scholarly journals Candida tropicalis as a Promising Oleaginous Yeast for Olive Mill Wastewater Bioconversion

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 640
Author(s):  
Bruna Dias ◽  
Marlene Lopes ◽  
Renata Ramôa ◽  
Ana S. Pereira ◽  
Isabel Belo
Keyword(s):  
Phenolic Compounds ◽  
Candida Tropicalis ◽  
Oxygen Demand ◽  
Olive Mill Wastewater ◽  
Cellular Growth ◽  
Added Value ◽  
Organic Load ◽  
Batch Cultures ◽  
Intracellular Lipids ◽  
Olive Mill

Olive mill wastewater (OMW), which is generated during olive oil production, has detrimental effects on the environment due to its high organic load and phenolic compounds content. OMW is difficult to biodegrade, but represents a valuable resource of nutrients for microbial growth. In this study, yeast strains were screened for their growth on phenolic compounds usually found in OMW and responsible for antimicrobial effects. Candida tropicalis ATCC 750 demonstrated an extraordinary capacity to grow in phenolics and was chosen for further experiments with OMW-based medium. The effects of nitrogen supplementation, the pH, and the stirring rate on cellular growth, OMW-components consumption, and added-value compounds production were studied in batch cultures in Erlenmeyer flasks and in a bioreactor. Candida tropicalis was able to reduce 68% of the organic load (chemical oxygen demand) and 39% of the total phenols of OMW in optimized conditions in bioreactor experiments, producing lipase (203 U·L−1) and protease (1105 U·L−1). Moreover, intracellular lipids were accumulated, most significantly under nitrogen-limited conditions, which is common in this type of wastewater. The high potential of C. tropicalis to detoxify OMW and produce added-value compounds from it makes this process an alternative approach to other conventional processes of OMW treatment.

scholarly journals Biodegradation of Olive Mill Wastewater by Trichosporon Cutaneum and Geotrichum Candidum

2010 ◽  
Vol 61 (4) ◽  
pp. 399-405 ◽  
Author(s):  
Tibela Dragičević ◽  
Marijana Hren ◽  
Margareta Gmajnić ◽  
Sanja Pelko ◽  
Dzoko Kungulovski ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Oxygen Demand ◽  
Geotrichum Candidum ◽  
Olive Mill Wastewater ◽  
Trichosporon Cutaneum ◽  
Aerobic Conditions ◽  
Wide Range ◽  
Dark Colour ◽  
Static Conditions ◽  
Olive Mill

Biodegradation of Olive Mill Wastewater by Trichosporon Cutaneum and Geotrichum CandidumOlive oil production generates large volumes of wastewater. These wastewaters are characterised by high chemical oxygen demand (COD), high content of microbial growth-inhibiting compounds such as phenolic compounds and tannins, and dark colour. The aim of this study was to investigate biodegradation of olive mill wastewater (OMW) by yeasts Trichosporon cutaneum and Geotrichum candidum. The yeast Trichosporon cutaneum was used because it has a high potential to biodegrade phenolic compounds and a wide range of toxic compounds. The yeast Geotrichum candidum was used to see how successful it is in biodegrading compounds that give the dark colour to the wastewater. Under aerobic conditions, Trichosporon cutaneum removed 88 % of COD and 64 % of phenolic compounds, while the dark colour remained. Geotrichum candidum grown in static conditions reduced COD and colour further by 77 % and 47 %, respectively. This investigation has shown that Trichosporon cutaneum under aerobic conditions and Geotrichum candidum under facultative anaerobic conditions could be used successfully in a two-step biodegradation process. Further investigation of OMW treatment by selected yeasts should contribute to better understanding of biodegradation and decolourisation and should include ecotoxicological evaluation of the treated OMW.

scholarly journals Sorbents Coupled to Solar Light TiO2-Based Photocatalysts for Olive Mill Wastewater Treatment

