Olive Oil Mill Wastewater Research Articles

Long-Term Changes in Soil Properties According to Different Strategies of Ferti-irrigation with Olive Oil Mill Wastewater in Olive Groves of a Mediterranean Region

Long-Term Changes in Soil Properties According to Different Strategies of Ferti-irrigation with Olive Oil Mill Wastewater in Olive Groves of a Mediterranean Region

Exploring the potential use of chitosan derived from Hermetia illucens waste for olive oil mill wastewater treatment

Exploring the potential use of chitosan derived from Hermetia illucens waste for olive oil mill wastewater treatment

Influence of Oleacein, an Olive Oil and Olive Mill Wastewater Phenolic Compound, on Caenorhabditis elegans Longevity and Stress Resistance.

Oleacein, a bioactive compound of olive oil and olive mill wastewater, has one of the strongest antioxidant activities among olive phenolics. However, few reports explore the in vivo antioxidant activity of oleacein, with no clear identification of the biological pathway involved. Earlier studies have demonstrated a link between stress resistance, such as oxidative stress, and longevity. This study presents the effects of oleacein on Caenorhabditis elegans mean lifespan and stress resistance. A significant lifespan extension was observed with an increase of 20% mean lifespan at 5 µg/mL with a hormetic-like dose-dependent effect. DAF-16 and SIR-2.1 were involved in the effects of oleacein on the longevity of C. elegans, while the DAF-2 receptor was not involved. This study also shows the capacity of oleacein to significantly enhance C. elegans resistance to oxidative and thermal stress and allows a better understanding of the positive effects of olive phenolics on health.

Systematic screening for the biocatalytic hydration of fatty acids from different oily substrates by Elizabethkingia meningoseptica oleate hydratase through a Design-of-experiments approach

The edible plant oils production is associated with the release of different types of by-products. The latter represent cheap and available substrates to produce valuable compounds, such as flavours and fragrances, biologically active compounds and bio-based polymers. Elizabethkingia meningoseptica Oleate hydratases (Em_OhyA) can selectively catalyze the conversion of unsaturated fatty acids, specifically oleic acid, into hydroxy fatty acids, which find different industrial applications. In this study, Design-of-experiment (DoE) strategy was used to screen and identify conditions for reaching high yields in the reaction carried out by Escherichia coli whole-cell carrying the recombinant enzyme Em_OhyA using Waste Cooking Oils (WCO)-derived free fatty acids (FFA) as substrate. The identified reaction conditions for high oleic acid conversion were also tested on untreated triglycerides-containing substrates, such as pomace oil, sunflower oil, olive oil and oil mill wastewater (OMW), combining the triglyceride hydrolysis by the lipase from Candida rugosa and the E. coli whole-cell containing Em_OhyA for the production of hydroxy fatty acids. When WCO, sunflower oil and OMW were used as substrate, the one-pot bioconversion led to an increase of oleic acid conversion compared to the standard reaction. This work highlights the efficiency of the DoE approach to screen and identify conditions for an enzymatic reaction for the production of industrially-relevant products.

Antilisterial activity of olive-derived polyphenols: an experimental study on meat preparations

Pork meat and processed pork products have been linked to multiple listeriosis outbreaks worldwide during the past years. Specifically, it has been highlighted that minced pork meat is easily perishable and may increase the growth of Listeria monocytogenes, which could be harmful to the general public's health. This study aimed to investigate the potential application of olive oil mill wastewater polyphenolic and red beet extracts as natural antimicrobial agents for L. monocytogenes growth control in burgers. The minced pork meat was mixed with the extracts and experimentally inoculated with L. monocytogenes, then molded into vacuum-packaged and cold-stored (4±1°C) burgers kept under alternating exposure to fluorescent light. The L. monocytogenes enumeration was performed on burgers at 0, 2, 5, and 10 days of shelf life. In uninoculated burgers, physicochemical (pH, water activity, color) and sensory determination (descriptive sensory analysis) were also conducted. At the end of storage, the samples treated with olive-derived extract showed the lowest value of L. monocytogenes (approximately 1.3 Log CFU/g). The physicochemical and sensory traits of burgers have benefited from the addition of both olive-derived and red beet extracts. Results suggest that olive mill wastewater polyphenolic extracts could be added to minced pork meat products to act as a natural antimicrobial agent.

