Photocatalytic degradation of CI Acid Blue 80 in aqueous suspensions of titanium dioxide under sunlight

The dye C.I. Acid Blue 80 (AB80) was easily degraded by TiO2-P25 assisted photocatalysis in aqueous dispersion under irradiation of sunlight. The optimal reaction conditions were [TiO2] = 2.0 g/L, pH = 10, [H2O2] = 5 mmol/L. The photocatalytic reaction followed pseudo-first order kinetics. The adsorption of AB80 onto TiO2 was in accord with Langmuir equation.

Comparison of the total amount of eggshell pigments in Dongxiang brown-shelled eggs and Dongxiang blue-shelled eggs

Based on the knowledge of the heme biosynthetic and metabolic pathway and the structures of biliverdin and protoporphyrin, experiments were carried out to compare the difference between the total quality of eggshell pigments in blue-shelled eggs and brown-shelled eggs from the same population (Dongxiang, China) and to analyze the correlation between the quantity of protoporphyrin and biliverdin in the 2 kinds of eggshells. It was found that there was no significant difference between the total quantity of eggshell pigments in Dongxiang blue-shelled eggs and Dongxiang brown-shelled eggs (P = 0.9006), and a highly significant positive correlation between the quantity of protoporphyrin and biliverdin in blue eggshells (P < 0.01) and a significant positive correlation between the quantity of protoporphyrin and biliverdin in brown eggshells (P < 0.05). These results suggested that eggshell protoporphyrin and eggshell biliverdin probably derived from common precursor material.

Study of adsorption of methylene blue and new methylene blue in liquid-solid interface by slab optical waveguide spectroscopy

A slab optical waveguide (SOWG) has been used for study of adsorption of both methylene blue (MB) and new methylene blue (NMB) in liquid-solid interface. Adsorption characteristics of MB and NMB on both bare SOWG and silanized SOWG by octadecyltrichlorosilane (ODS) were compared. Effect of pH on adsorption on MB and NMB was investigated. Binding rate constant analysis showed that both MB and NMB on bare SOWG demonstrates larger association constants than those on ODS-SOWG. Interactions of NIB and NMB on bare SOWG and ODS-SOWG were analyzed by molecular mechanics calculation method. The binding energy change was in the following order: ENMB-bare > EMB-bare > ENMB-ODS > EMB-ODS. (c) 2004 Elsevier B.V. All rights reserved.