Department of Environmental Health Engineering, School of Health, Shahrekord University of Medical Sciences, P.O. Box 8813733435, Shahrekord, Iran.
Department of Chemical Engineering, Isfahan University of Technology, P.O. Box 8415683111, Isfahan, Iran.
Arch Microbiol. 2021 Oct;203(8):4993-5009. doi: 10.1007/s00203-021-02462-9. Epub 2021 Jul 19.
The existence of synthetic dyes and heavy metals in textile wastewater is a serious problem. These compounds should be removed before discharge into the environment by an appropriate method. The present study was conducted for the characterization of efficient multi-functional strain Bacillus cereus MS038EH for the simultaneous removal of Reactive Black-5 and Chromium(VI). Maximum decolorization efficiency of 94.74% was achieved at pH 7, 35 °C, and 4% inoculum size for 900 mg/L of Reactive Black-5. Also, 94.10% efficiency was observed in the presence of 8 g/L of yeast extract as an optimum nitrogen source, while carbon sources had no significant effect on decolorization. It should be pointed out that the decolorization efficiency was decreased from 94 to 64% by increasing NaCl concentrations from 0 to 50 g/L, respectively. Bacillus cereus strain MS038EH could decolorize 94.31% of Reactive Black-5 (900 mg/L) and remove 87.31% of chromium(VI) (30 mg/L) within 36 h. Results of Gas chromatography-mass spectrometry and Fourier transform-infrared spectroscopy proved that Reactive Black-5 was cleaved into the lower molecular weight products without any azo bonds. However, the phyto-toxicity analysis showed that Reactive Black-5 was not toxic for Triticum aestivum and Maize, while biologically treated Reactive Black-5 was toxic for seeds. Therefore, ultraviolet-C/HO was applied for the detoxification of biotransformed products. When ultraviolet-C/HO was applied as post-treatment, the seeds were germinated completely. It is demonstrated that the application of ultraviolet-C/HO after anaerobic treatment is effective for toxicity reduction of textile wastewater.
纺织废水中合成染料和重金属的存在是一个严重的问题。这些化合物应通过适当的方法在排放到环境中之前去除。本研究旨在对高效多功能菌株蜡样芽孢杆菌 MS038EH 进行表征，以同时去除活性黑 5 和铬（VI）。在 pH 7、35°C 和 4%接种量下，900mg/L 活性黑 5 的最大脱色效率达到 94.74%。在 8g/L 酵母提取物作为最佳氮源的存在下，也观察到 94.10%的效率，而碳源对脱色没有显著影响。应当指出，当 NaCl 浓度从 0 增加到 50g/L 时，脱色效率从 94%降低到 64%。蜡样芽孢杆菌 MS038EH 可以在 36 小时内将 94.31%的活性黑 5（900mg/L）脱色，并去除 87.31%的铬（VI）（30mg/L）。气相色谱-质谱和傅里叶变换-红外光谱的结果证明，活性黑 5 被裂解成低分子量产物，而没有任何偶氮键。然而，植物毒性分析表明，活性黑 5 对小麦和玉米没有毒性，而生物处理的活性黑 5 对种子有毒。因此，紫外线-C/HO 被应用于生物转化产物的解毒。当紫外线-C/HO 被应用于后处理时，种子完全发芽。这表明厌氧处理后应用紫外线-C/HO 对降低纺织废水的毒性是有效的。
