Pilot-plant results of the electro-Fenton treatment of olive mill wastewaters followed by anaerobic digestion

2007 ◽  
Vol 55 (12) ◽  
pp. 259-265 ◽  
Author(s):  
S. Khoufi ◽  
F. Feki ◽  
F. Aloui ◽  
S. Sayadi
Keyword(s):  
Anaerobic Digestion ◽  
High Energy ◽  
Water Recovery ◽  
Combined Process ◽  
Integrated Technology ◽  
Mediterranean Countries ◽  
Olive Mill Wastewaters ◽  
Pre Treatment ◽  
Treatment Step ◽  
Olive Mill

In this work, we investigated an integrated technology for the treatment of the recalcitrant contaminants of olive mill wastewaters (OMW), allowing water recovery and reuse for agricultural purposes. The method involves an electrochemical pre-treatment step of the wastewater using the electro-Fenton reaction followed by an anaerobic bio-treatment. The electro-Fenton pre-treatment process removed 66% of the total polyphenolic compounds and subsequently decreased the OMW toxicity from 100 to 66.9% which resulted in improving the performance of the anaerobic digestion. A continuous lab-scale methanogenic reactor was operated at a loading rate of 10 g COD/L day without any apparent toxicity. Furthermore, in the combined process, a high overall reduction in COD, suspended solids, polyphenols and lipids content was achieved by the two successive stages. Moreover, this combined process which was experimented at a real scale (25 m3 digester), demonstrated its technical feasibility and opens promising perspectives for industrial application in the Mediterranean countries due to its easy conception and its high energy (methane) production.

Pilot-plant results of the electro-Fenton treatment of olive mill wastewaters followed by anaerobic digestion

2007 ◽  
Vol 55 (12) ◽  
pp. 67-73 ◽  
Author(s):  
S. Khoufi ◽  
F. Feki ◽  
F. Aloui ◽  
S. Sayadi
Keyword(s):  
Anaerobic Digestion ◽  
High Energy ◽  
Water Recovery ◽  
Combined Process ◽  
Integrated Technology ◽  
Mediterranean Countries ◽  
Olive Mill Wastewaters ◽  
Pre Treatment ◽  
Treatment Step ◽  
Olive Mill

In this work, we investigated an integrated technology for the treatment of the recalcitrant contaminants of olive mill wastewaters (OMW), allowing water recovery and reuse for agricultural purposes. The method involves an electrochemical pre-treatment step of the wastewater using the electro-Fenton reaction followed by an anaerobic bio-treatment. The electro-Fenton pre-treatment process removed 66% of the total polyphenolic compounds and subsequently decreased the OMW toxicity from 100 to 66.9%, which resulted in improving the performance of the anaerobic digestion. A continuous laboratory-scale methanogenic reactor was operated at a loading rate of 10 g COD/L per day without any apparent toxicity. Furthermore, in the combined process, a high overall reduction in COD, suspended solids, polyphenols and lipids content was achieved by the two successive stages. Moreover, this combined process which was experimented at a real scale (25 m3 digester) demonstrated its technical feasibility and opens promising perspectives for industrial application in the Mediterranean countries because of its easy conception and high energy (methane) production.

SBR treatment of olive mill wastewaters: dilution or pre-treatment?

2012 ◽  
Vol 65 (9) ◽  
pp. 1684-1691 ◽  
Author(s):  
G. Farabegoli ◽  
A. Chiavola ◽  
E. Rolle
Keyword(s):  
Biological Process ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Adequate Treatment ◽  
Olive Mill Wastewaters ◽  
Other Substances ◽  
Removal Efficiencies ◽  
Pre Treatment ◽  
Olive Mill ◽  
Gac Adsorption

