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The combination of treatment wetlands (TWs) with microbial electrochemical technologies (MET) is often studied in the lab to improve the performance and decrease the footprint of TWs. In this article we evaluated the long-term performance of four pilot-scale vertical sub-surface flow TWs for major pollutants' and organic micropollutants' removal from domestic wastewater. Three of them were filled with electroconductive material and operated under saturated (MET SAT), unsaturated (MET UNSAT) and unsaturated-saturated (MET HYBRID) conditions while the fourth one was a saturated intensified aerated system (AEW) filled with gravel. The MET-TWs achieved significant removals of COD (>78 %) with no clogging issues at the maximum applied OLR (249 g COD m-3 d-1) while under these loading conditions TSS removal exceeded 84 %. Among all electroactive TWs, UNSAT could remove 25 g NH4-N m-3 d-1 through nitrification when peak ammonium loading rate was applied; however this removal was significantly lower than AEW (35 g NH4-N m-3d-1). No important removal of P was observed in all systems with the exception of MET-SAT were precipitation reactions of P with iron occurred when anaerobic pretreated wastewater was used. The removal of the sum of studied organic micropollutants ranged between 70 ± 18 % (MET UNSAT) to 91 ± 4 % (AEW) and improved with feeding pulses increase. Moderate to high removal of specific microcontaminants was observed depending on the target compound, the studied system and the operational conditions. AEW and MET HYBRID systems complied with the limits set by EU for wastewater discharge to non-sensitive water bodies and for Class B water reuse. Scale-up calculations for a settlement of 500 PE showed that these systems require much less area per PE (0.51 m2 PE-1) comparing to conventional TWs while the operational cost was calculated to 0.07 € m-3 for the AEW and 0.02 € m-3 for the MET HYBRID.

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The microalgae Chlorella sorokiniana was used for the treatment of winery wastewater (WWW). Batch experiments were initially conducted to investigate how biomass acclimatization in different media, dilution of wastewater, and addition of ammonium nitrogen (NH4-N) affect the growth of microalgae and the removal of major pollutants. Afterwards, two sequencing batch reactor (SBR) systems were tested applying different configurations and hydraulic retention times. The biomass collected at the end of the experiments was characterized for proteins, lipids, carbohydrates, amino acid profile, and the existence of lutein, ß-carotene, chlorophyll a, and tocopherols. Batch experiments showed that Chlorella sorokiniana acclimatization to urban wastewater enhanced the removal of NH4-N and total phosphorus (TP). The operation of a two-stage SBR system achieved COD and NH4-N removal equal to 85 ± 9% and 91 ± 20%, respectively, while the use of a single-stage system feeding with anaerobically pretreated WWW resulted to COD and NH4-N removal of 78 ± 9% and 95 ± 9%, respectively. Analyses of biomass showed higher protein content (up to 58.8%) in batch experiments with NH4-N addition as well as in SBR experiments. The cultivation of microalgae under SBR conditions enhanced the production of pigments and tocopherols. The maximum concentrations of 1075 mg kg-1, 45.5 mg kg-1, and 131.2 mg kg-1 were achieved for lutein, ß-carotene, and tocopherols, respectively, in the one-stage system. Our findings suggested that Chlorella sorokiniana cultivation in WWW not only removed nutrients from WWW but also could potentially serve for the production of value-added ingredients used in food industry, cosmetics, and animal feedstock.

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Limited information is available on the removal of per- and polyfluoroalkyl substances (PFAS) in anaerobic digestion (AD). Τhe fate of six PFAS was studied in thermophilic bioreactors in the presence of granular activated carbon (GAC) and voltage application. Reactors with GAC exhibited lower concentrations of volatile fatty acids and higher methane production compared to those with and without the application of voltage. Analysis of PFAS in dissolved and solid phase showed that their distribution was dependent on perfluorocarbon chain length and functional group. Mass balances showed that PFAS were not removed during conventional AD or after applying voltage; however, significant removal (up to 61 ± 8 %) was observed in bioreactors with GAC for perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorooctane sulfonate (PFOS). Biomass characterization showed that in these bioreactors, the relative abundance of Acinetobacter and Pseudomonas was higher, indicating their potential role in PFAS biotransformation.

