Optimization of the decolorization conditions of Rose Bengal by using Aspergillus niger TF05 and a decolorization mechanism.

Aspergillus niger TF05 was applied to decolorize Rose Bengal dye. The effects of carbon source, nitrogen source, metal ion and spore concentration on Rose Bengal treatment with A. niger TF05 were studied. A Plackett-Burman design (PBD) and a uniform design (UD) were used to optimize the decolorization conditions of A. niger TF05 and enhance its decolorization effect. The mechanism of Rose Bengal decolorization by A. niger TF05 was examined by analysing degradation products via UV-visible light spectroscopy, IR spectroscopy and GC-MS. The best decolorization effect was achieved in the single factor test with glucose and ammonium chloride as carbon and nitrogen sources, respectively. Mg2+ was an essential ion that could improve the mould ball state and adsorption efficiency if the spore concentration was maintained at 106 spores ml-1. The optimal decolorization conditions obtained using the PBD and UD methods were 11.5 g l-1 glucose, 6.5 g l-1 ammonium chloride, 0.4 g l-1 magnesium sulphate, pH 5.8, 28 °C, 140 r.p.m. rotational speed, 0.18 g l-1 dye concentration, 0.5 ml of inocula and 120 h decolorization time. Under these conditions, the maximum decolorization rate was 106%. Spectral analysis suggested that the absorption peak of the product changed clearly after decolorization; GC-MS analysis revealed that the intermediate product tetrachlorophthalic anhydride formed after decolorization. The combined use of the PBD and UD methods can optimize multi-factor experiments. A. niger TF05 decolorized Rose Bengal during intracellular enzymatic degradation after adsorption.

Image of the environmental scientist.

The environmental scientist has been playing an important role in preventing and mitigating environmental pollution. Individuals' images of the environmental scientist will likely impact and meditate their interest and attitudes toward environmental science as well as their willingness to take up an environmental science profession. However, prior studies focusing on the image of a professional are primarily of the general scientist. The environmental scientist and the image thereof remains out of the limelight of environmental science community and has been under-researched. In this article, on the basis of the retrospect on the stereotypical images of the general and environmental scientist and the gaps in previous studies, we attempted to report young individuals' images of the environmental scientist in an alternative context. Drawing technique was employed and administered to 127 junior students aged from 13 to 15 year-old from a junior high school. The individuals' image of environmental scientists can be generally abstracted as a male with environmental protection knowledge and commitment to environmental protection who does work more like a green chemist, ecology restorer, or plant protector and observes or cleans outdoors, primarily in forest, jungle, and/or by riverside.