Optimization of the conditions for adsorption of fluoride in aqueous solution by carrot residue using central composite design of experiment

This study employs the use of carrot residue (CR) treated with dilute hydrochloric acid to remove fluoride ions in aqueous solution. The adsorption process parameters of pH, time of contact, adsorbent mass and initial ion concentration were optimized at ambient temperature by the use of central composite design of experiment. The CR absorbent was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microcopy (SEM). Quadratic model was used to correlate the variables to the responces obtained from the design matrix in the laboratory and analysis of variance was used to test the significance of the independent variables and their interactions. Predicted values of % adsorption at optimum conditions for commercial activated carbon (AC) which served as control and CR were validated. From the results obtained, the optimum adsorption conditions were pH 5, time of contact 96 min, mass of adsorbent 1g and initial ion concentration of 10mg/L with desirability of 1. The design predicted values and experimental values obtained for AC were 85.63% and 87.59%, while those of CR were 87.67±0.02% and 90.25±0.02% respectively. From the results obtained, it was concluded that CR was as effective and a better adsorbent for removal of fluoride ions in aqueous solution than AC. Therefore, CR is a potential alternative to AC for fluoride adsorption in aqueous solution.Keywords: Carrot Residue; Adsorption; fluoride; central composite desig

Technological advancements in valorization of second generation (2G) feedstocks for bio-based succinic acid production

Succinic acid (SA) is used as a commodity chemical and as a precursor in chemical industry to produce other derivatives such as 1,4-butaneidol, tetrahydrofuran, fumaric acid, and bio-polyesters. The production of bio-based SA from renewable feedstocks has always been in the limelight owing to the advantages of renewability, abundance and reducing climate change by CO2 capture. Considering this, the current review focuses on various 2G feedstocks such as lignocellulosic biomass, crude glycerol, and food waste for cost-effective SA production. It also highlights the importance of producing SA via separate enzymatic hydrolysis and fermentation, simultaneous saccharification and fermentation, and consolidated bioprocessing. Furthermore, recent advances in genetic engineering, and downstream SA processing are thoroughly discussed. It also elaborates on the techno-economic analysis and life cycle assessment (LCA) studies carried out to understand the economics and environmental effects of bio-based SA synthesis.Biotechnology and Biological Sciences Research Council (BBSRC): BB/S011951/1. Innovate UK. Department of Biotechnology, India

Towards determining details of anaerobic growth coupled to ferric iron reduction by the acidophilic archaeon 'Ferroplasma acidarmanus' Fer1

Elucidation of the different growth states of Ferroplasma species is crucial in understanding the cycling of iron in acid leaching sites. Therefore, a proteomic and biochemical study of anaerobic growth in 'Ferroplasma acidarmanus' Fer1 has been carried out. Anaerobic growth in Ferroplasma spp. occurred by coupling oxidation of organic carbon with the reduction of Fe3+; but sulfate, nitrate, sulfite, thiosulfate, and arsenate were not utilized as electron acceptors. Rates of Fe3+ reduction were similar to other acidophilic chemoorganotrophs. Analysis of the 'F. acidarmanus' Fer1 proteome by 2-dimensional polyacrylamide gel electrophoresis revealed ten key proteins linked with central metabolic pathways >= 4 fold up-regulated during anaerobic growth. These included proteins putatively identified as associated with the reductive tricarboxylic acid pathway used for anaerobic energy production, and others including a putative flavoprotein involved in electron transport. Inhibition of anaerobic growth and Fe3+ reduction by inhibitors suggests the involvement of electron transport in Fe3+ reduction. This study has increased the knowledge of anaerobic growth in this biotechnologically and environmentally important acidophilic archaeon