Olive Mill Wastewater as Renewable Raw Materials to Generate High Added-Value Ingredients for Agro-Food Industries

Olive oil production represents an agro-industrial activity of vital economic importance for many Mediterranean countries. However, it is associated with the generation of a huge amount of by-products, both in solid and liquid forms, mainly constituted by olive mill wastewater, olive pomace, wood, leaves, and stones. Although for many years olive by-products have only been considered as a relevant environmental issue, in the last decades, numerous studies have deeply described their antioxidant, anti-inflammatory, immunomodulatory, analgesic, antimicrobial, antihypertensive, anticancer, anti-hyperglycemic activities. Therefore, the increasing interest in natural bioactive compounds represents a new challenge for olive mills. Studies have focused on optimizing methods to extract phenols from olive oil by-products for pharmaceutical or cosmetic applications and attempts have been made to describe microorganisms and metabolic activity involved in the treatment of such complex and variable by-products. However, few studies have investigated olive oil by-products in order to produce added-value ingredients and/or preservatives for food industries. This review provides an overview of the prospective of liquid olive oil by-products as a source of high nutritional value compounds to produce new functional additives or ingredients and to explore potential and future research opportunities.

Download Full-text

A focus on pressure-driven membrane technology in olive mill wastewater reclamation: state of the art

Water Science & Technology ◽

10.2166/wst.2012.506 ◽

2012 ◽

Vol 66 (12) ◽

pp. 2505-2516 ◽

Cited By ~ 15

Author(s):

J. M. Ochando-Pulido ◽

A. Martinez-Ferez

Keyword(s):

Olive Oil ◽

Large Scale ◽

Wastewater Treatment Plants ◽

Domestic Wastewater ◽

Olive Mill Wastewater ◽

Operating Conditions ◽

Added Value ◽

Wastewater Reclamation ◽

Starting Point ◽

Olive Mill

Direct disposal of the heavily polluted effluent from olive oil industry (olive mill wastewater, OMW) to the environment or to domestic wastewater treatment plants is actually prohibited in most countries, and conventional treatments are ineffective. Membranes are currently one of the most versatile technologies for environmental quality control. Notwithstanding, studies on OMW reclamation by membranes are still scarce, and fouling inhibition and prediction to improve large-scale membrane performance still remain unresolved. Consequently, adequately targeted pretreatment for the specific binomium membrane-feed, as well as optimized operating conditions for the proper membranes, is today's challenge to ensure threshold flux values. Several membrane materials, configurations and pore sizes have been elucidated, and also different pretreatments including sedimentation, centrifugation, biosorption, sieving, filtration and microfiltration, various types of flocculation as well as advance oxidation processes have been applied so far. Recovery of potential-value compounds, such as a variety of polyphenols highlighting oleuropein and hydroxytyrosol, has been attempted too. All this research should constitute the starting point to proceed with OMW purification beyond recycling for irrigation or depuration for sewer discharge, with the aim of complying with standards to reuse the effluent in the olive oil production process, together with cost-effective recovery of added-value compounds.

Download Full-text

Monitoring Olive Oil Mill Wastewater Disposal Sites Using Sentinel-2 and PlanetScopeSatellite Images: Case Studies in Tunisia and Greece

Agronomy ◽

10.3390/agronomy12010090 ◽

2021 ◽

Vol 12 (1) ◽

pp. 90

Author(s):

Wissal Issaoui ◽

Dimitrios D. Alexakis ◽

Imen Hamdi Nasr ◽

Athanasios V. Argyriou ◽

Evangelos Alevizos ◽

...

