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An aerated greenhouse ecosystem, often referred to as a Living Machine®, is a technology for biological wastewater treatment within a greenhouse structure that uses plants with their roots submerged in the wastewater. This system has a small footprint relative to traditional onsite wastewater treatment systems and constructed wetland, can treat high-strength wastewater, and can provide a high level of treatment to allow for reuse for purposes such as irrigation, toilet flushing, and landscape irrigation. Synthetic and actual craft beverage wastewaters (wastewater from wineries, breweries, and cideries) were examined for their treatability in bench-scale greenhouse ecosystems. The tested wastewater was high strength with chemical oxygen demands (COD) concentrations of 1120 to 15,000 mg/L, total nitrogen (TN) concentrations of 3 to 45 mg/L, and total phosphorus (TP) concentrations of 2.3 to 90 mg/L. The COD, TN, and TP concentrations after treatment ranged from below 125 to 560 mg/L, 1.5 to 15 mg/L, and below 0.25 to 7.8 mg/L, respectively. The results confirm the ability of the aerated greenhouse ecosystem to be a viable treatment system for craft beverage wastewater and it is estimated to require 54 and 26% lower hydraulic retention time than an aerobic lagoon and a low temperature, constructed wetland, respectively, the types of systems that would likely be used for this type of wastewater for onsite locations. [ABSTRACT FROM AUTHOR]

Wastewaters, as the major waste stream of the wine industry, are usually disposed in crude form due to the lack of sustainable treatments, which poses rising environmental threat. Considering biodegradability, nutrients content and other specific characteristics, winery wastewaters are suitable for utilization in xanthan production. In this study, the screening of local wild-type Xanthomonas euvesicatoria strains, isolated from pepper leaves, for xanthan production on medium containing wastewaters from rose wine industry, with initial sugar content of 25 g/L, was performed. Bioprocess success was estimated based on the quantity and quality of separated biopolymer. Additionally, composition of collected wastewaters was determined, and the obtained data indicate the importance of their proper management. The results of screening experiments suggest that applied X. euvesicatoria isolates have a statistically significant effect on xanthan concentration in cultivation medium, its molecular weight, as well as on apparent viscosity of xanthan aqueous solution. According to the obtained results, xanthan concentration varied from 4.0 g/L to 10.0 g/L, while the values of average molecular weight of xanthan and apparent viscosity of its solution ranged from 2.5 ∙ 105 g/mol to 8.5 ∙ 105 g/mol and from 40 mPa ∙ s to 60 mPa ∙ s, respectively. The results from this study suggest that X. euvesicatoria PL2 isolate showed the greatest potential for xanthan production on medium containing wastewaters from rose wine industry because of determined quantity of good-quality biopolymer. Further research is necessary in order to improve proposed bioprocess as sustainable biotechnological solution for winery wastewaters utilization. [ABSTRACT FROM AUTHOR]

This study investigated the impact of process configuration and conditions on microbial communities and metabolic pathways in the anaerobic digestion of winery effluents. Four system configurations were analyzed for taxonomic and functional profiles using 16S rRNA gene sequencing and Tax4Fun2. Sporolactobacillus, Prevotella, and Acetobacter dominated (> 70%) in the acidogenic reactor with 5277 conserved functions across configurations. In the methanogenic reactor, methane production relied on Methanosaeta in the single-stage configuration (13%) and five archaea genera in the two-stage configuration (18%). Thermophilic conditions favored syntrophic acetate oxidation and hydrogenotrophic methanogenesis by Methanothermobacter (65%), significantly changing due to temperature. The two-stage configuration exhibited 3.0 times higher functional redundancy than the single-stage configuration. Mesophilic conditions displayed 2.5 times greater functional redundancy than thermophilic conditions. High organic loading rate and short hydraulic retention time reduced functional redundancy by 1.5 times. Assessing microbial functionality beyond their composition is crucial to understand stability and performance of anaerobic digestion systems. [ABSTRACT FROM AUTHOR]

The agricultural sector is one that requires and consumes enormous amounts of fresh water globally. Commercial wine production in particular uses large volumes of fresh water and, through various processes, generates significant quantities of wastewater. The wastewater produced by wineries typically exhibits elevated levels of chemical oxygen demand (COD), total suspended solids (TSS), an acidic pH, and varying salinity and nutrient contents. The overall characteristics of winery wastewater indicate that it is a potential environmental hazard if not processed and disposed of appropriately. Due to significant variations in wastewater contaminant levels among wineries, the implementation of a universally applicable, environmentally friendly, and sustainable waste management system seems practically unattainable. This study investigated the design, fabrication, and modification of a shear enhanced flotation separation (SEFS) pilot plant to be used as a primary treatment stage during winery wastewater processing. This technology combines the synergistic advantages of hydrodynamic shear, coagulation, flocculation, and dissolved air flotation. To date, there have been only limited publications on the feasibility and application of hydrodynamic shear and its potential to assist with coagulation/flocculation and flotation efficiencies specifically for winery wastewater treatment. The results obtained indicate that the SEFS pilot plant may well be able to process winery wastewater to a quality level where reuse of the water for irrigation of crops may be considered. [ABSTRACT FROM AUTHOR]

The production of Volatile Fatty Acids (VFAs) from wastewater holds significant importance in the context of biorefinery concepts due to their potential as valuable precursors for various bio-based processes. Therefore, the primary objective of this research is to investigate the fermentation of Winery Wastewater (WW) in an Upflow Anaerobic Sludge Blanket (UASB) reactor to generate VFAs, with particular emphasis on Caproic Acid (HCa) production and the dynamics of the microbiota, under varying Hydraulic Retention Time (HRT) periods (8, 5, and 2.5 h). The change from an 8 h to a 5 h HRT period resulted in an approximately 20% increase in total VFA production. However, when the HRT was further reduced to 2.5 h, total VFA production decreased by approximately 50%. Concerning the specific production of HCa, expressed in grams of Chemical Oxygen Demand (gCOD), the maximum yield was observed at around 0.9 gCOD/L for a 5-h HRT. Microbial population analysis revealed that Eubacteria outnumbered Archaea across all HRTs. Population dynamics analysis indicated that the Firmicutes Phylum was predominant in all cases. Within this phylum, bacteria such as Clostridium kluyveri and Clostridium sp., known for their ability to produce HCa, were identified. Based on the results obtained, the application of the UASB reactor for WW treatment, within the biorefinery framework, has the potential to provide a practical alternative for HCa production when operated with a 5 h HRT. [ABSTRACT FROM AUTHOR]

