Removal of Acid Yellow 25 from Aqueous Solution by Chitin Prepared from Waste Snow Crab Legs

Acid Yellow 25 (AY25) is used in the textile industry for dyeing of natural and synthetic fibers, and is also used as a coloring agent in paints, inks, plastics, and leathers. Effluents from such industries are major sources of water pollution. Hence, it is important to find simple, efficient, and inexpensive ways to remove these dyes from wastewater. Here, we determined the suitability of chitin extracted from waste crab legs as an adsorbent for removing AY25 dye. The adsorption kinetics was modeled using pseudo-first order, pseudo-second order, and intraparticle diffusion equations to determine the rate controlling step. Results showed that the pseudo-second order adsorption mechanism is predominant, and the overall rate of the dye adsorption process is therefore controlled by an adsorption reaction. Adsorption isotherms were analyzed by utilizing the Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherm models at 23˚C, with data collected by using various initial dye concentrations with different chitin dosages. Our results show the highest correlation with the Langmuir model, consistent with the fact that chitin contains both a monolayer and homogeneous adsorption sites. Based on the D-R model, the adsorption of AY25 dye onto chitin is via chemisorption. Furthermore, we have concluded that the rate constants of both pseudo-second order adsorption and film diffusion are correlated to the initial dye concentrations and chitin dosages. In conclusion, chitin from waste crab legs is a very suitable adsorbent material that is capable of rapidly removing up to 95% of the initial concentration of AY25 dye at a pH of 2 and room temperature

Body composition in lupus nephritis patients

Background: The assessment of body fat distribution is an important evaluation in patients with lupus nephritis (LN), which does not practice routinely. The objectives of this study were to determine the body composition by using bioelectrical impedance analysis and to identify the effects of age, body mass index, disease activity, and corticosteroid therapy on body composition.Methods: This was a single-centered, cross-sectional, and observational study conducted at the nephrology unit, National Hospital Kandy, Sri Lanka. Seventy-nine patients with biopsy-proven LN have participated in the study.Results: There were 79 lupus nephritis patients enrolled in this study. The duration of LN ranged from 8 months to 32 years. The main non-renal clinical manifestations included skin lesions (59%), arthritis (54%), and oral ulcers (48%). The disease activity was low with a mean SLEDAI score of 1.01 (SD=2.3). The body fat (BF) percentage (p=0.002) and subcutaneous fat (SF) percentage (p<0.001) were significantly low in males compared to females. And, BF percentage was significantly low among patients with SLEDAI-2K 6 (p=0.03). Moreover, there were positive correlations found between SLE disease activity with the BMI (p=0.004), body fat percentage (p=0.001), and visceral fat percentage (p=0.001).Conclusions: Females are more prone to have a high mean value of body composition parameters than males in this study. There is a negative influence of the body composition parameters reported against the disease activity among LN patients in Sri Lanka.