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Andrea Speltini ◽  
Federica Maraschi ◽  
Michela Sturini ◽  
Valentina Caratto ◽  
Maurizio Ferretti ◽  
...  
Keyword(s):  
Activated Carbons ◽  
Uv Light ◽  
Sol Gel ◽  
Oxygen Demand ◽  
Integrated Approach ◽  
Olive Mill Wastewater ◽  
Solar Light ◽  
Organic Load ◽  
One Pot ◽  
Olive Mill

The aim of this work was to couple physical-chemical approaches with photocatalysis to reduce by a simple, inexpensive way the organic load of olive mill wastewater (OMW), mandatorily prior to the final discharge. Before irradiation, different sorbents were tested to remove part of the organic fraction, monitored by measuring chemical oxygen demand (COD) and polyphenols (PP). Different low-cost, safe materials were tested, that is, Y zeolite (ZY), montmorillonite, and sepiolite. Considerable decrease of organic load was obtained, with the highest abatement (40%) provided by ZY (10 g L−1in 1 : 10 OMW). Use of the three sorbents, in particular ZY, was convenient compared to commercial activated carbons. UV light photocatalytic tests, performed using P25 TiO2on ZY-treated OMW, yielded quantitative remediation (ca. 90%). Also solar light provided significative results, PP being lowered by 74% and COD by 56%. Sol-gel anatase TiO2and N-doped anatase TiO2were also tested, obtaining good results, around-80% PP and-40% COD. Finally, an integrated approach was experimented by ZY-supported anatase TiO2(TiO2@ZY). Thisphotoreactive sorbentallowedone-pottreatment of OMW significative abatements of PP (-77%) and COD (-39%) with only 1 g L−1material, under solar light.

scholarly journals Structure of Microbial Communities When Complementary Effluents Are Anaerobically Digested

2021 ◽  
Vol 11 (3) ◽  
pp. 1293
Author(s):  
Ana Eusébio ◽  
André Neves ◽  
Isabel Paula Marques
Keyword(s):  
Anaerobic Digestion ◽  
Microbial Communities ◽  
Volatile Fatty Acids ◽  
Olive Mill Wastewater ◽  
Organic Load ◽  
Rrna Gene ◽  
Bacterial Populations ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing ◽  
Olive Mill

Olive oil and pig productions are important industries in Portugal that generate large volumes of wastewater with high organic load and toxicity, raising environmental concerns. The principal objective of this study is to energetically valorize these organic effluents—piggery effluent and olive mill wastewater—through the anaerobic digestion to the biogas/methane production, by means of the effluent complementarity concept. Several mixtures of piggery effluent were tested, with an increasing percentage of olive mill wastewater. The best performance was obtained for samples of piggery effluent alone and in admixture with 30% of OMW, which provided the same volume of biogas (0.8 L, 70% CH4), 63/75% COD removal, and 434/489 L CH4/kg SVin, respectively. The validation of the process was assessed by molecular evaluation through Next Generation Sequencing (NGS) of the 16S rRNA gene. The structure of the microbial communities for both samples, throughout the anaerobic process, was characterized by the predominance of bacterial populations belonging to the phylum Firmicutes, mainly Clostridiales, with Bacteroidetes being the subdominant populations. Archaea populations belonging to the genus Methanosarcina became predominant throughout anaerobic digestion, confirming the formation of methane mainly from acetate, in line with the greatest removal of volatile fatty acids (VFAs) in these samples.

scholarly journals Evaluation of olive mill waste as substrate for carotenoid production by Rhodotorula mucilaginosa

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Carolina Ghilardi ◽  
Paola Sanmartin Negrete ◽  
Amalia Antonia Carelli ◽  
Virginia Borroni
Keyword(s):  
Liquid Fraction ◽  
Added Value ◽  
Organic Load ◽  
Integral Approach ◽  
Rhodotorula Mucilaginosa ◽  
Total Sugars ◽  
Carotenoid Production ◽  
Total Sugar Concentration ◽  
Valuable Compounds ◽  
Olive Mill

