) waste and the effect of each pretreatment method on the Biochemical Methane Potential was evaluated for two options, namely using the whole slurry resulting from pretreatment or the separate solid and liquid fractions obtained. In addition, the effect of each pretreatment on carbohydrate solubilization and lignocellulossic content fractionation (to cellulose, hemicellulose, lignin) was also evaluated. The experimental results showed that the methane yield was enhanced with alkaline pretreatment and, the higher the NaOH concentration (20 g/100 gTotal Solids (TS)), the higher was the methane yield observed (427.07 L CH4/kg Volatile Solids (VS), which was almost 25.7% higher than the BMP of the untreated GL). Comparing the BMP obtained under the two options, i.e., that of the whole pretreatment slurry with the sum of the BMPs of both fractions, it was found that direct anaerobic digestion without separation of the pretreated biomass was favored, in almost all cases. A preliminary energy balance and economic assessment indicated that the process could be sustainable, leading to a positive net heat energy only when using a more concentrated pretreated slurry (i.e., 20% organic loading), or when applying NaOH pretreatment at a lower chemical loading.

ACS Style

Georgia Antonopoulou; Dimitrios Vayenas; Gerasimos Lyberatos. Biogas Production from Physicochemically Pretreated Grass Lawn Waste: Comparison of Different Process Schemes. Molecules 2020, 25, 296 .

AMA Style

Georgia Antonopoulou, Dimitrios Vayenas, Gerasimos Lyberatos. Biogas Production from Physicochemically Pretreated Grass Lawn Waste: Comparison of Different Process Schemes. Molecules. 2020; 25 (2):296.

Chicago/Turabian Style

Georgia Antonopoulou; Dimitrios Vayenas; Gerasimos Lyberatos. 2020. "Biogas Production from Physicochemically Pretreated Grass Lawn Waste: Comparison of Different Process Schemes." Molecules 25, no. 2: 296.

Journal article
Published: 06 September 2019 in Journal of Environmental Management
Reads 0
Downloads 0

The treatment of nitrate-contaminated groundwater was studied using a hybrid system comprising an electrocoagulation unit and a zeolite adsorption reactor. In the electrocoagulation (EC) process, aluminum alloy electrodes were used in an undivided cell. Experiments in the laboratory-scale reactor were carried out in unregulated temperature conditions to treat synthetic groundwater solutions containing initial nitrate concentrations of 10–100 mg NO3−-N·L−1 in batch mode and without using additional pH buffers. Various operating variables, such as applied current density (about 20 mA cm−2 to 80 mA cm−2), concentration of NaCl electrolyte (0.0–1.0 g L−1) and treatment time (up to 120 min), were tested for their effects on nitrate removal. Results showed that initial NO3−-N concentration, current density and electrolyte concentration, play important roles in EC. For all initial NO3−-N concentrations and current densities tested, the highest NO3−-N removal rates (up to 2.374 g L−1·d−1) were achieved without additional electrolyte and/or with the lowest electrolyte concentration of 0.1 g L−1. In these experiments, EC reduced NO3−-N to below the standard limit of 10 mg L−1 after 10–60 min of electrolysis. A significant quantity of by-products, ammonium and dissolved aluminum, formed during the process, however these were successfully removed by zeolite adsorption in the post-treatment step. The electrochemical reactor using the specific anode/cathode combination and an environmentally-friendly post-treatment step such as zeolite adsorption, can be used to efficiently remove nitrate from groundwaters because of its high efficiency.

ACS Style

Athina Ziouvelou; Athanasia Tekerlekopoulou; Dimitris V. Vayenas. A hybrid system for groundwater denitrification using electrocoagulation and adsorption. Journal of Environmental Management 2019, 249, 109355 .

AMA Style

Athina Ziouvelou, Athanasia Tekerlekopoulou, Dimitris V. Vayenas. A hybrid system for groundwater denitrification using electrocoagulation and adsorption. Journal of Environmental Management. 2019; 249 ():109355.

Chicago/Turabian Style

Athina Ziouvelou; Athanasia Tekerlekopoulou; Dimitris V. Vayenas. 2019. "A hybrid system for groundwater denitrification using electrocoagulation and adsorption." Journal of Environmental Management 249, no. : 109355.

Journal article
Published: 04 September 2019 in Process Safety and Environmental Protection
Reads 0
Downloads 0

Electrocoagulation-(EC) is investigated as an alternative, cost-efficient, method for the treatment or post-treatment of table olive processing wastewaters (TOPWs). Experiments were performed in both laboratory and pilot-scale reactors using aluminum and iron electrodes. Different initial chemical oxygen demand (COD) concentrations (3000, 5000 and 9000 mg L-1) and current densities (41.7, 83.3 and 166.7 mA cm-2) were tested in laboratory-scale experiments to determine maximum COD and color removal from untreated TOPWs. Pilot-scale experiments were also conducted using biologically pre-treated TOPW (COD 1000 mg L-1 and current densities of 3.87 and 5.65 mA cm-2) to ensure an efficient post-treatment process. Aluminum electrodes were found to be more efficient in reducing COD and color than iron electrodes in both laboratory and pilot-scale experiments. In laboratory-scale experiments the maximum COD and color removal (approximately 50% and 100%, respectively) was recorded for the lowest initial COD concentration of 3000 mg L-1 at 166.7 mA cm-2. In the pilot-scale reactor the maximum COD and color removal observed was 42.5% and 85.3%, respectively, for the current density of 5.65 mA cm-2. Lower energy and electrode consumption was recorded when working with aluminum electrodes and optimum results were obtained with the lowest initial COD and current density values tested.

