Indigo carmine removal by charcoal from rice bran as an agricultural by-product

On the utilization of agricultural by-product, charcoal from rice bran was produced. The adsorption characteristics of indigo carmine onto charcoals from rice bran were investigated by the batch method. The yield and surface area of charcoal were decreased and increased with increase of carbonization temperature, respectively. The removal ratio of indigo carmine was high with the charcoal carbonized at higher temperature. In the relationship between the amount of indigo carmine adsorbed and the square root of elapsed time, a good linearity was recognized. The kinetic constant of adsorption removal for indigo carmine was rapid in the charcoal carbonized at higher temperature. The adsorption characteristics for indigo carmine removal by charcoal from rice bran were dominated by the value of their surface area.     

Electrochemical degradation of the dye indigo carmine at boron-doped diamond anode for wastewaters remediation

Here we demonstrate that anodic oxidation with a boron-doped diamond (BDD) electrode can be applied to the remediation of wastewaters containing indigo carmine. This environmentally friendly method decontaminates completely acid and alkaline aqueous solutions of this dye. The degradation rate increases with increasing current and dye concentration. Indigo carmine is more rapidly removed in alkaline than in acid medium, but its kinetics does not follow a defined reaction order. Isatin 5-sulfonic acid is the main aromatic product formed. Oxalic and oxamic acids are generated as ultimate carboxylic acids. The nitrogen of the dye is converted into NH₄ ⁺ and NO₃ ⁻.     

Ti/SnO2-Sb2O5/PbO2电极的制备及降解不同污染物性能研究

采用溶胶凝胶法和电沉积法分别制备了Ti/SnO2-Sb2O5/PbO2电极的中间层和表面活性层,并通过XRD和SEM对电极的中间层和表面活性层进行了相关表征.结果表明,制得的电极表面为β型PbO2,表面形貌均匀致密.同时,采用线性伏安扫描和交流阻抗测试对电极的电化学性能进行了测试.结果表明,电解液中污染物的存在可提高电极的析氧电位,中间层的制备可以有效提高电极的催化性能.另外,通过测定电极对苯酚、靛蓝胭脂红、甲基橙3种不同类型污染物的去除率、COD去除率,研究了该电极对不同类型有机物的降解规律.结果表明,在相同条件下该电极对靛蓝胭脂红的去除速率较高且所需电压最低,降解1 h时靛蓝胭脂红去除率即达100%,甲基橙降解3 h时其COD去除率高达55%.     

Plasma induced degradation of Indigo Carmine by bipolar pulsed dielectric barrier discharge(DBD) in the water-air mixture

Degradation of the Indigo Carmine (IC) by the bipolar pulsed DBD in water-air mixture was studied. Effects of vadous parameters such as gas flow rate, solution conductivity, pulse repetitive rate and ect., on color removal efficiency of dying wastewater were investigated. Concentrations of gas phase O3 and aqueous phase H2O2 under various conditions were measured. Experimental results showed that air bubbling facil~tates the breakdown of water and promotes generation of chemically active species. Color removal efficiency of IC solution can be greatly improved by the air aeration under various solution conductivities. Decolorization efficiency increases with the increase of the gas flow rate, and decreases with the increase of the initial solution conductivity. A higher pulse repetitive rate and a larger pulse capacitor Cp are favorable for the decolorization process. Ozone and hydrogen peroxide formed decreases with the increase of initial solution conductivity. In addition, preliminary analysis of the decolorization mechanisms is given.     

胭脂红褪色光度法测定电镀废水中的镍

pH值为 5 4的六次甲基四胺 盐酸缓冲溶液 ,1 0 0℃恒温水浴中 ,Ni2 + 能催化H2 O2 氧化胭脂红褪色 ,研究了此反应的适宜条件和影响因素 ,建立了催化褪色光度法测定Ni2 + 的新方法。研究发现 ,溶液的最大吸收波长均在 5 1 8nm处。Ni2 + 的浓度在 0～ 1 0 4 μg mL范围内符合比耳定律 ,表观摩尔吸光系数为 1 4 96× 1 0 5L mol·cm。操作简便 ,仪器简单 ,准确度较高     

Triton X-100 induced cuboid-like BiVO4 microsphere with high photocatalytic performance

A highly active visible light-induced BiVO₄ photocatalyst was prepared by a simple co-precipitation method using ammonia solution as a pH adjustor and Triton X-100 (TX100) as a structure directing agent. The physical properties of the prepared BiVO₄ photocatalyst were investigated by several techniques such as X-ray diffractometer (XRD), Brunauer–Emmett–Teller (BET) surface area measurement, scanning electron microscopy (SEM), energy dispersive analysis (EDS), Fourier-transformed infrared spectroscopy (FT-IR), photoluminescence (PL), and UV–Vis diffused reflectance spectroscopy (DRS). XRD results revealed the existence of a monoclinic scheelite structure in both the unmodified and the modified samples. The TX100 played a crucial role to control the cuboid-like shape morphology of BiVO₄. The DRS results showed that the as-prepared cuboid BiVO₄ possessed enhanced visible light absorption range compared with that of the unmodified BiVO₄. The photocatalytic activity was evaluated via indigo carmine (IC) degradation under visible light irradiation. The modified BiVO₄ showed higher photocatalytic efficiency than the unmodified BiVO₄ and the commercial P25-TiO₂ which could be ascribed to the better charge separation efficiency.     

