Konstantinos Vasilios Plakas

• Chemical Engineer, PhD
• Research Assistant at Centre for Research and Technology Hellas

This paper examines the effect of humic acids (HA) and other solution constituents (Ca2+, Mg2+, Na+), frequently encountered in potable water sources, on the removal of a well-known herbicide, atrazine (ATR), by a laboratory-scale pilot Photocatalytic Membrane Reactor (PMR) system. Experimental results with different HA concentrations, in the prese...

Sulfonamides, including sulfadoxine (SDX), are widely used antibiotics, particularly for malaria treatment. However, their extensive use has led to environmental pollution, microbial resistance, and public health risks. Advanced Oxidation Processes (AOPs) offer promising methods to degrade such pollutants in water, though they may generate more tox...

Opening Ceremony Symposium CIMEE 2024

The sixth International Symposium On Materials, Electrochemistry and Environment, October 24-26, LEBANON

Scientific Programme conference

The present research employs a pilot-scale selective electrodialysis system to treat liquid digestate, fractionating nutrient ions and exploring fertilizer creation via ammonia stripping and phosphorus precipitation, while studying pharmaceutical transport behavior and examining membrane fouling. The influence of diverse potentials was studied in s...

Optimal site selection for the establishment of a municipal waste-water-treatment plant (WWTP) is an amazingly complex task that involves several factors such as regulations, as well as environmental, economic and social considerations. This paper presents the criteria and applied methods (geographic information system (GIS)/fuzzy analytical hierar...

Optimal site selection for the establishment of a municipal wastewater treatment plant (WWTP) is an amazingly complex task that involves several factors such as regulations, as well as environmental, economic, and social considerations. This paper presents the criteria and applied methods (Geographic Information System (GIS)/ Fuzzy Analytical Hiera...

Wastewater treatment and reuse are essential for addressing water shortages and promoting sustainable water security and sanitation development, particularly in rural areas. This paper aims to compare the performance of various oxidation processes, including UV/photo-Fenton, solar photo-Fenton, solar photocatalysis using TiO2, and UV/TiO2, for trea...

BACKGROUND The present study investigates the in situ electrogeneration of H2O2 by the 2e⁻ oxygen reduction reaction in an electrochemical flow cell using three commercially available cathodic electrode materials with different interfacial properties; that is, activated carbon felt (ACF), non‐activated carbon felt (NACF) and gas diffusion electrode...

Closing session CIMEE23

In the last few years, the in situ H2O2 electrogeneration through the 2e- oxygen reduction reaction (ORR) pathway has increasingly intrigued the scientific community. In particular, a wide experimental campaign has addressed the synthesis of different carbonaceous cathodes. This has resulted in a high number of 2D and 3D cathode materials, either p...

Complete valorization of various wastes and effluents, with significant organic content, remains a great challenge in the pursuit of a circular economy. The approach based on anaerobic fermentation, leading to valuable biogas production, has been broadly accepted and employed as an attractive processing scheme. However, despite notable research eff...

Vacuum Membrane Distillation (VMD) is systematically investigated herein, for recovering ammonia after phosphates precipitation, towards development of a sustainable process to valorize anaerobic-fermentation liquid-digestates (separated from the sludge). Initially, batch tests were performed, with representative synthetic solutions, to identify a...

The reuse of nutrient-rich waste in order to create green fertilizers in a sustainable and efficient way is a new strategy for the transition to a circular economy. Digestate is produced as a by-product from anaerobic digestion plants in large amounts creating a major management issue both for storage, utilization or disposal. The current work focu...

Decentralized wastewater treatment systems (DEWATS) in rural areas can be a smart alternative that helps communities to strengthen rural sanitation in improving clean water and sanitation management. To address these challenges, AquaCycle project, funded by the European Union under the ENI CBC MED Program, aims to bring an eco-innovative APOC syste...

Mediterranean Sea in an environmentally sensitive area and amongst the most threatened seas by oil pollution. Aim of this work was to assess the ability of floating constructed wetlands to treat petroleum hydrocarbons. The results revealed that bench scale floating wetland systems planted with Suaeda maritima, are able to reduce the concentration o...

Phytoremediation is an emerging concept for contaminated soil restoration via the use of resilient plants that can absorb soil contaminants. The harvested contaminated biomass can be thermochemically converted to energy carriers/chemicals, linking soil decontamination with biomass-to-energy and aligning with circular economy principles. Two thermoc...