Keyword(s):

Olive Oil ◽

Satellite Images ◽

Vegetation Index ◽

Satellite Image ◽

Olive Mill Wastewater ◽

Support Vector ◽

Inorganic Particles ◽

Mediterranean Countries ◽

Sentinel 2 ◽

Olive Mill

Mediterranean countries are known worldwide for their significant contribution to olive oil production, which generates large amounts of olive mill wastewater (OMW) that degrades land and water environments near the disposal sites. OMW consists of organic substances with high concentrations of phenolic compounds along with inorganic particles. The aim of this study is to assess the effectiveness of satellite image analysis techniques using multispectral satellite data with high (PlanetScope, 3 × 3 m) and medium (Sentinel-2, 10 × 10 m) spatial resolution to detect Olive Mill Wastewater (OMW) disposal sites, both in the SidiBouzid region (Tunisia) and in the broader Rethymno region on the island of Crete, (Greece). Documentation of the sites was carried out by collecting spectral signatures of OMW at temporal periods. The study integrates the application of a variety of spectral vegetation indices (VIs), such as the Normalized Difference Vegetation Index (NDVI), in order to evaluate their efficiency in detecting OMW disposal areas. Furthermore, a set of image-processing methods was applied on satellite images to improve the monitoring of OMW ponds including the false-color composites (FCC), the Principal Component Analysis (PCA), and image fusion. Finally, different classification algorithms, such as the ISODATA, the maximum likelihood (ML), and the Support Vector Machine (SVM) were applied to both satellite images in order to assist in the overall approach to effectively detect the sites. The results obtained from different approaches were compared, evaluating the efficiency of Sentinel-2 and PlanetScope images to detect and monitor OMW disposal areas under different morphological environments.

Download Full-text

Olive Mill and Olive Pomace Evaporation Pond’s By-Products: Toxic Level Determination and Role of Indigenous Microbiota in Toxicity Alleviation

Applied Sciences ◽

10.3390/app11115131 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5131

Author(s):

Houda Ben Slama ◽

Ali Chenari Bouket ◽

Faizah N. Alenezi ◽

Ameur Khardani ◽

Lenka Luptakova ◽

...

Keyword(s):

Olive Oil ◽

Oil Extraction ◽

Soil Toxicity ◽

Mediterranean Countries ◽

Three Phase ◽

Indigenous Microbiota ◽

Recalcitrant Waste ◽

By Products ◽

Olive Mill

Diverse vegetable oils are extracted from oleagenic trees and plants all over the world. In particular, olive oil represents a strategic socio-economic branch in the Mediterranean countries. These countries use either two or three-phase olive oil extraction systems. In this work, we focus on the by-products from three-phase olive oil extraction, which are the liquid olive mill wastewater (OMW) and the solid olive mill pomace (OMP) rejected in evaporative ponds. The disposal of this recalcitrant waste poses environmental problems such as the death of different species of insects and animals. In-depth ICP-OES analysis of the heavy metal composition of OMW and OMP revealed the presence of many metals ranging from non-toxic to highly toxic. The LC-HRMS characterization of these by-products indicated the presence of several secondary metabolites harmful to humans or to the environment. Thus, we aimed to identify OMW and OMP indigenous microbiota through metagenomics. The bacterial population was dominated by the Acetobacter (49.7%), Gluconobacter (17.3%), Gortzia (13.7%) and Nardonalla (5.3%) genera. The most abundant fungal genera were Nakazawaea, Saccharomyces, Lachancea and Candida. These microbial genera are responsible for OMW, OMP and soil toxicity alleviation.

Download Full-text

Bioactive Compounds in Waste By-Products from Olive Oil Production: Applications and Structural Characterization by Mass Spectrometry Techniques

Foods ◽

10.3390/foods10061236 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1236

Author(s):

Ramona Abbattista ◽

Giovanni Ventura ◽

Cosima Damiana Calvano ◽

Tommaso R. I. Cataldi ◽

Ilario Losito

Keyword(s):

