Ozone pretreatment of olive mill wastewaters (OMW) and its effect on OMW biochemical methane potential (BMP)

2013 ◽  
Vol 68 (12) ◽  
pp. 2712-2717 ◽  
Author(s):  
E. Tsintavi ◽  
N. Pontillo ◽  
M. A. Dareioti ◽  
M. Kornaros
Keyword(s):  
Oxygen Demand ◽  
Biochemical Methane Potential ◽  
Experimental Conditions ◽  
Olive Mill Wastewaters ◽  
Ozone Pretreatment ◽  
Methane Potential ◽  
Total Carbohydrates ◽  
Reactor Temperature ◽  
Glass Bubble ◽  
Olive Mill

The possibility of coupling a physicochemical pretreatment (ozonation) with a biological treatment (anaerobic digestion) was investigated for the case of olive mill wastewaters (OMW). Batch ozonation experiments were performed in a glass bubble reactor. The parameters which were tested included the ozone concentration in the inlet gas stream, the reactor temperature and the composition of the liquid medium in terms of raw or fractionated OMW used. In the sequel, ozone-pretreated OMW samples were tested for their biochemical methane potential (BMP) under mesophilic conditions and these results were compared to the BMP of untreated OMW. The ozonation process alone resulted in a 57–76% decrease of total phenols and a 5–18% decrease of total carbohydrates contained in OMW, depending on the experimental conditions. Nevertheless, the ozone-pretreated OMW exhibited lower chemical oxygen demand removal and methane production during BMP testing compared to the untreated OMW.

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.

scholarly journals Effect of key operating parameters on the non-catalytic wet oxidation of olive mill wastewaters

2009 ◽  
Vol 59 (12) ◽  
pp. 2509-2518 ◽  
Author(s):  
E. Chatzisymeon ◽  
E. Diamadopoulos ◽  
D. Mantzavinos
Keyword(s):  
Reaction Temperature ◽  
Treatment Time ◽  
Operating Conditions ◽  
Total Phenols ◽  
Oxidation Reactions ◽  
Catalytic Wet Oxidation ◽  
Air Oxidation ◽  
Experimental Conditions ◽  
Olive Mill Wastewaters ◽  
Olive Mill

The non-catalytic wet air oxidation (WAO) of olive mill wastewaters was investigated. The effect of operating conditions, such as initial organic loading (1,000 and 4,500 mg/L COD), reaction temperature (140 and 180°C), treatment time (1 and 4 h), initial pH (4.8 and 7) and the use of 500 mg/L H2O2 as an additional oxidant, on treatment efficiency was assessed implementing a factorial experimental design. Of the five parameters tested, the first two had a considerable effect on COD removal, while treatment time was of no significance implying that all oxidation reactions occur during the first hour of treatment. Although the level of mineralization was generally moderate, this was accompanied by nearly complete total phenols and color removal. The analysis was repeated at more intense conditions, i.e. initial COD up to 8,000 mg/L and reaction temperature up to 200°C; at this level, none of the studied effects were important. However, at optimal experimental conditions (i.e. 180°C, 1 h treatment and initial COD of 8,100 mg/L) WAO yielded 34, 94 and 74% removal of COD, total phenols and color respectively. Moreover, ecotoxicity to V. fischeri was slightly reduced after 2 h of treatment at the above conditions.

scholarly journals Biochemical Methane Potential Assessment by Anaerobic Digestion of Locally Available Grasses of Phuentsholing, Bhutan

2021 ◽  
pp. 135-144
Author(s):  
Yeshi Choden ◽  
Samten Zangmo ◽  
Saahin Tamang ◽  
Thinley Gyeltshen ◽  
Karma Phuntshok ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Resource Constraints ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Renewable Resource ◽  
Napier Grass ◽  
Inert Gases ◽  
Continuous Reactor ◽  
Biochemical Methane Potential ◽  
Methane Potential

Renewable energy is not only environmental friendly but also promotes sustainable development. Biogas being one of the abundantly used renewable resource, the enhancement and optimization of the yield of biogas can help in reduction of dependence on imported fuel. Biochemical methane potential (BMP) assessment of grass will determine the production of methane (CH4) from this substrate through the process of anaerobic digestion. After determining the parameters such as pH, Biochemical Oxygen Demand (BOD) and Total solids (TS) of three types of local grasses known as Basil, Bermuda and Napier, that affects the production of biogas, Napier grass resulted with the highest potential to produce CH4 gas. Batch and continuous reactor method under mesophilic condition was adopted. The composition of biogas from continuous reactor was obtained using a biogas analyzer (Biogas 5000 Geotech), from which 30.8% of CH4,  8% of CO2 and other inert gases were found. Also, methane to carbon dioxide (CH4: CO2) ratio of 3.81: 1 approximately (80% - 20%) was achieved. Moreover, the batch reactor method showed that 1L Napier grass silage would yield 0.81L of biogas. The concentration of CH4 gas from Napier grass in hydraulic retention time as short as 20 days was very significant. This study shows that Napier grass can be used as an alternative sustainable source of energy in the country which can improve resource constraints.

