Daily doses of light in relation to the growth of Scenedesmus obliquus in diluted three-phase olive mill wastewater

Abstract Olive mill wastewater has significant polluting properties due to its high phenolic content [mainly tyrosol (trs) and hydroxytyrosol (htrs)]. Growth kinetics and a series of fluorescence induction measurements for Scenedesmus obliquus cultures showed that microalgae can be tolerant of these phenolic compounds. Changes in the cellular energy reserves and concentration of the phenolic compounds adjust the “toxicity” of these compounds to the microalgae and are, therefore, the main parameters that affect biodegradation. Autotrophic growth conditions of microalgae and high concentrations of trs or htrs induce higher biodegradation compared with mixotrophic conditions and lower phenolic concentrations. When microalgae face trs and htrs simultaneously, biodegradation begins from htrs, the more energetically demanding compound. All these lead to the conviction that microalgae have a “rational” management of cellular energy balance. Low toxicity levels lead to higher growth and lower biodegradation, whereas higher toxicity levels lead to lower growth and higher biodegradation. The selection of appropriate conditions (compatible to the bioenergetic strategies of microalgae) seems to be the key for a successful biodegradation of a series of toxic compounds, thus paving the way for future biotechnological applications for solving complicated pollution problems, like the detoxification of olive mill wastewater.

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Development of a high-rate anaerobic thermophilic upflow packed bed reactor for efficient bioconversion of diluted three-phase olive mill wastewater into methane

Fuel ◽

10.1016/j.fuel.2021.122263 ◽

2022 ◽

Vol 310 ◽

pp. 122263

Author(s):

Konstantina Tsigkou ◽

Michael Kornaros

Keyword(s):

Packed Bed ◽

Olive Mill Wastewater ◽

Packed Bed Reactor ◽

High Rate ◽

Three Phase ◽

Olive Mill

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Valorization of Olive Mill Wastewater in the Control of Aphis pomi De Geer 1773 (Hemiptera, Aphididae) Infesting Apple Plants in Nurseries

10.5772/intechopen.100016 ◽

2021 ◽

Author(s):

Nahid Haouache ◽

Soukaina El Asri ◽

Adil Asfers ◽

Abdelhadi Ait Houssa ◽

Bouchra Tazi ◽

...

Keyword(s):

Organic Matter ◽

Large Scale ◽

The Elderly ◽

Olive Mill Wastewater ◽

Acidic Ph ◽

Natural Ecosystems ◽

Aphis Pomi ◽

Three Phase ◽

Short Period ◽

Olive Mill

Olive mill wastewater (OMW), are the liquid residues generated during the extraction of oil by traditional and modern three-phase type crushing units. These effluents are characterized by an acidic pH and composition rich in water, organic matter, minerals and polyphenols. In general, they are directly discharged into natural ecosystems. Their danger is linked to the enormous quantities produced in a short period between October and March. To mitigate the effects of vegetable waters on the environment, their valorization in different areas is discussed. As biopesticides, crude OMW have been shown to be very toxic to Aphis pomi; the LC50 and LC95 varied respectively from 27.17 to 45.59 and from 77.19 to 134.57 mg of OMW/L of water; they vary according to the stage of the aphid considered. The young stages of A. pomi were more sensitive than the elderly are. Therefore, the OMW can be used as a means of controlling aphids. However, before operating on a large scale, it is necessary to repeat the trials in field and assess their impact on non-target organisms and treated crops.

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Bioethanol production from thermochemically pre-treated olive mill solid residues using the yeast Pachysolen tannophylus

Global NEST Journal ◽

10.30955/gnj.000861 ◽

2013 ◽

Vol 14 (2) ◽

pp. 118-124 ◽

Cited By ~ 1

Keyword(s):

Olive Oil ◽

Ethanol Yield ◽

Solid Residue ◽

Residual Oil ◽

Edible Fungi ◽

Pachysolen Tannophilus ◽

Three Phase ◽

Different Types ◽

Pre Treatment ◽

Olive Mill

Olive oil mill solid residue (OMSR) is the solid waste generated during olive oil production process in three-phase olive mills. It consists of the remaining pulp of olive processing after the extraction of oil, as well as the cracked seeds of the olive fruits, containing thus mainly lignocellulose and residual oil. The commonly used practice for OMSR management is combustion, after having extracted the residual oil by secondary extraction using organic solvents. Other proposed ways of OMSR management are their exploitation as substrate for edible fungi production and compost, and as feedstock for biofuels generation such as methane and bioethanol. In the latter case, the complex carbohydrates (cellulose and hemicellulose) of the lignocellulose of OMSR have to be degraded towards their simple sugars and further fermented via microorganisms. The purpose of the present study was to investigate the effect of thermochemical pre-treatment of OMSR, on the final ethanol yield from the yeast Pachysolen tannophilus. Nine different types of OMSR-based substrates were tested i.e. raw OMSR, hydrolysates generated from pretreated OMSR with NaOH (0.5 %, 1.5 % w/v) and H2SO4 (0.5 %, 1.5 % v/v), and pretreated OMSR with NaOH (0.5 %, 1.5 % w/v) and H2SO4 (0.5 %, 1.5 % v/v) whole biomass. It was shown that in all cases pretreatment enhanced the consumption of carbohydrates as well as ethanol final yields.

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Screening of Commercial Catalysts for Steam Reforming of Olive Mill Wastewater

Renewable Energy ◽

10.1016/j.renene.2020.12.139 ◽

2021 ◽

Author(s):

Cláudio Rocha ◽

M.A. Soria ◽

Luís M. Madeira

Keyword(s):

Steam Reforming ◽

Olive Mill Wastewater ◽

Olive Mill

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Technoeconomic Analysis of the Recovery of Phenols from Olive Mill Wastewater through Membrane Filtration and Resin Adsorption/Desorption

Sustainability ◽

10.3390/su13042376 ◽

2021 ◽

Vol 13 (4) ◽

pp. 2376

Author(s):

Dimitris P. Zagklis ◽

Costas S. Papageorgiou ◽

Christakis A. Paraskeva

Keyword(s):

Capital Investment ◽

Membrane Filtration ◽

Hot Spot ◽

Treatment Method ◽

Olive Mill Wastewater ◽

Operational Cost ◽

Equipment Cost ◽

Fixed Capital Investment ◽

Adsorption Desorption ◽

Olive Mill

Olive mill wastewater is an important agro-industrial waste with no established treatment method. The authors have developed a phenol separation method that could potentially cover the treatment cost of the waste. The purpose of this study was to identify any economic hotspots in the process, the operational cost and examine the margin of profit for such a process. The equipment cost was scaled for different treatment capacities and then used to estimate the fixed capital investment and the yearly operational cost. The highest purchased equipment cost was identified for the membrane filtration system, while the cost for resin replacement was identified as the highest operational cost. The lifespan of the resin used in the adsorption step was identified as an economic hot spot for the process, with the phenols separation cost ranging from 0.84 to 13.6 €/g of phenols for a resin lifespan of 5–100 adsorption/desorption cycles. The lifespan of the resin proved to be the single most important aspect that determines the phenols separation cost. The price range that was calculated for the product of the process is very promising because of the typical value of antioxidants and the low concentration of phenols that are needed for food supplements and cosmetics.

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