Mass Spectrometry ◽

Olive Oil ◽

Bioactive Compounds ◽

Structural Information ◽

Oil Production ◽

Economic Problem ◽

Added Value ◽

Olive Leaves ◽

Mediterranean Countries ◽

By Products

In recent years, a remarkable increase in olive oil consumption has occurred worldwide, favoured by its organoleptic properties and the growing awareness of its health benefits. Currently, olive oil production represents an important economic income for Mediterranean countries, where roughly 98% of the world production is located. Both the cultivation of olive trees and the production of industrial and table olive oil generate huge amounts of solid wastes and dark liquid effluents, including olive leaves and pomace and olive oil mill wastewaters. Besides representing an economic problem for producers, these by-products also pose serious environmental concerns, thus their partial reuse, like that of all agronomical production residues, represents a goal to pursue. This aspect is particularly important since the cited by-products are rich in bioactive compounds, which, once extracted, may represent ingredients with remarkable added value for food, cosmetic and nutraceutical industries. Indeed, they contain considerable amounts of valuable organic acids, carbohydrates, proteins, fibers, and above all, phenolic compounds, that are variably distributed among the different wastes, depending on the employed production process of olive oils and table olives and agronomical practices. Yet, extraction and recovery of bioactive components from selected by-products constitute a critical issue for their rational valorization and detailed identification and quantification are mandatory. The most used analytical methods adopted to identify and quantify bioactive compounds in olive oil by-products are based on the coupling between gas- (GC) or liquid chromatography (LC) and mass spectrometry (MS), with MS being the most useful and successful detection tool for providing structural information. Without derivatization, LC-MS with electrospray (ESI) or atmospheric pressure chemical (APCI) ionization sources has become one of the most relevant and versatile instrumental platforms for identifying phenolic bioactive compounds. In this review, the major LC-MS accomplishments reported in the literature over the last two decades to investigate olive oil processing by-products, specifically olive leaves and pomace and olive oil mill wastewaters, are described, focusing on phenolics and related compounds.

Download Full-text

Olive mill wastewater biological treatment by fungi biomass

Water Science & Technology ◽

10.2166/wst.2007.311 ◽

2007 ◽

Vol 55 (10) ◽

pp. 89-97 ◽

Cited By ~ 5

Author(s):

S. Caffaz ◽

C. Caretti ◽

M. Morelli ◽

C. Lubello ◽

E. Azzari

Keyword(s):

Phenolic Compounds ◽

Olive Oil ◽

Biological Treatment ◽

Batch Reactor ◽

Food Industries ◽

Olive Mill Wastewaters ◽

Biomass Activity ◽

The One ◽

By Products ◽

Olive Mill

Olive oil extraction is one of the most important traditional food industries in the Mediterranean region, especially in Italy. In addition to olive oil, this industry produces by-products, in particular olive mill wastewaters (OMWs) and olive husks, which represent a serious environmental problem. OMWs can be rarely treated in a municipal WWTP, using conventional wastewater treatments. A novel biological process has to be considered in order to treat OMWs. Literature data show that yeasts and different kinds of fungi are able to reduce both the organic and the phenolic content of the OMW. The present work is aimed at investigating the growth of a biomass rich in fungi in a batch reactor filled with OMW and its capacity to degrade the organic and phenolic load. The aerobic OMW degradation obtained using this biomass reached a COD and TP removal efficiency of 86 and 70%, respectively. Respirometric tests have been carried out in order to measure the biomass activity on different substrates: OMW and phenolic compounds (gallic and p-coumaric acids). The polyphenolic biodegradation efficiency of fungi biomass was higher than the one of a non-acclimated activated sludge biomass. Fungi biomass was able to completely degrade pure phenolic compounds.

