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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.

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 39.81 mg/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 100 ppbv), 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 (R 2) greater than 0.98. Finally, the limitations of the method are mentioned and discussed.

The Eastern Mediterranean and Middle East (EMME) region is already experiencing the negative effects of increased temperatures and the increase in prolonged drought periods. The use of organic fertilization could be a valuable tool to meet the main challenges of climate change and maintain the productivity, quality, and sustainability of rainfed agricultural ecosystems. In the current study, we compare the effect of manure, compost, and chemical fertilization (NH4NO3) on barley grain and straw yield in a field study for three consecutive growing seasons. The hypothesis that the barley productivity, nutrient accumulation, and grain quality remain similar among the different nutrient management strategies was tested. The results showed that both growing season and type of nutrient source significantly affected barley grain and straw yield (F6,96 = 13.57, p < 0.01). The lowest productivity was noticed in the non-fertilized plots while chemical and organic fertilization exhibited similar grain yield, ranging from 2 to 3.4 t/ha throughout the growing seasons. For straw, the use of compost had no effect on the yield in any of the growing seasons examined. The use of manure and compost had a significant effect on grain macro- and micronutrient content but this was highly related to growing season. Principal component analysis (PCA) clearly demonstrated the discrimination of the different type of fertilization on barley performance during the course of the study, while the application of compost was highly associated with an increase in micronutrients in grain samples. Furthermore, structural equational modeling (SEM) showed that both chemical and organic fertilization had a direct positive effect on macro- (r = 0.44, p < 0.01) and micronutrient (r = 0.88, p < 0.01) content of barley grain and a positive indirect effect on barley productivity through N accumulation in grain (β = 0.15, p = 0.007). The current study showed that barley grain and straw yield was similar between manure and NH4NO3 treatments, while compost exhibited a residual positive effect causing an increase in grain yield during the growing season. The results highlight that N fertilization under rainfed conditions is beneficial to barley productivity through its indirect effects on N accumulation in grain and straw, while it improves grain quality through the increased accumulation of micronutrients.

Greenhouse gas emissions (i.e., carbon dioxide, methane, nitrous oxide) produced by agriculture contribute to global warming and climate change. Various practices followed by farmers in different environmental conditions contribute to the increase in the phenomena, and there is a need for immediate measures. The current study examines the environmental impact of barley production under rain-fed conditions in Cyprus. For this, four different nutrient management scenarios were investigated in order to evaluate the environmental performance of crop production, namely: (1) Nitrogen (20%), Phosphorous (20%), Potassium (10%); (2) Nitrogen (20%), Phosphorous (20%), Potassium (10%) and manure; (3) Nitrogen (25%), Phosphorous (10%), Potassium (0%); and (4) Nitrogen (25%), Phosphorous (10%), Potassium (0%) and manure. Data were collected from two different areas of Cyprus (Nicosia and Larnaca) through on-site visits and questionnaires. Life Cycle Assessment (LCA) was used as a method to quantify environmental impacts which were categorized into six impact categories: (i) acidification potential (AP), (ii) eutrophication potential (EP), (iii) global warming potential (GWP), (iv) ozone depletion potential (ODP), (v) photochemical, ozone creation potential (POCP), and (vi) terrestrial ecotoxicity (TAETP). LCA was used with system boundaries from field to harvest and a functional unit (FU) of one bale of hay. Research results showed that the addition of manure increased values in all impact categories. Comparing scenarios without manure (1 and 3) and with manure (2 and 4), the main process which contributed to GWP was field preparation, which resulted in 3 t CO2-Eq∙FU−1 and 46.96 t CO2-Eq∙FU−1, respectively. Furthermore, the highest contribution of sub-processes to GWP (kg CO2-Eq∙FU−1) was machinery maintenance (scenarios 2 and 4). The potential to reduce environmental impacts from barley and moreover, to mitigate the footprint of the agriculture sector in Cyprus is proposed by changing existing practices such as decreasing fuel consumption by agricultural machinery, and monitoring fertilizing and seeding. Conclusively, the carbon footprint of barley can be decreased through the improvement of nutrient management and cropping practices.