scholarly journals Eco-friendly approach for elimination of olive mill wastewaters (OMW) toxicity using cactus prickly pears juice as a coagulant

2020 ◽  
Vol 15 (4) ◽  
pp. 1050-1067
Author(s):  
M. Neffa ◽  
M. Taourirte ◽  
N. Ouazzani ◽  
H. Hanine
Keyword(s):  
Low Cost ◽  
Mixing Time ◽  
Oxygen Demand ◽  
Physicochemical Analysis ◽  
Jar Test ◽  
Coagulation Mechanism ◽  
Olive Mill Wastewaters ◽  
Series Of Experiments ◽  
Prickly Pears ◽  
Olive Mill

Abstract Currently, research focuses on the application of newer biocoagulant products in wastewater treatment. In this study, the performance of cactus juice to clarify Olive Mill Wastewater (OMW) was investigated by using Jar-test experimentation and assessed by physicochemical analysis of the obtained supernatant: turbidity, total suspended solids (TSS), (λ465; λ395) absorbance, polyphenols (pp), chemical oxygen demand (COD) and Fourier-Transform-Infrared spectroscopy (FTIR) on lyophilized sludge. A series of experiments were conducted to estimate the influence of various experimental parameters, such as the amounts of biocoagulants used, time, stirring speed, and pH. The study showed the optimal coagulation conditions were as follows: sample pH10; cactus juice dose, 10% (v/v); rapid mixing time, 30 s at a speed of 150 rp/min. Under these conditions, the overall removals of 74% for COD, 93% for turbidity and 51% for polyphenols were achieved. As referring to the FTIR analysis, the cactus juice of Opuntia spp. operates predominantly through an adsorption interparticle bridging coagulation mechanism. These results are encouraging in the context of developing a low-cost technology and eco-friendly approach for the effective management of OMW.

scholarly journals Novel Submerged Photocatalytic Membrane Reactor for Treatment of Olive Mill Wastewaters

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 769 ◽  
Author(s):  
Maria C. Fraga ◽  
Rosa M. Huertas ◽  
João G. Crespo ◽  
Vanessa J. Pereira
Keyword(s):  
Membrane Reactor ◽  
Suspended Solids ◽  
Sol Gel ◽  
Oxygen Demand ◽  
Treatment Technology ◽  
Olive Mill Wastewaters ◽  
Water And Wastewater ◽  
Gel Technique ◽  
Olive Mill ◽  
Photocatalytic Membrane Reactor

A new hybrid photocatalytic membrane reactor that can easily be scaled-up was designed, assembled and used to test photocatalytic membranes developed using the sol–gel technique. Extremely high removals of total suspended solids, chemical oxygen demand, total organic carbon, phenolic and volatile compounds were obtained when the hybrid photocatalytic membrane reactor was used to treat olive mill wastewaters. The submerged photocatalytic membrane reactor proposed and the modified membranes represent a step forward towards the development of new advanced treatment technology able to cope with several water and wastewater contaminants.

scholarly journals Pre-treatment of thickened waste activated sludge (TWAS) for enhanced biogas production via the application of a novel radial horn sonication technology

2017 ◽  
Vol 75 (9) ◽  
pp. 2179-2193 ◽  
Author(s):  
Sri Suhartini ◽  
Lynsey Melville ◽  
Tony Amato
Keyword(s):  
Activated Sludge ◽  
Biogas Production ◽  
Applied Pressure ◽  
Low Frequency ◽  
Waste Activated Sludge ◽  
Biochemical Methane Potential ◽  
Experimental Conditions ◽  
Working Volume ◽  
Methane Potential ◽  
Pre Treatment

The efficacy of sonication as a pre-treatment to anaerobic digestion (AD) was assessed using thickened waste activated sludge (TWAS). Efficiency was measured in relation to solubilisation, dewaterability, and AD performance. Eighteen experimental conditions were evaluated at low frequency (20 kHz), duration (2–10 s), amplitude (∼8–12 μm) and applied pressure (0.5–3.0 barg), using a sonix™ patented titanium sonoprobe capable of delivering an instantaneous power of ∼6 kW provided by Doosan Enpure Ltd (DEL). An optimised experimental protocol was used as a pre-treatment for biochemical methane potential (BMP) testing and semi-continuous trials. Four digesters, with a 2-L working volume were operated mesophilically (37 ± 0.5 °C) over 22 days. The results showed that the sonix™ technology delivers effective sonication at very short retention times compared to conventional system. Results demonstrate that the technology effectively disrupts the floc structures and filaments within the TWAS, causing an increase in solubilisation and fine readily digestible material. Both BMP tests and semi-continuous trials demonstrated that sonicated TWAS gave higher biodegradability and methane potential compared to untreated TWAS. Partial-stream sonication (30:70 sonicated to untreated TWAS) resulted in a proportionate increase in biogas production illustrating the benefits of full-stream sonication.

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