Development of energy efficient flower-shaped defective TiO2 materials for wastewater remediation of agro-industries and oil refineries

Wastewater containing high concentrations of phenolic compounds (PhCs), produced in large quantities by the world's expanding agro-industries and oil refineries, is one of the main polluters of rivers and streams. It is economically and technically reasonable to treat such wastewater using TiO2-based photocatalysis. But in order for photocatalysis to be used on a large scale, it must degrade PhCs efficiently while using less electrical energy (EE) and treating them at lower costs (t-cost). In this study, a modified hydrothermal method was used to produce the flower-shaped defective black TiO2 (BTNFs) from pre-prepared black TiO2 nanoparticles (BTNPs) as an energy saving strategy in wastewater remediation. The adsorption and photocatalytic performance, energy needs, and t-costs for both materials were examined for photodegradation of PhCs from simulated oil refinery wastewater (ORW), palm oil mill wastewater (POW), and olive oil mill wastewater (OMW). The findings revealed that BTNFs have improved properties which made them more effective in adsorption of PhCs and photocatalyzing their degradation. Combining photocatalysis and adsorption based on BTNFs led to an improved removal (49.75–98.40%) of PhCs depending on the wastewater matrix and reduced the EE consumption and t-cost by 8.96–23.86% for treating OMW, POW, and ORW.

Study of the phytotoxicity of margines on Pistia stratiotes L.

Abstract The olive trituration activity is one of the most important industrial activities in Fez, Morocco. These effluents are highly loaded with organic, inorganic, and phenolic compounds without any preliminary treatment that affects water quality. In this sense, the waters of Oued Fez are deteriorating due to the discharge of wastewater from oil mills and the excessive proliferation of Pistia stratiotes L., an invasive macrophyte that represents a significant stress to the aquatic ecosystem, eutrophication, and a reduction in biodiversity. This ecological situation has prompted us to carry out phytotoxicity bioassays based on the detection of the lethal concentration of P. stratiotes in the wastewater from the olive oil mill to evaluate the sensitivity and tolerance of macrophytes to the different concentrations of total polyphenols (TPP) present in the olive mill wastewater. To estimate their impact on the environment. Fresh whole plants of P. stratiotes were exposed to varying concentrations of olive oil mill wastewater with a series of TPP concentrations (0–30 mg/l) for 1 week in the natural environment. The results also show that P. stratiotes is able to grow rapidly in culture with 20 mg/l of TPP; the highest growth of wet weight of P. stratiotes occurred at 20 mg/l treatment with an average of 13 g wet weight increase. At 0 mg/l, treatment is known to cause very slow growth with an average of 2 g. Olive oil mill wastewater was toxic to the plant at concentrations higher than 30 mg/l, and the phytotoxic effect was manifested by retardation of growth, detachment of roots, wilting, and chlorosis of leaves. This indicates that polyphenols have great potential to inhibit the proliferation of P. stratiotes in aquatic environments.

Tyrosol removal by photo–Fenton–like process using CaAlFe mixed oxides synthesized via hydrocalumite from aluminum salt cake

Solids with potential application in tyrosol (Ty) removal by photo–Fenton processes have been synthesized using aluminum salt cake as a source. Two series of hydrocalumite layered double hydroxides (LDH) were synthesized: one containing structural Fe3+ (occupying octahedral positions in the LDH) and another containing surface impregnated Fe3+; all solids were calcined in air at 750 °C. The solids were characterized by powder X–ray diffraction, FT–infrared spectroscopy, thermal analysis, N2 adsorption–desorption isotherms at –196 °C, particle size distribution and electron microscopy. One of the main differences between the two series was that Fe3+ impregnation by the incipient wetness method and subsequent calcination at 750 °C did not lead to the formation of CaAlFe mixed oxides. The calcined solids were evaluated as photocatalysts in the photo–Fenton process for Ty removal (a typical compound found in olive oil mill wastewater), the samples containing surface Fe3+ showing better results. The solid prepared by impregnation of hydrocalumite with 20% iron and subsequently calcined at 750°C, under the optimum reaction conditions (catalyst dose = 0.5 g/L, [H2O2] = 0.468 g/L and [Ty]0 = 100 mg/L, in the presence of UV light), reached complete Ty removal with contaminant mineralization of 95% after only 60 min reaction. The cyclic study showed that this sample maintained its stability after 3 cycles of reuse without iron leaching, and a better performance than other materials reported in the literature.