ACS Style

Andreas K. Benekos; Charikleia Zampeta; Rafailia Argyriou; Christina N. Economou; Irene-Eva Triantaphyllidou; Triantafyllos I. Tatoulis; Athanasia Tekerlekopoulou; Dimitris V. Vayenas. Treatment of table olive processing wastewaters using electrocoagulation in laboratory and pilot-scale reactors. Process Safety and Environmental Protection 2019, 131, 38 -47.

AMA Style

Andreas K. Benekos, Charikleia Zampeta, Rafailia Argyriou, Christina N. Economou, Irene-Eva Triantaphyllidou, Triantafyllos I. Tatoulis, Athanasia Tekerlekopoulou, Dimitris V. Vayenas. Treatment of table olive processing wastewaters using electrocoagulation in laboratory and pilot-scale reactors. Process Safety and Environmental Protection. 2019; 131 ():38-47.

Chicago/Turabian Style

Andreas K. Benekos; Charikleia Zampeta; Rafailia Argyriou; Christina N. Economou; Irene-Eva Triantaphyllidou; Triantafyllos I. Tatoulis; Athanasia Tekerlekopoulou; Dimitris V. Vayenas. 2019. "Treatment of table olive processing wastewaters using electrocoagulation in laboratory and pilot-scale reactors." Process Safety and Environmental Protection 131, no. : 38-47.

Journal article
Published: 01 May 2019 in Water
Reads 0
Downloads 0

The efficiency of natural zeolite to treat second cheese whey (SCW) and remove ammonium from artificial wastewater (AWW) was examined. Since zeolite has been reported to improve nitrogen availability in soils, its effect on wheat plant growth was also examined. Continuing a previous study using batch reactors, results are presented concerning experiments in fixed-bed columns under continuous operation. Results from the continuous flow column experiments using AWW and zeolite (2.0–2.8 mm) indicated that low flow rates (4 mL/min and 8 mL/min) did not significantly affect zeolite adsorption ability, while maximum zeolite adsorption capacity reached 15.30 mg NH4+-N/g. Finally, the effect of zeolite saturated with NH4+-N on plant growth was examined. The application of saturated zeolite affected significantly wheat plant growth and resulted in faster growth and higher biomass production.

ACS Style

Aggelos Kotoulas; Dimitra Agathou; Irene E. Triantaphyllidou; Triantafyllos I. Tatoulis; Christos S. Akratos; Athanasia G. Tekerlekopoulou; Dimitrios V. Vayenas. Second Cheese Whey Treatment Using Zeolite under Continuous Flow Mode and Its Application on Wheat Growth. Water 2019, 11, 928 .

AMA Style

Aggelos Kotoulas, Dimitra Agathou, Irene E. Triantaphyllidou, Triantafyllos I. Tatoulis, Christos S. Akratos, Athanasia G. Tekerlekopoulou, Dimitrios V. Vayenas. Second Cheese Whey Treatment Using Zeolite under Continuous Flow Mode and Its Application on Wheat Growth. Water. 2019; 11 (5):928.

Chicago/Turabian Style

Aggelos Kotoulas; Dimitra Agathou; Irene E. Triantaphyllidou; Triantafyllos I. Tatoulis; Christos S. Akratos; Athanasia G. Tekerlekopoulou; Dimitrios V. Vayenas. 2019. "Second Cheese Whey Treatment Using Zeolite under Continuous Flow Mode and Its Application on Wheat Growth." Water 11, no. 5: 928.

Journal article
Published: 27 February 2019 in Journal of Environmental Management
Reads 0
Downloads 0

The present study investigates the treatment of real printing ink wastewater by using the electrocoagulation (EC) process. Effects of initial chemical oxygen demand (COD) concentrations, electrode materials and current densities were examined to determine the maximum COD and color removal from the wastewater. In parallel, raw and treated printing ink wastewater toxic potential was further estimated via the application of toxicity tests using the freshwater crustacean Thamnocephalus platyurus for assessing EC process efficiency. According to the results, it was observed that the EC is efficient under most of the operating conditions used, as COD and color removal ranged between 72.03 to 85.81% and 98.7–100%, respectively. The total cost of the EC process, considering the treatment time, applied current, applied voltage and the total anode electrode mass consumption was also estimated. The Fe electrode proved to be of lower cost than the Al electrode, however the use of Al electrode produced better decolorization results in the solutions. Moreover, toxicity tests currently performed with the use of larvae of the fairy shrimp Thamnocephalus platyurus revealed a substantial decrease in the toxic potential of printing ink wastewater, thus indicating the efficiency of the proposed EC process.

