Intermolecular interactions in mixed dye systems and the effects on dye wastewater treatment processes.

Dye wastewater discharge is a critical concern across textiles, paper, cosmetics, and other industries. This study explores the impact of dye-dye interactions on chemical coagulation and ultrafiltration process. Using basic and reactive dyes, representing cationic and anionic compounds, the intricate interplay between these dyes was examined through spectroscopic analysis. Remarkably, interactions between dyes of opposite charges exhibited significant effects on both techniques. Electrostatic attractions played a key role. Positive coagulant hydrolysates selectively attracted negative dyes, while negatively charged membranes effectively captured positive dyes. Combining dyes with opposite charges resulted in enhanced removal efficiency, addressing challenging dyes collectively. This discovery offers a novel approach to improving dye removal, utilizing opposite-charged dye mixtures can tackle stubborn dyes unmanageable by conventional methods.

Efficiently Removing Heavy Metals from High-Salinity Wastewater via Ionic Liquid-Based Aqueous Biphasic Systems.

For the separation of metal ions, ionic liquid-based aqueous biphasic systems (IL-ABSs) offer a promising alternative to solvent extraction. However, the incorporation of an extensive quantity of inorganic salts restricts their practical application. Because heavy metal wastewater often contains high concentrations of inorganic salts, it offers good prospects for the application of IL-ABSs in the separation of heavy metals. In this work, an IL-ABS was formed by tributyltetradecylphosphonium chloride ([P44414]Cl), and simulated high-salinity wastewater (NaCl and Na2SO4 as the main inorganic salts) was used for the separation of heavy metals. The phase diagram results indicated that the formation of a two-phase system required a relatively high salt concentration. The extraction process followed the mechanism of anion exchange; thus, heavy metals such as zinc and cadmium that formed complexes with chloride ions could be effectively extracted (extraction rate >99.5%) with a very fast rate (extraction time <1 min) at a wide pH range (pH = 2-7). After extraction, the metals could be stripped well (stripping rate >99.5%) after contact with the NaOH solution. This research provided a new approach for treating heavy metals in high-salinity effluents, which has the advantages of IL-ABS and avoids the disadvantages of adding large amounts of inorganic salts at the same time.

[Epidemiological study on developmental delay of 18-month-old children from four districts/counties in Beijing].

OBJECTIVE: To investigate epidemiological characteristics of prevalence, impact factors and etiology on developmental delay of 18-month-old children from four districts/counties in Beijing. METHODS: An epidemiological study on developmental delay was designed to investigate all the 18-month-old children enrolled from Shunyi,Daxing,Miyun and Yanqing districts/counties in Beijing from May to September, 2011. Combining the tertiary network of child health with hospital clinical study was used. Child developmental questionnaires were completed by doctors in communities of the first network of child health. Gesell Developmental Schedules for children with Denver developmental screening test (DDST) screening positive results were assessed by doctors in districts/counties hospitals of the second network of child health. The children diagnosed as developmental delay were transferred to the tertiary hospitals of the third network of child health for further etiological diagnosis, follow-up and developmental evaluation. The case-control study compared between children with/without developmental delay were performed in accordance with the 1:4 ratios by gender and residence community matched. SPSS 16.0 was adopted for data analysis of the case-control study. RESULTS: A total of 3 182 children were screened among the 4 037 children fitting the criteria,and the coverage rate was 78.8% (3 182/4 037). Of the 3 182 screened children, 22 children were diagnosed as developmental delay. The prevalence rate was 6.91 ‰ (22/3 182). Out of the 22 children with developmental delay, 15 were boys and 7 were girls. The sex ratio was 2.1:1. The prevalence rates of the children with developmental delay in Shunyi, Daxing, Miyun and Yanqing were 3.45 ‰ (4/1 160), 4.50 ‰(5/1 111), 15.87 ‰(7/441) and 12.77 ‰ (6/479), respectively. The results from one-way ANOVA analysis showed the main risk factors in children with developmental delay included low-income families, mothers' low educational level, small size for gestational age infant, multiple fetuses, serious diseases after birth, congenital malformations and physical retardation (P<0.05). CONCLUSION: The screening coverage rate of this study is 78.8%. The prevalence rate of children with developmental delay is 6.91 ‰, which is significantly different in sex ratio and districts of the subjects. The etiology of developmental delay might be associated with social-economic and biological factors.

Determination of phenolic compounds and ascorbic acid in different fractions of tomato by capillary electrophoresis with electrochemical detection.

Tomato (Lycopersicon esculentum Mill.), one of the most important crops worldwide, contains different classes of substances with antioxidant properties such as carotenoids, vitamin C, and phenolics. A method based on capillary electrophoresis with electrochemical detection has been developed to analyze ascorbic acid and phenolics in the peel, pulp, and seeds of tomatoes. Operating in a wall-jet configuration, a 300 microm diameter carbon disk electrode was used as the working electrode, which exhibits a good response at +0.90 V (vs saturated calomel electrode) for the analytes. Under optimum conditions, the analytes were baseline separated within 20 min in a 50 mmol/L borate buffer (pH 8.7). Notably, excellent linearity was obtained over 3 orders of magnitude with detection limits (S/N=3) ranging from 1x10(-8) to 2x10(-7) g/mL for all analytes. This proposed method has been successfully applied to monitor the content of ascorbic acid and phenolics in real samples, and the assay results were satisfactory.