High-strength wastewaters from a variety of sources, including the food industry, domestic septage, and landfill leachate, are often hauled to municipal wastewater treatment plants (WWTPs) for co-treatment. Due to their high organic loadings, these wastewaters can cause process upsets in both a WWTP's liquid and solids treatment trains and consume organic treatment capacity, leaving less capacity available to service customers in the catchment area. A novel pre-treatment method, the Waste Activated Sludge-High Rate (WASHR) process, is proposed to optimize the co-treatment of high-strength wastewaters. The WASHR process combines the contact stabilization and sequencing batch reactor processes. It utilizes waste activated sludge from a municipal WWTP as its biomass source, allowing for a rapid start-up. Bench-scale treatment trials of winery wastewater confirm the WASHR process can reduce loadings on the downstream WWTP's liquid and solids treatment trains. A case study approach is used to confirm the economic viability and environmental sustainability of the WASHR process compared to direct co-treatment, using life-cycle cost analyses and greenhouse gas emissions estimates. [ABSTRACT FROM AUTHOR]

Agro-industrial activities generate large volumes of wastewater. When this wastewater is discharged to the environment without proper treatment, it represents a serious problem. Bioenergy production can be conducted using wastewater, but the presence of some recalcitrant compounds may require a pre-treatment step. Advanced oxidation processes (AOPs) were traditionally used to treat hazardous materials but have recently been applied in various bioenergy production processes. AOPs are highly competitive water/wastewater treatment technologies and their application in the bioenergy sector is increasing as a pre-treatment process. Despite the increasing interest in using AOPs to enhance biofuel production, there is a lack of comprehensive documentation on their integration into biofuel production operations. This critical review highlights the application of AOPs as pre-treatment for agro-industrial wastewater (AIW) to enhance bioenergy production. It was noted that AOP applications can reduce the COD, VS, TS and total polyphenols, resulting in an improvement in their biodegradability. Moreover, these processes help remove hemicellulose and lignin contents, increasing the production of biogas, biodiesel and bioethanol. Among the different AOPs presented in this work, wet air oxidation showed promise for pre-treating lignocellulosic biomass to produce various energy types, while sonolysis and ozonation proved effective as a biosolid pre-treatment. Ozonolysis, Fenton reagents and photocatalysis are commonly used to selectively remove phenolic compounds and colorants from organic effluents. The high energy requirements and chemicals reagents costs are identified as obstacles to the application of AOPs in bioenergy production. Further studies should investigate the integration of AOPs with other treatment processes to improve the cost-effectiveness. [ABSTRACT FROM AUTHOR]

The recovery of anthocyanins from winery wastewater constitutes an attractive option for both environmental and commercial valorization, as food colorants and nutraceutical ingredients. In this study, the electric field induced ion drift method is proposed as a promising technique for the purification of wastewater solutions as well as for the accumulation of anthocyanins. The cation of the anthocyanidin malvidin (C17H15O7+) was selected as the most representative of winery waste, in order to develop a theoretical model. The main principle of the model is based on the displacement of charged anthocyanin ions, under the influence of an electric field vertical to the flow of the solution, and their accumulation on the side walls of a conductor. Apparatus inducing an electric field drift is described, and critical parameters (i.e., final spatial distribution of concentration, electric field intensity, surface charge density, and potential) were calculated. The proposed model succeeded in reducing anthocyanin concentration by more than 90%, for duct widths smaller than 1 mm in the bulk of the solution, for applied potentials φ(0) in the range of 0.2–0.4 V and target concentrations equal to 1.2 × 10−3 mol/m3. [ABSTRACT FROM AUTHOR]

The process of wine making is well known to produce large amounts of wastewater with highly variable characteristics. The disposal of untreated winery wastewater is strictly prohibited since it adversely affects the recipient environment. Due to the variability in characteristics of winery wastewater, developing a treatment system which can handle high organic and inorganic loads, especially during the vintage season, is a complex challenge. This study investigated the theory, methodology and implementation of a wastewater treatment technology called shear enhanced flotation separation (SEFS) as a potential primary treatment stage towards the treatment of winery wastewater. Winery effluent was subjected to a coagulation process in a high shear environment, with and without the introduction of air, followed by flocculation. Upon successful optimization of operating parameters, a polymeric-based coagulant AB121 and polyelectrolyte flocculant AB796 yielded the highest reduction in turbidity (95%) with typical values of 630 NTU for the raw wastewater and 25 NTU for the SEFS-treated effluent. A substantial reduction in total suspended solids (97%) was achieved with average raw winery wastewater values of 2275 mg/L compared to the 50 mg/L obtained for the SEFS-treated effluent. Furthermore, a notable reduction (54%) in COD (from 11,250 mg/L to 5220 mg/L) using SEFS technology was achieved. [ABSTRACT FROM AUTHOR]

Winery wastewater (WWW) handling strategies often include co-treatment at municipal wastewater treatment plants (WWTPs). Despite this, definitive information regarding oxidation kinetics and process and performance impacts due to co-treatment is lacking. A combined Michaelis–Menten–University of Cape Town kinetic model has been found to best describe the pH-inhibited aerobic biological oxidation of WWW by heterotrophs in activated sludge from four municipal WWTPs. The specific rate of substrate consumption was highest in biomass that had been exposed to WWW (57.3 mg COD/g MLVSS·h) compared to biomass that had not (20.7 mg COD/g MLVSS·h). Bench-scale aerobic co-treatment trials confirm that sorption is a key removal mechanism, with up to 98% chemical oxygen demand and 97% total organic carbon removal after 6 h of reaction time. The WWW solids are quickly incorporated into the biological floc and may improve settleability at loading rates above 75 mg WWW suspended solids/L bioreactor volume at the expense of significantly increasing the observed yield. The aerobic-activated sludge system at municipal WWTPs can effectively co-treat WWW, provided the organic loading rates are limited and the WWTP is designed to accommodate the seasonal loadings of winery wastewater. The identified mitigation measures can be used by co-treating facilities to optimize the co-treatment performance of WWW along with domestic wastewater. [ABSTRACT FROM AUTHOR]

Value-Added Compounds (VACs) are molecules that have attracted great attention in the literature regarding their potential for integration into existing processes or products. In Winery Wastewater (WW), VACs are valuable because of their antioxidant characteristics. Furthermore, integrated systems for recovery of these molecules and treatment of WW can be a powerful strategy towards an environmentally efficient way of wine production. Therefore, a bibliometric analysis was conducted to establish the status and trace research trends on that topic. The analysis investigated the Web of Science database from 1953–2023, where the software VOSviewer® and R were used. Secondly, an extensive literature review was carried out on VACs recovery from WW by membrane process, which was identified as a promising strategy. As a result, the historical evolution of publications has a growing behavior while citations take time to grow. The most productive authors, journals, and countries were analyzed, with Spain being the leading country in publications on that topic. Lastly, keyword mapping revealed the relevance of "circular economy" and "biorefinery" as knowledge transfer concepts where both traditional and emergent technologies are connected towards the achievement of sustainable development goals. The recovery of phenolic compounds from wine production through membrane processes stands out as a promising technology. Different recovery approaches using membrane processing were assessed in the review. Studies could achieve up to 100% phenolic compound and polysaccharide rejections and also addressed the possibility of fractioning these compounds. [ABSTRACT FROM AUTHOR]

