Comparison of oxidation efficiency of disperse dyes by chemical and photoelectrocatalytic chlorination and removal of mutagenic activity

Degradation of Disperse Orange 1, Disperse Red 1 and Disperse Red 13 dyes has been performed using electrochemical oxidation on Pt electrode, chemical chlorination and photoelectrochemical oxidation on Ti/TiO(2) thin film electrodes in NaCl or Na(2)SO(4) medium. 100% discoloration was obtained for all tested methods after 1 h of treatment. Faster color removal was obtained by photoelectrocatalytic oxidation in 0.1 mol L(-1) NaCl pH 4.0 under UV light and an applied potential of +1.0V (vs SCE reference electrode), which indicates also values around 60% of TOC removal. The conventional chlorination method and electrochemical oxidation on Pt electrode resulted in negligible reduction of TOC removal. All dyes showed positive mutagenic activity in the Salmonella/microsome assay with the strain TA98 in the absence and presence of S9 (exogenous metabolic activation). Nevertheless, there is complete reduction of the mutagenic activity after 1 h of photoelectrocatalytic oxidation, suggesting that this process would be good option to remove disperse azo dyes from aqueous media. (C) 2008 Elsevier Ltd. All rights reserved.

Removal of sunscreen compounds from swimming pool water using self-organized TiO2 nanotubular array electrodes

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

Processos diurnos e noturnos de remoção de NO2 e NH3 atmosféricos na região de Araraquara-SP

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

Efficiency of bioaugmentation in the removal of organic matter in aquaculture systems

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

2 END-TO-SIDE NEURORRHAPHIES AND NERVE GRAFT WITH REMOVAL OF THE EPINEURAL SHEATH - EXPERIMENTAL-STUDY IN RATS

We have studied a new type of end-to-side nerve repair in rats. The healthy (donor) nerve was not divided but an epineural window was created. In our experiment, a nerve graft bridged the tibial nerve to the distal end of the divided peroneal nerve. Electrophysiological studies showed electrical impulses conducted through both end-to-side nerve junctions. Histological studies demonstrated axons leaving the lateral surface of the healthy (donor) nerve. Based on these observations, we suggest that end-to-side neurorrhaphy from a healthy nerve may bridge a neural deficit.

Removal of radionuclides from acid mine waters by retention on adsorbing materials

This study proposes a method for decontamination of acid drainage water from a uranium mine, as an alternative process to lime treatment. The research embodied the recovery of uranium with an ion-exchange resin, treatment of effluent resin with lime, or with inorganic adsorbents and biosorbents. The uranium decontamination level using the resin process was 94% and allowed the recovery of this element as a commercial product. Among the inorganic adsorbents studied, phosphogypsum was effective for Ra-226, Ra-228, and Pb-210 removal. Among the biosorbents, Sargassum sp.was superior in relation to its specific capacity to accumulate and remove Ra-226.

The acid-base impact of free water removal from, and addition to, plasma

Water, compared with plasma at a pH of 7.4, is a weak acid. The addition of free water to a patient should have an acidifying effect (dilutional acidosis) and the removal of it, an alkalinizing effect (concentrational alkalosis). The specific effects of free water loss or gain in a relatively complex fluid such as plasma has, to the authors' knowledge, not been reported. This information would be useful in the interpretation of the effect of changes in free water in patients. Plasma samples from goats were either evaporated in a tonometer to 80% of baseline volume or hydrated by the addition of distilled water to 120% of baseline volume. The pH and partial pressure of carbon dioxide, sodium, potassium, ionized calcium, chloride, lactate, phosphorous, albumin, and total protein concentrations were measured. Actual base excess (ABE), standard bicarbonate, anion gap, strong ion difference, strong ion gap, unmeasured anions, and the effects of sodium, chloride, phosphate, and albumin changes on ABE were calculated. Most parameters changed 20% in proportion to the magnitude of dehydration or hydration. Bicarbonate concentration, however, increased only 11% in the evaporation trial and decreased only -2% in the dehydration trial. The evaporation trial was associated with a mild, but significant, metabolic alkalotic effect (ABE increased 3.2 mM/L), whereas the hydration trial was associated with a slight, insignificant metabolic acidotic effect (ABE decreased only 0.6 mM/L). The calculated free water ABE effect (change in sodium concentration) was offset by opposite changes in calculated chloride, lactate, phosphate, and albumin ABE effects.

