Natural minerals are widely used in numerous environmental applications, mainly as sorbents in ion exchange and sorption processes. Minerals, such as zeolites and clays, can be found all over the world, but they are mined containing a variety of different impurities; this prevents their accurate characterization. The present study examines various methods used for the characterization of three common natural silicate minerals, one zeolite (clinoptilolite) and two clays (montmorillonite and vermiculite). Their characterization was performed through a series of analytical measurements so as to gather all the information needed regarding their structural properties. Therefore, �similar� minerals such as clinoptilolite vs. heulandite and vermiculite vs. hydrobiotite can be distinguished; revealing important properties when comes to their practical application. The methods used in the present study are X-ray powder diffraction (XRD), X-ray fluorescence, Fourier transform infrared (FTIR) spectroscopy, TG/DTG/DTA and N2-porosimetry (BET). An extensive literature review of the natural silicate minerals has been conducted and the relevant results and methods are comparatively reported. The analytical results enabled the distinguish of the examined minerals. XRD, FTIR, TG/DTG/DTA showed that all three minerals have characteristic bands that can be used to easily distinguish from others. � 2018 Desalination Publications. All rights reserved.

A headspace high sorptive extraction (HS-HiSorb) Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS) method was developed and optimized for the determination of the volatile profile of extra virgin olive oil (EVOO). The HS-HiSorb extraction parameters of temperature, sample mass, stirring rate, and adsorption time were optimized by applying the one-factor-at-a-time (OFAT) approach. A total of 21 multi-varietal olive oil samples were collected from four different olive mills in Cyprus during the harvesting period 2020-2021. Seventy-six volatile organic compounds (VOCs) were identified and semi-quantified, belonging to several chemical categories such as hydrocarbons (31) three of which are terpenes, aldehydes (22), carboxylic acids (6), ketones (5), esters (4), alcohols (3), ethers (2), furans (2), and others (1). Aldehydes (40.20%) and hydrocarbons (41.08%) represented the main components of olive oil's volatile profile. The overall concentrations of VOCs in the samples ranged from 8.73 to 39.81mg/kg. The HiSorb-TD-GC-MS method was evaluated in terms of repeatability and linearity for selected VOCs. Repeatability was performed at three different concentrations (1, 10, and 100ppbv), and the relative standard deviation (RSD) ranged from 2.21 to 15.86%. The calibration curves of (E)-2-hexenal, 1-penten-3-one, nonanal, and hexanal were developed to evaluate the linearity range. The results were satisfactory, with the correlation coefficient (R2) greater than 0.98. Finally, the limitations of the method are mentioned and discussed. � 2023 IUPAC & De Gruyter. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. For more information, please visit: http://creativecommons.org/licenses/by-nc-nd/4.0/.

Biochars produced from various organic waste feedstocks have lately been utilized as adsorbents for the decontamination of antibiotics-contaminated environmental matrices. The aims of the present study were a) the assessment of the adsorption capacity of three distinct derived biochars [biosolids (BD�), cattle manure (MDB) and spent coffee grounds (SCGDB)], applied either at a low (1 g L?1) or high (10 g L?1) dose on seven antibiotics (tetracycline, TET; erythromycin, ERY; clarithromycin, CLA; ampicillin, AMP; ofloxacin, OFL; sulfamethoxazole, SMX; trimethoprim, TMP) spiked as mixture in environmentally relevant concentration (100 �g L?1) of an aqueous solution (8.27 < pH < 10.48), and b) the understanding of the relative adsorption mechanisms. Batch sorption experiments showed that all biochars applied at the low dose efficiently removed more than 70%, reaching even 100%, of TET, ERY, CLA, whereas MDB also removed AMP. Biochars applied at the high dose (10 g L?1) exhibited enhanced adsorption capacity, resulting in the quick (within 5 min of incubation) and complete removal of TET, ERY, CLA, as well as increased removal (>85%) of AMP and TMP. However, the studied biochars failed to remove OFL and SMX. The adsorption results were best fitted to the Freundlich model with the sole exception of SMX. The main responsible mechanisms for the adsorption of antibiotics included surface complexation, H-bonding, �-� electron-donor-acceptor (EDA) interactions, pore-filling effects or the simultaneous occurrence of several of these mechanisms. Overall, the results highlighted the potential utilization of BDB, MDB and SCGDB for the decontamination of antibiotics-contaminated water bodies, while promoting the circular economy strategy. � 2021 Elsevier Ltd