Headspace solid-phase micro extraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS) was performed for the analysis of volatile organic compounds (VOCs) emitted from books. Towards this, books of different ages were examined (old = 50-300 years and new = 2-25 years) using a CAR/PDMS fiber. The examined books were placed into an in-house made glass sampling chamber, where they remained enclosed for 24 h prior to SPME sampling and subsequent analysis. SPME is a green and non-destructive preconcentration technique based on the absorption of analytes on a fiber coating placed inside the sample’s headspace volume. The results were in line with previous reports; the most prominent VOCs released from old books were furfural, acetic acid, and acetone, whereas new books emitted toluene, acetone, and heptanal. This natural process takes place over time due to the decay of paper and degradation of ink and its mitigation is important for the preservation of texts that are considered cultural heritage. The method can be leveraged for monitoring the decay process, as well as the effect of external pollution on the books.

Sulfur compounds in liquid fuel are undesirable and the level of these compounds in diesel fuel is strictly regulated in the last 15 years by the European Union. These stringent regulations are imposing an urgent requirement for fuel terminals to produce fuels having ultra-low sulfur content. A promising Eco-Technology is to employ Biodesulfurization (BDS), a process where the bacteria (liquid phase) are mixed with oil at ambient temperature and pressure to selectively remove organosulfur components from oil fractions without degrading the carbon skeleton of the compounds. Most of the studies have examined the BDS under aerobic conditions using pure cultures or mix inoculum, and the main byproducts remain in the liquid phase. However, the present study explored a new proof of concept; BDS under anaerobic conditions using inoculums from various anaerobic sources. The enrichment in each inoculum took place several months and electron donors were used. In addition, the microbial profile over time was examined at the end of the BDS using next generation sequencing. The BDS of oil under anaerobic conditions profits of aeration cost, as well as the advantage of releasing H2S in the gas phase, which can be easily treated using the existing H2S technologies.

Carob’s recognized nutritional and medicinal value next to its unique agriculture importance is associated with an array of social, economic, and cultural activities. The carob fruit is popular for its intense aroma due to the emitted volatile organic compounds (VOCs). The composition of VOCs released from carob fruits changes during ripening, rendering it a non-invasive tool for the determination of the ripening period and freshness of the fruit. Therefore, headspace solid-phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC/MS) was applied to reveal the respective gaseous signal molecules related to fruit maturity. The sampling was implemented during weeks 26–36 from five different locations in Cyprus. Additionally, the gaseous emissions of total VOCs (TVOCs) and carbon dioxide (CO2) were recorded next to the moisture content of the fruit. The major chemical classes in the ripening are acids, followed by esters, and ketones. More specifically, the most abundant VOCs during ripening are propanoic acid, 2-methyl-(isobutyric acid), 2-heptanone, propanoic acid, 2-methyl-, 2-methylbutyl ester, acetic acid, methyl isobutyrate, propanoic acid, 2-methyl-, 3-methylbutyl ester, 2-pentanone, butanoic acid and propanoic acid, 2-methyl-ethyl ester. Finally, CO2 emissions and moisture content showed a rapid decline until the 31st week and then stabilized for all examined areas. The methodology revealed variations in VOCs’ profile during the ripening process.

In the framework of circular economy, the need of new feedstock materials for the production of alternative new products is of high priority. Biowastes such as manure, sewage sludge (biosolids, BS) and food-waste are used as raw materials for the production of biochar. The present study aims at characterizing biochars produced from three distinct biowastes (i) manure from cattle waste (manure-derived biochar; MDB), (ii) biosolids (BS) from a conventional Urban Wastewater Treatment Plant (UWTP) (biosolids-derived biochar; BDB), and (iii) spent coffee grounds (SCG)-derived biochar (SCGDB). Samples were slowly pyrolyzed in a small-scale kiln with a capacity of 20–24 kg. The samples were heated under nitrogen atmosphere at approximately 6–7 °C min−1 up to the desired temperature (550 °C) and held for 1.5h. The physicochemical characterization of biochars showed the production of alkaline materials with similarities and variations in their characteristics, which depend to the type of feedstock used. The surface area of the raw materials was considerably low (

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.

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.