Valorizing Olive Oil Mill Wastewater: Transforming Waste into Natural Soaps

In this research, the main objective is to find a solution to the problem of olive mill wastewater (OMWW). This solution involves the recovery of liquid waste produced by the crushing units, which contain a significant amount of oily residues despite their initial treatment. The concept is based on separating these discharges into aqueous and oil phases and using the latter to manufacture natural soaps. The liquid waste from the extraction of olive oil has a significant content of oily residues, characterized by a very high acidity (2.73%), exceeding the value of edible olive oil, as well as a high saponification index (186.2 mg KOH/g), making it an ideal source of fat for saponification. The results of the valorization of the OMWW in soap manufacturing reveal several significant elements. First, following the characterization of cold and hot products, a clear preference emerges in favor of soaps made using the cold process. In addition, the production yield is notable, with a rate of 94% for cold saponification and 89.9% for hot saponification, highlighting the efficiency of the process. Finally, the study highlights the importance of the quantities of fatty acids used in the formulation of soaps. An optimal formula is identified, comprising 40% oils recovered from the OMWW, 30% olive oil, 20% cocoa oil, and 10% castor oil, demonstrating the need for a precise balance to obtain quality soaps. This study solves the problem of the OMWW by reusing them to make natural soaps, thus reducing industrial waste. It also opens up new economic opportunities by creating a profitable and environmentally responsible production chain, promoting the transition to a circular economy.

The impact of olive mill wastewater on soil properties, nutrient and heavy metal availability – A study case from Syrian vertisols

Olive oil mill wastewater (OMW) is an environmental concern in olive oil producers' regions due to its use in agricultural soils as an organic amendment. However, OMW can also be used as organic fertilizer due to their high organic matter and nutrient levels, but its use, when it occurs without environmental management, can cause serious environmental implications for soils and waters. This work evaluated the impact of different OMW levels on a set of physicochemical parameters from an agricultural vertisol where wheat grew (Triticum aestivum L var. Douma 1). A set of physicochemical parameters were conducted before adding different levels of OMW (0, 5, 10 and 15 L m−2) at two soil depths (0–30 and 30–60 cm) and for the two growing seasons to determine: i) the effect of OMW treatments on the studied physicochemical soil properties (bulk density, soil porosity, soil pH, electrical conductivity and organic matter), ii) available primary (N, P, K) and secondary macronutrients (Ca, Mg and Na), ii) micronutrients (Cu Fe, Mn and Zn), and iv) available heavy metals (Cd and Pb). The results indicated that soil physicochemical parameters were slightly improved, mainly due to improvement in organic matter, macro- and micronutrients, usually proportionally to the olive mill wastewater dose. Cadmium and Pb were within the permissible limits. The increased OMW had different behaviour on the soil nutritional balances of different elements, leading to nutrient imbalances, although in some cases, they were improved. However, the plant growth was not affected, and it was improved under 10 L m−2 and 15 L m−2 doses. The results offer valuable data about the use of OMW as organic fertilizer for crops and their potential impact on soil properties.

Bio-nanoremediation of olive oil mill wastewater by Alternaria alternata fungi coupled with Ag-doped TiO2 nanoparticles and its use as biofertilizer for cereal crops

Bio-nanoremediation of olive oil mill wastewater by Alternaria alternata fungi coupled with Ag-doped TiO2 nanoparticles and its use as biofertilizer for cereal crops

AQP7 as a Novel Marker of p-Cresol-Induced Renal Cell Damage: Beneficial Effects of Hydroxytyrosol and a Polyphenolic Enriched Complex Derived from Olive Oil Mill Wastewater

AQP7 as a Novel Marker of p-Cresol-Induced Renal Cell Damage: Beneficial Effects of Hydroxytyrosol and a Polyphenolic Enriched Complex Derived from Olive Oil Mill Wastewater

Performance of Rebars with Different Percentages of the Olive Oil Mill and Brine Wastewater in Terms of Bonding Stress and Strength

Performance of Rebars with Different Percentages of the Olive Oil Mill and Brine Wastewater in Terms of Bonding Stress and Strength

Valorization of Olive Mill Byproducts: Recovery of Biophenol Compounds and Application in Animal Feed.

This study aimed to recover the phenols from olive oil mill wastewater, a major pollutant of the oil industry, by using spray-drying technology to produce a new feed with a nutraceutical value for animal feed supplementation and to evaluate its effect on the productivity and nutritional quality of ewe milk. Forty-five Sarda ewes in late lactation (150 ± 2 d) and with homogeneous live weight (52 ± 1.5 kg) were randomly allotted into three groups and fed with three dietary treatments containing increasing levels of polyphenols: 0% (C), 0.1% (T0.1), and 0.2% (T0.2) of dry matter. No effect of the dietary treatments was found on the milk yield and composition. Interestingly, milk urea content (p < 0.0001) and somatic cell counts (p < 0.001) decreased as the level of polyphenols inclusion in the diet increased. The inclusion of phenols (0.2% of dry matter) in the diet of sheep was effective in increasing the vaccenic (C18:1 trans-11) and rumenic acid (C18: cis-9 trans-11) levels, which are beneficial for human health. Finally, the recovery of polyphenols via spray-drying technology and their incorporation into a new fortified feed can be a valid strategy for naturally improving the nutritional value of milk while valorizing an oil industry byproduct, reducing environmental impact, and promoting waste reuse that is in line with circular economy principles.