HiSorb and solid-phase microextraction (SPME), two environmentally friendly micro-extraction techniques based on the same fundamental principles, were evaluated for their extraction efficiency of volatile organic compounds (VOCs) from goat cheese whey wastewater. For this purpose, a sample preparation method based on the headspace-HiSorb technique was developed and evaluated for its efficiency in terms of the amount of extracted compounds and reproducibility of results. Thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) and GC/MS analytical methods were used to perform the wastewater analysis, respectively. The experimental parameters of HiSorb were evaluated in terms of probe coating, extraction time, stirring speed, sample volume, extraction temperature and salt addition. Under optimal extraction conditions, it was observed that the use of the divinylbenzene/carbon wide range/polydimethylsiloxane (DVB/CWR/PDMS) triple coating for HiSorb and DVB/Carboxen (CAR)/PDMS for SPME, was best suited to extract a broader range of VOCs with higher peak intensities. A total of 34 VOCs were extracted and determined with the DVB/CWR/PDMS HiSorb probe, while only 23 VOCs were determined with the conventional DVB/CAR/PDMS SPME fiber. The DVB/CWR/PDMS HiSorb probe has a higher adsorbent capacity which results in a higher sensitivity for VOCs compared to the DVB/CAR/PDMS SPME fiber. Furthermore, the HiSorb technique exhibits better reproducibility, as indicated by the lower relative standard deviation (RSD) of 3.7% compared to 7.1% for SPME. Therefore, the HiSorb technique is an effective method for detecting VOCs in complex matrices, such as wastewater. � 2023 Elsevier Ltd

Whey wastewater is considered to be the main polluting product of the dairy industry. Electrocoagulation (EC) and electrooxidation (EO) processes using aluminum electrodes and inactive boron-doped diamond (BDD), respectively, were applied to reduce the chemical oxygen demand (COD), total nitrogen (TN), phosphate (PO4-3), nitrate (NO3-), chloride (Cl-), total phenolic compounds (TPCs), and optical density. In parallel, thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) with HiSorb passive sorption extraction probe was employed to monitor the emitted volatile organic compounds (VOCs) from the electrochemical treatments. A total of 35 VOCs were extracted and identified in the raw whey wastewater, while 27 and 53 VOCs were identified in the EC and EO treated whey wastewater, respectively. EO-treatment was more concerning as chlorinated VOCs were detected showing a total presence of 50%. Two trichloromethanes (THMs), methane bromodichloro and trichloromethane, as well as ethane 1,2-dichloro, and propane 1,2-dichloro were quantified and their mean concentrations were 5.0, 125.2, 15.1, and 6.4 ppbv, respectively. Overall, the aroma profile remained mostly unaffected by the EC-treatment. Also, COD, TN, Cl-, NO3-, PO4-3, TPCs, and optical density presented a reduction of 7.4, 52.5, 11.9, 27, 16.8, 54.8, and 17.3% with EC. On the contrary, EO was only effective for COD and optical density, with removal of 14.3, and 23.5%, respectively, while all the other concentrations of pollutants increased (TN, Cl-, NO3-, PO4-3, TPCs). � 2022 Elsevier B.V.

Biogenic volatile organic compounds (VOCs) contribute to the communication, growth, breeding, and defense of plant; their role in plant kingdom is vital. Carob tree is cultivated mainly in Middle East and eastern European countries (e.g., Spain, Italy, Greece, Cyprus) and lately in Australia, the USA, and South Africa. Therefore, it is examined as a case study for its volatile emissions in the environment. Apart from the VOCs emitted from carob flowers and fruit, carob is considered of great interest for the food industry (carob powder), not only for its health benefits but also due to its characteristic strong aroma, which can be maintained even after processing (roasting). Solid-phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS) analyses of carob flowers, fruit, and powder (commercial samples) were performed and the detected VOCs are presented and discussed. The most prominent chemical classes emitted from carob fruit and powder appeared to be acids followed by esters and aldehydes/ketones, whereas from carob flowers the terpenoids. The strongest VOCs both in carob fruits and powder were propanoic acid, 2-methyl (isobutyric acid) and in flowers ethanol. The uniqueness of carob benefits is well known in the agriculture, pharmaceutical, cosmetic, and food sector and is closely related to the agro-economy and long history of eastern Mediterranean countries. � 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