The positive effects of biochar applied as soil conditioner for boosting soil fertility and thus plant growth are sufficiently documented, mostly through in-situ experimentation. This field study evaluated the effects of soil amendment (5% v/v) with distinct types of biochar (biosolids-derived biochar, BDB; cattle manure-derived biochar, MDB; spent coffee grounds-derived biochar, SCGDB) on the growth, physiology and quality attributes of lettuce (Lactuca sativa L.) plants grown in sandy clay loam-textured soil, under temperate climatic conditions. Peat moss (PM) was also used, to serve as internal control due to its wide use. Plants grown on MDB-amended soil showed a significant increase of biomass production rate, evident through elevated mean fresh and dry weight values compared with all other treatments. Increased growth was also found in BDB treatment, though failed to reach significance. None of the treatments impacted the photosynthetic pigment content, however they did reduce the nitrates content in leaves. Leaves sampled from BDB and MDB treatments showed reduced soluble solids content (SSC) and titratable acidity (TA), and increased sucrose content. MDB-treated plants showed increased fructose content while BDB-treated plants showed increased total soluble sugar and total phenolics content. Moreover, plants grown in MDB- and BDB-amended soil showed increased total antioxidant capacity, despite maintaining ascorbic acid content in values similar to control. SCGDB and PM treatment did not affect any of the parameters tested. Overall, results showed that BDB and MDB applied as soil amendments may serve as means for enhancing the growth, and partially the nutritional value of lettuce plants.

In the current study, a novel process of ex-situ biogas upgrading to biomethane is presented which is based on a system consisted of anaerobic sludge and zero valent iron (ZVI). The ZVI when is added in an aquatic system with anaerobic granular sludge generates H2 under anaerobic abiotic conditions. Then, the H2 and CO2 are converted by the hydrogenotrophic methanogens to CH4. Biogas upgrading to biomethane was achieved in 4 days in a system of anaerobic granular sludge, 50 g L1 ZVI initial pH 5 and 20 g L1 NaHCO3. In this system when zero valent scrap iron (ZVSI) was added instead of ZVI required longer period (21 days) to achieve biogas upgrading. Volatile organic compounds (VOCs) analysis in raw biogas (in system of anaerobic sludge and ZVI) showed mainly the reduction of low mass straight- and branched-chain alkanes (C6-C10); however, no other particular trend regarding the removal of other VOCs was observed. H2S and NH3 were found to be substantially reduced, when the anaerobic sludge was exposed to ZVI compared to no decrease in serum bottles free of ZVI.

A laboratory analysis is presented in this study that evaluates the impact of three different biochars, derived from biowastes of sludge (SDB), manure (MDB) and spent coffee grounds (SCGDB), on the physical properties of a loamy sand soil. Column experiments are conducted to measure the hydraulic conductivity and water content of these biochars when mixed with soil at a fixed concentration (5% with respect to (w.r.t) reference soil) under saturated conditions. The results show a substantial increase of the hydraulic conductivity for the biochars derived from SCGDB and SDB, whereas no changes were observed for MDB. The saturated water content is increased with the addition of SCGDB and trivial changes are observed for the remaining treatments. Numerical computations using HYDRUS-1D are conducted for a hypothetical scenario, revealing the different impact that each biochar has on the reference soil.

Hairdressing personnel is daily exposed to various chemical air pollutants, and specifically to Volatile Organic Compounds (VOCs) and Particulate Matter (PM) in hair salons. This is of concern, due to the hazardous effects of these chemicals on the individual's health. Nevertheless, a limited exposure assessment of indoor air quality (IAQ) has been performed. The aim of this study was to analyze the indoor air in 5 hair salons, to assess the IAQ of the occupational exposure, and to identify the main VOCs produced or activities responsible for the respective indoor pollution. The chemical analysis took place inside the salon environment by monitoring the emitted VOCs, as well as the PM of 1, 2.5, 4, and 10 μm aerodynamic diameter. The sampling of VOCs was performed by adsorption of pollutants on Tenax TA sorbent tubes, that were subsequently analyzed using a thermal desorption unit coupled to gas chromatography/mass spectrometry (TD-GC/MS). The obtained results showed that hair products are a major source of air pollutants, as elevated concentrations of VOCs and PM are released in the working environment. Furthermore, the type and concentration of VOCs are affected by the various hair treatment activities taking place in the salons. Among the main compounds detected there was benzene, toluene, ethylbenzene, and xylenes, known as BTEX, as well as, diethyl phthalate, 1,4-dioxane, etc. More than 50 VOCs were identified (occurrence ≥60%) and 14 of them were quantified. Their average concentration levels varied from 12 μg m