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This study investigates the effectiveness of vertical flow constructed wetlands (VFCWs) planted with a climbing ornamental plant for on-site treatment of real laundry wastewater. Specifically, the presence or absence of Trachelospermum jasminoides was evaluated for the removal performance of conventional pollutants (turbidity, TSS, COD, TP) and benzotriazoles (BTRs): 1H-benzotriazole (BTR), 5-methyl-1H-benzotriazole (5-TTR), 5-chlorobenzotriazole (CBTR), and xylytriazole (XTR). Results revealed that high removal efficiencies ranging from 92 to 98% were presented in both planted and unplanted systems for turbidity, TSS, and COD. Moreover, high removal rates were observed for CBTR and XTR, which were the only compounds found in real laundry wastewater, in both VFCW systems (planted: 100%; 94%; unplanted: 87%; 92%, respectively). The contribution of plants to the pollutant's removal was not statistically significant for all examined parameters. However, T. jasminoides demonstrated the ability to survive and grow without any visible symptoms under the harsh conditions of laundry wastewater, enabling the development of green facade. According to the findings, the application of VFCWs for on-site laundry wastewater treatment in buildings seems to be a highly promising solution, not only for primarily removing conventional pollutants but also for addressing emerging contaminants, specifically BTRs.

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Microalgae and macrophytes are commonly used as human and animal food supplements. We examined the cultivation of the microalgae Chlorella sorokiniana and the duckweed Lemna minor in thermal waters under batch and sequencing batch conditions and we characterized the produced biomass for the presence of essential nutrients as well as for heavy metals and radioisotope content. The highest specific growth rate for the microalgae was observed when 5 or 15 mg/L N were supplemented while the optimal conditions for Lemna minor were observed in the co-presence of 5 mg/L N and 1.7 mg/L P. Lemna minor presented higher concentrations of proteins and lipids comparing to the studied microalgae. Both organisms contained high amounts of lutein (up to 1378 mg/kg for Lemna minor) and chlorophyll (up to 1518 mg/kg for Lemna minor) while ß-carotene and tocopherols were found at lower concentrations, not exceeding a few tens of mg/kg. The heavy metal content varied between the two species. Lemna minor accumulated more Cd, Cu, K, Mn, Na, Ni, and Zn whereas Al, Ca and Mg were higher in Chlorella sorokiniana. Both organisms could be a significant source of essential metals but the occasional exceedance of the statutory levels of toxic metals in food products raises concern for potential risk to either humans or animals. Application of gamma-spectroscopy to quantify the effective dose to humans from 228Ra, 226Ra and 40K showed that Chlorella sorokiniana was well under the radiological limits while the collected mass of Lemna minor was too small for radiological measurements with confidence.

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Floating treatment wetlands are considered a promising and low-cost technology for the treatment of polluted water and wastewater. However, their functionality and efficiency in different types of wastewater are not fully understood. In this study, several ornamental plant species (monocultures: Canna sp., Iris sp., polyculture: Iris orientalis, Cyperus sp., Acorus gramineus) were tested in two different types of floating mats, including a media supported floating mat (MSFM) or a simple plastic grid, and evaluated for optimal removal of the studied pollutants. The results regarding pollutant removal revealed that planted systems grown in MSFM achieved significantly higher removal rates (up to 90 %) compared to the plastic grid (up to 80 %). Statistically significant higher removal rates were obtained for the planted systems compared to the unplanted systems either grown in MSFM (for turbidity (planted: 82-90 %; unplanted: 44 %), COD (planted: 74-84 %; unplanted: 32 %) and BOD5 (planted: 76-85 %; unplanted: 51 %), respectively) or grown in the plastic grid (for turbidity (planted: 64-78 %; unplanted: 44 %) and COD (planted: 43-75 %; unplanted: 32 %), respectively). During the experimental period (7 months), all plants managed to survive and withstand the weather variations. The plants in polyculture followed by Iris sp. plants in plastic grid floating mats were better adapted, as indicated by maximum quantum efficiency of PSII values and chlorophyll content index, while all the plants were considered well adapted in the MSFM. Overall, the implementation of floating treatment wetlands with ornamental vegetation for greywater treatment in urban areas seems to be a sustainable and efficient approach.