ACS Style

Konstantinos P. Papadopoulos; Rafailia Argyriou; Christina N. Economou; Nikolina Charalampous; Stefanos Dailianis; Triantafyllos I. Tatoulis; Athanasia Tekerlekopoulou; Dimitris V. Vayenas. Treatment of printing ink wastewater using electrocoagulation. Journal of Environmental Management 2019, 237, 442 -448.

AMA Style

Konstantinos P. Papadopoulos, Rafailia Argyriou, Christina N. Economou, Nikolina Charalampous, Stefanos Dailianis, Triantafyllos I. Tatoulis, Athanasia Tekerlekopoulou, Dimitris V. Vayenas. Treatment of printing ink wastewater using electrocoagulation. Journal of Environmental Management. 2019; 237 ():442-448.

Chicago/Turabian Style

Konstantinos P. Papadopoulos; Rafailia Argyriou; Christina N. Economou; Nikolina Charalampous; Stefanos Dailianis; Triantafyllos I. Tatoulis; Athanasia Tekerlekopoulou; Dimitris V. Vayenas. 2019. "Treatment of printing ink wastewater using electrocoagulation." Journal of Environmental Management 237, no. : 442-448.

Journal article
Published: 14 January 2019 in Water
Reads 0
Downloads 0

The efficiency of natural zeolite to remove ammonium from artificial wastewater (ammonium aqueous solutions) and to treat second cheese whey was examined, aiming to recover nitrogen nutrients that can be used for further applications, such as slow-release fertilizers. Sorption experiments were performed using artificial wastewater and zeolite of different granulometries (i.e., 0.71–1.0, 1.8–2.0, 2.0–2.8, 2.8–4.0, and 4.0–5.0 mm). The granulometry of the zeolite had no significant effect on its ability to absorb ammonium. Nevertheless, smaller particles (0.71–1.0 mm) exhibited quicker NH4+-N adsorption rates of up to 93.0% in the first 10 min. Maximum ammonium removal efficiency by the zeolite was achieved at ammonium concentrations ranging from 10 to 80 mg/L. Kinetic experiments revealed that chemisorption is the mechanism behind the adsorption process of ammonium on zeolite, while the Freundlich isotherm model fitted the experimental data well. Column sorption experiments under batch operating mode were performed using artificial wastewater and second cheese whey. Column experiments with artificial wastewater showed high NH4+-N removal rates (over 96% in the first 120 min) for all granulometries and initial NH4+-N concentrations tested (200 and 5000 mg/L). Column experiments with second cheese whey revealed that natural zeolite can remove significant organic loads (up to 40%, 14.53 mg COD/g of zeolite) and NH4+-N (about 99%). For PO43−-P, the zeolite appeared to saturate after day 1 of the experiments at a removal capacity of 0.15 mg P/g of zeolite. Desorption experiments with water resulted in low NH4+-N and PO43−-P desorption rates indicating that the zeolite could be used as a substrate for slow nitrogen release in soils.

ACS Style

Aggelos Kotoulas; Dimitra Agathou; Irene E. Triantaphyllidou; Triantafyllos I. Tatoulis; Christos S. Akratos; Athanasia G. Tekerlekopoulou; Dimitrios V. Vayenas. Zeolite as a Potential Medium for Ammonium Recovery and Second Cheese Whey Treatment. Water 2019, 11, 136 .

AMA Style

Aggelos Kotoulas, Dimitra Agathou, Irene E. Triantaphyllidou, Triantafyllos I. Tatoulis, Christos S. Akratos, Athanasia G. Tekerlekopoulou, Dimitrios V. Vayenas. Zeolite as a Potential Medium for Ammonium Recovery and Second Cheese Whey Treatment. Water. 2019; 11 (1):136.

Chicago/Turabian Style

Aggelos Kotoulas; Dimitra Agathou; Irene E. Triantaphyllidou; Triantafyllos I. Tatoulis; Christos S. Akratos; Athanasia G. Tekerlekopoulou; Dimitrios V. Vayenas. 2019. "Zeolite as a Potential Medium for Ammonium Recovery and Second Cheese Whey Treatment." Water 11, no. 1: 136.