Abstract The “alperujo” is a waste from the olive oil industry with great potential for valorization. It has a high organic load, with the presence of valuable compounds such as biophenols and sugars. The use of this waste can be thought of as a biorefinery from which different compounds of high added value can be obtained, whether they are present in the “alperujo” such as biophenols or can be generated from the “alperujo”. Therefore, the production of carotenoids by Rhodotorula mucilaginosa was evaluated using the liquid fraction of ‘alperujo’ (Alperujo Water, AW) or an aqueous extract (AE) of “alperujo” at different concentrations (5, 10, 20 and 30% w/V) as substrates. The AEs had an acidic pH, a total sugar concentration ranging from 1.6 to 7.6 g/L, a polyphenols content from 0.4 to 2.9 g/L and a significant amount of proteins (0.5–3 g/L). AW is similar in composition as 30% AE, but with a higher amount of total sugars. Rh. mucilaginosa was able to grow at the different mediums with consumption of glucose and fructose, a reduction in protein content and alkalinization of the medium. Maximum total carotenoid production (7.3 ± 0.6 mg/L) was achieved at AW, while the specific production was higher when the yeast grew at AW or at 30% AE (0.78 ± 0.06 and 0.73 ± 0.10 mg/g of biomass, respectively). Torulene and torularhodin were the main carotenoids produced. Polyphenol content did not change; thus, it is still possible to recover these compounds after producing carotenoids. These results demonstrate the feasibility of using alperujo-based mediums as cheap substrates to produce torularhodin and torulene and to include this bioprocess as a step in an integral approach for alperujo valorization.

scholarly journals Ability of the aquatic fern Azolla to remove chemical oxygen demand and polyphenols from olive mill wastewater

2007 ◽  
Vol 58 (1) ◽  
Author(s):  
Alba Ena ◽  
Pietro Carlozzi ◽  
Benjamin Pushparaj ◽  
Raffaella Paperi ◽  
Silvia Carnevale ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Oxygen Demand ◽  
Olive Mill Wastewater ◽  
Aquatic Fern ◽  
Olive Mill

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

2012 ◽  
Vol 66 (12) ◽  
pp. 2505-2516 ◽  
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.

scholarly journals Comparison of aerobic processes for olive mill wastewater treatment

2020 ◽  
Vol 81 (9) ◽  
pp. 1914-1926 ◽  
Author(s):  
Y. Jaouad ◽  
M. Villain-Gambier ◽  
L. Mandi ◽  
B. Marrot ◽  
N. Ouazzani
Keyword(s):  
Stable State ◽  
Oxygen Demand ◽  
Industrial Effluents ◽  
Olive Mill Wastewater ◽  
Organic Loading Rate ◽  
Efficient Technology ◽  
Treated Water ◽  
Conventional Activated Sludge ◽  
Olive Mill

Abstract Membrane bioreactor (MBR) has been proven to be an efficient technology capable of treating various industrial effluents. However, the evaluation of its performances in the case of olive mill wastewater (OMW) over a conventional activated sludge (CAS) have not been determined yet. The present study aims to compare OMW treatment in two laboratory scale pilots: an external ceramic MBR and CAS starting with an acclimation step in both reactors by raising OMW concentration progressively. After the acclimation step, the reactors received OMW at 2 gCOD/L with respect to an organic loading rate of 0.2 and 0.3 kgCOD/kgMLVSS/d for MBR and CAS, respectively. Biomass acclimation occurred successfully in both systems; however, the MBR tolerated more OMW toxicity than CAS as the MBR always maintained an effluent with a better quality. At a stable state, a higher reduction of 95% chemical oxygen demand (COD) was obtained with MBR compared to CAS (86%), but both succeeded in polyphenols removal (80%). Moreover, a higher MLSS elimination from the MBR treated water (97%) was measured against 88% for CAS. Therefore, CAS was suitable for OMW treatment and MBR could be proposed as an alternative to CAS when a better quality of treated water is required.

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