The air quality of modern cities is considered an important factor for the quality of life of humans and therefore is being safeguarded by various international organizations, concentrating on the mass concentration of particulate matter (PM) with an aerodynamic diameter less than 10, 2.5 and 1 &mu, m. However, the different physical and anthropogenic processes and activities within the city contribute to the rise of fine (&lt, 1 &mu, m) and coarse (&gt, m) particles, directly impacting human health and the environment. In order to monitor certain natural and anthropogenic events, suspecting their significant contribution to PM concentrations, seven different events taking place on the coastal front of the city of Limassol (Cyprus) were on-site monitored using a portable PM instrument, these included both natural (e.g., dust event) and anthropogenic (e.g., cement factory, meat festival, tall building construction, tire factory, traffic jam, dust road) emissions taking place in spring and summer periods. The violations of the limits that were noticed were attributed mainly to the various anthropogenic activities taking place on-site, revealing once more the need for further research and continuous monitoring of air quality.

The wide use of fossil fuels and their associated environmental concerns, highlighted the importance of affordable and clean energy (goal 7), as adopted by the Sustainable Development Goals of the United Nations for 2030. For years now, the detection of sulfur components in liquid fuels is performed mainly for environmental and health purposes in compliance with the respective legislations. Towards this, the aerobic and anaerobic biodesulfurization (BDS) process, which entails the use of microorganisms to limit the sulfur concentration is followed. To ensure effective BDS, several traditional analytical methods are utilized, although they require bench-top, bulky, costly, and time-consuming instruments along with skilled personnel. The currently employed analytical methods are mostly chromatographic techniques (e.g. liquid and gas) coupled with various detectors. To start with, high-performance liquid chromatography with ultraviolet detector (HPLC-UV), as well as electrospray ionization-LC-mass spectrometry (ESI-LC-MS) were mostly reported. Additionally, many detectors were coupled to gas chromatography (CG) including atomic emission detector (GC-AED), flame ionization detector (GC-FID), flame photometric detector (GC-FPD), sulfur fluorescence detector (GC-SFD), mass selective detector (GC–MS), etc. The solid-phase microextraction (SPME) technique provides extra capabilities when added to the separation techniques. Towards the continuous interest in oil supercomplex synthesis, other atmospheric and surface desorption ionization techniques, as well as the multidimensional 2D chromatographic systems (GC × GC and LC × LC) were also investigated, due to their unsurpassed resolution power. The current review ends with final remarks per applied methodology and the necessity to respect and protect the human environment and life.

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. α-pinene, β-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.

The ability of biochar to be used as filter or as additive for the adsorption of volatile organic compounds (VOCs) emitted from cattle manure is investigated. The employed biochar was produced from cattle manure after slow pyrolysis at 550 °C (under nitrogen). Towards this, in-house-made glass emission reactors were filled with fresh cattle manure samples and a thin layer of biochar (10% w/w) was placed on the top of the manure layer. The mixture was left for 24 h to equilibrate and air samples were collected from the headspace air. The samples were then analyzed using the headspace solid-phase micro-extraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) method. Cattle manure emissions are considered unpleasant and odoriferous. The respective changes in the emitted cattle manure VOCs were reported; these included mainly reduction in sulfur- (thiols and sulfides) and oxygen-containing VOCs (alcohols, ketones, phenolics), showing a promising application of biochar for the removal of such compounds from manure wastes. Also, five VOCs were selected as sorbents for further laboratory studies: hexane, dimethyl trisulfide, phenol, p-cresol, and 2-methyl-3-pentanone. The results of cattle manure-derived biochar, revealed a reduction in their emitted concentrations (low ppbv). The present application highlights a straightforward example of cyclic economy, where a waste product is reused after being processed; its re-usage as odor adsorbent serves again the agriculture sector.

Use of viscosifiers have been shown helpful for mobility control when displacing higher viscosity fluids, and to improve sweep in heterogeneous media. Foam can be used as a viscosifier for this purpose. Selected surfactant solutions were investigated for their ability to generate foam within porous media and foam stability through batch and column experiments using field-obtained soil. The approach used to generate foam in-situ consisted of several cycles (7) of surfactant-alternating-gas originally developed to recover crude oil; 0.25 pore volumes (PV) surfactant followed by 0.25 PV of air. The apparent viscosity ranged from 60 to 100 cP from the 3rd to 7th cycle, respectively. Foam was collected from the column exit after being shut-in for 3 days as a proof of foam generation and stability. Results showed that the selected surfactant formulation can be used to generate foam in-situ for use in the field for environmental restoration.

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.

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 (BDΒ), 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 μg L−1) of an aqueous solution (8.27 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, π-π 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.