Journal article
Published: 20 November 2018 in Water
Reads 0
Downloads 0

The use of cyanobacteria in biological wastewater treatment technologies can greatly reduce operation costs by combining wastewater bioremediation and production of lipid suitable as biodiesel feedstock. In this work, an attached growth system was employed to achieve the above-mentioned dual objective using a mixed microbial culture dominated by Leptolyngbya and Limnothrix species in diverse heterotrophic consortia. Kinetic experiments on different initial pollutant concentrations were carried out to determine the ability of the established culture to remove organic load (expressed by d-COD, dissolved-Chemical Oxygen Demand), N and P from agroindustrial wastewaters (dairy, winery and raisin). Biomass and oil productivity were determined. It was found that significant removal rates of nutrients were achieved in all the wastewaters examined, especially in that originated from winery in which the highest d-COD removal rate (up to 97.4%) was observed. The attached microbial biomass produced in winery wastewater contained 23.2% lipid/biomass, wt/wt, which was satisfying. The growth in the dairy wastewater yielded the highest attached biomass productivity (5.03 g m−2 day−1) followed by the mixed effluent of winery-raisin (4.12 g m−2 day−1) and the winery wastewater (3.08 g m−2 day−1). The produced microbial lipids contained high percentages of saturated and mono-unsaturated fatty acids (over 89% in total lipids) in all substrates examined. We conclude that the proposed attached growth photobioreactor system can be considered an effective wastewater treatment system that simultaneously produces microbial lipids suitable as biodiesel feedstock.

ACS Style

Olga N. Tsolcha; Athanasia G. Tekerlekopoulou; Christos S. Akratos; George Aggelis; Savvas Genitsaris; Maria Moustaka-Gouni; Dimitrios V. Vayenas. Agroindustrial Wastewater Treatment with Simultaneous Biodiesel Production in Attached Growth Systems Using a Mixed Microbial Culture. Water 2018, 10, 1693 .

AMA Style

Olga N. Tsolcha, Athanasia G. Tekerlekopoulou, Christos S. Akratos, George Aggelis, Savvas Genitsaris, Maria Moustaka-Gouni, Dimitrios V. Vayenas. Agroindustrial Wastewater Treatment with Simultaneous Biodiesel Production in Attached Growth Systems Using a Mixed Microbial Culture. Water. 2018; 10 (11):1693.

Chicago/Turabian Style

Olga N. Tsolcha; Athanasia G. Tekerlekopoulou; Christos S. Akratos; George Aggelis; Savvas Genitsaris; Maria Moustaka-Gouni; Dimitrios V. Vayenas. 2018. "Agroindustrial Wastewater Treatment with Simultaneous Biodiesel Production in Attached Growth Systems Using a Mixed Microbial Culture." Water 10, no. 11: 1693.

Data article
Published: 28 October 2018 in Data in Brief
Reads 0
Downloads 0

Yarrowia lipolytica, which is model oleaginous yeast with high industrial interest, was cultivated on fatty substrates. Data concerning fatty acid composition of both substrate and yeast lipids and comparisons of the experimental data with model predictions presented in “Biomodification of fats and oils and scenarios of adding value on renewable fatty materials through microbial fermentations: Modelling and trials with Yarrowia lipolytica” (Vasiliadou et al., 2018) were provided. Furthermore, the total yeast lipids were fractionated into their main fractions, that is, phospholipids, glucolipids plus sphingolipids and neutral lipids, and the fatty acid composition of each lipid fraction was reported.

ACS Style

Alexandra Daskalaki; Ioanna A. Vasiliadou; Stamatia Bellou; Ludwika Tomaszewska-Hetman; Chrisanthi Chatzikotoula; Barbara Kompoti; Seraphim Papanikolaou; Dimitris Vayenas; Stavros Pavlou; George Aggelis. Data on cellular lipids of Yarrowia lipolytica grown on fatty substrates. Data in Brief 2018, 21, 1037 -1044.

AMA Style

Alexandra Daskalaki, Ioanna A. Vasiliadou, Stamatia Bellou, Ludwika Tomaszewska-Hetman, Chrisanthi Chatzikotoula, Barbara Kompoti, Seraphim Papanikolaou, Dimitris Vayenas, Stavros Pavlou, George Aggelis. Data on cellular lipids of Yarrowia lipolytica grown on fatty substrates. Data in Brief. 2018; 21 ():1037-1044.

Chicago/Turabian Style

Alexandra Daskalaki; Ioanna A. Vasiliadou; Stamatia Bellou; Ludwika Tomaszewska-Hetman; Chrisanthi Chatzikotoula; Barbara Kompoti; Seraphim Papanikolaou; Dimitris Vayenas; Stavros Pavlou; George Aggelis. 2018. "Data on cellular lipids of Yarrowia lipolytica grown on fatty substrates." Data in Brief 21, no. : 1037-1044.