The ceramic separator has been interested in low-cost alternative proton exchange membranes in a microbial fuel cell (MFC). In this study, the silica-modified ceramic separator has been integrated with the yeast-based MFC for electricity generation and phenol treatment from the winery wastewater. The 30% (w/w) silica powder was mixed with the 70% (w/w) natural clay. The modified ceramic plates (0.2, 0.5, and 1.0 cm of thickness) were prepared at 680°C and used for MFC operation. As an anolyte, synthetic winery wastewater (2,000 mg COD/L and 100 mg/L phenol) with 5% (v/v) ethanol was used. The ethanol-tolerant yeast Pichia sp. ET-KK was used as an anodic catalyst. The results showed the maximal power density of 0.212 W/m2 and phenol removal of 95.05% were reached from the 0.2-thick ceramic plate integrated MFC. This study demonstrated that the silica-modified ceramic separator has a high potential for enhancing electricity generation in the yeast-based MFC.

The production of Volatile Fatty Acids (VFAs) from wastewater holds significant importance in the context of biorefinery concepts due to their potential as valuable precursors for various bio-based processes. Therefore, the primary objective of this research is to investigate the fermentation of Winery Wastewater (WW) in an Upflow Anaerobic Sludge Blanket (UASB) reactor to generate VFAs, with particular emphasis on Caproic Acid (HCa) production and the dynamics of the microbiota, under varying Hydraulic Retention Time (HRT) periods (8, 5, and 2.5 h). The change from an 8 h to a 5 h HRT period resulted in an approximately 20% increase in total VFA production. However, when the HRT was further reduced to 2.5 h, total VFA production decreased by approximately 50%. Concerning the specific production of HCa, expressed in grams of Chemical Oxygen Demand (gCOD), the maximum yield was observed at around 0.9 gCOD/L for a 5-h HRT. Microbial population analysis revealed that Eubacteria outnumbered Archaea across all HRTs. Population dynamics analysis indicated that the Firmicutes Phylum was predominant in all cases. Within this phylum, bacteria such as Clostridium kluyveri and Clostridium sp., known for their ability to produce HCa, were identified. Based on the results obtained, the application of the UASB reactor for WW treatment, within the biorefinery framework, has the potential to provide a practical alternative for HCa production when operated with a 5 h HRT.

Acidic effluent such as winery wastewater is challenging to remediate. Biological sand reactors can simultaneously remove organics and neutralize winery wastewater via biotic and abiotic mechanisms. The systems have been shown to be suitable for treating the intermittent flow of wastewater at small wineries. It has been shown that dissolution of calcite is the most important abiotic mechanism for increasing the pH of the influent. In this study, sand column experiments were used to determine the effects of (i) sand particle size distribution on calcite dissolution kinetics, and (ii) the effects of calcite particle dissolution on the hydraulic conductivity. The results were then used to calculate the theoretical temporal abiotic neutralization capacity of biological sand reactors with differently sized sand fractions, including unfractionated (raw) sand. The results were compared with those determined from a pilot system treating winery wastewater over a period of 3 years. Sand fractions with larger particles contained lower amounts of calcite (using Ca as a proxy), but exhibited higher hydraulic conductivities (3.0 ± 0.05 %Ca and 2.57 to 2.75 mm·s−1, respectively) than those containing smaller particles and/or raw sand (4.8 ± 0.04 to 6.8 ± 0.03 %Ca and 0.19 to 1.25 mm·s−1, respectively). The theoretical abiotic neutralization capacity of biological sand reactors was compared with a pilot system with the same flow rates, and a temporal abiotic neutralization capacity of 37 years was calculated for biological sand reactors, which compared favorably with the theoretical results obtained for wastewater with pH values between 2 (8.2 years) and 3 (82 years). It was concluded that biological sand filters with around 10% calcite will be able to abiotically neutralize winery wastewater and other wastewaters with similar acidities for the projected life span of the system. Future work should focus on determining the effect of sand grain size on the bioremediation capacity, as well as the use of biological sand reactors for treating other acidic organic wastewaters such as fruit processing, food production and distillery wastewater. [ABSTRACT FROM AUTHOR]

The removal of dissolved organic carbon (DOC) and total polyphenols (TPh) from agro-industrial wastewater was evaluated via the application of coagulation–flocculation–decantation (CFD) and Fenton-based processes. For the CFD process, an organic coagulant based on Acacia dealbata Link. leaf powder (LP) was applied. The results showed that the application of the LP at pH 3.0, with an LP:DOC ratio of 0.5:1 (w/w), achieved a high removal of turbidity, total suspended solids (TSS), and volatile suspended solids (VSS) of 84.7, 79.1, and 76.6%, respectively. The CFD sludge was recycled as fertilizer in plant culture (germination index ≥ 80%). Afterwards, the direct application of Fenton-based processes to raw WW was assessed. The Fenton-based processes (UV/Fenton, UV/Fenton-like, and heterogeneous UV/Fenton) showed high energy efficiency and a cost of 1.29, 1.31 and 1.82 €/g/L DOC removal, respectively. The combination of both processes showed the near complete removal of TPh and DOC after 240 min of reaction time, with high energy efficiency. In accordance with the results obtained, the combination of CFD with Fenton-based processes achieves the legal limits for the disposal of water into the environment, thus allowing the water to be recycled for irrigation. [ABSTRACT FROM AUTHOR]

• Co-digestion of winery wastewater (WW) with Sewage sludge (SS) produced a higher methane yield than digesting SS alone. • With the higher proportion of WW (80% vol WW), the accumulation of butyrate synergistically with acetate occurred. • Co-digestion improves hydrolysis rates, buffering capacity, and reduces volatile fatty acid accumulation by using complementary feedstocks. • Co-digestion of WW with SS enriches specific electroactive bacteria, facilitating the establishment of the Direct Interspecies Electron Transfer (DIET) pathway and enhancing system stability. Combining winery wastewater (WW) with sewage sludge (SS) in anaerobic co-digestion (AcoD) presents a promising approach for effective waste management and enhanced energy recovery. This study aimed to evaluate the efficiency and changes in microbial communities during the AcoD of WW with SS at 35 °C, using a mix of batch and semi-continuous testing methods. In the batch experiments, the highest hydrolysis rate (0.19 day−1) and methane production (285.61 ± 4.83 mL/g VS) were achieved at a WW:SS ratio of 3:2, exceeding those of SS mono-digestion by 126 % and 113 %, respectively. Furthermore, the semi-continuous experiments revealed a significant 30.0 % boost in the electron transport system activity and a notable 25.8 % increase in coenzyme F420 activity within the AcoD of WW with SS. Microbial analysis illustrated that AcoD of WW with SS significantly enriched the prevalence of potential genera associated with direct interspecies electron transfer (DIET), such as Longilinea , Bellilinea (genus of Chloroflexi), Syntrophomonas , Pseudomonas , Methanosarcina , and Methanobacterium species. Additionally, semi-continuous experiments demonstrated that AcoD facilitated interspecies hydrogen transfer between syntrophic bacteria and hydrogenotrophic methanogens, resulting in increased methane yield. Co-digestion of WW with SS is a more economical strategy that significantly enhances the stability of microbial communities through the use of complementary feedstocks. These results may offer valuable guidance for the efficient resource utilization of co-digestion processes involving WW and SS. [ABSTRACT FROM AUTHOR]