The olive-oil extraction industry is an economically important activity for many countries of the Mediterranean Sea area, with Spain, Greece and Italy being the major producers. This activity, however, may represent a serious environmental problem due to the discharge of highly polluted effluents, usually referred to as ‘olive mill wastewaters’ (OMWs). They are characterized by high values of chemical oxygen demand (COD) (80–300 g/L), lipids, total polyphenols (TPP), tannins and other substances difficult to degrade. An adequate treatment before discharging is therefore required to reduce the pollutant load. The aim of the present paper was to evaluate performances of a biological process in a sequencing batch reactor (SBR) fed with pre-treated OMWs. Pre-treatment consisted of a combined acid cracking (AC) and granular activated carbon (GAC) adsorption process. The efficiency of the system was compared with that of an identical SBR fed with the raw wastewater only diluted. Combined AC and GAC adsorption was chosen to be used prior to the following biological process due to its capability of providing high removal efficiencies of COD and TPP and also appreciable improvement of biodegradability. Comparing results obtained with different influents showed that best performances of the SBR were obtained by feeding it with raw diluted OMWs (dOMWs) and at the lowest dilution ratio (1:25): in this case, the removal efficiencies were 90 and 76%, as average, for COD and TPP, respectively. Feeding the SBR with either the pre-treated or the raw dOMWs at 1:50 gave very similar values of COD reduction (74%); however, an improvement of the TPP removal was observed in the former case.

Olive mill wastewater treatment: an experimental study

2006 ◽  
Vol 54 (8) ◽  
pp. 17-25 ◽  
Author(s):  
E. Bettazzi ◽  
M. Morelli ◽  
S. Caffaz ◽  
C. Caretti ◽  
E. Azzari ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Biological Treatment ◽  
Batch Reactor ◽  
Organic Load ◽  
Toxic Substances ◽  
Mediterranean Countries ◽  
Three Phase ◽  
Olive Mill Wastewaters ◽  
Biological Treatability ◽  
Olive Mill

Olive oil production, one of the main agro-industries in Mediterranean countries, generates significant amounts of olive mill wastewaters (OMWs), which represent a serious environmental problem, because of their high organic load, the acidic pH and the presence of recalcitrant and toxic substances such as phenolic and lipidic compounds (up to several grams per litre). In Italy, traditional disposal on the soil is the most common way to discharge OMWs. This work is aimed at investigating the efficiency and feasibility of AOPs and biological processes for OMW treatment. Trials have been carried out on wastewaters taken from one of the largest three-phase mills of Italy, located in Quarrata (Tuscany), as well as on synthetic solutions. Ozone and Fenton's reagents applied both on OMWs and on phenolic synthetic solutions guaranteed polyphenol removal efficiency up to 95%. Aerobic biological treatment was performed in a batch reactor filled with raw OMWs (pH =4.5, T=30 °C) without biomass inoculum. A biomass rich of fungi, developed after about 30 days, was able to biodegrade phenolic compounds reaching a removal efficiency of 70%. Pretreatment of OMWs by means of oxidation increased their biological treatability.

scholarly journals Feasibility of Coupling Anaerobic Digestion and Hydrothermal Carbonization: Analyzing Thermal Demand

2021 ◽  
Vol 11 (24) ◽  
pp. 11660
Author(s):  
Rubén González ◽  
Marcos Ellacuriaga ◽  
Alby Aguilar-Pesantes ◽  
Daniela Carrillo-Peña ◽  
José García-Cascallana ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Energy Demand ◽  
Biological Process ◽  
Biogas Production ◽  
Hydrothermal Carbonization ◽  
Energy Performance ◽  
High Energy ◽  
Subsequent Treatment ◽  
Treatment Unit ◽  
Pre Treatment