Journal article
Published: 01 August 2018 in Journal of Cleaner Production
Reads 0
Downloads 0

The ex novo lipid accumulation process in the yeast Yarrowia lipolytica was systematically studied in the current investigation. Various fatty materials of plant (i.e. olive, sunflower, palm, linseed oils) or animal (i.e. cod liver oil, beef tallow) origin, the fatty acid (FA) composition of which resembled in several cases to the one of important low- or negative-cost hydrophobic resources (i.e. stickwaters, fat-rich wastes from meat-processing facilities, used-cooked oils, etc) were employed as substrates and a detailed mathematical model which included description of substrate fat hydrolysis, biomass and reserve lipid formation and cellular lipid turnover was developed. The kinetic parameter values were calculated by fitting the model on experimental data and used to estimate the ability of the yeast to grow on the various substrate fats and modify their FA composition. With few exceptions the substrate fat was efficiently converted into yeast cells (biomass) rich in lipids consisting mainly of neutral lipids (often >90% on the total lipids), indicating, therefore the potential of the yeast Y. lipolytica as cell factory amenable to ferment several types of low-cost fatty materials. The contribution of each substrate fatty acid (FA) to the synthesis of fat free biomass varied according to the theoretical FA uptake rate and typically was higher for palmitic, oleic and linoleic acid than the remaining FAs. Eicosapentaenoic and docosohexaenoic acids, typically found in several stickwaters or crude fish oils, were also rapidly taken up when cod liver oil was used as substrate. Respectively, the contribution of the substrate FAs to the synthesis of storage lipid was more important for linoleic and palmitic acids. Higher proportions of unsaturated FAs were esterified in phospholipid fraction. Upon exhaustion of the substrate fat, storage lipid degradation occurred. Unsaturated (primarily monounsaturated) FA uptake rates were higher than those of saturated FAs and therefore storage lipid was enriched in saturated FAs during lipid turnover. Storage lipid degradation can be successfully repressed (or even its biosynthesis can be restored) with the addition of a carbon source (e.g. glycerol, glucose, olive oil) in the culture medium during lipid degradation. We concluded that the mathematical approach proposed in this paper can constitute an effective tool for better understanding several key biochemical events, including substrate fat modification, during growth of Y. lipolytica on common oils. Through the proposed approach, low cost fatty materials such as stickwaters, fat-rich wastewaters from meat-processing facilities, used-cooked oils, soap stocks, stearins, etc., can be efficiently converted in higher-value cellular lipids by Y. lipolytica through completely eco-friendly and green processes.

ACS Style

Ioanna Vasiliadou; Stamatia Bellou; Alexandra Daskalaki; Ludwika Tomaszewska- Hetman; Chrisanthi Chatzikotoula; Barbara Kompoti; Seraphim Papanikolaou; Dimitris Vayenas; Stavros Pavlou; George Aggelis. Biomodification of fats and oils and scenarios of adding value on renewable fatty materials through microbial fermentations: Modelling and trials with Yarrowia lipolytica. Journal of Cleaner Production 2018, 200, 1111 -1129.

AMA Style

Ioanna Vasiliadou, Stamatia Bellou, Alexandra Daskalaki, Ludwika Tomaszewska- Hetman, Chrisanthi Chatzikotoula, Barbara Kompoti, Seraphim Papanikolaou, Dimitris Vayenas, Stavros Pavlou, George Aggelis. Biomodification of fats and oils and scenarios of adding value on renewable fatty materials through microbial fermentations: Modelling and trials with Yarrowia lipolytica. Journal of Cleaner Production. 2018; 200 ():1111-1129.

Chicago/Turabian Style

Ioanna Vasiliadou; Stamatia Bellou; Alexandra Daskalaki; Ludwika Tomaszewska- Hetman; Chrisanthi Chatzikotoula; Barbara Kompoti; Seraphim Papanikolaou; Dimitris Vayenas; Stavros Pavlou; George Aggelis. 2018. "Biomodification of fats and oils and scenarios of adding value on renewable fatty materials through microbial fermentations: Modelling and trials with Yarrowia lipolytica." Journal of Cleaner Production 200, no. : 1111-1129.

Book chapter
Published: 06 July 2018 in Constructed Wetlands for Industrial Wastewater Treatment
Reads 0
Downloads 0

Dairy wastewater is a source of pollution in many countries around the world, especially in rural areas. These wastewaters are generated in milk processing units for the pasteurization and homogenization of fluid milk, and also during the production of dairy products (e.g., butter, cheese, milk powder etc.). The management of this pollution load of these wastewaters usually includes intensified and energy‐consuming mechanical and/or chemical technologies. The green technology of Constructed Wetlands increasingly appears as an attractive alternative, which provides several economic and environmental benefits. Therefore, the goal of this chapter is to combine and present the experiences from three different countries (Belgium, the Netherlands and Greece) on Constructed Wetlands systems applied for dairy wastewater treatment.

ACS Style

C.S. Akratos; D. Van Oirschot; A.G. Tekerlekopoulou; Dimitrios V. Vayenas; Alexandros Stefanakis. Dairy Wastewater Treatment with Constructed Wetlands: Experiences from Belgium, the Netherlands and Greece. Constructed Wetlands for Industrial Wastewater Treatment 2018, 175 -202.

AMA Style

C.S. Akratos, D. Van Oirschot, A.G. Tekerlekopoulou, Dimitrios V. Vayenas, Alexandros Stefanakis. Dairy Wastewater Treatment with Constructed Wetlands: Experiences from Belgium, the Netherlands and Greece. Constructed Wetlands for Industrial Wastewater Treatment. 2018; ():175-202.