This study proposes liquid-liquid extraction (LLE) for the recovery of phenolic acids from winery wastewater replacing common volatile organic compounds (VOCs) with environmentally friendly solvents. On one hand, terpenes (α-pinene and p-cymene) and terpenoids (eucalyptol and linalool) were selected as green solvents and compared to common VOCs (ethyl acetate or 1-butanol). On the other hand, gallic acid (GA), vanillic acid (VA), syringic acid (SA) and caffeic acid (CA) were selected as phenolic acids to be recovered. The extraction performance was evaluated under different operation conditions: solvent-to-feed ratio, initial concentration of phenolic acids and temperature. This work also evaluated the back-extraction whole process global recovery and solvent regeneration, by means of aqueous NaOH solution. Eucalyptol has shown the highest overall global extraction performance (21.07 % for GA, 93.21 % for VA, 78.79 % for SA, and 80.57 % for CA) and lower water solubility compared to the best performing VOC solvent (1-butanol). Therefore, eucalyptol can be a potential eco-friendly solvent to replace VOCs for sustainable phenolic acid recovery from winery wastewater. Finally, to ensure a clean water stream after the LLE, the traces of solvent were completely removed by electrooxidation with boron-doped diamond anode at a current density of 422.54 A/m2. [Display omitted] • Phenolic acids contained in wastewater are recovered by liquid-liquid extraction. • The use of conventional and bio-based solvents is compared. • The influence of crucial parameters in recovery performance is assessed. • Solvent regeneration and phenolic acids back-extraction are verified. • Solvent traces removal from the wastewater is achieved by electrooxidation. [ABSTRACT FROM AUTHOR]

The present study demonstrates the feasibility of a two-phase biorefinery process applied to waste substrates producing ethanol rich effluents. The process includes a dark fermentation step followed by photo fermentation and it is able to optimize hydrogen production from waste biomass. The study was conducted using winery wastewater as feedstock. The results indicate that no additional treatments are required when an appropriate dilution of the initial waste is applied. Microbial consortia contained in the winery wastewater promoted a fermentative ethanol pathway. The ethanol rich effluent was converted into hydrogen by phototrophic microorganisms. Despite the presence of inhibiting compounds, the adoption of a mixed phototrophic culture allowed to obtain good results in terms of hydrogen production. Specifically, up to 310 mLH 2 gCOD consumed −1 were obtained in the photo fermentative stage. The effectiveness of ethanol rich dark fermentation effluents for hydrogen production enhancement was demonstrated. Noteworthy, polyhydroxybutyrate was also produced during the experiments. The work faces two of the major challenges in the sequential dark fermentation and photo fermentation technology applied to real waste substrates: the minimization of pre-treatments and the enhancement of the hydrogen production yields using ethanol rich DFEs. [Display omitted] • A dark-photo fermentation process for winery wastewater treatment is proposed. • Indigenous cultures of winery wastewater promote the ethanol production pathway. • Dark fermentation intermediates define the photo fermentative hydrogen yield. • Ethanol rich dark fermentation effluents are effective substrates for PNSB. • Use of mixed PNSB cultures is beneficial to reduce pre-treatments. [ABSTRACT FROM AUTHOR]

Aims: The use of microbial fuel cells (MFC) to treat winery wastewater is promising; however, an initial acidic pH, fluctuating chemical oxygen demand (COD) levels and a lack of natural buffering in these wastewaters make providing a suitable buffer system at an ideal buffer to COD ratio. Methods and Results: A lab scale MFC was designed, inoculated with anaerobic winery sludge and fed with synthetic winery wastewater. It was observed that at pH 6·5, the MFC performed best, the maximum output voltage was 0·63 ± 0·01 V for 60 ± 3 h, and the COD removal efficiency reached 77 ± 7%. The electrogens were affected by pH much more than the bulk COD degrading organisms. Fluorescent in situ hybridization suggested Betaproteobacteria played a significant role in electron transfer. Conclusions: A ratio of 1 mmol l−1 phosphate buffer to 100 mg l−1 COD was ideal to maintain a stable pH for MFCs treating synthetic winery wastewater. Significance and Impact of the Study: The results find the narrow pH tolerance for MFCs treating winery wastewater and demonstrate the significance of pH and buffer to COD ratio for steady performance of MFCs. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fly ash is an important source of trace elements that can act as cofactors of enzyme systems and improve anaerobic digestion processes. However, its effect on anaerobic digestion using real wastewater has not yet been studied. In the present work, the effect of fly ash on the anaerobic digestion of real winery wastewaters was studied, by means of specific methanogenic activity assays and with a special focus on its effect on the specific methane production and the microbial communities present. Five fly ash concentration (25, 50, 75, 100, and 150 mg L−1) were supplemented under mesophilic conditions. RESULTS: The results showed that 25 mg L−1 of fly ash improved the specific methane production by 18% compared to the control assay; meanwhile, a concentration of 100 mg L−1 of fly ash generated inhibition of the methanogenesis and a 20% specific methane production decrease with respect to the control experiment. The microbial community analysis verified that fly ash supplementation affected the bacterial communities, with a significant effect on acetogenic bacteria, such as Cloacimonetes and Firmicutes. CONCLUSION: The addition of adequate concentrations of fly ash to the process can raise the relative abundance of some microorganisms and, consequently, could increase the specific methane production in the anaerobic digestion of winery wastewater. © 2021 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Winemaking is a water‐intensive operation; it is estimated that 70% of the water input is downgraded, mainly via cleaning processes, to wastewater. The quality and the quantity of the waste effluents vary considerably due to the seasonal operation of wineries and the diversity of winemaking technologies applied. High organic load, acidic pH, significant polyphenolic content, and residual concentration of phytosanitary products are included among the main characteristics of winery wastewater (WiWW). Discharge of untreated or partially treated WiWW into watercourses or land poses high environmental risks. To this end, biological oxidation has been thoroughly studied for the treatment of WiWW yielding up to 95% reduction of chemical oxygen demand (COD) at a low cost and in an environmentally benign manner. Biological treatment, however, cannot provide a barrier to the slip of bio‐recalcitrant compounds present in WiWW, such as phenols and pesticides, into the environment. The release of these compounds raises serious concerns over ecological well‐being due to their toxicity and endocrine‐disrupting effects. Sustainable post‐treatment technologies are sought, able of breaking down the bio‐recalcitrant fraction of WiWW to harmless products without stressing the environmental resources. Advanced oxidation processes (AOPs) can offer a sound technological solution towards the integrated WiWW treatment. This paper presents an up‐to‐date overview of the AOPs (TiO2‐, sulfate radical‐, Fe‐, ozone‐based AOPs, and wet oxidation processes) that have been studied for the treatment of WiWW, remarks the most efficient ones, and identifies research areas and concepts aiming towards process sustainability and, ultimately, actual application. © 2021 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The removal of dissolved organic carbon (DOC) and total polyphenols (TPh) from agro-industrial wastewater was evaluated via the application of coagulation–flocculation–decantation (CFD) and Fenton-based processes. For the CFD process, an organic coagulant based on Acacia dealbata Link. leaf powder (LP) was applied. The results showed that the application of the LP at pH 3.0, with an LP:DOC ratio of 0.5:1 (w/w), achieved a high removal of turbidity, total suspended solids (TSS), and volatile suspended solids (VSS) of 84.7, 79.1, and 76.6%, respectively. The CFD sludge was recycled as fertilizer in plant culture (germination index ≥ 80%). Afterwards, the direct application of Fenton-based processes to raw WW was assessed. The Fenton-based processes (UV/Fenton, UV/Fenton-like, and heterogeneous UV/Fenton) showed high energy efficiency and a cost of 1.29, 1.31 and 1.82 €/g/L DOC removal, respectively. The combination of both processes showed the near complete removal of TPh and DOC after 240 min of reaction time, with high energy efficiency. In accordance with the results obtained, the combination of CFD with Fenton-based processes achieves the legal limits for the disposal of water into the environment, thus allowing the water to be recycled for irrigation.

