CONTRIBUTION TO THE PHYTOCHIMIC STUDY AND THE ANTIOXIDANT ACTIVITY OF THE ESSENTIAL OIL OF THE WILD CARROT

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Co-Adsorption of Alkylphenols and a Non-Ionic Surfactant onto Bentonite

The influence of a non-ionic surfactant on the adsorption behaviour of alkylphenols onto bentonite was studied via measurements of their adsorption isotherms in the absence and presence of various concentrations of the surfactant. Irrespective of the presence of the surfactant, the alkylphenols were always adsorbed by the same mechanism. However, on adding the non-ionic surfactant TX100 to the medium, the adsorption properties were modified in a manner which depended on the alkyl chain length of the alkylphenol molecule. The longer the chain length, the weaker the influence of the TX100 surface aggregates on the adsorption behaviour. In terms of the relative hydrophobicity of these molecules, this behaviour is unexpected. However, it may be due in part to the adsorbing properties of the alkylphenols that are capable of self-aggregating at the bentonite/water interface and in part to the limited swelling capacity of the TX100 micelles or surface micelles. Partition coefficients between aqueous solution and surface aggregates were determined and compared with those calculated for the bulk micelles

Assessment of dehulling effect on volatiles, phenolic compounds and antioxidant activities of faba bean seeds and flours

The effects of dehulling and milling of seeds on the volatiles of two Vicia faba L. cultivars were evaluated using headspace-solid phase micro-extraction (HS-SPME) coupled to gas chromatographymass spectrome- try (GC-MS). The phenolic constituents and antioxidants activities were also estimated on the same kind of samples. A total of 36 volatiles belonging to six different chemical classes were identified. Among them, 11 compounds were determined in the emission profile of whole faba bean seeds, 19 from dehulled legume seeds, 14 from whole seed flours, and 24 from dehulled seed flours. A difference in term of volatiles was observed between whole and dehulled seeds and flours. Additionally, the evaluation of phenolic compounds and antioxidant activities showed significant differences between dehulled seeds in comparison to the corre- sponding whole ones, in terms of total antioxidant capacity, DPPH radical scavenging activity, b-carotene bleaching test, and iron reducing power. Nevertheless, the dehulling effect did not affect the total phenols, flavonoids, and tannins contents. Besides phenolic compounds in whole and dehulled faba bean flours, ascor- bic acid was detected by HPLC-UV-DAD in both cultivars

Advanced treatments for the removal of alkylphenols and akylphenol polyethoxylates from wastewater

International audienceSince the 2000s, among organic contaminants, alkylphenols and alkylphenol polyethoxylates have been listed as hazardous substances by several national, European and international agencies because they are considered endocrine disruptors. Among the molecules classified as priority substances in terms for monitoring and action, nonylphenols and octylphenols and their polyethoxylated derivatives receive particular attention, especially in developing countries. Effluents from treatments plants are considered to be the largest source of alkylphenols in the environment. Although legislation concerning their use has become increasingly strict, these substances are still found in the environment, especially in water resources. The existing water and wastewater treatment plants have not been designated for these emerging contaminants. Conventional treatments such as biodegradation, sand filtration, carbon adsorption and/or chemical oxidation in place are not effective in their elimination removal. No appropriate methods have been developed to deal them at the urban or industrial scale. Thus, alkylphenols have become a relevant research topic for scientists interested in water engineering issues related to their treatment. However, the challenge is not simple, as it is difficult to remove trace contaminants from complex mixtures of substances in a way that is chemically effective, technologically simple, economically viable, and environmentally friendly.The main objective of this chapter is to summarize recent trends in proposed advanced treatment methods for the removal of alkylphenols and alkylphenol polyethoxylates from wastewater. After general and brief considerations on these emergingcontaminants, this chapter focuses on adsorption-oriented processes, biotechnological methods, and advanced oxidation processes. Among the advanced methods described and discussed are removal of alkylphenols and alkylphenol polyethoxylates by adsorption onto cyclodextrin polymers, clays or molecularly imprinted polymer, biodegradation using microalgae or constructed wetlands or by sequential anaerobic-aerobic digestion processes, treatments based on ozone-carbon coupling, electrochemical degradation, photocatalysis, zero-valent iron-activated persulfate coupling and catalytic ozonation. Among these technologies, advanced oxidation processes, in association with biodegradation and/or adsorption, seem to be the technique of the future, although their costs still prevent their widespread use

Innovative technologies to remove alkylphenols from wastewater: a review

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