Rhamnolipid Biosurfactant: Use for the Removal of Phenol from Aqueous Solutions by Micellar Solubilization

Abstract

Selective measurements of the self-diffusion coefficients of molecules of the biological surfactant rhamnolipid (RL) in individual aqueous solutions and in solutions with phenol as a solubilizate were carried out by nuclear magnetic resonance (NMR) diffusometry. Based on the obtained results, the solubilization characteristics of RLs were calculated. They are the fraction of solubilized phenol molecules, the phenol micelle−water distribution coefficient, the molar solubilization coefficient, the hydrodynamic radii of RL monomers and micelles, the aggregation numbers of micelles, and the solubilization capacity of micelles. Fraction of the solubilized phenol molecules increases and approaches 80−90% with increasing RL concentration. The solubilization capacity of the micelles increases from several units to 10 2 with an increase in both the concentration of RLs and the concentration of phenol in solution.

A Low-Cost Ecofriendly Oxidation Process to Manufacture High-Performance Polymeric Biosurfactants Derived from Municipal Biowaste

“…The SBP Ri fractions listed in Figure 3 contain all of the C types present in the above bacterial biosurfactants [ 55 , 56 , 57 ] together with aromatic C. In the Ri fractions, these C types represent the memories of the lipids and lignocellulosic proximates of the pristine materials chain from which they are derived, i.e., the crude as collected MBW, the crude SBP, and the oxidized SBP. For the products reported in Table 4 , which were analyzed for the surface activities, Table S1 reports the C types and functional groups composition and the values of several empirical parameters based on the sum and/or ratios of the C types and functional groups mol/mol % values.…”

“…For example, in the case of the chemical surfactants listed in Table 4 , obtained by the chemical-photochemical technology depicted in schemes 1 and 2, the relative impacts of the costs of the feedstock and of the product manufacture process are much different from the case of the rhamnolipids and sophorolipids bacterial surfactants produced exclusively through biotechnology. Rhamnolipids and sophorolipids are referred to as second-generation biosurfactants [ 53 , 54 , 55 , 56 , 57 ], which are produced through biological processes (biocatalysis or fermentation). Compared to chemical processes, biological processes present severe cost drawbacks for their scale up to the industrial level.…”