The assessment of a pilot-scale hybrid system coupling powdered activated carbon (PAC) adsorption with membrane ultrafiltration (UF), in respect of activated carbon regeneration and organic micropollutant removal, was investigated in this study. Field tests with two adsorbents (i.e. a commercial PAC and a PAC-Fe(II) composite), conducted in the pre...

The growing environmental awareness of society, the advancement of nature-based solutions (NbSs), and the need for reliable and cost-effective solutions create a favorable environment of opportunities for floating wetlands as alternative solutions for marine water pollution control. The aim of this work was to screen, through OpenLCA, the environme...

Mediterranean Sea is widely regarded as one of the most threatened environments in the world because of the high population densities, the lack of consistent waste-management schemes, the large influxes of tourists and the strategic merchant navigation. The growing environmental awareness of society, the advancement of Nature-based Solutions, and t...

This paper offers a concise overview of the main strengths, weaknesses, opportunities and threats, as derived from the institutional, policy and regulatory framework governing wastewater treatment and reuse in three Mediterranean countries. The SWOT analysis is based on a desk review of available reports, assessment studies and interviews with repr...

Water resources in the Mediterranean countries, are subjected to many pressures related to water quality pollution, anthropogenic activities, urbanization and climate change. These pressures reached the UN-Sustainable Development Goal 6 (SDG 6) and Goal 13 (SDG 13) to strengthen the rural sanitation in improving clean water and sanitation managemen...

Reduction of nitrates in a photo-catalytic membrane reactor in the presence of organic acids, Journal of Environmental Management 298 (2021) 113526 https://doi.org/ Abstract The present study explores the capability of the Photocatalytic Membrane Reactor (PMR) technology to remove nitrates from drinking water sources in the presence of organic elec...

This study addresses the degradation of carbon-PTFE cathodes conforming a commercial plate-and-frame cell from ElectroCell with a Nb-BDD anode. Cell is arranged within an electrochemical pilot plant designed for treating wastewaters by electrochemical Fenton-like processes, thus an efficient electrocatalytic production of H2O2 is necessary to guara...

Results are reported of a systematic study on the performance of an advanced oxidation treatment that couples anodic oxidation (AO) and in situ generation of strong oxidants (Cl2, S2O8²⁻) in the electrolytic cell, for removing benzene, toluene, ethyl benzene, and xylenes (i.e. BTEX) from high salinity waters. A batch-mode pilot electrochemical unit...

Electrodialysis is a promising electrochemical process for separation and recovery of useful ions from waste waters. The large number of parameters involved in electrodialysis models makes their estimation challenging. This work proposes a systematic sensitivity analysis approach to identify the impact model parameter variations exert on multiple e...

Electrodialysis is a promising electrochemical process for separation and recovery of useful ions from waste waters. The large number of parameters involved in electrodialysis models makes their estimation challenging. This work proposes a systematic sensitivity analysis approach to identify the impact model parameter variations exert on multiple e...

Results are reported of a systematic study on the performance of an advanced oxidation treatment that couples anodic oxidation (AO) and in situ generation of strong oxidants (Cl2, S2O82−) in the electrolytic cell, for removing benzene, toluene, ethyl benzene, and xylenes (i.e. BTEX) from high salinity waters. A batch-mode pilot electrochemical unit...

The present document brings the analysis of the Strengths, Weaknesses, Opportunities and Threats (SWOT) of the local Governance Framework in the three countries where the APOC demonstration pilots are planned to installed, i.e. Lebanon, Spain and Tunisia.

The synthesis, characterization, and performance of composite photocatalytic adsorbents are investigated in this work using the dip-coating and the electrophoretic coating methods for the deposition of titanium dioxide (TiO2) on porous activated carbon fiber (ACF) substrates. The adsorption and photocatalytic efficiency of the synthesized catalytic...

Enhanced mineralization of phenol in brines with high chloride content was investigated by employing an electrochemical advanced oxidation treatment that couples anodic oxidation, electrochlorination and electro-Fenton in a single process. Experimental work was carried out in a pilot scale unit with an undivided plate-and-frame cell equipped with a...