Indoor air quality (IAQ) has attracted a lot of attention due to its complexity and direct effect on human health. Indoor settings in libraries entail various volatile organic compounds (VOCs) linked to the aging and degradation of print material. The effect of the storage environment on paper life expectancy was investigated�by targeting the VOC emissions of old and new books using headspace solid phase micro extraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS) analysis. �Sniffing� of book degradation markers showed both ubiquitously and infrequently occurring VOCs. Old book �degradomics� revealed mostly alcohols (57%) and ethers (12%), whereas new books resulted mainly to ketones (40%) and aldehydes (21%). Chemometric processing of the results with principal component analysis (PCA) corroborated our initial observations and was able to discriminate the books by age into three groups: very old books (from the 1600�s to mid-1700), old books (from the 1800s to the early 1900s), and modern books (from the mid-twentieth century onwards) based on their gaseous markers. The measured mean concentrations of selected VOCs (acetic acid, furfural, benzene, and toluene) were below the respective guidelines set for similar places (i.e. museums). The applied non-invasive, green analytical methodology (HS-SPME-GC/MS) can assist librarians, stakeholders, and researchers to evaluate the IAQ, as well as the degree of degradation, and take the appropriate measures for book restoration and monitoring protocols. Graphical abstract: (Figure presented.) � The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2023.

The current study presented a novel process of biogas upgrading to biomethane (higher than 97%) based on anaerobic sludge and zero-valent iron (ZVI) system. When ZVI was added into an aquatic system with anaerobic granular sludge (AnGrSl) under anaerobic abiotic conditions, H2 was generated. Then, the H2 and CO2 were converted by the hydrogenotrophic methanogens to CH4. Biogas upgrading to biomethane was achieved in 4�days in the AnGrSl system (50�g L?1 ZVI, initial pH 5 and 20�g L?1 NaHCO3). In this system, when zero-valent scrap iron (ZVSI) was added instead of ZVI, a more extended period (21�days) was required to achieve biogas upgrading. X-ray diffraction (XRD) analysis revealed that the materials in a reactor with CO2 or biogas headspace, exhibited a mixture of ferrite and the iron carbonate phase of siderite (FeCO3), with the latter being the dominant phase. VOCs analysis in raw biogas (in the system of anaerobic sludge and ZVI) highlighted the reduction of low mass straight- and branched-chain alkanes (C6�C10). Also, H2S and NH3 were found to be substantially reduced when the anaerobic sludge was exposed to ZVI compared to the cases where ZVI was not added. This study found that simultaneously with biogas upgrading, VOCs, H2S and NH3 can be removed in a system of ZVI or ZVSI and AnGrSl under aquatic anaerobic conditions. � 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

Solid phase micro extraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS) analysis was performed in exhaled breath samples of 48 healthy volunteers: 20 non-smokers, 10 smokers and 18 e-cigarette (EC, vape) users. Each volunteer provided 1 L of exhaled breath in a pre-cleaned Tedlar bag, in which an SPME fiber was exposed to absorb the emitted breath volatile organic compounds (VOCs). The acquired data were processed using multivariate data analysis (MDA) methods in order to identify the characteristic chemicals of the three groups. The results revealed that the breath of non-smokers demonstrated inverse correlation with a variety of molecules related to the breath from smokers including furan, toluene, 2-butanone and other organic substances. Vapers were distinguished from smokers by the chemical speciation of the e-liquids, such as that of esters (e.g. ethyl acetate), terpenes (e.g. �-pinene, �-pinene, d-limonene, p-cymene, etc.) and oxygenated compounds (e.g. 3-hexen-1-ol, benzaldehyde, hexanal, decanal, etc). Two classification models were developed (a) using principal component analysis (PCA) with hierarchical cluster analysis (HCA) and (b) using partial least squares-discriminant analysis (PLS-DA). Both models were validated using 8 new samples (4 vapers and 4 smokers), collected in addition to the 48 samples of the calibration set. The combination of GC/MS breath analysis and MDA contributed successfully in classifying the volunteers into their respective groups and highlighted the relevant characteristic VOCs. The respective dynamic combination (SPME-GC/MS and MDA) provides a means for long term non-invasive monitoring of the population's health status for early detection purposes. � 2020 Elsevier B.V.