Three methodologies for the calculation of the methane production rate (MPR) were evaluated using an acidogenic effluent of a two-stage process for methane production. A simple method to evaluate the MPR was presented. The MPR was evaluated under different initial substrate concentrations (5, 10, and 15 g L−1), temperatures (35 and 55 °C), and adaptation periods of the thermophilic inoculum. Different patterns of methane were observed for the MPR. The mesophilic sludge degraded the substrate with high initial rates, whereas a thermophilic sludge, acclimated for 226 days, produced the maximal rate after 70 h. This behavior agrees with the different microbial communities observed for each inoculum. The proposed methodology, measuring the instantaneous rates from cumulative methane production, was accurate and straightforward to calculate the MPR independently of the different patterns generated due to the inocula tested. [ABSTRACT FROM AUTHOR]

Background and Aims: Optimising the treatment and reuse of winery wastewater (WWW) can have positive environmental significance. Estimating the concentration of various organic compounds, nutrients, and metals via correlations with easily determined parameters could provide a rapid and cost‐effective method of characterising WWW and allow real‐time process adjustments to optimise the process performance. Methods and Results: A total of 367 samples of WWW collected in the Niagara Region, Ontario, Canada, were analysed for pH, electrical conductivity, solids fractions, oxidisable materials, nutrients and metals. The data were subjected to least and median squares regression. Conclusions: Robust correlations were developed between pH, electrical conductivity, total solids, total volatile solids and total suspended solids; and key measures of organic and nutrient loadings to wastewater treatment trains, including chemical oxygen demand, 5‐day biochemical oxygen demand, total Kjeldahl nitrogen and total phosphorus. The ability to predict metal concentration was more limited. Least median squares regression was used to identify potential outliers and to improve the fit of the equations (adjusted R2 as high as 0.95). Significance of the Study: The correlations provide a promising, rapid and cost‐effective means of characterising WWW in the Niagara Region. This approach could also be used to develop relationships specific to other winemaking regions. [ABSTRACT FROM AUTHOR]

BACKGROUND The term 'grape (Vitis vinifera) water' refers to a by‐product from the cryoconcentration of must that, if not reclaimed, would be considered as wastewater. In this study, the nutraceutical potential of waters reclaimed from the cryoconcentration of Grillo and Moscato musts was evaluated. RESULTS: Both waters showed physicochemical parameters in agreement with Italian regulation for drinking water, and interesting levels of F− (3.02–8.02 mg L−1) and SO4− (52.85–49.34 mg L−1). Inorganic elements, including Mg (5.54–7.78 mg L−1), K (47.12–59.87 mg L−1), Fe (219.09–205.32 μg L−1), and Zn (189.65–127.30 μg L−1), and phenolic contents <35 mg GAE L−1 contributed to determine moderate antioxidant activities. Considering fatty acid composition, oleic and linoleic acids predominated, being higher in Moscato than Grillo samples (64.42% versus 58.22%, and 5.42% versus 6.07%). Grape waters displayed also rich aroma profiles, including mainly esters, alcohols and terpenoids. The latter components (i.e. linalool and α‐terpineol) were more abundant in Moscato than in Grillo (13% versus 8%). Interestingly, some minor volatiles, characterized the vine of provenance (e.g. benzaldehyde and 3‐methylbutylacetate in Moscato). All grape waters showed also a considerable fraction of ethyl lactate, six‐carbon compounds and acetates, reflecting the proximity of samples to the grapes of origin. CONCLUSION: In a growing scenario of environmental decay and resource depletion, results from this study support an innovative and profitable waste recycling strategy for the wine industry. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Solar energy exploitation is one of the most challenging applications for sustainable energy production. In this work a photoactivated fuel cell was developed, using visible light and the Fe(III)/Fe(II) redox couple for the simultaneous production of electrical energy and oxidation of polluting organics (alcohols) contained in synthetic and real wastewaters. WO 3 was selected as a cheap and environmentally friendly photocatalyst more efficient than TiO 2 (i) under visible light irradiation and (ii) in the presence of in-situ photodeposited Pd. Pd photodeposition was found to reduce the band gap of bare WO 3 , thus increasing visible light capture and limiting the occurrence of photogenerated hole/electron recombination. Higher photocatalytic performances were recorded over WO 3 –Pd compared to TiO 2 and bare WO 3 , despite the low BET superficial area of WO 3 –Pd (2.34 m2 g−1). Optimal conditions were identified at pH = 2.0 with 2% w/w Pd load. The results also evidenced the influence of the selected sacrificial organics and water matrices. A quantum yield of 84.89% and an energy efficiency of 4.15% were the best results achieved so far for the proposed system. The present photoelectrochemical cell offers a very promising system for electrical energy production by using wastewater from wine manufacturing industry and solar light radiation. Image 1 • A low-priced WO 3 -based fuel cell was developed exploiting visible light. • In situ photodeposited Pd was demonstrated to enhance the catalytic efficiency of WO 3. • Real and synthetic alcohol-containing matrices were used in the process. • A variety of techniques were used to characterize the adopted materials. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fermentative hydrogen production has an inherent limitation caused by hydrogen‐consuming metabolic pathways such as homoacetogenesis related to high hydrogen partial pressures. In this study, a strategy based on recirculating the headspace gas was applied to increase the hydrogen release from the liquid to the gas phase in an upflow anaerobic sludge blanket(UASB) reactor fed with winery effluents. The influence of the gas upflow recirculation velocity on hydrogen production, hydrogen consumption by homoacetogenesis, and microbial community structure was evaluated. RESULTS: Under the control condition (only liquid recirculation), the hydrogen productivity was as much as 22 mL H2 L−1 h−1. Conversely, the hydrogen productivity increased up to 62 mL H2 L−1 h−1 when the reactor was operated with an upflow gas recirculation velocity of 28.6 m d−1. The increase in mass transfer, due to the gas recirculation, produces a decrease (up to 70%) in the hydrogen consumption rate associated with homoacetogenesis. High‐throughput 16s rDNA sequencing characterization showed that the gas recirculation strategy promoted the development of hydrogen‐producing microorganisms related to Megasphaera elsdenii and decreased the abundance of hydrogen‐consuming bacteria related to Clostridium carboxidivorans and C. ljungdahlii. CONCLUSION: The results indicated that headspace recirculation at gas upflow velocities higher than 17.8 m d−1 increased the hydrogen production rate concomitantly with the reduction of both the homoacetogenic activity and the abundance of H2‐consuming bacteria. The study demonstrated that headspace recirculation could be a promising way to control homoacetogenesis, and therefore, to increase the biohydrogen productivity from complex substrates such as winery effluents. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Wastewater produced during the wine-making process often contains an order of magnitude greater chemical oxygen demand (COD) concentration than is typical of domestic wastewater. This waste stream is also highly variable in flow and composition due to the seasonality of wine-making. The recent growth of small-scale wineries in cold climates and increasing regulations present a need for low-cost, easily-operable treatment systems that do not require large amounts of land, yet maintain a high level of treatment in cool temperatures. This research investigates the use of a subsurface vertical flow constructed wetland (SVFCW) to treat winery wastewater. In this study, clinoptilolite, tire chips, and a nano-enhanced iron foam were used to enhance bench-scale gravel cells to adsorb ammonia, nitrate, and phosphorus, respectively. The treatment systems, without nitrogen adsorption media, performed well, with >99% removal of COD and 94% removal of total nitrogen. Treatment systems with the nitrogen adsorption media did not enhance nitrogen removal. Equilibrium was reached within two weeks of start-up, regardless of prior inoculation, which suggests that microbes present in the winery wastewater are sufficient for the start-up of the wastewater treatment system; therefore, the seasonality of winery wastewater production will not substantially impact treatment. Operating the treatment systems under cool temperatures did not significantly impact COD or total nitrogen removal. Further, the use of nano-enhanced iron foam exhibited 99.8% removal of phosphorus, which resulted in effluent concentrations that were below 0.102 mg/L P. [ABSTRACT FROM AUTHOR]

