Fermentation Production Of Bacterial Cellulose And Its Adsorpyion To Heavy Metal Ions

The effects of different fermentation conditions and nutrient content on the synthesis of bacterial cellulose?BC?were studied of the laboratory Strains,named Komagataeibacter,and to optimize the factors that affect the production of bacterial cellulose.The effects of pH,inoculation and culture temperature on the contents of carbon,nitrogen,organic and phosphate in the culture medium were investigated.Explore the effects of the concentration media components on the amount of bacterial cellulose synthesis,three main elements of the response surface test design center point:30 g/L,2 mL/L,1.0 g/L.Finally,the highest synthesis of BC was achieved by response surface analysis,The highest synthesis of BC could reach 6.281g/L.The optimal medium composition was glucose 24 g/L,sucrose 17 g/L,yeast leaching 32.153 g/L,acetic acid 2.013 mL/L,KH₂PO₄ 1.026 g/L.The optimum culture conditions were obtained by test at a temperature of 30°C,an inoculation amount of 1.5%and an initial pH of 5.0.According to the validation experiment,it was possible to obtain 6.713 g/L by using the optimized culture condition.The structure and properties of the obtained bacterial cellulose were studied by a variety of analytic instruments The result was consistent with the structure of the group contained in the cellulose standard,indicating that the bacterial cellulose was extracted from the experiment.Then,the elements were analyzed.Bacterial cellulose contains C,H,O.The purity of the bacterial cellulose obtained in the laboratory was higher than 98%,and the purity of the bacterial cellulose reached a high level.Observing the bacterial cellulose by scanning electron microscopy,it can be seen that the bacterial cellulose is presented with the intertwined and irregular flocculation between the microfine cellulose filaments with a large number of microstructures.Analysis of bacterial cellulose for water retention,we can see that the bacterial cellulose membrane has a high water content and water absorption.Since the bacterial cellulose is a nanoscale ultrastructure,the drying process causes the original structure of the bacterial cellulose to be destroyed and can not be restored to the swelling state before drying,resulting in a higher moisture content of the cellulose.In this paper,the bacterial cellulose was measured for water retention,and it was found that its water absorption and water holding capacity were particularly good.The adsorption effect of bacterial cellulose on some heavy metal ions was investigated.The effects of pH,ion concentration and the amount of adsorbent on the experimental results were investigated under different conditions.The adsorption conditions of Cr²⁺were pH 1.5,the dosage of bacterial cellulose was1.0 g/L,the adsorption effect was the best when the ion concentration was 100?g/mL,and the adsorption condition of Cu²⁺was pH 5.0,The dosage of cellulose was 1.0 g/L,and the ion concentration was 100?g/m L,the adsorption effect was the best.The adsorption effect of bacterial cellulose on Cr⁶⁺was better than Cu²⁺,and the adsorption capacity was 16.1 mg/g and10.5 mg/g,respectively.The results showed that Cu²⁺and Cr⁶⁺could adsorb Cu²⁺and Cr⁶⁺,which was able to be effectively desorbed by 0.02 mol/L HCl solution.After two cycles of adsorption,BC was able to adsorb Cu²⁺and Cr⁶⁺desorption rate was 90.6%and 93.2%,so the bacterial cellulose as a heavy metal adsorbent can be repeated.