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The sustainable management of landfill leachates remains a matter of important concern in many countries. We used as case study a medium-sized Greek landfill, and we initially investigated the performance of the existing secondary leachate treatment system. The activated sludge process removed chemical oxygen demand (COD), biochemical oxygen demand (BOD), NH4-N, and PO4-P by 55%, 84%, 94%, and 14%, respectively, but the effluents did not meet the legislation requirements for discharge or reuse. Afterwards, different management options of these effluents (co-treatment with sewage in the centralized treatment plant, onsite tertiary treatment with reverse osmosis, granular activated carbon (GAC), ozonation, photo-Fenton, or constructed wetlands) were evaluated regarding their operational costs and environmental footprint. The use of constructed wetlands presented the lower operational cost, energy requirements, and greenhouse gas (GHG) emissions, not exceeding 21.5 kg CO2eq/day. On the other hand, the power consumption and the GHG emissions of the other on-site technologies ranged from 0.37 kWh/m3 and 5.56 kg CO2eq/day (use of GAC) to 39.19 kWh/m3 and 588.6 kg CO2eq/day (use of ozonation), respectively. The co-treatment of the leachates with municipal wastewater required 0.6 kWh/m3 and emitted 30.18 kg CO2eq/day. For achieving zero-discharge of the treated leachates, a system consisting of constructed wetlands and evaporation ponds in series was designed.

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An integrated lab-scale wastewater treatment system consisting of an anaerobic Moving Bed Biofilm Reactor (AnMBBR) and an aerobic Membrane Bioreactor (AeMBR) in series was used to study the removal and fate of pharmaceuticals during wastewater treatment. Continuous-flow experiments were conducted applying different temperatures to the AnMBBR (Phase A: 35 °C; Phase B: 20 °C), while batch experiments were performed for calculating sorption and biotransformation kinetics. The total removal of major pollutants and target pharmaceuticals was not affected by the temperature of the AnMBBR. In Phase A, the average removal of dissolved chemical oxygen demand (COD), biological oxygen demand (BOD), and ammonium nitrogen (NH4-N) was 86%, 91% and 96% while in Phase B, 91%, 96% and 96%, respectively. Removal efficiencies ranging between 65% and 100% were observed for metronidazole (MTZ), trimethoprim (TMP), sulfamethoxazole (SMX), and valsartan (VAL), while slight (<30%) or no removal was observed for carbamazepine (CBZ) and diclofenac (DCF), respectively. Application of a mass balance model showed that the predominant mechanism for the removal of pharmaceuticals was biotransformation, while the role of sorption was of minor importance. The AeMBR was critical for VAL, SMX and TMP biodegradation; the elimination of MTZ was strongly enhanced by the AnMBBR. In both bioreactors, Bacteroidetes was the dominant phylum in both bioreactors over time. In the AnMBBR, Cloacibacterium and Bacteroides had a higher abundance in the biocarriers compared to the suspended biomass.

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This work examines the continuous addition (5 g/L) of conductive granular activated carbon (GAC) in an integrated pilot-scale unit containing an anaerobic digester (180 L) and an aerobic submerged membrane bioreactor (1600 L) connected in series for the treatment of agro-industrial wastewater. Biogas production increased by 32 % after the addition of GAC. Methanosaeta was the dominant methanogen in the digester, and its relative abundance increased after the addition of GAC. The final effluent after post-treatment with the aerobic membrane bioreactor had a total solids content <0.01 g/L and a chemical oxygen demand between 120 and 150 mg/L. A simple cost analysis showed that GAC addition is potentially profitable, but alternatives ways of retaining the GAC in the system need to be found. Overall, this study provides useful scientific data for the possible application of GAC in full-scale biogas projects.