The objective of this work was to determine the ability of a pilot-scale hybrid system to treat real (non-synthetic) winery wastewater. The experimental treatment system consisted of two stages: An attached growth pilot-scale bioreactor (biological trickling filter with plastic support material) was initially used to remove a significant amount of dissolved chemical oxygen demand (d-COD) from winery wastewater, and then a pilot-scale, horizontal subsurface flow constructed wetland (CW) was examined as a post-treatment step for further d-COD removal. Results from the biofilter revealed that the recirculation rate of 1.0 L/min lead to higher d-COD removal rates than that of 0.5 L/min for all feed d-COD concentrations tested (3500, 7500, 9000 and 18,000 mg d-COD/L). Experiments in the CW were performed using feed d-COD concentrations of about 1500 mg/L (equivalent to biofilter effluent when initial filter feed d-COD concentrations are 18,000 mg/L). The wetland polishing stage managed to further remove d-COD and produced effluent concentrations below current legislation limits for safe disposal. Furthermore, the presence of zeolite in CW (one third of the length of CW) enhanced ammonium removal. The experimental results indicate that the combination of a biological trickling filter and a constructed wetland could effectively treat effluents originating from small wineries typical of the Mediterranean region. [ABSTRACT FROM AUTHOR]

Nature-based solutions, such as ConstructedWetlands (CWs), for the treatment of industrial wastewater can be more efficiently operated making use of online monitored parameters as inlet/outlet flows and concentrations for specific substances. The present study compares different datasets acquired in a two-and-a-half-year-long period by normal laboratory methods and also from a specific COD/BOD sensor installed at a winery CWs wastewater treatment plant in Tuscany, Italy. The CW wastewater treatment plant (WWTP) is composed of: equalization tank (70 m³); French Reed Bed (1200 M²); horizontal subsurface flow (HF) CW (960 M²): free water system (850 M²); optional post-treatment sand filter (50 M²); and emergency recirculation. The obtained average performances for this last period are for COD 97.5%, for MBAS 93.1%, for N-NO2-84.7%, for NO3-39.9%, and for TP 45.5%. The online sensor has shown excellent performance in following the COD concentration patterns along the observed period. The qualitative and quantitative validity of the online sensor measurements has been assessed by statistical analysis (t-test) and reported in the paper. Online data, acquired every 30 min, availability is of extreme importance for the CW system performance optimization, for understanding the behavior of theWWTPin different operative scenarios, and finally for driving the powering on or off eventual process enhancement tools. [ABSTRACT FROM AUTHOR]

A pot trial was conducted to assess the effect of simulated rainfall on six soils with different textures, irrigated with winery wastewater diluted to a chemical oxygen demand (COD) level of 3000 mg/L over one simulated irrigation season. Thereafter, simulated winter rainfall was applied to the pots. The rainfall was simulated according to the long term averages of the regions where the soils originated. Leaching of cations, particularly K+ and Na+ occurred only from four of the six soils when winter rainfall was simulated. In one of the sandy soils, the simulated rainfall was too low to allow leaching. In another soil, high clay content of 35% in combination with low rainfall prevented leaching. In three soils that received the same amount of rainfall, more cations leached from the duplex sandy soil compared to the two other soils. These trends indicated that leaching of cations was a function of soil texture and rainfall. The study showed that in regions with low rainfall, irrigation with winery wastewater would lead to the accumulation of cations thereby increasing soil salinity. The study confirmed that for sustainable use of winery wastewater irrigation in agriculture, different soil types will require individual management in order to avoid or minimize the negative environmental impact on natural resources by wastewater irrigation. [ABSTRACT FROM AUTHOR]