Download Full-text

WEEE data management in Germany and Serbia

Global NEST Journal ◽

10.30955/gnj.002657 ◽

2018 ◽

Vol 20 (4) ◽

pp. 751-757 ◽

Cited By ~ 1

Keyword(s):

Olive Oil ◽

Ferric Oxide ◽

Oxygen Demand ◽

Olive Mill Wastewater ◽

Municipal Sewage ◽

Removal Capacity ◽

Mediterranean Countries ◽

High Chemical Oxygen Demand ◽

The University ◽

Olive Mill

<p>In Jordan and as in many other Mediterranean countries olive oil production is one of the major agricultural production, it is estimated that the annual production of olive oil in Jordan approximately 21.5 thousand tons per year. O the other hand the process of olive oil extraction generates around 200,000 m3 of olive mill wastewater (OMW) and it is considered as a a serious problem in. In this study the real sample of wastewater is collected from the outlet at the mill near by the university campus. The analysis of this collected wastewater has shown a very high Chemical Oxygen Demand COD (253.648 kg/l) and Bilogical Oxygen Demand, BOD (89.365kg/l). These high BOD and COD reveals a real need to treat it before sent to municipal sewage. The study also focuses on reducing an organ phenol component which has been measured and found equal to 0.5698mg/l. The use of Ferric Oxide in the form of nanoparticles was successfully used to oxide organic phenols from olive mill wastewater (OMW) and has reduced to 0.002 mg/l. The results show that 0.1g of Ferric Oxide in the form of nanoparticles when mixed with sand has the capacity to remove the phenols from the collected samples. The removal percentage obtained here reached 97%. When the mixture of ferric nanoparticles used with sand in a ratio of 0.1 g Fe2O3and 1 kg of sand, the removal capacity of organic phenols has reached to 99%, and COD () in percentage of 97.2%. The results show an interesting behavior towards other minerals that exists in solution, that ferric nanoparticles have a good capacity to remove Cr+3Cu+3 K+Ca+2Na+.minerals exist in wastewater.</p>

Download Full-text

Olive Mill Wastewater (OMW) Treatment by Using Ferric Oxide Dephenolization and Chemical Oxygen Demand Removal

Global NEST Journal ◽

10.30955/gnj.002650 ◽

2018 ◽

Vol 20 (3) ◽

pp. 558-563

Keyword(s):

Chemical Oxygen Demand ◽

Olive Oil ◽

Ferric Oxide ◽

Oxygen Demand ◽

Olive Mill Wastewater ◽

Municipal Sewage ◽

Removal Capacity ◽

Mediterranean Countries ◽

High Chemical Oxygen Demand ◽

Olive Mill

Download Full-text

The Valorisation of Olive Mill Wastewater from Slovenian Istria by Fe3O4 Particles to Recover Polyphenolic Compounds for the Chemical Specialties Sector

Molecules ◽

10.3390/molecules26226946 ◽

2021 ◽

Vol 26 (22) ◽

pp. 6946

Author(s):

Kelly Peeters ◽

Ana Miklavčič Višnjevec ◽

Esakkiammal Esakkimuthu ◽

Matthew Schwarzkopf ◽

Črtomir Tavzes

Keyword(s):

Phenolic Compounds ◽

Olive Oil ◽

Extraction Methods ◽

High Reactivity ◽

Polyphenolic Compounds ◽

Olive Mill Wastewater ◽

Beneficial Effects ◽

Two Phases ◽

By Products ◽

Olive Mill

Olive oil production using three-phase decanter systems creates olive oil and two by-products: olive mill wastewater (OMWW) and pomace. These by-products contain the highest share of polyphenolic compounds that are known to be associated with beneficial effects on human health. Therefore, they are an attractive source of phenolic compounds for further industrial use in the cosmetic, pharmaceutical and food industries. The use of these phenolics is limited due to difficulties in recovery, high reactivity, complexity of the OMWW matrix and different physiochemical properties of phenolic compounds. This research, focused on OMWW, was performed in two phases. First, different polyphenol extraction methods were compared to obtain the method that yields the highest polyphenol concentration. Twenty-five phenolic compounds and their isomers were determined. Acidifying OMWW, followed by five minutes of ultrasonication, resulted in the highest measured polyphenol content of 27 mg/L. Second, the collection of polyphenolic compounds from OMWW via adsorption on unmodified iron (II, III) oxide particles was investigated. Although low yields were obtained for removed polyphenolic compounds in one removal cycle, the process has a high capability to be repeated.

