Evaluation of color removal and degradation of a reactive textile azo dye on nanoporous TiO2 thin-film electrodes

The feasibility of the photobleaching of a textile azo dye, reactive orange 16 (C.I. 17757), in aqueous solution using titanium dioxide thin-film electrodes prepared by the sol-gel method was investigated. The best conditions for maximum photoelectrocatalytic degradation were found to be pH > 10 for Na2SO4 medium and pH < 6 for NaCl. In both situations, an applied potential of +1.0 V and low dye concentration are recommended, when 100% of color removal is obtained after 20 min of photoelectrocatalysis. The effects of side reaction pathway on the degradation rate of dye in sulfate and chloride medium were presented and the best performance are optimized to situations closed to that verified in the textile effluent. The influence of variables as applied potential, pH, supporting electrolyte and dye concentration on the kinetics of photoelectrochemical degradation also were investigated. Oxalic acid is identified by HPLC and UV-Vis spectrophotometric methods as the main degradation product generated after 180 min of photoelectrocatalysis of 4 x 10(-5) mol l(-1) dye in sodium sulphate pH 12 and NaCl pH 4.0 and a maximum reduction of 56 and 62% TOC was obtained, respectively. (C) 2004 Elsevier Ltd. All rights reserved.

GENETIC MECHANISMS FOR THE DEVELOPMENT OF REPRODUCTIVE-ORGANS OF APIS-MELLIFERA WORKERS AND DIPLOID DRONES - A COMPLEMENTARY HYPOTHESIS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

ALTERATIONS IN THE OMMATIDIA OF THE COMPOUND EYES OF APIS-MELLIFERA EYE-COLOR MUTANT WORKERS .3.

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Degradation of Acid Blue 40 dye solution and dye house wastewater from textile industry by photo-assisted electrochemical process

In this paper, electrochemical and photo-assisted electrochemical processes are used for color, total organic carbon (TOC) and chemical oxygen demand (COD) degradation of one of the most abundant and strongly colored industrial wastewaters, which results from the dyeing of fibers and fabrics in the textile industry. The experiments were carried out in an 18L pilot-scale tubular low reactor with 70% TiO2/30% RuO2 DSA. A synthetic acid blue 40 solution and real dye house wastewater, containing the same dye, were used for the experiments. By using current density of 80 mA cm(-2) electrochemical process has the capability to remove 80% of color, 46% of TOC and 69% of COD. When used the photochemical process with 4.6 mW cm(-2) of 254nm UV-C radiation to assist the electrolysis, has been obtained 90% of color, 64% of TOC and 60% of COD removal in 90 minutes of processing; furthermore, 70% of initial color was degraded within the first 15 minutes. Experimental runs using dye house wastewater resulted in 78% of color, 26% of TOC and 49% of COD in electrolysis at 80 mA cm(-2) and 90 min; additionally, when photo-assisted, electrolysis resulted in removals of 85% of color, 42% of TOC and 58% of COD. For the operational conditions used in this study, color, TOC and COD showed pseudo-first-order decaying profiles. Apparent rate constants for degradation of TOC and COD were improved by one order of magnitude when the photo-electrochemical process was used.

ULTRASTRUCTURE OF THE MANDIBULAR GLANDS OF PACHYCONDYLA-STRIATA ANTS (HYMENOPTERA, PONERINAE) .1. WORKERS

The mandibular glands of Pachycondyla striata workers consists of a proximal reservoir and secretory portion. The secretion is transported from the cytoplasm of the secretory cells to reservoir through individual canaliculi which is subdivided into two portions : an intracytoplasmatic and extracellular one. The reservoir consists of an epithelium made up of thin cells has a thick cuticle. The secretory cells showed a large amount of structures forming the citoskeleton always associated with myelin figures.

Decolorization of textile indigo dye by ligninolytic fungi

The indigo dye is extensively used by textile industries and is considered a recalcitrant substance, which causes environmental concern. Chemical products used on textile processing, which affect the environment through effluents, can be voluminous, colored and varied. Vat textile dyes, like indigo, are often used and dye mainly cellulosic fibers of cotton. Decolorization of this dye in liquid medium was tested with ligninolytic basidiomycete fungi from Brazil. Decolorization started in a few hours and after 4 days the removal of dye by Phellinus gilvus culture was in 100%, by Pleurotus sajor-caju 94%, by Pycnoporus sanguineus 91% and by Phanerochaete chrysosporium 75%. No color decrease was observed in a sterile control. Thin layer chromatography of fungi culture extracts revealed only one unknown metabolite of Rf = 0.60, as a result of dye degradation. (C) 2001 Published by Elsevier B.V. B.V.