In this study, the xanthan biosynthesis by Xanthomonas campestris ATCC 13951 is presented as a sustainable solution for winery wastewater utilisation. To improve examined biotechnological process, optimisation of temperature, aeration rate and agitation speed for xanthan production in stirred tank bioreactor was carried out. Experimental design methodology and statistical approaches were used to define mathematical models which describe the individual and interactive effects of varied parameters on the xanthan biosynthesis and to optimise their values. The optimal conditions for the most profitable xanthan production on winery wastewater based medium with 30g/L sugar were found to be temperature of 29.34 °C, air flow rate of 1.95 vvm and agitation speed of 475.50rpm. Performing bioprocess under these conditions resulted in accumulation of large quantity of good-quality xanthan (23.85 g/L) and achievement of significant purification levels of winery effluents which is confirmed by high values of sugar, nitrogen and phosphorus conversion (90.79%, 71.74% and 83.14%, respectively). The present study provides valuable information about efficacy of winery wastewater utilisation under different operational conditions that can be used for bioprocess scale up and design of bioreactors with appropriate constructional characteristics, which is a prerequisite of the industrialization of examined bioprocess. [ABSTRACT FROM AUTHOR]

Wine production is one of the leading sectors of the food processing industry. The wine industry produces a large amount of wastewater characterized by a high strength in terms of organic pollution and large variability throughout the year. Most of the organic matter is soluble and easily biodegradable. On the other hand, nitrogen and phosphorous are lacking. The aerobic and anaerobic processes are largely applied for winery wastewater treatment because they can quickly react to changes in the organic loading. This review analyzes e applied biological systems, considering both aerobic and anaerobic processes, and different reactor configurations. The performances of different biological processes are evaluated in terms of operational conditions (organic loading rate and hydraulic retention time). Aerobic processes can guarantee chemical oxygen demand removal up to 98% for organic loading rates of some 1-2 kg of chemical oxygen demand m−3d−1 but requires good aeration systems to supply the required process oxygen. The management cost of these processes could be high considering the power density in the range 60-70 W m−3reactor and that nutrients should be added to support biomass growth. On the other hand, anaerobic processes are able to face high organic loads with low running costs, but COD removal is generally limited to 90%. Combination of the two treatment systems (anaerobic followed by aerobic) could reduce management costs and meet high discharge standards. [ABSTRACT FROM AUTHOR]

Abstract A Life Cycle Assessment was carried out in order to assess the environmental performance of constructed wetland systems for winery wastewater treatment. In particular, six scenarios which included the most common winery wastewater treatment and management options in South-Western Europe, namely third-party management and activated sludge systems, were compared. Results showed that the constructed wetland scenarios were the most environmentally friendly alternatives, while the third-party management was the worst scenario followed by the activated sludge systems. Specifically, the potential environmental impacts of the constructed wetlands scenarios were 1.5–180 and 1–10 times lower compared to those generated by the third-party and activated sludge scenarios, respectively. Thus, under the considered circumstances, constructed wetlands showed to be an environmentally friendly technology which helps reducing environmental impacts associated with winery wastewater treatment by treating winery waste on-site with low energy and chemicals consumption. Graphical abstract Unlabelled Image Highlights • A Life Cycle Assessment of winery wastewater treatment was performed. • Constructed wetlands, third-party management and activated sludge were considered. • Constructed wetlands showed to be the most environmentally friendly solution. • Environmental impacts of constructed wetlands were up to 180 times lower. [ABSTRACT FROM AUTHOR]

Abstract Winery wastewater generated during vinification is often co-treated with the municipal wastewater at the biological sections of the municipal wastewater treatment plants prior to its discharge into the environment, and the grey water footprint associated with these discharges are often neglected from water footprint assessments of the wine-making process. This study presents a method for assessing the grey water footprint associated with winery wastewater co-treated with the municipal wastewater at municipal wastewater treatment plants. The applicability of this method is illustrated with a case study for the Niagara Region of Ontario, Canada. The total grey water footprint of treated winery wastewater effluents discharged to surface waters was determined to be 1.47 × 107 m3/yr. Co-treatment substantially decreased the grey water footprint compared to that of the untreated winery wastewater (99.3% reduction). However, the co-treated winery wastewater still exerts a substantial grey water footprint equivalent to over 960 times its total average annual volume and should not, therefore, be excluded from a water footprint assessment of wine-making processes. The grey water footprint is very sensitive to changes in the assumed values of background concentration and maximum allowable parameter concentrations in the surface water receiver, and varies significantly for each parameter of concern. Accounting for variations in background concentration of the receiver, Lake Ontario, Canada, between the discharge locations of the individual wastewater treatment plants increased the calculated grey water footprint by an order of magnitude. An understanding of the variations in receiver water quality should be considered as a part of a grey water footprint analysis that combines the footprints of multiple effluent streams. Highlights • Grey water footprint assessments of treated winery wastewater effluents are missing in the literature. • Total grey water footprint of treated WWW discharged into surface water receivers was estimated for Niagara Region, Canada. • Co-treatment of winery wastewaters in municipal WWTPs reduced their grey water footprint. • Treated winery wastewater effluents that meet regulatory requirements still exert a substantial grey water footprint. • The grey water footprint of treated winery wastewater should not be excluded from water footprint assessments. [ABSTRACT FROM AUTHOR]

• Treatment of winery wastewaters by sulphate radical-based AOPs. • Thermal vs UV-assisted activation of persulphate. • Influence of temperature, UV, pH and transition metals in SR-AOPs. • Comparison between SR-AOPs and HR-AOPs. Winery wastewater is characterized by the presence of organic and inorganic contaminants with significant environmental impact if released without proper treatment. Thus, the application of sulphate radical-based advanced oxidation processes (SR-AOP) in winery wastewater treatment, with emphasis on the removal of organic matter, has been investigated. Several experiments were performed to assess the influence of temperature, UV-C radiation and transition metals in the thermal and photolytic/photocatalytic activation of sodium persulphate. COD removal was higher in the UV-C/S 2 O 8 2- process than in the heat/S 2 O 8 2- using an initial COD concentration of 600 mg O 2 L-1. After a reaction time of 90 min (at pH = 7.0), using 15 mM of S 2 O 8 2- driven by a UV-C lamp allowed achieving 59% of COD removal while the heat/S 2 O 8 2- process attained a removal of only 41%. Afterwards, combining the thermal activation with transition metals, and using the optimal operational conditions ([S 2 O 8 2-]/[Cu2+] = 1, pH = 7.0 and 90 min of reaction time), 61% of COD removal was obtained. Additional experiments with higher S 2 O 8 2- concentrations and longer reaction time led to 96% and 71% of COD and TOC removal, respectively. To attain this target was used 25 mM of S 2 O 8 2-, at pH 7.0 during a reaction time of 240 min. This removal rate proved to be higher than the achieved with hydroxyl radical-based advanced oxidation processes (HR-AOPs). Under the same optimal conditions, using 25 mM of H 2 O 2 achieved 22% of COD removal and UV-C/Fe2+/H 2 O 2 experiments obtained 48%. Overall, SR-AOP experiments, particularly UV-C assisted processes, have proven to be very effective in COD removal and can be seen as a promising technology to use in winery wastewater treatment. [ABSTRACT FROM AUTHOR]