Anaerobic digestion is a biological process with wide application for the treatment of high organic-containing streams. The production of biogas and the lack of oxygen requirements are the main energetic advantages of this process. However, the digested stream may not readily find a final disposal outlet under certain circumstances. The present manuscript analyzed the feasibility of valorizing digestate by the hydrothermal carbonization (HTC) process. A hypothetical plant treating cattle manure and cheese whey as co-substrate (25% v/w, wet weight) was studied. The global performance was evaluated using available data reported in the literature. The best configuration was digestion as a first stage with the subsequent treatment of digestate in an HTC unit. The treatment of manure as sole substrate reported a value of 752 m3/d of biogas which could be increased to 1076 m3/d (43% increase) when coupling an HTC unit for digestate post-treatment and the introduction of the co-substrate. However, the high energy demand of the combined configurations indicated, as the best alternative, the valorization of just a fraction (15%) of digestate to provide the benefits of enhancing biogas production. This configuration presented a much better energy performance than the thermal hydrolysis pre-treatment of manure. The increase in biogas production does not compensate for the high energy demand of the pre-treatment unit. However, several technical factors still need further research to make this alternative a reality, as it is the handling and pumping of high solid slurries that significantly affects the energy demand of the thermal treatment units and the possible toxicity of hydrochar when used in a biological process.

scholarly journals Use of Olive Mill Wastewaters as Bio-Insecticides for the Control of Potosia Opaca in Date Palm (Phoenix dactylifera L.)

2020 ◽  
Author(s):  
Abdelilah Meddich ◽  
Abderrahim Boutasknit ◽  
Mohamed Anli ◽  
Meriame Ait Ahmed ◽  
Abdelilah El Abbassi ◽  
...  
Keyword(s):  
Date Palm ◽  
Phenolic Content ◽  
Negative Impact ◽  
Phoenix Dactylifera ◽  
The North ◽  
Palm Trees ◽  
Phoenix Dactylifera L ◽  
Olive Mill Wastewaters ◽  
Pre Treatment ◽  
Olive Mill

The date palm is one of the most economically important perennial plants of the North Africa and in Morocco, where it is extensively cultivated for food and many other commercial purposes. Palm trees are threatened by many pests such as Potosia opaca newly identified in Morocco, especially in Marrakesh and Errachidia regions. In addition, olive mill wastewaters (OMW) are an environmental problem in olive oil producing countries such as Morocco. Generally, these effluents are drained into ecosystems without any pre-treatment. To reduce their negative impact and to get benefits in particular from their high phenolic content, OMW were used as bio-insecticides in crude form. The results showed that crude OMW were effective to control this pest causing a weight loss similar to Cordus insecticide (17% vs. 15%) and mortality almost similar to Kemaban insecticide. OMW’s biocide potential was related principally to their high phenolic content. Based on HPLC analysis, ten phenolic molecules were identified, including two which were revealed as the major monomeric phenolic compounds in OMW, 0.248 g/L of hydroxytyrosol and 0.201 g/L of tyrosol. In this chapter, the potential use of OMW as bio-insecticides for the control of P. opaca in date palm is discussed.

scholarly journals Detoxification of Olive Mill Wastewaters by Fenton’s Process

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 662 ◽  
Author(s):  
Eva Domingues ◽  
João Gomes ◽  
Margarida Quina ◽  
Rosa Quinta-Ferreira ◽  
Rui Martins
Keyword(s):  
Process Integration ◽  
Combined Treatment ◽  
Organic Load ◽  
Strong Impact ◽  
Water Recovery ◽  
Solid Catalysts ◽  
Olive Mill Wastewaters ◽  
Sea Area ◽  
Olive Mill ◽  
Fenton's Process

Olive mill wastewaters (OMW) constitute an environmental problem affecting mainly Mediterranean Sea area countries where the olive mill industry is a very important economic sector. The strong impact and management issues of these effluents are mainly due to their seasonality, localized production, and high organic load with high toxic features and low biodegradability. As the olive oil industry is highly water demanding, the search for suitable water recovery strategies requires the development and optimization of advanced treatment technologies. The classical Fenton’s process is an interesting alternative, as it operates at room conditions of pressure and temperature. However, it shows some drawbacks, such as the generation of iron sludges, which require further management. Nevertheless, because of its features that make it industrially desirable, overcoming these limitations has been the focus of researchers in the last years. Bearing this in mind, this paper focuses on the recent research regarding OMW treatment using Fenton’s process. The use of Fenton’s peroxidation treatment at homogenous, heterogeneous, and photo-aided conditions is analysed. The use of solid catalysts may be an interesting way to avoid sludge formation. Light-driven Fenton can also reduce the amount of iron needed for effective degradation. Moreover, Fenton’s process integration in combined treatment schemes is discussed. Finally, remarks regarding its application at full scale are given.

