Burkholderia cepacia immobilized on eucalyptus leaves used to simultaneously remove malachite green (MG) and Cr(VI).

A multifunctional biomaterial capable of simultaneously removing malachite green (MG) and Cr(VI) was prepared by immobilizing Burkholderia cepacia (B. cepacia) on eucalyptus leaves (EL). The maximum uptake of MG (60 mg/L) and Cr(VI) (20 mg/L) were 94.8% and 71.9% respectively, which was more efficient than when using EL or free cells alone. SEM-EDS demonstrated that B. cepacia was attached to EL and that Cr(VI) was biosorbed into the immobilized cells. FTIR showed that the degradation by functional groups of immobilized cells was in keeping with the products, detected by GC-MS, which suggested that MG could be degraded to 4-dimethylamino benzophenone and 4-dimethylamino phenol. The removal of both MG and Cr(VI) by EL immobilized cells fit the pseudo-second order adsorption kinetic model well (with both R2>0.983). The equilibrium adsorption capacity of MG was 9.59, 18.67 and 28.64 mg/g for initial MG concentrations of from 30, 60, 90 mg/L, respectively when the concentration of Cr(VI) was held constant at 20 mg/L. The adsorption capacity of Cr(VI) increased from 3.49, 7.68 to 9.79 mg/g as the initial Cr(VI) concentrations increased (10, 20, 30 mg/L) while the MG concentration was kept constant at 60 mg/L. The results showed that eucalyptus leaves as a low cost and eco-friendly material have some potential to be an effective immobilization for environmental applications.

Burkholderia vietnamiensis C09V as the functional biomaterial used to remove crystal violet and Cu(II).

Burkholderia vietnamiensis C09V (B.V. C09V) was used to remove both crystal violet (CV) and Cu(II) because dye effluents often contain dyes and metal ions. Inhibiting the strain׳s growth through the biosorption of Cu(II) on B.V. C09V and promoting its growth by using CV as a carbon source led to the degradation of CV (30mg/L). It fell to 36.9 percent and the amount of Cu(II) (50mg/L) removed rose to 34.9 percent in the presence of both CV and Cu(II). This outcome is comparable to the single presence of CV and Cu(II). EDS analysis showed that Cu(II) was adsorbed onto the strain (the atomic percentage of Cu(II) was 1.9 percent), while kinetic studies indicated that firstly, the decolorization of CV fitted well to the pseudo first-order degradation kinetic model and secondly, the biosorption of Cu(II) fitted well to the pseudo second-order kinetic model. The degradation rate constants of CV were stable in the 0.101-0.0068/h range and R(2) was both higher than 0.981 when Cu(II) concentrations were present. Furthermore, the biosorption capacity of Cu(II) ranged from 38.8 to 20.3mg/g at the CV concentration of 30mg/L (both R(2)>0.96). This suggests that the strain has the potential to degrade CV and facilitate the biosorption of Cu(II) in dye effluent.