Potentiality of white-rot fungi in biosorption of nickel and cadmium: Modeling optimization and kinetics study.

The present study aimed to analyze simultaneous biosorption of Cd+2 and Ni+2 by living Phanerochaete chrysosporium as low-cost and eco-friendly biosorbent following optimization by applying a central composite design. The effect of operating parameters such as solution pH (4.0-8.0), temperature (20-40 °C), contact time (3-15 h), initial Cd+2 and Ni+2 concentrations (15-35, 5-25 mg L-1, respectively) was evaluated by response surface methodology (RSM) for optimizing biosorption process. The Cd+2 and Ni+2 ions at 25 and 16 mg L-1 were accumulated in P. chrysosporium with the efficiency of 96.23% and 89.48%, respectively, at pH of 6 and 36 °C after around 9 h under well mixing. The equilibrium data were fitted well with Langmuir isotherm model with maximum biosorption capacity of 71.43 and 46.50 mg g-1 for Cd+2 and Ni+2, respectively. In addition, the pseudo-second order kinetic model could describe the kinetic data adequately. Further, possible interaction pathway among metals and P. chrysosporium functional groups were studied by Fourier transform infrared (FT-IR) spectroscopy. Furthermore, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) techniques were applied for morphology investigation and semi elemental analysis.

Fabrication of polyethyleneimine modified cobalt ferrite as a new magnetic sorbent for the micro-solid phase extraction of tartrazine from food and water samples.

In this research, a facile synthesis route was used for preparation of cobalt ferrite@SiO2@polyethyleneimine magnetic nanoparticles (Co-Fe2O4@PEI) as a new sorbent in the service of ultrasound assisted dispersive micro-solid phase extraction (UA-DMSPME) for influential clean-up, preconcentration, and determination of tartrazine (TA) prior to UV-Vis spectrophotometric detection. The understudy sorbent was fully characterized by transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Energy dispersive X-ray analysis (EDX), and vibrating sample magnetometer (VSM). Different operating parameters which affected the extraction efficiency of TA viz. sorbent dosage, extraction time, pH, and volume of eluent were investigated and optimized by using central composite design (CCD). Under optimal conditions, the enrichment and preconcentration factor, limit of detection (LOD), quantification (LOQ), and precision were obtained 98.01, 66.67, 5.09, and 16.96 ng mL-1, and <5.5% respectively. Good linear response (20-4000 ng mL-1) over the tested concentration range was achieved with the value of R2 = 0.9977. Satisfactory recoveries (>99.5%) of TA in complicated samples including saffron spray, cotton candy and water samples were achieved. This superior validation implies high applicability of the purposed method in terms of it being simple, fast, effective, and accessible: all of these allow for accurate analysis at the trace level.