In this study, the removal of biophenols from olive mill wastewater by activated carbon of different particle sizes has been carried out using the batch adsorption technique. The effects of the sorbent specific surface area and concentration, temperature, initial biophenols concentration, and contact time on the adsorption efficiency have been analyzed independently. The sorbent yields higher removal efficiency of biophenols as its specific surface area increases. When increasing the sorbent concentration from 10 to 50 g L À1 , the sorbent uptake capacity increases from 20% to 41%, and it reaches a maximum value of 65 mg g À1 at 298.2 K. Adsorption of olive mill wastewater biophenols is moderately rapid, being about 38% to 40% of the initial phenolic content after 120 min. Kinetic analysis shows that the adsorption process can be approximated by a pseudo-second-order model for which pore diffusion is the essential rate-controlling step. Equilibrium modeling by linearized adsorption isotherms reveals that a Langmuir-type isotherm with a preferable monolayer sorption would likely proceed. Calculated thermodynamic parameters such as Gibbs energy, enthalpy, entropy, activation energy, and sticking probability indicate that adsorption is a typical endothermic yet spontaneous process with a preferable physisorption mechanism. An external mass transfer coefficient model has been developed to determine the rate of adsorption controlled initially by the boundary layer film, with particular focus on its predictive performance.
Fifteen novel aryl, substituted aryl and heteroaryl γ-hydroxy- (2a-e), γ-methoxyimino- (3a-e), and γ-benzyloxyimino- (4a-e) butyric acid methyl esters were investigated for their enzyme inhibition, and the synthesis of 10 compounds (3a-e, 4a-e) is given in this study. The other five compounds (2a-e) were synthesized before in another study. Compounds 3a-e and 4a-e were synthesized in this work as original compounds and characterized by H and C NMR, IR, mass, and elemental analyses. Their (E/Z)-isomerisation ratios were analyzed by H and C NMR. All of them are of pure (E)-configuration. Due to the literature survey, the elastase inhibition activity was not studied for these compounds. Elastase inhibition ability was investigated in this work for five γ-hydroxy- (2a-e), five γ-methoxy- (3a-e), and five γ-benzyloxyimino- (4a-e) butyric acid methyl esters. All these 15 compounds showed elastase inhibition activity. Compound 2b was the best one and exhibited a better activity than the standard ursolic acid whereas compound 2a worked like the standard. All these compounds can be novel elastase inhibitor agents in the pharmaceutical and cosmetic industries.
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