Sleep-wake patterns of student workers and non-workers

Adolescents usually exhibit late sleep phase and irregular sleep patterns. As a result, they do not get enough sleep and report daytime sleepiness. This condition could be aggravated in working students who have a more limited time for sleep. In this survey, we investigated the impact of evening classes and employment on the sleep patterns of adolescents. We compared female (n = 17) and male (n = 14) non-worker students to female (n = 28) and male (n = 20) worker students who attended the same high school. The volunteers (aged 17.4 years +/- 11 months) answered a sleep log during a 16-day period. Worker students slept and woke up earlier, had a shorter nocturnal sleep length and a shorter daily (nocturnal plus diurnal) sleep length compared to non-working pupils. The four groups of students delayed sleep onset time on weekends, but only worker students delayed wake-up time on Sundays. The wake-up time was similar among groups on Sundays. While student workers tended to increase the sleep length in the weekends, non-working students increased it on Mondays and/or Tuesdays. The results showed that sleep schedules and sleep length were different according to the work status. Going to bed later on Saturday by the four groups of students suggests the influence of social activities, while a later wake-up time on Sundays could result from a shorter sleep length on workdays.

Analysis of aromatic amines in surface waters receiving wastewater from a textile industry by liquid chromatographic with electrochemical detection

A high performance liquid chromatography ( HPLC) method with electrochemical detection (ED) was developed for the determination of benzidine, 3,3-dimethylbenzidine, o-toluidine and 3,3-dichlorobenzidine in the wastewater of the textile industry. The aromatic amines were eluted on a reversed phase column Shimadzu Shimpack C-18 using acetonitrile + ammonium acetate (1 x 10(-4) mol L-1) at a ratio 46: 54 v/v as mobile phase, pumped at a flow rate of 1.0 mL min(-1). The electrochemical oxidation of the aromatic amines exhibits well-defined peaks at a potential range of +0.45 to +0.78 V on a glassy carbon electrode. Optimum working potentials for amperometric detection were from 0.70 V to +1.0 V vs. Ag/AgCl. Analytical curves for all the aromatic amines studied using the best experimental conditions present linear relationship from 1 x 10(-8) mol L-1 to 1.5 x 10(-5) mol L-1, r = 0.99965, n = 15. Detection limits of 4.5 nM (benzidine), 1.94 nM (o-toluidine), 7.69 nM (3,3-dimethylbenzidine), and 5.15 nM (3,3-dichlorobenzidine) were achieved, respectively. The detection limits were around 10 times lower than that verified for HPLC with ultra violet detection. The applicability of the method was demonstrated by the determination of benzidine in wastewater from the textile industry dealing with an azo dye processing plant.

HERITABILITY OF THE NUMBER OF OVARIOLES IN HONEY-BEE WORKERS (APIS-MELLIFERA L) (HYM, APIDAE)

Narrow and broad sense heritabilities (h(2)) of the number of ovarioles in Apis mellifera L. workers were estimated using two distinct data sets, based on groups of half (queens inseminated by several drones) and super-sisters (single drone insemination). The values found are in the usual range for economically important characters (0.25-0.38).

Morphological caste differences and non-sterility of workers in Brachygastra augusti (Hymenoptera, Vespidae, Epiponini), a neotropical swarm-founding wasp

Morphological caste differences and ovary conditions were analyzed in four colonies of Brachygastra augusti collected in different stages of the colony cycle. Differences between castes are distinct suggesting pre-imaginal determination. Many intermediates (non-inseminated ovary-developed females) were found. Because these intermediate females were morphologically similar to workers, it is suggested that they are young ovary-developed workers. Because there is a more evident overlap between queens and workers in the colony in pre-emergence of workers stage, and in three colonies in latter stages, especially in worker-production colonies, it is suggested that smaller queens are probably less viable than larger queens as observed in previously studied epiponines.