The oxidation of pharmaceutical diclofenac (DCF) was investigated in a catalytic membrane reactor (CMR) comprising a tubular porous alumina (α-Al 2 O 3 ) membrane, as support material, with embedded iron oxide nanoparticles (nFe) in situ generated in its pores. The performance of the heterogeneous Fenton-type oxidation reaction was examined in a la...

The disclosed invention relates to a novel method for purification of water for human consumption and similar uses, capable of removing organic pollutants originating from synthetic compounds, taste and odor compounds or natural matter. The disclosed hybrid process, involving combination of powdered activated carbon (PAC) adsorption, membrane separ...

Electrochemical treatment of phenol in brine water using a plate-and-frame Gas Diffusion Electrode (GDE)/Boron Doped Diamond (BDD) reactor - A pilot plant study.

This manuscript summarizes the successful start-up and operation of a hybrid eco-engineered water treatment system, at pilot scale. The pilot unit, with 100 L capacity, has been devised for the efficient electrocatalytic production of H2O2 at an air-diffusion cathode, triggering the formation of [rad]OH from Fenton's reaction with added Fe²⁺ cataly...

Despite extensive research on several aspects of photocatalytic membrane reactors (PMRs) and their well-recognized attributes, no significant large-scale applications have been reported in the area of water treatment. A comprehensive assessment of the three components of this potential technology (i.e., photocatalysts, light source, and membranes)...

This chapter deals with the main techno-economic and environmental issues involved in assessing the sustainability of RO membrane technology for water desalination. The technical and economic aspects of desalination plant design and operation are reviewed, focusing on the key parameters of specific energy consumption (SEC) and product water unit co...

The reported pilot-scale development of hybrid process alternatives, combines in-situ regenerated powdered activated carbon (PAC), H2O2-based advanced oxidation techniques and membrane ultrafiltration (UF). Commercial PAC and special iron-impregnated PAC (PAC-Fe) were used as adsorbents, whereas diclofenac (DCF), a commonly detected pharmaceutical...

In this chapter critical discussion is provided on the recent innovations and the potential of the Electro-Fenton (EF) and EF-related processes as eco-engineered technologies in the field of water treatment. Emphasis is placed on the treatment of water and wastewater to eliminate a wide variety of synthetic organic pollutants, such as pesticides, p...

A hybrid photocatalysis – membrane separation system, based on the catalytic activity of UV-irradiated semi-conductor nanoparticles, in combination with membrane filtration, is attractive for water purification, in particular for removal of recalcitrant organic compounds. A typical successful implementation of this Photocatalytic Membrane Reactor (...

In recent years, indirect electro-oxidation methods (electrochemical AOPs-EAOPs) are considered for removal of toxic and persistent organic micropollutants from water sources. The most popular technique among EAOPs is the electro-Fenton (EF) process, in which hydrogen peroxide (H2O2) is generated at a cathode with O2 or air feeding while an iron ca...

This work focuses on the preparation and characterization of iron-impregnated carbon felts (CF) as cathodic electrodes of a novel flow-through electro-Fenton device of “filter” type, recently developed by the authors for the efficient degradation of toxic organic substances present in water at neutral pH. Two different procedures were followed for...

A novel, fully automated Photocatalytic Membrane Reactor (PMR) pilot unit is presented and evaluated (at different operating process parameters and real treatment conditions) for degradation of the pharmaceutical diclofenac (DCF), a typical recalcitrant micropollutant. The PMR-pilot has a maximum system capacity of 1.2 m3/d of treated water, 52 W o...

This paper reports on the fabrication, characterization and testing of iron oxide nanoparticles - powdered activated carbon (PAC) composites for water treatment and PAC regeneration by Fenton reactions. Different wet impregnation procedures and iron loadings were assessed in terms of organic micropollutant adsorption, by using the pharmaceutical di...

To assess the performance of a novel ‘filter’-type electro-Fenton (EF) device, results are reported from pilot-scale studies of continuous water treatment, to degrade diclofenac (DCF), a typical organic micropollutant, with no addition of oxidants. The novel ‘filter’ consisted of three pairs of anode/cathode electrodes made of carbon felt, with cat...

The multi-criteria analysis gives the opportunity to researchers, designers and decision-makers to examine decision options in a multi-dimensional fashion. On this basis, four tertiary wastewater treatment (WWT) technologies were assessed regarding their sustainability performance in producing recycled wastewater, considering a 'triple bottom line'...