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The heat-activated persulfate system showed encouraging results for the destruction of the widely used antibiotic Ampicillin (AMP). AMP removal follows exponential decay, and the observed kinetic constant was enhanced with persulfate (PS) dosage at the range 50-500 mg L-1 and temperature (40-60 °C), while AMP thermolysis at 60 °C was almost negligible. The apparent activation energy was estimated to 124.7 kJ mol-1. Alkaline conditions, water matrix constituents like bicarbonates, humic acid, and real water matrices retarded AMP oxidation. Experiments performed with tert-butanol and methanol as scavengers demonstrated the contribution of sulfate radicals as the dominant reactive species. Seven transformation products (TPs) of AMP have been identified from AMP destruction. An EC50 value equal to 187 mg L-1 was calculated for 72 h of exposure of the microalgae Chlorella sorokiniana to AMP. According to the ecotoxicity experiments that conducted after treatment of AMP with PS for different reaction times, no important inhibition of microalgae was noticed for contact time of 72 h and 10 d. These results indicate the formation of no toxic AMP by-products for the applied experimental conditions.

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Recent studies have shown the widespread occurrence of microplastics in multiple environmental compartments. When discharged into the aquatic environment, microplastics interact with other chemicals acting as vectors of organic and inorganic micropollutants. In the present study, we examined the sorption of two commonly used antihypertensive drugs, valsartan (VAL) and losartan (LOS), onto polystyrene (PS) microplastics and we studied the effects of water matrix, solution's pH, salinity, and microplastics' aging on their sorption. According to the results, the sorption of VAL and LOS onto PS is a slow process that reaches equilibrium after 12 days. The sorption of both target micropollutants was pH-dependent and significantly decreased under alkaline conditions. The removal of VAL was enhanced in the presence of 100 mM of Ca2+ while no statistical significant effects were observed when Na+ was added. The increase of salinity either did not affect or decreased the removal of LOS. Lower sorption of both drugs was observed when aged PS was used despite that the specific surface area for aged PS was 39% higher than pristine. Calculation of the sorption distribution coefficient (Kd) for different water matrices showed that the increase of matrix complexity inhibited target compounds' removal and the sorption rate decreased from bottled water > river water ≈ treated wastewater for the two compounds. For VAL, the Kd values ranged between 795 ± 63 L/kg (bottled water) and 384 ± 88 L/kg (river water), while for LOS between 4453 ± 417 L/kg (bottled water) and 3078 ± 716 L/kg (treated wastewater). Both VAL and LOS sorption onto PS microplastics can be described by hydrophobic and electrostatic interactions. The current results indicate that PS particles could affect the transportation of antihypertensive drugs in the aquatic environment causing potential adverse effects on the environment and public health.

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Dairy industry consumes high water amounts and generates highly contaminated wastewater. EU-27 is the second largest milk producer and the main cheese exporter in the world. The main objectives of the current study was to estimate the amounts of dairy wastewater (DWW) that are produced annually in different EU countries and to present the relevant existing EU legislation. The main treatment practices currently applied as well as the future opportunities for sustainable DWW management were also discussed. According to the results a total amount of 192.5 × 106 m3 of DWW are annually produced in EU-27 countries, 49% of them are due to the production of cheeses, while 19%, 18% and 13% are due to the production of drinking milk, acidified milk and butterfat products, respectively. Six countries (Germany, France, Italy, Poland, Spain and Netherlands) contribute to the generation of more than 73% of DWW, while the annual per capita DWW production ranges between 36 L (Luxembourg) and 1441 L (Ireland). Since 2019, EU has established best available techniques (BAT) for the dairy industry in order to achieve efficient monitoring of the produced wastewater, reduced water consumption and increased resource efficiency. The main on-site treatment processes that are currently applied include in series wastewater pretreatment for the removal of fat and pH adjustment, anaerobic or/and aerobic biological processes for the decrease of organic loading and nutrients and use of membranes for the cases that recovered water is going to be reused. Limited information is so far available for the operational treatment cost of the different processes. Data originated from a large dairy industry in Cyprus showed an operational cost equal to 1.21 €/m3 of treated wastewater. The main future challenge for the dairy industry and water treatment sector is the adoption of novel processes aiming to DWW valorization under the frame of circular economy.