Rubber sheet strewn with TiO2 particles:Photocatalytic activity and recyclability

A new method for the preparation of rubber sheet strewn with titanium dioxide particles (TiO₂-strewn sheet) is presented. This simple and low cost method is based on the use of TiO₂ powder (Degussa P25) being strewn onto the sheet made from rubber latex (60% HA) through a steel sieve. The characteristic of the TiO₂-strewn sheet was studied by using scanning electron microscopy/energy dispersive X-ray spectrometer (SEM/EDS) and X-ray diffractometer (XRD) techniques. The photocatalytic activity of TiO₂-strewn rubber sheet was evaluated using Indigo Carmine (IC) dye as a model for organic dye pollutant in water. The results showed that the TiO₂-strewn sheet could degrade IC dye solution under UV light irradiation. The effects of pH, initial concentration, and the intensity of UV light on the photodegradation were also investigated. Kinetics of the photocatalytic degradation was of the first-order reaction. The used TiO₂-strewn sheet can be recovered and reused. The recycling uses did not require any cleaning between successive uses and no decline in the photodegradation efficiency was observed compared with freshly prepared TiO₂-strewn sheet.     

Differences in Predators of Artificial and Real Songbird Nests: Evidence of Bias in Artificial Nest Studies

Abstract:  In the past two decades, many researchers have used artificial nests to measure relative rates of nest predation. Recent comparisons show that real and artificial nests may not be depredated at the same rates, but no one has examined the mechanisms underlying these patterns. We determined differences in predator-specific predation rates of real and artificial nests. We used video cameras to monitor artificial nests baited with quail and plasticine eggs and Field Sparrow ( Spizella pusilla ) and Indigo Bunting ( Passerina cyanea ) nests in field habitats in central Missouri (U.S.A.). Although daily predation estimates (all predators pooled) were similar between artificial and real nests, predators differed substantially in their depredation of artificial versus real nests. Snakes were the major predator at real nests, and raccoons ( Procyon lotor) were the major predator at artificial nests. We found strong support for models that distinguished predation between two or among three predator groups and between artificial and real nests. There was no snake predation of artificial nests, and the odds of predation of artificial nests was 115–551% (95% confidence interval) and 2–154% of the odds of predation of real nests by mammals and birds, respectively. Artificial nests with plasticine eggs could not be used reliably to identify predators. In several cases plasticine eggs were marked by mice, and raccoons were recorded on video removing the quail egg. Because biases for artificial nests were positive for some predators and negative for other predators (and could be compensating), and potentially existed for all predator groups, conclusions based on artificial nest studies should be suspect even when there is evidence that overall predation rates are similar among real and artificial nests.     

Comparison of three chemical tests to assess seed viability: the seed dispersal system of the Macaronesian endemic plant <Emphasis Type="Italic">Rubia fruticosa</Emphasis> (Rubiaceae) as an example

Summary. Three chemical viability tests were evaluated in the seed dispersal system of Rubia fruticosa, in which three main groups of dispersers participate: reptiles, birds and mammals. Tetrazolium chloride (TTC) and indigo carmine (IC) indicated a lower viability of seeds from droppings of introduced rabbits (Oryctolagus cuniculus) than of those from control plants and the native dispersers, lizards and gulls. In the rabbit seed treatment, significant differences were observed between results obtained with TTC and IC tests. Interpretation of these data, due to the presence of doubtful embryo staining, was more difficult using the IC test. Furthermore, some seeds that were clearly dead had been underestimated. In contrast with results obtained from the two staining methods, the EC test did not confirm that viability of control seeds and those seeds consumed by native dispersers were clearly higher than in seeds ingested by O. cuniculus. Further, compared to the other two tests, the EC method requires more careful handling of the embryo during the extraction process to avoid errors in viability estimation, since this method measures concentration of electrolytes that are released through cellular membranes. Thus, TTC was the most reliable test to assess seed viability in the seed dispersal system of R. fruticosa, and these results agree with those obtained in previous germination experiments made on the same set of seeds given the same treatments.     

载银TiO2催化剂的制备与性能研究

本文是采用负载金属银对TiO2改性后得到了载银TiO2,利用不同反应时间的胭脂红降解率反映光催化氧化反应的速率,结果表明,载银TiO2比TiO2的催化反应速率提高了3倍.通过实验确定最佳含银量和催化剂最佳投加量,并讨论了载银TiO2的催化机理,提出了制取载银TiO2催化剂的方法.