Chicago/Turabian Style

C.S. Akratos; D. Van Oirschot; A.G. Tekerlekopoulou; Dimitrios V. Vayenas; Alexandros Stefanakis. 2018. "Dairy Wastewater Treatment with Constructed Wetlands: Experiences from Belgium, the Netherlands and Greece." Constructed Wetlands for Industrial Wastewater Treatment , no. : 175-202.

Book chapter
Published: 06 July 2018 in Constructed Wetlands for Industrial Wastewater Treatment
Reads 0
Downloads 0

Olive Mill Wastewater (OMW) represents a significant environmental threat in all olive producing countries, mainly in the Mediterranean basin such as Italy, Greece, Tunisia and Spain, which cover almost 78% of the global olive oil production. The specific characteristics of OMW (dark color, strong smell, acid pH, high salinity, high content of phenolic and fatty substances, high organic matter concentrations) combined with their large production volumes and extremely unequal annual production distribution (production mainly during the winter months), give OMW a strong polluting potential and strong antibacterial and phytotoxic properties. Hence, OMW production requires the development and implementation of strict management. Considering this, the technology of Constructed Wetlands appears as an ideal solution for OMW treatment of small and remote agro‐industrial facilities, due to the extremely low operational costs, relatively easy and simple operation, minimum mechanical equipment, almost zero by‐products and the autonomous operation without the need for specialized staff. This chapter presents the experiences of Greece on the use of wetland systems for OMW treatment and a successful innovative pilot system in Italy. Finally, advantages, disadvantages, and lessons learnt from the described case studies are discussed.

ACS Style

F. Masi; A. Rizzo; R. Bresciani; Dimitrios V. Vayenas; C.S. Akratos; A.G. Tekerlekopoulou; Alexandros Stefanakis. Olive Mill Wastewater Treatment in Constructed Wetlands. Constructed Wetlands for Industrial Wastewater Treatment 2018, 163 -174.

AMA Style

F. Masi, A. Rizzo, R. Bresciani, Dimitrios V. Vayenas, C.S. Akratos, A.G. Tekerlekopoulou, Alexandros Stefanakis. Olive Mill Wastewater Treatment in Constructed Wetlands. Constructed Wetlands for Industrial Wastewater Treatment. 2018; ():163-174.

Chicago/Turabian Style

F. Masi; A. Rizzo; R. Bresciani; Dimitrios V. Vayenas; C.S. Akratos; A.G. Tekerlekopoulou; Alexandros Stefanakis. 2018. "Olive Mill Wastewater Treatment in Constructed Wetlands." Constructed Wetlands for Industrial Wastewater Treatment , no. : 163-174.

Book chapter
Published: 06 July 2018 in Constructed Wetlands for Industrial Wastewater Treatment
Reads 0
Downloads 0

Due to their simplicity and low operation costs, Constructed Wetlands are becoming more prevalent in wastewater treatment all over the world. Their range of applications is no longer limited to municipal wastewater, but has expanded to the treatment of heavily polluted wastewaters such as tannery and textile wastewater. This chapter provides a comprehensive literature review of the application of Constructed Wetlands in treating wastewaters derived from tanning and dyeing processes, by discussing the role of Constructed Wetland type, pretreatment stages and plant species in pollutant removal efficiency, as well as pollutant surface loads and removal efficiencies for specific pollutants (i.e., phenols, Cr(VI), color, etc.). Results indicate that Constructed Wetlands can tolerate high pollutant loads and toxic substances without reducing their removal ability; thus these systems are very effective bio‐reactors even in hostile environments. Additionally, a case study is presented, in which Constructed Wetlands were used to remove Cr(VI) from contaminated water. Experimental results indicated that the specific Constructed Wetlands could operate under extremely low hydraulic residence time (i.e., 1 day) and fully remove Cr(VI). Lastly, a viable solution for plant biomass management is proposed.

ACS Style

Christos S. Akratos; A.G. Tekerlekopoulou; Dimitrios V. Vayenas. Treatment of Wastewater from Tanneries and the Textile Industry using Constructed Wetland Systems. Constructed Wetlands for Industrial Wastewater Treatment 2018, 1 .

AMA Style

Christos S. Akratos, A.G. Tekerlekopoulou, Dimitrios V. Vayenas. Treatment of Wastewater from Tanneries and the Textile Industry using Constructed Wetland Systems. Constructed Wetlands for Industrial Wastewater Treatment. 2018; ():1.

Chicago/Turabian Style

Christos S. Akratos; A.G. Tekerlekopoulou; Dimitrios V. Vayenas. 2018. "Treatment of Wastewater from Tanneries and the Textile Industry using Constructed Wetland Systems." Constructed Wetlands for Industrial Wastewater Treatment , no. : 1.