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Little information exists on the effects of shipping and handling on per- and polyfluoroalkyl substances (PFASs) in environmental samples. Thus, we evaluated the integrity of dried wastewater extracts and the sensitivity of our high-resolution mass spectrometry (HRMS) instrument to perform such analyses by monitoring 13 representative PFASs in samples extracted, evaporated, and stored at room temperature up to one month. Relative to zero-day recoveries of six detected PFASs ranged between 94 and 124% (RSD <38%) for influents, between 88 and 126% (RSD <18%) for effluents after 28 days. Larger variabilities are tentatively associated with the lack of specific mass-labeled standards and the interactions between analytes and remaining matrix components over time. In a second stage, a mix of local and international dry-shipped wastewater samples were analyzed and the same PFASs were quantified. Up to six PFASs were identified, with median concentrations ranging from 1.3 (perfluoro butyl sulfonate (PFBS)) to 7.7 ng/L (perfluoro hexanoic acid (PFHxA)) and from 1.5 (PFBS) to 13.8 ng/L (PFHxA) in local influents and effluents respectively; and from 0.7 (perfluoro hexyl sulfonate (PFHxS)) to 52.8 ng/L (PFHxA) and from 0.5 (PFHxS) to 21.4 ng/L (PFHxA) in Greek influents and effluents, respectively. The importance of this study lies on the need to consider the wider recovery shifts and expanded variability ranges of PFASs derived from the transport and storage times of dried extracts, particularly when applied to HRMS and wide-scope screening approaches.

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Two systems were compared for medium-strength dairy wastewater treatment. The first comprised a methanogenic Moving Bed Biofilm Reactor (AnMBBR) and an aerobic MBBR (AeMBBR), while the second an AnMBBR and a sequencing batch reactor (SBR) with Chlorella sorokiniana. The AnMBBR, under ambient conditions, achieves biogas production sufficient enough to attain energy autonomy. The produced energy was 0.538 kWh m-3, whereas the energy consumption 0.025 kWh m-3. Its coupling with the AeMBBR removed COD, NH4-N TKN, and PO4-P by 93 ± 4%, 97 ± 3%, 99 ± 1% and 49 ± 15%, respectively, while the use of the SBR as a second step eliminated totally COD but partially the other pollutants. The higher nitrogen removal in the first system was due to nitrification occurring in the AeMBBR. The acclimatization of microalgae to dairy wastewater enhanced their growth. Their protein content was 54.56%, while starch and lipids were 3.39% and 23.1%, respectively.

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The national infrastructure FoodOmicsGR_RI coordinates research efforts from eight Greek Universities and Research Centers in a network aiming to support research and development (R&D) in the agri-food sector. The goals of FoodOmicsGR_RI are the comprehensive in-depth characterization of foods using cutting-edge omics technologies and the support of dietary/nutrition studies. The network combines strong omics expertise with expert field/application scientists (food/nutrition sciences, plant protection/plant growth, animal husbandry, apiculture and 10 other fields). Human resources involve more than 60 staff scientists and more than 30 recruits. State-of-the-art technologies and instrumentation is available for the comprehensive mapping of the food composition and available genetic resources, the assessment of the distinct value of foods, and the effect of nutritional intervention on the metabolic profile of biological samples of consumers and animal models. The consortium has the know-how and expertise that covers the breadth of the Greek agri-food sector. Metabolomics teams have developed and implemented a variety of methods for profiling and quantitative analysis. The implementation plan includes the following research axes: development of a detailed database of Greek food constituents; exploitation of "omics" technologies to assess domestic agricultural biodiversity aiding authenticity-traceability control/certification of geographical/genetic origin; highlighting unique characteristics of Greek products with an emphasis on quality, sustainability and food safety; assessment of diet's effect on health and well-being; creating added value from agri-food waste. FoodOmicsGR_RI develops new tools to evaluate the nutritional value of Greek foods, study the role of traditional foods and Greek functional foods in the prevention of chronic diseases and support health claims of Greek traditional products. FoodOmicsGR_RI provides access to state-of-the-art facilities, unique, well-characterised sample sets, obtained from precision/experimental farming/breeding (milk, honey, meat, olive oil and so forth) along with more than 20 complementary scientific disciplines. FoodOmicsGR_RI is open for collaboration with national and international stakeholders.

