Wastewater treatment enhancement by applying a lipopeptide biosurfactant to a lignocellulosic biocomposite.

In this work, a natural lipopeptide biosurfactant obtained from corn steep liquor was included in the formulation of a lignocellulosic biocomposite used for the treatment of wastewater. The results obtained indicate that the dye sorption capacity of the hydrogel containing hydrolysed vineyard pruning waste can be significantly promoted via surfactant modification using natural detergents. The elimination of dye compounds and the removal of sulphates were increased around 10% and 62%, respectively, when the biocomposite modified with biosurfactant was used. This outcome can be intrinsically related to the rougher, rounder, more compact and better-emulsified sphere achieved after the addition of the lipopeptide biosurfactant. The bioadsorption process followed a pseudo-second order kinetic model and both intraparticle diffusion and liquid film diffusion were involved in the bioadsorption mechanism. Therefore, the utilisation of biosurfactants shows great potential in the formulation of eco-friendly adsorbents for environmental application.

Selective removal of ATP degradation products from food matrices II: Rapid screening of hypoxanthine and inosine by molecularly imprinted matrix solid-phase dispersion for evaluation of fish freshness.

A water compatible molecularly imprinted polymer (MIP), synthesized using theophylline (TPH) as dummy-template and acrylamide (AM) as functional monomer, has been employed as supporting material in matrix solid-phase dispersion combined with ultra performance liquid chromatography-photodiode array detection (MSPD-UPLC-PDA) for selective determination of adenosine triphosphate (ATP) derivatives in fish samples. ATP degradation products are used as freshness index for assessment of fish quality. The solid sample was directly blended with MIP in MSPD procedure resulting in sample disruption and subsequent adsorption of the compounds on the MIP. By using n-hexane and ammonium hydroxide aqueous solution at pH 9 as the washing and elution solvent, respectively, satisfactory recoveries and clean chromatograms have been obtained. Good linearity for hypoxanthine (HYP) and inosine (INO) has been observed with correlation coefficients (R(2)) of 0.9987 and 0.9986, respectively. The recoveries of the two ATP derivatives at three different spiked levels ranged from 106.5% to 113.4% for HYP and from 103.1% to 111.2% for INO, with average relative standard deviations lower than 4.2% in both cases. This new method, which is rapid, simple and sensitive, can be used as an alternative tool to conventional tedious methods.

Removal of pigments from aqueous solution by a calcium alginate-grape marc biopolymer: a kinetic study.

In this work, the potential use of a biopolymer based on grape marc entrapped in calcium alginate beads for the removal of pigments from an agro industrial effluent was evaluated. The parameters that affect the pigment adsorption such as pH (3.5-7.0), temperature (10-40°C) and initial pigment concentration (6.9-55.1mg/L) were studied by applying an incomplete factorial design. The dependent variables evaluated consisted of color effluent parameters from CIELAB and Tristimulus system, as well as the concentration of pigments in the wastewater after the adsorption treatment. The most significant independent variables tested were the pigments concentration followed by pH, whereas temperature had a negligible effect on the adsorption process. Moreover, at the optimal operational conditions (pH 3.5 and room temperature) kinetic studies were carried out by applying pseudo-first order, pseudo-second order, Chien-Clayton and intraparticle diffusion models, observing a good agreement between theoretical and experimental results.