Manuscript Due Friday, 25 December 2015 First Round of Reviews Friday, 18 March 2016 Publication Date Friday, 13 May 2016

This paper reports on the results obtained in pilot studies of continuous water treatment, to degrade diclofenac (DCF), a typical recalcitrant micro-pollutant, by a novel electro-Fenton filter. The latter consisted of three pairs of anode/cathode electrodes, of 4.5gr total mass and an effective volume ~49cm3. All electrodes were made of carbon felt...

A novel, fully automated Photocatalytic Membrane Reactor (PMR) pilot unit is presented and evaluated herein. PMR combines two modern processes; i.e. heterogeneous photocatalysis and membrane ultrafiltration, employing dispersed TiO2 nanoparticles with UV-C irradiation and hollow UF fibers in a submerged module, respectively. The PMR-pilot aims at t...

This paper reports on the development of hybrid water treatment technologies that take advantage of the attributes of activated carbon adsorption and Fenton oxidation through the development of novel hybrid process schemes: i) a continuous Powdered Activated Carbon (PAC) – Fenton process using a dilute suspension of PAC in a well-mixed reactor vess...

Μια πρότυπη πιλοτική μονάδα φωτοκαταλυτικού αντιδραστήρα μεμβρανών, η οποία συνδυάζει δύο μοντέρνες διεργασίες, τη φωτοκατάλυση, με χρήση διεσπαρμένων νανοσωματιδίων καταλύτη διοξειδίου του τιτανίου (Titanium dioxide – TiΟ2) και υπεριώδους UV-C ακτινοβολίας, και τη διήθηση διαμέσου μεμβρανών, με ένα εμβαπτισμένο στοιχείο κοίλων ινών μικροδιήθησης (...

Στην παρούσα εργασία περιγράφονται τα αποτελέσματα πειραματικών δοκιμών πιλοτικής κλίμακας με αντικείμενο την οξείδωση/απομάκρυνση οργανικών ρύπων του νερού με τη βοήθεια μίας καινοτόμου ηλεκτροχημικής διάταξης/«φίλτρου» που αναπτύχθηκε στο Εργαστήριο Φυσικών Πόρων και Εναλλακτικών Μορφών Ενέργειας του ΙΔΕΠ/ΕΚΕΤΑ. Συγκεκριμένα μελετήθηκε η απόδοση...

The Multi-Criteria Analysis gives the opportunity to the researchers, designers and decision makers to examine decision options in a multidimensional fashion. On this basis, four tertiary wastewater treatment (WWT) technologies were assessed regarding their sustainability performance considering a ‘triple bottom line’ (TBL) approach (i.e. economic,...

New results are presented on the preparation and performance of iron-impregnated carbon electrodes for a novel electro-Fenton “filter”-type device, reported in a previous publication. Two composite Fe/carbon-felt electrodes were prepared via different procedures: one under oxidizing conditions (i.e. dissolved oxygen) through immersion of carbon fel...

Taking into consideration the significant advantages of the hybrid sUF concept and the EF processes, a novel hybrid sUF-EF technology based on Powdered Activated Carbon (PAC) absorption and in situ regeneration, is pursued in this Laboratory, with applications in water treatment/purification. In this work the design characteristics of the new sUF-E...

This paper examines the effect of humic acids (HA) and other solution constituents (Ca2+, Mg2+, Na+), frequently encountered in potable water sources, on the removal of a well-known herbicide, atrazine (ATR), by a laboratory-scale pilot Photocatalytic Membrane Reactor (PMR) system. Experimental results with different HA concentrations, in the prese...

This work examines the effect of humic acids (HA) and other solution constituents (Ca2+, Mg2+, Na+), frequently encountered in potable water sources, on the removal of a well-known herbicide, atrazine (ATR), by a laboratory pilot Photocatalytic Membrane Reactor (PMR) system. Experimental results with different HA concentrations, in the presence (or...

The efficient performance of a novel electrochemical oxidation device (a “filter”) is presented herein, for degrading several non-steroidal anti-inflammatory drugs (NSAIDs) and antibiotics. The “filter” is comprised of a stack of suitable carbon anodic and cathodic electrode pairs capable of electro-generating H2O2, whereas ferric ions (Fe3+) impre...

Significant progress is reported on the development of an efficient heterogeneous photocatalysis-based process coupled with membrane separation, for degradation of Refractory Organic Substances, with broad applicability to water treatment operations. The distinct advantages of this process, for degrading assorted types of organic matter, are the co...