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This article studies the ecotoxicity of 3,3',4',5-tetrachlorosalicylanilide (TCSA) using different bioassays and examines its fate in activated sludge batch experiments. Despite of the common use of TCSA as chemical uncoupler in wastewater treatment systems and as preservative in several products, limited data has been published for its ecotoxicity, while no information is available for its biodegradation. Among different bioassays, the highest toxicity of TSCA was noticed for Daphna magna (48-h LC50: 0.054 mg L-1), followed by Vibrio fischeri (15-min EC50: 0.392 mg L-1), Lemna minor, (7-d EC50: 5.74 mg L-1) and activated sludge respiration rate (3-h EC50: 31.1 mg L-1). The half-life of TSCA was equal to 7.3 h in biodegradation experiments with activated sludge, while use of mass balances showed that 90% of this compound is expected to be removed in an aerobic activated sludge system, mainly due to biodegradation. A preliminary risk assessment of TSCA using the Risk Quotient methodology showed possible ecological threat in rivers where wastewater is diluted up to 100-fold. Comparison with the structurally similar 5-chloro-2-(2,4-dichlorophenoxy)phenol (triclosan, TCS) showed that both compounds have similar biodegradation potential and seem to cause analogous toxicity to Vibrio fischeri and activated sludge. Specifically, TCS was biodegraded quite rapidly by activated sludge (half-life: 6.2 h), while EC50 values equal to 0.134 mg L-1 and 39.9 mg L-1 were calculated for Vibrio fischeri, and activated sludge respiration rate. Future research should focus on monitoring of TSCA concentrations in the environment and study its effects in long-term toxicity and bioaccumulation tests.

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The ready biodegradability of twenty food additives, belonging to the classes of artificial sweeteners, natural sweeteners, preservatives and colorings, was investigated using activated sludge as inoculum and OECD 301F respirometric test. According to the results, saccharin, aspartame, sodium cyclamate, xylitol, erythritol, maltitol, potassium sorbate, benzoic acid and sodium ascorbate are characterized as readily biodegradable compounds, partial biodegradation (<60% during the test) was noticed for steviol, inulin, alitame, curcumin, ponceau 4R and tartrazine, while no biodegradation was observed for the other five compounds. The duration of lag phase before the start of biodegradation varied between the target compounds, while their ultimate biodegradation half-life values ranged between 0.7 ±â€¯0.1 days (benzoic acid) and 24.6 ±â€¯1.0 days (curcumin). The expected removal of target compounds due to ultimate biodegradation mechanism was estimated for a biological wastewater treatment system operated at a retention time of one day and percentages higher than 40% were calculated for sodium cyclamate, potassium sorbate and benzoic acid. Higher removal percentages are expected in full-scale Sewage Treatment Plants (STPs) due to the contribution of other mechanisms such as sorption to suspended solids, (bio)transformation and co-metabolic phenomena. Further biodegradation experiments should be conducted under different experimental conditions for the food additives that did not fulfill the requirements of the applied protocol. Future studies should also focus on the occurrence and fate of food colorants and natural sweeteners in full-scale STPs.

