New Insights on Protein Recovery from Olive Oil Mill Wastewater through Bioconversion with Edible Filamentous Fungi

Olive oil mills represent an important sector in the Mediterranean Sea Basin but also an environmental hazard due to untreated wastewater. Recovery of nutrients from olive oil mill wastewater (OMWW) as protein-rich microbial biomass can produce novel feed and reduce its chemical oxygen demand; however, low-protein containing products have been reported. New strategies leading to higher protein-containing fungal biomass could renew the research interest on bioconversion for pollution mitigation of OMWW. In this work, through cultivation of edible filamentous fungi (Aspergillus oryzae, Neurospora intermedia, and Rhizopus delemar), a link between the protein content in the originated fungal biomass, and the addition of nitrogen and medium dilution was established. Addition of nitrogen in the form of NaNO3 reduced the cultivation time from 96 h to 48 h while achieving a similar biomass mass concentration of 8.43 g/L and increased biomass protein content, from w = 15.9% to w = 29.5%. Nitrogen addition and dilution of OMWW, and consequent reduction of suspended solids, led to an increase in the protein content to up to w = 44.9%. To the best of our knowledge, the protein contents achieved are the highest reported to date and can open new research avenues towards bioconversion of OMWW using edible filamentous fungi.

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Effect of spent cotton stalks on color removal and chemical oxygen demand lowering in olive oil mill wastewater by white rot fungi

Folia Microbiologica ◽

10.1007/bf02825660 ◽

1999 ◽

Vol 44 (6) ◽

pp. 673-676 ◽

Cited By ~ 13

Author(s):

S. Kahraman ◽

O. Ye§ilada

Keyword(s):

Chemical Oxygen Demand ◽

Olive Oil ◽

Oxygen Demand ◽

White Rot Fungi ◽

Color Removal ◽

White Rot ◽

Olive Oil Mill Wastewater ◽

Cotton Stalks

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ADSORPTION OF PHENOLS FROM OLIVE OIL MILL WASTEWATER AS WELL AS N AND P FROM A SIMULATED CITY WASTEWATER LIQUID ON ACTIVATED GREEK LIGNITES

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.11629 ◽

2017 ◽

Vol 43 (5) ◽

pp. 2294

Author(s):

C. Papanicolaou ◽

G. Triantafyllou ◽

Ν. Pasadakis ◽

Α,Ε. Foscolos

Keyword(s):

Olive Oil ◽

Surface Area ◽

Oxygen Demand ◽

Medium Size ◽

Nitrogen And Phosphorus ◽

Olive Oil Mill Wastewater ◽

Cod Reduction ◽

Economic Exploitation ◽

Activated Coal ◽

Adsorption Of Nitrogen

The results show that surface area of activated coal samples increased substantially and in some more than the commercial one. The increase in surface area was higher the higher the carbon content and the lower the ash content. The adsorption capacity of phenols and the decrease of COD (Chemical Oxygen Demand) in olive oil mil wastewater disposals were measured in selected samples as well as the decrease of COD and the adsorption of nitrogen and phosphorus from a solution which simulates city waste disposals were measured in 14 selected Greek lignites and 1 commercially available activated lignite sample (HOK). The maximum recorded adsorption of phenol was 30.6 mg/g of activated lignite while the commercial one (HOK) adsorbed 16 mg/g of activated lignite. The COD reduction was 1262 mg of COD/g of activated lignite while in the commercial one the reduction was 439 mg of COD/g of activated lignite. The maximum adsorption of N and P from the simulated city waste liquid was 6.41 mg/g of activated lignite and 2.52 mg/g of activated lignite, respectively. while the commercial one (HOK) adsorbed 2.84 mg/g and 2.42 mg/g, respectively. Finally, the COD reduction was 50.28 mg/g of activatedlignite and 34.92 mg/g for the commercially one (HOK). The results show that Greek activated lignites can be used successfully for cleaning industrial and city wastes. These findings open the door for the economic exploitation of small to medium size lignite deposits in Greece, which are widespread in Greece.

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Olive Oil Mill Wastewater Treatment by the Electro-Fenton Process

Environmental Chemistry ◽

10.1071/en05080 ◽

2006 ◽

Vol 3 (5) ◽

pp. 345 ◽

Cited By ~ 25

Author(s):

Nizar Bellakhal ◽

Mehmet A. Oturan ◽

Nihal Oturan ◽

Mohamed Dachraoui

Keyword(s):