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.

Comparison between gutta-percha and Resilon removal using two different techniques in endodontic retreatment

This study compared the remaining filling material and working time when removing gutta-percha/AH 26 and Resilon/Epiphany from root filled extracted teeth. The root fillings were removed using chloroform and two different rotary systems (K3 and Liberator files). The amount of residual filling material on the canal walls was imaged and measured using image analyzer software. The group filled with Resilon/Epiphany and retreated with K3 files demonstrated the least residual filling material on the walls (p < 0.05). There was no statistically significant difference between the guttapercha/AH26 and Resilon/Epiphany groups when the Liberator files were used (p > 0.05). In the groups filled with Resilon/Epiphany, the filling was removed faster than groups filled with gutta-percha/AH 26 (p < 0.05). K3 rotary system was faster than Liberator to remove both gutta-percha and Resilon (p < 0.05). Resilon/ Epiphany was effectively removed with K3 or Liberator rotary files.

Effect of exercise mode on the blood lactate removal during recovery of high-intensity exercise

The aim of this study was to determine the effect of exercise mode on the blood lactate removal during recovery of high-intensity exercise. Nine male individuals performed the following tests in order to determine the blood lactate removal: Running - 2x200 m, the subjects ran at their maximum capacity, and rested 2 min between each bout. Swimming - 2x50 m, the subjects swam at their maximum capacity, and rested 2 min between each bout. Each test was realized on different days with three recovery modes: passive (sitting down), swimming, or running. Recovery exercise intensity was corresponding to the aerobic threshold. All recovery activities lasted 30 min. The two forms of active recovery were initiated 2 min after the end of high-intensity exercise and lasted 15 min, and were followed by 13 min of seated rest. After 1,7, 12,17, and 30 min of the end of high-intensity exercise, blood samples (25 mu l) were collected in order to determine the blood lactate concentration. By linear regression, between the logarithm of lactate concentration and its respective time of recovery, the half-time of blood lactate removal (t1/2) was determined. Time of high-intensity exercise and the lactate concentration obtained in the 1(st) min of recovery were not different between running and swimming. Passive recovery (PR) following running (R-PR=25.5+/-4.3 min) showed a t1/2 significantly higher than PR after swimming (S-PR=18.6+/-4.3 min). The t1/2 of the sequences running-running (R-R=13.0 min), running-swimming (R-S=12.9+/-3.8 min), swimming-swimming (S-S=13.2+/-2.8 min), and swimming-running (S-R=12.9+/-3.8 min) were significantly lower than the t1/2 of the R-PR and S-PR. There was no difference between the t1/2 of the sequences R-R R-S, and S-S. on the other hand the sequence S-R showed a t1/2 significantly lower than the sequences S-S and R-R. It was concluded that the two forms of active recovery determine an increase in the blood lactate removal, regardless of the mode of high-intensity exercise performed previously. Active recovery performed by the muscle groups that were not previously fatigued, can improve the blood lactate removal.

Dietary vitamin or mineral mix removal during the finisher period on broiler chicken performance

The effect of dietary vitamin (VS) and mineral (MS) mix withdrawal between 42 and 49 d of age on broiler chicken performance was evaluated. The diets were formulated based on corn and soybean meal, and the experiments were conducted in floor pens using wood shavings as litter. Trial I evaluated withdrawal of VS and MS mix at 42, 45, and 49 d. The results of this trial showed that VS and MS mix withdrawal at 42 d of age did not impair feed intake (FI) or weight gain (WG), but feed conversion (FC) was improved (P = 0.043) when both mixes were maintained in the diets until 49 d of age. Trial 2 assessed the withdrawal of VS or MS mix at 42 d of age. FI and WG were not affected by withdrawal, but FC was poorer (P = 0.035) for the broilers fed the diet without VS. The relative liver weight was reduced by VS or MS mix withdrawal (P = 0.014 and P = 0.001, respectively). Carcass, breast, and leg yields were not affected by VS or MS mix withdrawals in either trial. The findings of the study suggested that VS mix withdrawal during the final period of broiler chicken growth was more deleterious than the withdrawal of MS mix, because it affected FC ratio. VS or MS withdrawal during this period did not affect carcass yield.