Concentrating Model Solutions and Fruit Juices Using CO2 Hydrate Technology and Its Quantitative Effect on Phenols, Carotenoids, Vitamin C and Betanin

Fruits have an important economic impact in the context of plant-based food production. The consumption of fruit juices, mostly produced from concentrates, is particularly noteworthy. Conventional concentration methods do not always enable a sustainable and gentle concentration. The innovative gas hydrate technology addresses this point with its energy-saving, gentle character, and high concentration potential. In this study, the concentration of fruit juices and model solutions using CO2 hydrate technology was investigated. To find a suitable operating point for hydrate formation in the used bubble column, the hydrate formation in a water–sucrose model solution was evaluated at different pressure and temperature combinations (1, 3, 5 °C and 32.5, 37.5, 40 bar). The degrees of concentration indicate that the bubble column reactor operates best at 37.5 bar and 3 °C. To investigate the gentle processing character of the hydrate technology, its quantitative effects on vitamin C, betanin, polyphenols, and carotenoids were analyzed in the produced concentrates and hydrates via HPLC and UV/VIS spectrophotometry. The results for fruit juices and model solutions imply that all examined substances are accumulated in the concentrate, while only small amounts remain in the hydrate. These amounts can be related to an inefficient separation process.

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Degradación del 2,5-DCP en agua destilada y en agua residual por los procesos de oxidación avanzada con ozono y ozono-UV combinados con un tratamiento biológico

10.24275/uama.6735.7459 ◽

2016 ◽

Author(s):

◽

Jacqueline Catherine Alexander

Keyword(s):

Activated Sludge ◽

Municipal Wastewater ◽

Bubble Column ◽

Bubble Column Reactor ◽

High Concentration ◽

Ozone Dose ◽

Pore Glass ◽

Pharmaceutical Industries ◽

Uv Lamp ◽

By Products

In recent years, there have been increases in contamination of water supplies, due to the continuous discharge of wastewater from chemical and pharmaceutical industries, without them being properly treated to remove the refractory organic compound they may contain. These contaminants endanger the quality of surface and groundwater, the ecosystems, and the health of the world´s population. In view of these problems, the present work examined the effectiveness of combining ozone and ozone-UV processes with a biological treatment to increase biodegradability and reduce toxicity levels of the chlorophenolic compound, 2,5-dichlorophenol (2,5-DCP) and its oxidative intermediates. A comparative study was carried out in a glass bubble column reactor equipped with a fine-pore glass diffuser with a volumetric mass transfer kLa of 1.58 min-1. Each experiment was done using a 1.5 L volume of 2,5-DCP (3.07 mM) aqueous solution of distilled water and municipal wastewater, at pH 7 with an applied ozone dose of 22 mg min-1 and an oxygen-ozone flow rate of 0.7 L min-1. Additionally, a low mercury UV lamp with wavelength of 254 nm was used during ozone-UV treatments. The results obtained, showed that 2,5-DCP was completed degraded with an ozone dose of approximately 1.2 g h-1 in both solutions, treated with ozone and ozone-UV processes. The best results were obtained with the ozone-UV processes after 60 min of oxidation, showing that the addition of photolysis treatment (UV lamp intensity = 4 mW cm-2) to ozone, accelerated COD removal (75%), mineralization (53%) and biodegradability (BOD5/COD) of 2,5-DCP from 0.2 to 0.85 in the wastewater. The toxicity of 2,5-DCP and its oxidation by-products were monitored at different time intervals using activated sludge respiration inhibition tests. The test analyses showed that ozone and ozone-UV treatments were effective in reducing the toxicity of 2,5-DCP and its by-products, which were less toxic to the microorganisms in activated sludge (IC25 = 135 mg/L), than the untreated 2,5-DCP solutions (EC50= 50 mg/L). The results achieved in this work, showed that the presence of organic and inorganic matters in the wastewater, had a positive effect on the oxidation of 2,5-DCP, which support the potential use of ozone and ozone-UV processes for the treatment of effluent with high concentration of chlorophenols.

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