Research article
Published: 22 April 2018 in Environmental Science and Pollution Research
Reads 0
Downloads 0

A mixed cyanobacterial-mixotrophic algal population, dominated by the filamentous cyanobacterium Leptolyngbya sp. and the microalga Ochromonas (which contributed to the total photosynthetic population with rates of less than 5%), was studied under non-aseptic conditions for its efficiency to remove organic and inorganic compounds from different types of wastes/wastewaters while simultaneously producing lipids. Second cheese whey, poplar sawdust, and grass hydrolysates were used in lab-scale experiments, in photobioreactors that operated under aerobic conditions with different initial nutrient (C, N and P) concentrations. Nutrient removal rates, biomass productivity, and the maximum oil production rates were determined. The highest lipid production was achieved using the biologically treated dairy effluent (up to 14.8% oil in dry biomass corresponding to 124 mg L−1) which also led to high nutrient removal rates (up to 94%). Lipids synthesized by the microbial consortium contained high percentages of saturated and mono-unsaturated fatty acids (up to 75% in total lipids) for all the substrates tested, which implies that the produced biomass may be harnessed as a source of biodiesel.

ACS Style

Olga N. Tsolcha; Athanasia G. Tekerlekopoulou; Christos S. Akratos; Georgia Antonopoulou; George Aggelis; Savvas Genitsaris; Maria Moustaka-Gouni; Dimitris Vayenas. A Leptolyngbya-based microbial consortium for agro-industrial wastewaters treatment and biodiesel production. Environmental Science and Pollution Research 2018, 25, 17957 -17966.

AMA Style

Olga N. Tsolcha, Athanasia G. Tekerlekopoulou, Christos S. Akratos, Georgia Antonopoulou, George Aggelis, Savvas Genitsaris, Maria Moustaka-Gouni, Dimitris Vayenas. A Leptolyngbya-based microbial consortium for agro-industrial wastewaters treatment and biodiesel production. Environmental Science and Pollution Research. 2018; 25 (18):17957-17966.

Chicago/Turabian Style

Olga N. Tsolcha; Athanasia G. Tekerlekopoulou; Christos S. Akratos; Georgia Antonopoulou; George Aggelis; Savvas Genitsaris; Maria Moustaka-Gouni; Dimitris Vayenas. 2018. "A Leptolyngbya-based microbial consortium for agro-industrial wastewaters treatment and biodiesel production." Environmental Science and Pollution Research 25, no. 18: 17957-17966.

Journal article
Published: 25 March 2018 in Water
Reads 0
Downloads 0

Hexavalent chromium (Cr(VI)) was co-treated either with second cheese whey (SCW) or winery effluents (WE) using pilot-scale biological trickling filters in series under different operating conditions. Two pilot-scale filters in series using plastic support media were used in each case. The first filter (i.e., Cr-SCW-filter or Cr-WE-filter) aimed at Cr(VI) reduction and the partial removal of dissolved chemical oxygen demand (d-COD) from SCW or WE and was inoculated with indigenous microorganisms originating from industrial sludge. The second filter in series (i.e., SCW-filter or WE-filter) aimed at further d-COD removal and was inoculated with indigenous microorganisms that were isolated from SCW or WE. Various Cr(VI) (5–100 mg L−1) and SCW or WE (d-COD, 1000–25,000 mg L−1) feed concentrations were tested. Based on the experimental results, the sequencing batch reactor operating mode with recirculation of 0.5 L min−1 proved very efficient since it led to complete Cr(VI) reduction in the first filter in series and achieved high Cr(VI) reduction rates (up to 36 and 43 mg L−1 d−1, for SCW and WW, respectively). Percentage d-COD removal for SCW and WE in the first filter was rather low, ranging from 14 to 42.5% and from 4 to 29% in the Cr-SCW-filter and Cr-WE-filter, respectively. However, the addition of the second filter in series enhanced total d-COD removal to above 97% and 90.5% for SCW and WE, respectively. The above results indicate that agro-industrial wastewater could be used as a carbon source for Cr(VI) reduction, while the use of two trickling filters in series could effectively treat both industrial and agro-industrial wastewaters with very low installation and operational costs.

ACS Style

Triantafyllos I. Tatoulis; Michail K. Michailides; Athanasia G. Tekerlekopoulou; Christos S. Akratos; Stavros Pavlou; Dimitris Vayenas. Simultaneous Treatment of Agro-Industrial and Industrial Wastewaters: Case Studies of Cr(VI)/Second Cheese Whey and Cr(VI)/Winery Effluents. Water 2018, 10, 382 .

AMA Style

Triantafyllos I. Tatoulis, Michail K. Michailides, Athanasia G. Tekerlekopoulou, Christos S. Akratos, Stavros Pavlou, Dimitris Vayenas. Simultaneous Treatment of Agro-Industrial and Industrial Wastewaters: Case Studies of Cr(VI)/Second Cheese Whey and Cr(VI)/Winery Effluents. Water. 2018; 10 (4):382.