Carobs unique compositional and biological synthesis enables their characterization as functional foods. In the present study, 76 samples derived from fruit and seeds of carobs, with origin from the countries of the Mediterranean region (Cyprus, Greece, Italy, Spain, Turkey, Jordan and Palestine) were analyzed for their nutritional composition, in order to identify potential markers for their provenance and address the carobs’ authenticity issue. Moisture, ash, fat, proteins, sugars (fructose, glucose, sucrose), dietary fibers and minerals (Ca, K, Mg, Na, P, Cu, Fe, Mn, Zn) were estimated following official methods. Due to the large number of data (76 samples × 17 parameters × 7 countries), chemometric techniques were employed to process them and extract conclusions. The samples of different geographical origin were discriminated with 79% success in total. The carobs from Cyprus, Italy and Spain were correctly classified without error. The main discriminators were found to be the dietary fibers, the carbohydrates and Cu, Zn and Mn, which emphasize their specific nutritional added value to the product and the country of origin impact. The results suggest that the proposed analytical approach is a powerful tool that enables the discrimination of carobs based on their country of origin. This research contributes to authenticity of carobs, adding value to local products.

The performance of biomass char production and application systems depends strongly on feedstock characteristics, conversion techniques, and methods of char handling, transport, and utilization. Although several combinations of biomass resources, conversion processes, and applications have been reported in the literature, few studies are focused on their environmental and economic benefits. This chapter provides a sustainability assessment for biomass utilization in char production and utilization in various applications, including soil amendment, energy production, and the synthesis of green adsorbents, catalysis, and supercapacitors.

Surfactants offer two mechanisms for recovering NAPLs: 1) to mobilize NAPL by reducing NAPL/water interfacial tension, and; 2) to increase the NAPL's aqueous solubility-called solubilization-as an enhancement to pump & treat. The second approach has been well-studied and applied successfully in several pilot-scale and a few full-scale tests within the last 15years, known as Surfactant Enhanced Aquifer Remediation (SEAR). A useful source of information for this second approach is the "Surfactant-enhanced aquifer remediation (SEAR) design manual" from the U.S. Navy Facilities Engineering Command. Few attempts, however, have been made at recovering NAPLs using the mobilization approach presented in this paper. Now, a full-scale field implementation of the mobilization approach is planned to recover an LNAPL (Jet A fuel) from a surficial sand aquifer located in Denmark using a smaller amount of surfactant solution and fewer PVs of throughput compared with the SEAR approach. The approach will rely on mobilizing the LNAPL so that it is recovered ahead of the surfactant microemulsion, also known as a micellar flood. This paper will review the laboratory work performed as part of the design for a full-scale implementation of a micellar flood. Completed lab work includes screening of surfactants, phase behavior and detailed salinity scans of the most promising formulations, and generating a ternary diagram to be used for the numerical simulations of the field application. The site owners and regulators were able to make crucial decisions such as the anticipated field results based on this work.

Mining in Cyprus resulted in a significant number of abandoned sulphide mines without any rehabilitation measures. The present study aims to describe and compare the environmental parameters in three such mines with respect to water chemistry, waste dumps geochemistry, slope-topography and plant growth. The mines under study are that of Kokkinopezoula, North and South Mathiatis located at the northeast of the Troodos massif. A synopsis of the previous studies conducted for the above-mentioned mines is presented, which includes water and soil samples analyses. Although, in these areas environmental degradation is reported, there are some plants which grow naturally. Therefore, a preliminary attempt to report these plants is conducted, while remediation options presented in the literature including technosols, revegetation, phytoremediation and phytostabilization are proposed. Potential use of native plants such as Phragmites australis, Tamarix smyrnensis, Poaceae, Pinus brutia and Schoenus nigricans Poaceace could be applied for phytoremediation of the sulphide mines in Cyprus. These plants seem to have great strength at low pH values and high metal content in contaminated soils and water. The three mines under study are also compared with three other old mines located in the broader area of Cyprus; that of Xeros, Limni and Skouriotissa, which operated under similar climatic conditions. By improving abandoned mines environment with technosols, the action of native plants will be enhanced and thus work towards a successful phytoremediation treatment, resulting in the minimization of future pollutants generated by the solid waste dumps.

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.

