Improved levulinic acid production from agri-residue biomass in biphasic solvent system through synergistic catalytic effect of acid and products.

In this study, levulinic acid (LA) was produced from rice straw biomass in co-solvent biphasic reactor system consisting of hydrochloric acid and dichloromethane organic solvent. The modified protocol achieved a 15% wt LA yield through the synergistic effect of acid and acidic products (auto-catalysis) and the designed system allowed facile recovery of LA to the organic phase. Further purification of the resulting extractant was achieved through traditional column chromatography, which yielded a high purity LA product while recovering ∼85% wt. Upon charcoal treatment of the resultant fraction generated an industrial grade target molecule of ∼99% purity with ∼95% wt recovery. The system allows the solvent to be easily recovered, in excess of 90%, which was shown to be able to be recycled up to 5 runs without significant loss of final product concentrations. Overall, this system points to a method to significantly reduce manufacturing cost during large-scale LA preparation.

Removal of ofloxacin from aqueous phase using Ni-doped TiO2 nanoparticles under solar irradiation.

Ni-doped TiO2 nanoparticles were prepared using hydrothermal method and characterized by means of XRD, TEM, and TGA. The detailed characterization results revealed that the catalyst possessed spherical morphology and excellent crystalline and thermal properties. Photocatalytic capability of Ni-doped TiO2 nanoparticles was estimated by means of ofloxacin degradation under solar light. About 70% degradation of ofloxacin (25 mg/L, natural pH) was obtained with 1 g/L catalyst dose. The microbiological analysis was carried by examining its antibacterial activity against E. coli culture on agar plate. The results indicated a decrease in antibacterial activity of drug solution with increase in irradiation time, which further supported the excellent catalytic behavior of the prepared Ni-doped TiO2.