Activated carbons from a mixture of olive-residue, oil and vegetable water, known as alperujo, OR, were prepared by KOH and H3PO4 activation. KOH activations were made following two different methods ...(carbonization-activation and impregnation-activation) with two different KOH/carbon ratios. Textural characterization with N2 and CO2 reveals that a prior carbonization of samples followed by the activation with KOH, produces samples with similar textural and chemical properties to the impregnated ones at low KOH ratio, while at high KOH ratio; more porous samples are obtained by carbonization. However, no differences are observed increasing the KOH ratio for the impregnated samples. As a consequence, similar or even more porous samples are obtained by using an easier preparation method such as carbonization-activation. On the other side, H3PO4 activation leads to samples with less surface area but with a more developed mesoporosity. In addition, the chemical surfaces of KOH and H3PO4 activated samples are very different as shown by XPS and TPD results. XPS data denote a similar chemical texture in KOH activated samples in spite of the different preparation methods and KOH ratio, whereas the H3PO4 method fixed different phosphorus surface groups. Analysing TPD data while on KOH activated samples, oxygenated surface groups (OSG) decompose mainly as CO2 (carboxylic acid, anhydrides, lactones, etc.) during the TPD experiments, on H3PO4 activated one those OSG ones evolve as CO (semiquinone, carbonyl, etc.) which has been attributed to the presence of COP species that decompose in the form of CO at around 860°C. As a consequence, similar electrochemical capacitances are obtained using KOH activated samples, which depend linearly on the surface area while the H3PO4 activated one presents higher capacitance value and capacitance stability in spite of its smaller surface area. This fact was related with the presence and nature of phosphorus surface groups.
► We studied the effects of olive horticultural conditions on olive mill wastewater. ► Irrigation and fruit maturation significantly influenced wastewater properties. ► There was no correlation ...between fruit water content and wastewater properties. ► The variability of olive mill wastewaters should be considered in their management.
Olive mill wastewaters (OMW) were obtained at laboratory scale by milling olives from four cultivars grown at different irrigation levels and harvested at different times. Samples were compared based on wastewater quantity, pH, suspended matter, salinity, organic load, total phenols, NPK, and phytotoxicity. Principal component analysis discriminated between harvest times, regardless of olive cultivar, indicating substantial influence of fruit ripeness on OMW characteristics. OMW properties were affected both by the composition and the extraction efficiency of fruit water. As the fruit water content increased, the concentrations of solutes in the fruit water decreased, but the original fruit water composed a larger portion of the total wastewater volume. These contradicting effects resulted in lack of correlation between fruit water content and OMW properties. The significant effects shown for fruit ripeness, irrigation and cultivar on OMW characteristics indicate that olive horticultural conditions should be considered in future OMW management.
The present study reports the valorization of the olive vegetable water in natural dyeing. HPLC analysis of the phenolic extract obtained from the used olive vegetable water showed that the ...predominant flavonoid compounds were luteolin and apigenin. Hydroxytyrosol and various phenolic acids were also identified. This abundant waste was used as a possible dye bath for dyeing polyamide fabrics in conventional and ultrasonic techniques. It was found that these synthetic fibers possess high affinity to the olive vegetable water giving brownish shades with generally good fastness properties. Factors affecting the dyeing performances such as pH, temperature, and duration of the dyeing time were studied. Ultrasonic dyeing showed marked improvement in the dye uptake compared to the conventional heating. The results also showed that the use of this method enhanced some fastness properties compared to the conventional method. Moreover, it was found that using ultrasonic technique can reduce the concentration of polyphenols so that it reduced the chemical oxygen demand
COD
and biological oxygen demand
BOD
5
better than conventional heating method.
Effect of methanol extracts of rosemary and olive vegetable water on the stability of olive oil and sunflower oil. Methanol phenolic extracts of dry rosemary leaves and olive vegetable water ...filtrate, in combination with BHA, were added to olive oil (blend of refined and virgin olive oil, 3 to 1) and to sunflower oil and their antioxidant effects under accelerated conditions were evaluated. Accelerated conditions included the oven test (at 63 °C) and the conductivity method (Rancimat at 120 °C). Frying process at 180 °C was also applied. The methanol phenolic extracts and the BHA were added to each oil at the following concentrations: 200 ppm rosemary extract; 200 ppm olive vegetable water extract; 100 ppm rosemary extract + 100 ppm BHA; 100 ppm vegetable water extract + 100 ppm BHA and 200 ppm BHA. In general, antioxidant effect of phenolic additives of rosemary and of BHA was in the following order: 200 ppm rosemary extract > 100 ppm rosemary extract + 100 ppm BHA > and 200 ppm BHA. The addition of 200 ppm vegetable water extract and 100 ppm vegetable water extract + 100 ppm BHA exhibited similar antioxidant effect to that of 200 ppm BHA.
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