Peatlands represent a valuable global carbon store and are critical for preserving biodiversity. In order to reduce peat mining a significant effort is made to search for substitutes of peat in its different uses. Organic products obtained by hydrothermal carbonization processes could fully or partially replace peat in growing media if they possess some suitable properties. The study focused on the properties of a hydrochar produced from wheat (HTC) and included its chemical characterization and stability estimates using microbial respiration and nitrogen mineralization essays. As inhibition to seed germination could significantly restrict the eventual use of HTC in growing media, a number of seed germination trials were carried out to reveal the magnitude of phytotoxicity in relation to sphagnum peat and biochar and the effect that some simple and low-cost pre-conditioning treatments have on the rate of germination. This rate was greatly increased by simply wetting the material a few days prior to use or by mixing it with compost. It was shown that the positive effect on seedling emergence should be attributed, at least partly, to the degradation by microorganisms of toxic substances presumably produced during carbonization.

In this work, the fixed bed removal kinetics of Pb2+, Zn2+, Mn2+, Cr3+, Fe3+ and Cu2+ from aqueous solutions on natural zeolites was studied. For this aim, a non-dimensional two-phase homogeneous solid diffusion model including axial dispersion and equipped with a universal double-selectivity equilibrium model is developed and applied. In total 9 isotherms, representing 128 experimental points and 25 breakthrough curves, representing 764 experimental points are used in modeling. The application of the model is satisfactory resulted in an average deviation from the experimental data of 11.19 ± 5.53%. The solid phase diffusion coefficients are between 10−7 and 10−9 cm2/s depending on the metal, flow rate and particle size in the decreasing order of Cu > Fe, Cr > Zn, Pb > Mn. The study is supplemented by an extended literature review on fixed bed models and experimentally derived solid phase diffusion coefficients in zeolites.

In the present study, batch and fixed bed experiments were conducted in order to compare clinoptilolite and vermiculite for the removal of Mn2+, Zn2+, and Cr3+ from aqueous solutions under the same experimental conditions. Ion-exchange equilibrium is examined by use of batch equilibrium isotherms, distribution coefficients, and maximum exchange levels (MEL). Fixed bed experiments were conducted, and breakthrough curves and operational capacity were determined. Furthermore, diffusion coefficients were estimated by use of simplified fixed bed models. Concerning the comparison of the two minerals, in all experiments, for both batch (distribution coefficients and MEL) and fixed bed (breakthrough points and operating capacity (OC)), vermiculite showed better performance than clinoptilolite for all metals. Vermiculite selectivity series derived from batch distribution coefficients as well as in fixed beds is Cr3+ > Zn2+ > Mn2+ and is the same for clinoptilolite for liquid-phase equilibrium at relative c...

The abandoned gold–silver enrichment plant of Mitsero village is located in Cyprus and is an example of the long-term environmental impact of mining activity when no rehabilitation measures are undertaken. We conducted a study at a plant that has been abandoned for 70 years to investigate potential environmental contamination and, if discovered, describe the extent of the contamination. Soil and water samples were collected from five potentially-polluted zones and the results are summarized as follows: soil pH of samples collected from inside the abandoned enrichment plant was low, around 3.4 to 5.4, while samples from the tailings were extremely low, ranging between 1.9 and 2.0. The tailing samples also exhibit high leachability of metals, particularly for Cu, Fe, Zn, Cr, Pb and Mn when subjected to the SPLP. Furthermore, the samples from the tailings also contain high cyanide levels of 25.05 mg/kg and 45.85 mg/kg, which are well-above allowable limits of 0.9 mg/kg (Canadian Environmental Quality Guidelines, 2007). It is particularly interesting that no arsenic leachability was measured for the tailings, although arsenic is present in these samples as determined by XRF analysis. Our results indicate that the low pH environment combined with high leachability of metals is reflected in the quality of water samples collected from the ephemeral stream: high levels of metals were detected in the water samples measured using ICP-OES. While the pH of the water samples was neutral (7.6), aqueous concentrations of Cu, Fe, Zn, As, Cr, Pb and Mn ranged between 173.95 μg/l and 3678.8 μg/l. Thus, our findings indicate that areas of the site contain significant concentrations of metals and cyanide, leading us to conclude that, in conjunction with the low soil pH in those same areas, the potential exists to form acidic runoff (regardless of the pH of the rain itself) capable of leaching metals, thus mobilizing the contaminants. That the contamination, particularly the presence of cyanide, is still found some 70 years after closure makes a compelling argument for remediation of such legacy sites.