scholarly journals Influence of Microwave Pre-Treatment on the Digestion and Higienisation of Waste Activated Sludge/Wpływ Dezintegracji Mikrofalowej Na Proces Fermentacji Oraz Higienizacji Nadmiernych Osadów Ściekowych

2014 ◽  
Vol 21 (3) ◽  
pp. 447-464 ◽  
Author(s):  
Jolanta Bohdziewicz ◽  
Mariusz Kuglarz ◽  
Klaudiusz Grűbel
Keyword(s):  
Anaerobic Digestion ◽  
Microwave Irradiation ◽  
Treatment Effectiveness ◽  
Biogas Production ◽  
Salmonella Spp ◽  
Biogas Yield ◽  
Treatment Conditions ◽  
Higher Power ◽  
Pre Treatment ◽  
Treatment Step

Abstract The article presents the results of determining the most appropriate conditions of microwave sludge pre-treatment (500-1200 W), prior to its anaerobic digestion in a continuous mode. The assessment of the pre-treatment conditions (microwave power, sludge temperature after pre-treatment) was based on: the release of organic (COD, protein) and inorganic (NH4+, PO43-) substances into liquid, the quantity of methane produced, sludge higienisation and the susceptibility of the pre-treated sludge to dewatering. The power of the microwaves applied did not play significant role on the pre-treatment effectiveness. Taking into account the fact that sludge pre-treatment by microwave irradiation requires the delivery of energy, the pre-treatment by microwaves of higher power (1200 W) and resulting in sludge temperature of 70°C was recommended for further experiments. Sludge pre-treatment by means of microwave irradiation as a pre-treatment step influenced the effectiveness of the subsequent anaerobic digestion, conducted in continuous conditions, in a positive way. The largest amount of biogas was obtained for HRT in the range of 15-20 days. As compared to the sludge which did not undergo pre-treatment, daily biogas production and biogas yield increased by 18-41% and 13-35% respectively. The combination of microwave pre-treatment and mesophilic anaerobic digestion ensured the elimination of pathogens (Salmonella spp., Escherichia coli).

scholarly journals EFFECT OF THERMAL PRETREATMENT ON THE SOLUBILIZATION OF ORGANIC MATTERS IN A MIXTURE OF PRIMARY AND WASTE ACTIVATED SLUDGE

2015 ◽  
Vol 9 (1) ◽  
pp. 82-88 ◽  
Author(s):  
Ahmed M. Aboulfotoh ◽  
E.H. El Gohary and O.D. El Monayeri
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Treatment Time ◽  
Chemical Properties ◽  
High Energy ◽  
Gas Production ◽  
Waste Activated Sludge ◽  
Thermal Pretreatment ◽  
Treatment Methods ◽  
Pre Treatment

The increased demand for advanced techniques in anaerobic digestion over the last few years has led to the employment of various pre-treatment methods prior to anaerobic digestion to increase gas production. These pre-treatment methods alter the physical and chemical properties of sludge in order to make it more readily degradable by anaerobic digestion. Although the thermal pre-treatment presents high energy consumption, the main part of this energy to heat can be recovered from the biogas produced in the anaerobic process. In this research a mixture of primary and waste activated sludge was thermally pretreated at 100, 125, 150, 175 and 200o C in order to determine the effect of thermal pretreatment on improving the solubilization of sludge by increasing the soluble organic fraction (expressed as soluble COD and VFA). Experimental results proved that the solubilization ratio of sludge is depends on the treatment time and the applied temperature and the optimal temperature ranged between 175 and 200o C. The COD solubilization ratio (at 175o C) increased from 11.2% to 15.1% and 25.1% when the time of treatment increased from 60 min to 120 and 240 min respectively. The experimental data could be fitted to obtain an empirical model (Known as the enzyme-kinetic equation) relating the COD solubilization ratio of sludge and VFA concentration to the applied temperature and the heating time.

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