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Fig fruit (Ficus carica L.) is one of the most important agricultural products of the tropic and subtropics areas. In the Middle East and the Mediterranean region, the fig is included in diet since the ancient years and it is considered as the symbol of longevity. This review presents the main phytochemical compounds found in fresh and dried figs of different varieties, describes the analytical methods used for their determination and discuss the antioxidant capacity and the potential effects of figs in human health. Phenolic acids and flavonoids are the major types of phytochemical compounds that have been found in fresh and dried figs. Their levels are strongly influenced by various factors such as the color, the part of fruit, the maturity and the drying process. Gallic acid, chlorogenic acid, rutin, quercetin-3-O-rutinoside and epicatechin are the most predominant phenolic acids and flavonoids in dried and fresh fig varieties. Extracts of dark-colored varieties contain higher amount of phenolic compounds than the light-colored varieties. Fruit skin contributes most to the amount of phenolic compounds compared to the fruit pulp. The ripening stage affects the concentrations of phenolic compounds in figs, the maximum have been found in ripe fruit. On the other hand, contradictory results have been reported in the literature regarding the effect of air- and sun- drying on the total content of phytochemical compounds, as well as on the concentrations of individual phenolic compounds and carotenoids in figs. The antioxidant capacity of figs is highly correlated with their amount of phenolic compounds. The leaves, roots, fruit and latex of the plant are known for their health properties including acetyl cholinesterase inhibition, antifungal, anti-helminthic and anticarcinogenic activities. Future efforts should be focused on the application of fig extracts as functional ingredients of food products, on clinical trials in order to confirm the beneficial effect of plant extracts in human health and, on the valorization of the waste material produced during figs' processing.

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Since 2015, Lesvos Island (Greece) is a key entry location for people seeking asylum in the EU. This article presents information for the production of municipal solid waste and sewage in the asylum seekers reception sites of Moria and Kara Tepe for the period between May 2016 and April 2017. According to the results, the annual produced municipal solid waste and sewage in the refugees' camps were 1464 tons and 95,550 m3, respectively. Taking into account the population served, the average daily per capita generation of municipal solid waste was 0.88 kg per asylum seeker and day, significantly lower than that calculated for the permanent population the same period (1.39 kg per inhabitant and day). The daily production of sewage was 54 L per asylum seeker and day, while the corresponding value for the permanent population was 211 L per inhabitant and day. The total methane emissions from solid waste and sewage production in studied refugees' camps were estimated to 178.6 tons per year or 35.5 kg CH4 per asylum seeker and year. Further investigation is needed for the characterization of the produced solid waste and sewage in order to assure the sustainable design and operation of these sites.

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Benzotriazoles are among the most commonly found organic micropollutants in the aquatic environment. In this study, toxicity experiments were conducted in order to investigate the effects of different benzotriazoles on Chlorella sorokiniana growth. Four compounds were tested; 1H-benzotriazole (BTR), xylytriazole (XTR), 5-methyl-1H-benzotriazole (5TTR) and 5-chlorobenzotriazole (CBTR). The fate of these micropollutants was also studied under batch conditions and the effect of different mechanisms on their elimination was investigated. According to the results, the EC50 values in single-substance toxicity experiments were calculated to 8.3 mg L-1 for BTR, 22 mg L-1 for 5TTR and 38.7 mg L-1 for CBTR. A slight inhibition on microalgae growth was noted at the maximum tested concentration of XTR (77 mg L-1), while no inhibition was observed when a mixture of target BTRs was tested at 200 µg L-1. Calculation of the Risk Quotient (RQ) showed no possible ecological threat in the presence of 5TTR, XTR and CBTR, while RQ values close or higher than 1 were estimated for BTR. All target contaminants were significantly eliminated in microalgae experiments that lasted 16 days. Their removal efficiency ranged between 42.2 ±â€¯3.1% (XTR) to 97.2 ±â€¯0.9% (XTR), while their half-life values were estimated to 2.4 ±â€¯0.5 days for 5TTR, 6.5 ±â€¯0.6 days for BTR, 15.2 ±â€¯1.4 days for CBTR and 20.7 ±â€¯2.0 days for XTR. Photodegradation was the main mechanism affecting BTR, XTR and CBTR removal, while bioremoval processes enhanced 5TTR elimination. The addition of sodium acetate decreased the removal efficiency of BTRs possibly due to catabolite repression. This is the first study investigating the toxicity and fate of BTRs in microalgae cultures.

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