Chicago/Turabian Style

Triantafyllos I. Tatoulis; Michail K. Michailides; Athanasia G. Tekerlekopoulou; Christos S. Akratos; Stavros Pavlou; Dimitris Vayenas. 2018. "Simultaneous Treatment of Agro-Industrial and Industrial Wastewaters: Case Studies of Cr(VI)/Second Cheese Whey and Cr(VI)/Winery Effluents." Water 10, no. 4: 382.

Journal article
Published: 01 November 2017 in Chemosphere
Reads 0
Downloads 0

The use of Constructed Wetlands (CWs) has been nowadays expanded from municipal to industrial and agro-industrial wastewaters. The main limitations of CWs remain the relatively high area requirements compared to mechanical treatment technologies and the potential occurrence of the clogging phenomenon. This study presents the findings of an innovative CW design where novel materials were used. Four pilot-scale CW units were designed, built and operated for two years. Each unit consisted of two compartments, the first of which (two thirds of the total unit length) contained either fine gravel (in two units) or random type high density polyethylene (HDPE) (in the other two units). This plastic media type was tested in a CW system for the first time. The second compartment of all four units contained natural zeolite. Two units (one with fine gravel and one with HDPE) were planted with common reeds, while the other two were kept unplanted. Second cheese whey was introduced into the units, which were operated under hydraulic residence times (HRT) of 2 and 4 days. After a two-year operation and monitoring period, pollutant removal rates were approximately 80%, 75% and 90% for COD, ammonium and ortho-phosphate, respectively, while temperature and HRT had no significant effect on pollutant removal. CWs containing the plastic media achieved the same removal rates as those containing gravel, despite receiving three times higher hydraulic surface loads (0.08 m/d) and four times higher organic surface loads (620 g/m(2)/d). This reveals that the use of HDPE plastic media could reduce CW surface area requirements by 75%.

ACS Style

Triantafyllos Tatoulis; Christos S. Akratos; Athanasia G. Tekerlekopoulou; Dimitris Vayenas; Alexandros I. Stefanakis. A novel horizontal subsurface flow constructed wetland: Reducing area requirements and clogging risk. Chemosphere 2017, 186, 257 -268.

AMA Style

Triantafyllos Tatoulis, Christos S. Akratos, Athanasia G. Tekerlekopoulou, Dimitris Vayenas, Alexandros I. Stefanakis. A novel horizontal subsurface flow constructed wetland: Reducing area requirements and clogging risk. Chemosphere. 2017; 186 ():257-268.

Chicago/Turabian Style

Triantafyllos Tatoulis; Christos S. Akratos; Athanasia G. Tekerlekopoulou; Dimitris Vayenas; Alexandros I. Stefanakis. 2017. "A novel horizontal subsurface flow constructed wetland: Reducing area requirements and clogging risk." Chemosphere 186, no. : 257-268.

Journal article
Published: 01 November 2017 in Journal of Environmental Management
Reads 0
Downloads 0

In this work, electrochemical oxidation of aerobically pre-treated dairy wastewaters using IrO2-Pt coated dimensionally stable anodes was investigated. It was found that IrO2/Ti electrode outperforming Pt/Ti and IrO2-Pt/Ti at lower current densities, while Pt/Ti achieved better efficiency at higher current density. Among the different parameters which were studied, the current density was the most crucial for the efficiency of the process. A current density of 100 mA/cm(2) led to almost complete removal of 3700 mg/L COD after 360 min of treatment using IrO2/Ti electrode and 0.2 M of sodium chloride while complete decolorization was achieved in less than 60 min. Electrolytes also found to significantly affect the process. More specific, the use of sodium chloride instead of sodium sulfate enhanced both COD and color removal due to the formation of active chlorine species. The effect of temperature was relative low; the process was favourable at elevated temperatures while increasing COD loading resulted in a decrease of COD and color removal.

ACS Style

Vlasia Markou; Maria-Christina Kontogianni; Zacharias Frontistis; Athanasia G. Tekerlekopoulou; Alexandros Katsaounis; Dimitris Vayenas. Electrochemical treatment of biologically pre-treated dairy wastewater using dimensionally stable anodes. Journal of Environmental Management 2017, 202, 217 -224.

AMA Style

Vlasia Markou, Maria-Christina Kontogianni, Zacharias Frontistis, Athanasia G. Tekerlekopoulou, Alexandros Katsaounis, Dimitris Vayenas. Electrochemical treatment of biologically pre-treated dairy wastewater using dimensionally stable anodes. Journal of Environmental Management. 2017; 202 ():217-224.

Chicago/Turabian Style

Vlasia Markou; Maria-Christina Kontogianni; Zacharias Frontistis; Athanasia G. Tekerlekopoulou; Alexandros Katsaounis; Dimitris Vayenas. 2017. "Electrochemical treatment of biologically pre-treated dairy wastewater using dimensionally stable anodes." Journal of Environmental Management 202, no. : 217-224.