In this work, both red and white winery wastewaters (WW) and olive mill wastewater (OMW) were submitted to a treatment by Fenton-based processes (FBPs). The main aim was to evaluate the most efficient and economic process. Initial tests, resorting to a batch reactor, demonstrated that UV-C/Fenton (λ = 254 nm) was the most effective process. Operational conditions such as pH, H 2 O 2 and Fe2+ concentrations revealed to have a superior influence within dissolved organic carbon (DOC) removal as well as regarding the reactor's energy consumption. As a means to prevent iron precipitation, the addition of nitrilotriacetic acid (NTA) was tested. With experimental conditions pH = 3.0, [H 2 O 2 ] = 194 mM, [Fe2+] = 1.0 mM, [NTA] = 1.0 mM, radiation UV-C (254 nm), time = 240 min, the kinetic rate related with DOC removal showed a k red WW = 0.0128 min−1 > k OMW = 0.0124 min−1 > k white WW = 0.0104 min−1 and both the WW and OMW achieved the Portuguese legal limit values for wastewater discharge. Furthermore, comparative experiments were performed in a semi-continuous reactor, being that the results put in evidence that the concentration of H 2 O 2 added and the flow rate of reagents' addition (F) had a significant effect on the efficiency of the reactor. Under an optimum experimental procedure pH = 3.0, [H 2 O 2 ] = 97 mM, [Fe2+] = 1.0 mM, [NTA] = 1.0 mM, radiation UV-C (254 nm), F = 1 mL min−1, time = 240 min, there were observed higher DOC removal kinetic rates (k OMW = 15.20 × 10−3 min−1 > k red WW = 11.64 × 10−3 min−1 > k white WW = 11.57 × 10−3 min−1) and a cost ranging between 0.0402 and 0.0419 €/g.DOC. These results showed that semi-continuous reactors have the potential to be applied to large scale treatments, with low reagents consumption and reduced energy requirements. [Display omitted] • Fenton-based processes are highly effective for organic matter reduction (79.7%). • Nitrilotriacetic acid reduced the precipitation of iron in batch and semi-continuous systems. • Semi-continuous consumed less H 2 O 2 (193.6 mM) than batch systems (73.6 mM). • Semi-continuous systems are energy and cost effective for wastewaters treatment. [ABSTRACT FROM AUTHOR]

In the Mediterranean region, climate change is likely to generate an increase in water demand and the deterioration of its quality. The adoption of precision viticulture and the best available techniques aiming at sustainable production, minimizing the impact on natural resources and reducing production costs, has therefore been a goal of winegrowers. In this work, the water footprint (WFP) in the wine sector was evaluated, from the vineyard to the bottle, through the implementation of a methodology based on field experiments and life cycle assessment (LCA) on two Portuguese case studies. Regarding direct water footprint, it ranged from 366 to 899 L/FU (0.75 L bottle), with green water being the most significant component, representing more than 50% of the overall water footprint. The approach used in the current study revealed that although more than 97.5% of the water footprint is associated with vineyard, the winery stage is responsible for more than 75% of the global warming potential indicator. A linear correlation between the carbon footprint and the indirect blue water footprint was also observed for both case studies. Climate change is expected to cause an earlier and prolonged water stress period, resulting in an increase of about 40% to 82% of blue WFP.

Wastewater produced during the wine-making process often contains an order of magnitude greater chemical oxygen demand (COD) concentration than is typical of domestic wastewater. This waste stream is also highly variable in flow and composition due to the seasonality of wine-making. The recent growth of small-scale wineries in cold climates and increasing regulations present a need for low-cost, easily-operable treatment systems that do not require large amounts of land, yet maintain a high level of treatment in cool temperatures. This research investigates the use of a subsurface vertical flow constructed wetland (SVFCW) to treat winery wastewater. In this study, clinoptilolite, tire chips, and a nano-enhanced iron foam were used to enhance bench-scale gravel cells to adsorb ammonia, nitrate, and phosphorus, respectively. The treatment systems, without nitrogen adsorption media, performed well, with >99% removal of COD and 94% removal of total nitrogen. Treatment systems with the nitrogen adsorption media did not enhance nitrogen removal. Equilibrium was reached within two weeks of start-up, regardless of prior inoculation, which suggests that microbes present in the winery wastewater are sufficient for the start-up of the wastewater treatment system; therefore, the seasonality of winery wastewater production will not substantially impact treatment. Operating the treatment systems under cool temperatures did not significantly impact COD or total nitrogen removal. Further, the use of nano-enhanced iron foam exhibited 99.8% removal of phosphorus, which resulted in effluent concentrations that were below 0.102 mg/L P.

Winery wastewaters are acidic effluents with high content of organic matter and nutrients. Different initial values of chemical oxygen demand (COD), ranging from 4 to 50 g L−1, were tested in batch assays to evaluate the fermentative hydrogen production followed by a methane production step. The influence of adding a typical nutrient solution for hydrogen production was investigated. Nutrients include N-NH4, Mg, Fe, Co, Mn, I, Ni, and Zn. The best hydrogen production potential was obtained at a COD of 50 g L−1 without nutrient addition. This condition produced 528 mL H2 L−1. At a COD ≥ 35 g L−1, tests with only WW had a hydrogen potential 1.6 to 1.9 times higher than did tests where nutrients were added. The use of added nutrients reduced the hydrogen production by producing additional reduced acids, such as propionate and valerate. In a second stage, biomethane potential was evaluated using the effluent of a selected condition from hydrogen production tests. The methane production reached values of 207 ± 2.2 mL CH4 g−1 COD at 10 g COD L−1. The COD affected the specific methane production. The results of this study demonstrated the potential of winery effluents as a substrate for sequential hydrogen and methane production to increase the energy recovery from this effluent, with a maximum energetic yield and productivity of 7.15 kJ gCOD−1 and 11.51 kJ d−1. [ABSTRACT FROM AUTHOR]

The effective removal of organics from winery wastewater was obtained in real residual effluents from the wine industry using anodic oxidation (AO). The effluent had an initial organic load of [COD] 0 of 3490 mg L −1 equal to [TOC] 0 of 1320 mg L −1 . In addition, more than 40 organic compounds were identified by means of GC-MS. Different density currents as well as the addition of electrolytes were tested during electrolysis. The results show the decay of [COD] t by 63.6% when no support electrolyte was added, whereas almost total mineralization and disinfection was reached after adding of 50 mM of sodium sulfate and sodium chloride and applying higher density currents. The presence of sulfate and chloride in large concentration favors the production of oxidants such as hydroxyl radicals and active chlorine species that react with organics in solution. Moreover, the addition of a supporting electrolyte to industrial wastewater increases conductivity, reduces cell potential and therefore, decreases the energy consumption of the AO process. [ABSTRACT FROM AUTHOR]