Download Full-text

Advanced oxidation technologies for the treatment and detoxification of olive mill wastewater: a general review

Journal of Water Reuse and Desalination ◽

10.2166/wrd.2019.033 ◽

2019 ◽

Vol 9 (4) ◽

pp. 463-505 ◽

Cited By ~ 5

Author(s):

Reda Elkacmi ◽

Mounir Bennajah

Keyword(s):

Olive Oil ◽

Advanced Oxidation Processes ◽

Advanced Oxidation ◽

Olive Mill Wastewater ◽

Mediterranean Countries ◽

Quality Of Waters ◽

Oil Sector ◽

High Treatment ◽

Olive Mill

Abstract Olive oil production has an economic importance for Mediterranean countries, ensuring employment opportunities and export earnings. The crushing units produce two types of residues, one solid (pomace) and the other liquid, called olive mill wastewater (OMW). This by-product has adverse effects on the olive oil sector and particularly on the quality of waters into which they are discharged. Hence, there is a critical need to orient the scientific research toward the treatment of this hazardous waste. Several techniques have been proposed and developed for OMW management. However, the advanced oxidation processes (AOP) remain the most advantageous with high treatment efficiencies. This trend allowed achieving a significant detoxification of OMW. A considerable amount of effort has been expanded to provide detailed and critical reviews on the use of this alternative technology in the treatment of water and wastewaters. Regrettably most, if not all, of these review papers were not focused mainly on OMW application. This paper aims to highlight the ancient and recent progress of various types of oxidation techniques for OMW treatment. Moreover, principles, advantages, limitations, and efficiencies of each method are presented, to gain a more scientific understanding of the most feasible approach regarding the treatment of this harmful residue.

Download Full-text

Antioxidant Properties of Olive Mill Wastewater Polyphenolic Extracts on Human Endothelial and Vascular Smooth Muscle Cells

Foods ◽

10.3390/foods10040800 ◽

2021 ◽

Vol 10 (4) ◽

pp. 800

Author(s):

Anna Maria Posadino ◽

Annalisa Cossu ◽

Roberta Giordo ◽

Amalia Piscopo ◽

Wael M Abdel-Rahman ◽

...

Keyword(s):

Antioxidant Activity ◽

Cell Death ◽

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Olive Oil ◽

Vascular Smooth Muscle Cells ◽

Muscle Cells ◽

Olive Mill Wastewater ◽

Olive Mill

This work aims to analyze the chemical and biological evaluation of two extracts obtained by olive mill wastewater (OMW), an olive oil processing byproduct. The exploitation of OMW is becoming an important aspect of development of the sustainable olive oil industry. Here we chemically and biologically evaluated one liquid (L) and one solid (S) extract obtained by liquid–liquid extraction followed by acidic hydrolysis (LLAC). Chemical characterization of the two extracts indicated that S has higher phenol content than L. Hydroxytyrosol and tyrosol were the more abundant phenols in both OMW extracts, with hydroxytyrosol significantly higher in S as compared to L. Both extracts failed to induce cell death when challenged with endothelial cells and vascular smooth muscle cells in cell viability experiments. On the contrary, the higher extract dosages employed significantly affected cell metabolic activity, as indicated by the MTT tests. Their ability to counteract H2O2-induced oxidative stress and cell death was assessed to investigate potential antioxidant activities of the extracts. Fluorescence measurements obtained with the reactive oxygen species (ROS) probe H2DCF-DA indicated strong antioxidant activity of the two OMW extracts in both cell models, as indicated by the inhibition of H2O2-induced ROS generation and the counteraction of the oxidative-induced cell death. Our results indicate LLAC-obtained OMW extracts as a safe and useful source of valuable compounds harboring antioxidant activity.

Download Full-text