---

In current research, Pseudomonas putida @ Chitosan hybrid biosorbent capability for U(VI) biosorption in a fixed bed column was investigated. The results showed that the increase in inlet concentration from 50 to 200 mg/L increased the biosorption capacity from 188.75 to 429.28 mg/g. In the column system, the sorption capacity was higher than that of the batch system because fixed bed column make best use of the inlet concentration difference as sorption driving force. Decrease in inlet flow rate through increase in the residence time for better diffusion or interaction as well as greater access to binding sites for uranium ions caused an improvement in column performance. Decline in the biosorption capacity due to increase in the inlet flow rate demonstrated that intraparticle diffusion was the rate-controlling step. With decreasing in the sorbent particle size from 1.5 to 1 mm, a significant increase in the biosorption capacity from 179.02 to 296.87 mg/g was achieved. FTIR and potentiometric titration confirmed that while –NH₃⁺ was the dominant functional group in the chitosan, –NH₃⁺, –NH₃, –OH, –COOH were responsible for the hybrid biosorbent. In conclusion, the present study indicated that Pseudomonas putida @ Chitosan could be a suitable biosorbent for U(VI) biosorption from aqueous solution in the continuous system.

---

In this work, the physicochemical properties of commercial guar gum powder were investigated after air atmospheric pressure cold plasma treatment at three different times (5, 10 and 15 min). The results of steady shear flow test showed that behavior of both control and cold plasma treated samples was pseudoplastic. Among the rheological models, the Hershel bulkley model had higher coefficient of determination (R²). The n_H in the control and treated samples was less than 1. Also, K_H decreased significantly with time (except 5 minutes). In strain sweep, storage module G′ and loss module G″ decreased significantly as the time increased. The crossover point (G′=G″) of 5 minutes treated sample for 5 minutes was higher than the control samples, which decreased with increasing the treatment time. In the low frequency range of frequency sweep, G″ module of the control and treated samples was higher than G′ module. From the frequency of 0.1 to 1 Hz, the G′ and G″ modules depended on the frequency. After crossover, the G″ module prevailed over the G′ module and the guar gum showed weak gel behavior. The value of tanδ in samples was less than 1 and higher than 0.1. The complex viscosity (η*) significantly decreased, as the time of treatment increased. The slope of complex viscosity decreased with the increasing time. The FTIR data demonstrated that the absorption spectrum of the treated samples was similar to the control one.

---

Nowadays, cold atmospheric pressure plasmas are used as an efficient method in food industries. The advantage of plasma method compared to other method are high productivity, cost-effectiveness and reduction of harmful chemical pollutants. In this study, cold atmospheric
pressure dielectric barrier discharge plasma in surface and volumetric treatment mode was produced, and its effect on the physical and chemical properties of saffron was investigated. For this purpose, after the production and characterization of plasma structures including electrode structure, electrical properties and optical emission spectroscopy, the influence of these structures on the physical and chemical properties of saffron was investigated. At first, the effect of surface and volumetric plasma treatment on degradation of Escherichia coli bacteria was investigated. The results showed that surface dielectric barrier discharge plasma treatment with high treatment time has a great effect on inactivation of Escherichia coli. Then, the effect of surface and volume treatments on the main properties of saffron including crocin, picrocrocin and safranal were investigated. The results showed that surface and volumetric plasma treatment increase the main properties of saffron,surprisingly.  Finally, the effect of surface and volumetric plasma treatments on increasing harmful substance in saffron including nitrate and ammonium was investigated. The results showed that volumetric treatment of plasma due to direct processing increase the harmful substances in saffron, including nitrate and ammonium. According to the results of this research, it can be concluded that the dielectric barrier discharge in surface treatment mode has advantages against volumetric treatment. The latter suffers from harmful by-products. In this regard, the surface treatment of saffron is  preferable to volumetric