Wastewater Treatment ◽

Olive Oil ◽

Model Compound ◽

Oxidation Process ◽

Oxygen Demand ◽

Fenton Process ◽

Colour Intensity ◽

Olive Oil Mill Wastewater ◽

Chemical Reagents ◽

Mediterranean Countries

Environmental Context. The combination of the Fenton’s reagent with electrochemistry (the electro-Fenton process) represents an efficient method for wastewater treatment. This study describes the use of this process to clean olive oil mill wastewater, which is a real environmental problem in Mediterranean countries. Contrary to the conventional methods which reduce the pollution by removing the pollutants from the wastewater, the electro-Fenton process is shown to fully destroy (mineralize) olive oil mill wastes in water without previous extraction and without addition of chemical reagents. Abstract. Treatment of olive oil mill wastewater is one of the most important environmental problems for Mediterranean countries. This wastewater contains many organic compounds like polyphenols, which are very difficult to treat by classical techniques. An advanced electrochemical oxidation process, the electro-Fenton process, has been used as a way of removing chemical oxygen demand and colour intensity from olive oil mill wastewater. Vanillic acid, which has been selected as a model compound, and olive oil mill wastewater have been completely mineralized by the electro-Fenton process with a carbon felt cathode, using Fe2+ ions as the catalyst.

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The combination of coagulation, acid cracking and Fenton-like processes for olive oil mill wastewater treatment: phytotoxicity reduction and biodegradability augmentation

Water Science & Technology ◽

10.2166/wst.2015.080 ◽

2015 ◽

Vol 71 (7) ◽

pp. 1097-1105 ◽

Cited By ~ 17

Author(s):

Ahmadreza Yazdanbakhsh ◽

Fayyaz Mehdipour ◽

Akbar Eslami ◽

Hajar Sharifi Maleksari ◽

Farshid Ghanbari

Keyword(s):

Olive Oil ◽

Ferric Chloride ◽

Oxygen Demand ◽

Suitable Condition ◽

Organic Load ◽

Olive Oil Mill Wastewater ◽

Polyaluminum Chloride ◽

Coagulation Process ◽

Cracking Process ◽

Final Effluent

Olive oil mill wastewater (OOMW) is one of the most important industrial wastewaters in the world due to high organic load and phenolic compounds. In this study, an integration of three processes including coagulation, acid cracking and Fenton-like was evaluated to treat OOMW. The performance of alum, ferric chloride and polyaluminum chloride was studied as coagulants. Among coagulants, ferric chloride showed the best results in comparison with the others. Coagulation process with FeCl3 removed 91.2% chemical oxygen demand (COD), 91.3% phenol, 98.9% total suspended solids and 99.2% turbidity at condition of pH = 6 and 3,000 mg/L coagulant dosage. Acid cracking process following the coagulation process with ferric chloride could slightly degrade organic compounds and provided suitable condition for the next process. Fenton-like process with zero valent iron (ZVI) was applied after coagulation and acid cracking. The optimal removal efficiency was achieved by Fenton-like process which was accomplished in condition of 7 g/L ZVI, 1,000 mg/L H2O2 and 180 min reaction time. The biodegradability of final effluent of this integration was improved significantly and biochemical oxygen demand5/COD value increased from 0.14 to 0.83. The results of germination tests revealed that phytotoxicity of the final effluent decreased.

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Brewing process development by integration of edible filamentous fungi to upgrade the quality of brewer’s spent grain (BSG)

BioResources ◽

10.15376/biores.16.1.1686-1701 ◽

2021 ◽

Vol 16 (1) ◽

pp. 1686-1701

Author(s):

Mohsen Parchami ◽

Jorge A. Ferreira ◽

Mohammad J. Taherzadeh

Keyword(s):

Protein Content ◽

Filamentous Fungi ◽

Process Development ◽

Environmental Benefits ◽

Submerged Cultivation ◽

Content Increase ◽

Brewer’S Spent Grain ◽

High Fiber ◽

Spent Grain ◽

Edible Filamentous Fungi

Brewer’s spent grain (BSG) is the main solid by-product of the brewing sector. High moisture and nutrient-rich content render BSG easily perishable, leading to waste generation and environmental impacts. BSG has narrow applications in both feed and food sectors due to its composition including high fiber and low protein. Therefore, a processing strategy leading to the nutritional valorization of BSG could widen its applications. In this study, submerged cultivation of edible filamentous fungi (Aspergillus oryzae, Neurospora intermedia, and Rhizopus delemar) was introduced as a strategy to enhance the protein content of BSG. The growth of all strains in BSG increased the protein content of the fermented BSG. The highest increase of protein content (from 22.6% to 34.6%), was obtained by cultivation using A. oryzae and medium supplementation. The protein content increase was followed by a decrease in the content of polysaccharides (up to ca. 50%), namely starch, glucan, xylan, and arabinan. The addition of cellulase resulted in enhanced ethanol production from BSG but led to lower concentration of recovered solids. In conclusion, simple processing of BSG using edible filamentous fungi can lead to quality improvement of BSG, providing potential economic and environmental benefits to the brewing sector.

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