In this study, the carcinogenic risk from polyaromatic hydrocarbons (PAHs) in particulate matter, in the area of Thessaloniki, Greece is investigated. A 6 month campaign (October 2012 midApril 2013) of ambient air PM measurements was carried out, capturing the transition between the warm and cold period of the year. PM2.5 and PM10 particles were co...

This paper reports on the efficiency of the novel electro-Fenton “filter” to electro-generate H2O2 as a function of the main process parameters (i.e., electrode potential, water pH, ionic strength) and electrode materials; degradation of the pharmaceutical diclofenac is used as a test case. The results show satisfactory removal of diclofenac at low...

In this paper a novel method is described, which involves coupling the suspended-type TiO2 photocatalysis process with ultrafiltration membranes for particle separation. The Photocatalytic Membrane Reactor (PMR) is used to treat water containing three different types of organic compounds (Sodium Alginate - SA, Humic Acids - HA and DiCloFenac - DCF)...

Στην παρούσα εργασία περιγράφεται η λειτουργία πρωτότυπης εργαστηριακής διάταξης (σε μορφή “φίλτρου”) η οποία έχει ως στόχο την εξουδετέρωση του ετερόκλητου πλήθους οργανικών τοξικών μικρο-ρυπαντών, που εντοπίζονται συχνά σε φυσικές πηγές πόσιμου νερού, για προστασία της ανθρώπινης υγείας. Η μέθοδος στηρίζεται στην ηλεκτροχημική οξείδωση των οργανι...

Σε κάθε είδους υδατικά ρεύματα εντοπίζεται συνήθως πλήθος από δύσκολα διασπάσιμες οργανικές ενώσεις (Refractory Organic Matter) σε μικρές συγκεντρώσεις. Τα μίγματα αυτών των ουσιών μπορεί είτε να έχουν φυσική προέλευση (Natural Organic Matter), αποτελούμενα κυρίως από χουμικές ενώσεις, πολυσακχαρίτες, πρωτεΐνες κλπ., είτε να είναι ανθρωπογενή (Xeno...

The use of a novel electrochemical oxidation system is investigated for in situ generation of hydrogen peroxide, which constitutes the major reactant for hydroxyl radical (OH •) production via the Fenton reaction. The novel electro-Fenton (EF) "filter" is comprised of a stack of carbon anodic and cathodic electrode pairs, for operation in continuou...

Αντικείμενο της παρούσας εργασίας αποτελεί η περιγραφή της υφιστάμενης κατάστασης και των προβλημάτων που αντιμετωπίζουν οι Δήμοι του Νομού Θεσσαλονίκης στη διαχείριση των Αστικών Στερεών Απορριμμάτων (Α.Σ.Α.) με έτος αναφοράς το 2009. Συγκεκριμένα, παρουσιάζεται και σχολιάζεται η πολιτική διαχείρισης των Α.Σ.Α. που ακολουθείται, οι αδυναμίες που δ...

The subject of the present work involves the description of the current situation and problems that are dealt with the former Kapodistrian Municipalities of the Prefecture of Thessaloniki, related to special wastes management, with reference year 2009. In particular, the issues examined refer to waste management of: (a) electrical and electronic eq...

This paper reports on the development of a novel electro-Fenton system as an alternative method for eliminating toxic organic substances (e.g. pesticides, pharmaceutically active compounds) from drinking water sources in a simple and continuous process. The novel treatment technology proposed here is based on an advanced electrochemical oxidation m...

The frequent detection of pesticides in water sources is of great concern to the public, to authorities and all those involved in potable water production, wastewater treatment and reuse, due to potentially adverse health effects associated with these compounds, even at very small concentrations. In view of problems inherent in conventional process...

Ο διττός ρόλος των σύγχρονων μεμβρανών νανοδιήθησης (nanofiltration-NF), που εξασφαλίζει την αποσκλήρυνση του νερού, σε συνδυασμό με την υψηλή απόρριψη των φυσικών και συνθετικών οργανικών ρύπων, δικαιολογεί τη συνεχώς αυξανόμενη προτίμηση αυτών των συστημάτων για επεξεργασία του πόσιμου νερού. Στην παρούσα εργασία αξιολογούνται οι κύριες παράμετρο...