Ceratonia siliqua L. is a typical Mediterranean tree species that has also been introduced to the temperate regions of Central America, Australia, and Africa. The carob fruit consists of the pulp and the seed (endosperm and germ), each one of which is used in a great variety of bakery products and beverages, as animal feed, food additives, syrups, ice creams, dietetic products, and for the photographic emulsion. For instance, the carob pulp is used to make carob syrup and molasses through the recovery of sugars, whereas the seed is used to produce Locust Bean Gum (LBG), which is used as a growth medium, and as a thickener, chemically known as E410. Currently, there is a strong interest in carob re-cultivation due to the tree�s ability to withstand drought and adapt to climate change, further to its medical and food exploitation potential. In 2016 and 2017, the global carob production exceeded 170,000 tons, with the highest volumes of carob production coming from Spain, Portugal, and Italy, followed by Morocco, Turkey, Greece, Cyprus, Lebanon, and Algeria. Carob fruit harvesting and processing does not produce significant amounts of agricultural and industrial waste. Agricultural waste mainly includes traps for rodents, plastic packaging waste, and field residues such as stems and leaves. On the other hand, industrial processing from carob mills and the food industry produces waste such as solid residual parts and plant biomass (e.g., leaves), which can be composted or used as animal feed. In carob factories, during the roasting and milling processes, air pollutants such as particulate matter (PM) and biogenic volatile organic compounds (VOCs) are released. Carobs and their waste have been studied by various research groups as a source of phenolic compounds and carbohydrates, as an alternate source for the production of biofuels (e.g., biohydrogen and bioethanol), in food packaging applications, in wastewater treatment, as well as a soil organic amendment. Overall, carob and carob waste have promising applications as raw material for further investigation and utilization. � The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.

The dairy industry is currently one of the most important industrial sectors in the world, and due to the high demand for products, is considered the largest source of industrial wastewater in the food sector. Whey wastewater is the most abundant liquid by-product and is characterized by a high concentration of organic load. Thus, the treatment of cheese whey wastewater before discharge is considered important. Therefore, the processes of electrocoagulation (EC), electrooxidation (EO), as well as their combination (EC/EO) have been purposefully used for the treatment of goat cheese wastewater. The main parameters (current density (mA/cm2), agitation (rpm), pH, and operating time (min)) affecting the removal efficiency of chemical oxygen demand (COD) were studied for each process. Whey effluent was treated under the optimal conditions of EC with aluminum electrodes, and EO with a boron-doped diamond electrode (BDD), removing 40.5% and 55.3% of COD, respectively. The combined use of EC/EO eliminated 82.4% of COD in a total time of 90 min. Total nitrogen (TN), chloride (Cl?), nitrate (NO3?), and phosphate (PO4?3) pollutants were also determined. The aroma profile of the raw substrate changed during the electrochemical processes. The determination of the volatile organic compounds (VOCs) in raw and treated (EC, EO, and EC/EO) goat whey wastewater was monitored using a thermal desorption unit followed by gas chromatography/mass spectrometry (TD-GC/MS) after extraction of VOCs using the HiSorb technique. Coupling electrochemical technologies increased odor emissions from goat cheese whey wastewater. � 2023 Elsevier B.V.

In the present work a combined process is proposed for recovery of metallic copper from industrial electroplating wastewaters comprising electrocoagulation, acidic digestion and electrowinning. The wastewater with the initial Cu2+ ion concentration of 92 mg/L was first subjected to electrocoagulation where it successfully decreased under the upper allowed limit of 2 mg/L. Then, the obtained electrocoagulation sludge was treated with sulfuric acid for digestion and with caustic soda to reach pH 4.8 for precipitation and separation of insoluble aluminum hydroxide, whereas Cu2+ ions remain in solution. Finally, pure metallic copper was produced by electrowinning from the obtained concentrated Cu2+ ions solution. The work proposes the possibility of effectively treating toxic industrial electroplating wastewater accompanied by recovery of significant amounts of valuable pure metals, such as copper. � 2019 Eastern Macedonia and Thrace Institute of Technology.