Moringa oleifera organic coagulant to eliminate pollution in olive oil mill wastewater

Wastewater from the olive oil mill (OMW) is an environmental hazard as it contains toxic and persistent compounds with significant organic load and high turbidity. The purpose of the present investigation is to assess the effectiveness of OMW treatment by flotation and coagulation procedure using Moringa oleifera. Physicochemical analysis of OMW showed high levels of the original chemical oxygen demand (COD) with a concentration of about 230.4 g/L, turbidity, and polyphenols with an initial concentration of around 5.4 g/L. After natural flotation, polyphenols, turbidity, and COD were reduced by 16.6%, 50%, and 31.2%, respectively. Turbidity, suspended solids, COD, polyphenols, and nitrates were all removed by natural flotation and coagulation by Moringa oleifera with percentages of about 83%, 74.5%, 57.6%, 65.6%, and 73.3%, respectively. Principal component correlation analysis between pollution removal parameters indicates that all variances are in the first component, with pH, nitrate, polyphenol, COD, and turbidity concentrations positively correlated. The proposed treatment process, which uses Moringa oleifera as a coagulant, can be applied in many industries due to its unique characteristics, including cheap cost and environmentally friendly approach.

Correction to: Bio-nano-remediation of Olive Oil Mill Wastewater using Silicon Dioxide Nanoparticles for Its Potential Use as Biofertilizer for Young Olive Plants

Correction to: Bio-nano-remediation of Olive Oil Mill Wastewater using Silicon Dioxide Nanoparticles for Its Potential Use as Biofertilizer for Young Olive Plants

Bio-nano-remediation of Olive Oil Mill Wastewater using Silicon Dioxide Nanoparticles for Its Potential Use as Biofertilizer for Young Olive Plants

Bio-nano-remediation of Olive Oil Mill Wastewater using Silicon Dioxide Nanoparticles for Its Potential Use as Biofertilizer for Young Olive Plants

Olive Oil Mill Waste-Water: An Approach to Valorize it as an Edible Film in Kashar Cheese Packaging

Olive Oil Mill Waste-Water: An Approach to Valorize it as an Edible Film in Kashar Cheese Packaging

Process simulation and techno-economic analysis of olive oil mill wastewater steam reforming

Olive oil production contributes to environmental deterioration, mainly due to the land spreading of the pollutant effluents. One solution to treat these liquid effluents (olive mill wastewater - OMWW) is the steam reforming (OMWWSR) reaction.In this work, the effects of the main parameters that affect the OMWWSR process were studied: composition of the effluent, total pressure, and temperature of the reformer; furthermore, several reactor configurations were simulated: traditional reactor (TR), autothermal reactor (ATR), sorption-enhanced reactor (SER), and sorption-enhanced autothermal reactor (SEATR). All reactor configurations treated an effluent flow rate of approximately 12 tons/h, which equals the quantity of OMWW produced by a big Portuguese olive oil producer company. In addition, energy integration and techno-economic analyses were elaborated to reveal which reactor configuration(s) presented the most attractive results. It was verified that the ATR and SER presented higher performances in terms of H2 production per kmol of OMWW fed and energy consumption per kmol of H2 produced. Finally, it was observed that the ATR achieved a net present value (NPV) that ranged from 7.2 to 9.2 M€ and payback times (PB) which ranged from 3 to 2 years. Regarding the SER configuration, the NPV and PB ranged from 4.7 to 12.2 M€ and 5-2 years, respectively.

Antimicrobial Activities of Olive Oil Mill Wastewater Extracts against Selected Microorganisms

Discovering eco-friendly alternatives to synthetic chemicals has become an increasingly popular area of research. Natural products are now in the spotlight for their potential use as replacements for synthetic chemicals. To maximize the benefits of these natural products, it is important to use efficient extraction methods, especially from agroindustrial waste. Olive oil mill wastewater (OOMW) is a byproduct of the olive oil production process and is considered a pollutant; however, OOMW contains a wide range of phenolic compounds that have proven antimicrobial properties. This study investigates the extraction of these compounds from OOMW, with the aim of determining their potential antimicrobial activities against several bacterial strains and fungi, including Bacillus spizizenii, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella aerogenes, Streptococcus uberis, Enterococcus faecalis, and Candida albicans. The OOMW extracts (OEs) were prepared by using three different solvents: ethyl acetate, ethanol, and methanol. The highest total phenolic contents (4.03 g, GAE/L) and the strongest antibacterial activity were obtained with methanol extraction. All OEs showed no antifungal activity against C. albicans. OEs, particularly methanol extracts of OOMW, can be used as bioactive substances in various industries as nutraceuticals and food ingredients, respectively.