Vaping is promoted as a healthier alternative to smoking over the recent years, and e-cigarette (EC) users are considered to affect air quality (and thus contribute to passive smoking) much less than tobacco cigarette (TC) smokers. Here we test this hypothesis, by comparing measurements of the size distributions of particles and the levels of Volatile Organic Compounds (VOCs) exhaled by both EC and TC users. A total of 26 individuals (16 EC users and 10 TC users) provided exhaled air samples that were analyzed using the same protocol. Our measurements show that the particle number concentration emitted by both EC and TC users are comparable, but the size distributions of the particles emitted by the former exhibit significantly higher variability compared to those from the latter. The burden of the VOCs was much higher in the exhaled air of TC smokers compared to that of EC users. Although some of the VOCs measured in the exhaled air of EC users were expected, as they are used directly in the e-liquids, the collected mixtures were highly variable (i.e., varying significantly from case to case) with only 8 compounds being common among all individuals participating in the study. In contrast, we identified 65 compounds among the TC smokers that were common among the participants. Toxic compounds (e.g., benzene, acetaldehyde, toluene, xylenes, styrene, phenol, naphthalene, etc.) were also present in the exhaled air of EC users. The high variabilities observed in the size distributions of the exhaled particles and the levels of VOCs from different EC users (i.e., due to different devices, operational settings and liquids) warrants for further research in order to fully understand the main- and side-stream effects of EC use in the human micro-environment. Despite that, the high particle emissions and the presence, even at trace levels, of toxic VOCs in the exhaled air of EC users that are reported in this study, suggests that ECs should not be considered as harmless substitutes of TCs. � 2019 Elsevier Ltd

Coffee is perhaps one of the most vital ingredients in humans� daily life in modern world. However, this causes the production of million tons of relevant wastes, i.e., plastic cups, aluminum capsules, coffee chaff (silver skin), and spent coffee grounds (SCG), all thrown untreated into landfills. It is estimated that 1�kg of instant coffee generates around 2�kg of wet SCG; a relatively unique organic waste stream, with little to no contamination, separated directly in the source by the coffee shops. The produced waste has been under researchers� microscope as a useful feedstock for a number of promising applications. SCG is considered a valuable, nutrients rich source of bioactive compounds (e.g., phenolics, flavonoids, carotenoids, lipids, chlorogenic and protocatechuic acid, melanoidins, diterpenes, xanthines, vitamin precursors, etc.) and a useful resource material in other processes (e.g., soil improver and compost, heavy metals absorbent, biochar, biodiesel, pellets, cosmetics, food, and deodorization products). This paper aims to provide a holistic approach for the SCG waste management, highlighting a series of processes and applications in environmental solutions, food industry, and agricultural sector. Thus, the latest developments and approaches of SCG waste management are reviewed and discussed. � 2018, Springer-Verlag GmbH Germany, part of Springer Nature.

The original publication of this paper contains an error.The correct caption of Fig. 2 is shown in this paper.(Fihure preseneted). � 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

Ceratonia siliqua L. is quite popular for the sweetness of its fruit (�natural chocolate�) and the strong, persistent, characteristic odor that associates not only carob fruit, but also its traditional food products. This is due to the emission of an array of volatile organic compounds (VOCs). The released odor is a complex mixture, and therefore, needs to be separated prior detected, especially when its origin varies and is engaged. Therefore, Headspace�Solid-Phase Microextraction�Gas Chromatography�Mass Spectrometry (HS�SPME�GC�MS) analysis was performed in ground carob pods from three different European countries to decode their released aroma. The method was applied to Cypriot (Kountourka, Koumpota, Tilliria), Spanish (Negra, Rojal, Matalafera) and Italian (Saccarata, Racemosa, Gibiliana) cultivars, and the released volatile species were further processed with multivariate data analysis (MDA). The chromatographic separation highlighted 54 common VOCs in the grounded carob pods; the most abundant appeared to be propanoic acid 2-methyl (isobutyric acid), acetic acid, butanoic acid, hexanoic acid, and propanoic acid 2-methyl-methyl ester. The quantitative results for acetic acid, propanoic acid 2-methyl, butanoic acid, furfural and pentanoic acid revealed their emission in the low ppbv levels. The engage of MDA on the obtained results showed a clear differentiation of the carobs based on their geographical and botanical origin. The combination of HS�SPME�GC�MS and chemometrics contributes to the quality characterization of carobs and highlights their authenticity markers. � 2020, Springer-Verlag GmbH Germany, part of Springer Nature.

This research work examined how biodiesel produced from frying oils affects the physicochemical properties of its mixtures with conventional heating oil. Through the characterization of biodiesel blends and heating oil, the purpose is to produce an improved heating oil that will meet the specifications of the existing legislation for heating oil, while positively contributing to reducing the production of pollutants. The percentage of biodiesel added to a conventional diesel fuel contributes to the reduction of the pollutants produced during combustion. The examined biodiesel is considered the residual product, which was produced at a factory in Cyprus, and was deemed unsuitable for export, because it does not meet the legal requirements. Using specific volumes of these mixtures, twelve parameters were determined in order to investigate the effect of the mixtures: kinematic viscosity, sulfur content, micro carbon residue (MCR), distillation curves, density, cloud point (CP), fatty acid methyl esters (FAMEs) content, heat of combustion, iodine value (IV), cetane index (CI) after distillation, oxidation stability, and cold filter plugging point (CFPP). A number of fuel properties including the kinematic viscosity, MCR, distillation temperature�up to 80% distillate�and density showed an increase as the percentage of FAMEs raised from 2.5 to 50%, while others showed a mixed behavior (e.g., IV, CP, CI, CFPP), and the rest an inverse trend (e.g., sulfur content, heat of combustion and oxidation stability). An efficient potential utilization of a residual domestic product is proposed, while the pollutants that accumulate on the urban atmospheres during the winter months, due to increased heating needs of homes and other public or private buildings, will be significantly reduced. � 2018 by the authors Licensee MDPI, Basel, Switzerland.

Four novel fruit-derived biochars were developed: pomegranate peels (PB), prickly pear peels (PPB), carob (CB), and locust bean gum (LBGB). The feedstocks were pyrolyzed at 350 and 550 ? (under N2), respectively, and characterized using Scanning Electron Microscopy (SEM), Elemental Analysis (EA), Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), Brunauer�Emmett�Teller (B.E.T) analysis, and Thermogravimetric analysis (TGA). A systematic and comprehensive comparison for the adsorption of selected volatile organic compounds (VOCs) by biochar was established. Cresol, dimethyl trisulfide (DMTS), hexane, and benzene were examined as a function of contact time (30�480 min), mass (0.1�1 g), concentration levels (50�1000 ppbv), efficiency, and reusability, using the headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC�MS) method. PB 550 ? revealed a specific surface area of 8.3 m2 g?1, the fastest complete removal, an ideal mass of 1 g, 3-times reuse, and ? 99% removal of 500 ppbv benzene, cresol, DMTS, and 100 ppbv hexane. � 2021 Elsevier Ltd

Abstract: Cattle wastewater (CWW) is considered an important source of contamination in the livestock sector. Therefore, electrocoagulation (EC) using Aluminium electrodes and electrooxidation (EO) through Boron Doped Diamond (BDD) electrodes processes, were applied to the liquid fraction of cattle waste (CW) to decrease the levels of certain pollutants such as nitrogen (N-NO3, T-N), phosphates (P-PO4) and organic content (Chemical Oxygen Demand, COD), in order to eliminate their environmental impacts to soil, groundwater and atmosphere. The respective electrochemical methods, were compared with chemical coagulation process by using Al2(SO4)3 and FeCl3 as a coagulant. CWW samples were derived from three cattle farms. As experimentally was revealed, the main parameters strongly affecting the experimental procedure were the solid density of the sample and the high concentration of pollutants. Other operating parameters such as current density, electroprocessing time, dilution ratio and agitation speed were studied and optimised. Results showed an optimal removal efficiency after using the combined EC-EO processes at current density of 200A/m2, agitation at 300�rpm, duration time of 2�h for both processes at room temperature, with a 1:5 dilution ratio. The results also showed that P-PO4 were fully removed, COD up to 70%, N-NO3 at 80% and T-N close to 20%. The combined use of EC and EO improved the quality of CWW in regard to P-PO4, COD, N-NO3 and T-N content. Nevertheless, further experiments are needed in order to verify the respective results in a pilot scale. Graphic Abstract: [Figure not available: see fulltext.]. � 2020, Springer Nature B.V.

Bentonite is a clay mineral often used in ion exchange processes due to its high ion exchange capacity. In the present study, a commercially available in Greece market bentonite was obtained and characterized by XRD, XRF, FTIR, BET, and TG/DTA analysis. Monmorillonite was the main component of bentonite sample (>80%). Ion exchange equilibria of Zn2+, Cr3+, and Mn2+ on bentonite was examined by use of batch equilibrium isotherms, distribution coefficients, and maximum exchange levels (MELs) under the same normality for all metals (0.01�N) at 25���2�C. The equilibrium isotherms for the metals studied exhibit a favorable-type isotherm. Selectivity series deduced from equilibrium isotherms are Cr3+�>�Zn2+�>�Mn2+, and the same occurs for MELs. The Langmuir and Freundlich models were applied and fitted the equilibrium data for the metal ion uptake. A detailed literature review on heavy metals-bentonite equilibrium is provided. � 2016 Balaban Desalination Publications. All rights reserved.