Abstract

Dyes are priority pollutants, commonly found at significant concentrations in textile effluents. The presence of dye stuffs in wastewater can cause severe problems to aquatic life and human beings. Therefore, the removal of dyes from wastewater is important in order to minimize their hazardous effects on the environment. The best microbial species for such an application was selected amongst the isolated bacterial populations by conducting cold bifunctional reactive dye namely CI Reactive Yellow 174 (CI RY 174) batch degradation studies using bacterial strains. The most suitable species were Sphingomonas paucimobilis, Pseudomonas putida and Lactobacillus acidophilus. Process parameters were optimized using response surface methodology (RSM) and under the optimum conditions (e.g. inoculum size of 10% (OD_600nm = 1), temperature of 35 °C, 150 ppm, and time of 5 days). The maximum COD and color removal efficiencies, when tested with 750 ppm dye using batch reactors were found to be 86% and 90%, respectively. Our results showed that bacteria had a high decolorization capacity. High regression coefficient values (predicted R² = 83.65%) confirmed that the predicted values were in compliance with the experimental values implying the appropriateness of the employed regression model. The adequacy of the model was validated by different descriptive statistics viz, regression, residual error, F and p values. UV–visible and FTIR spectroscopy analysis confirmed the biodegradation of CI RY 174. Using phytotoxicity endpoints, toxicological studies of CIRY 174 before and after biodegradation were studied. Toxicity assay proved that biodegradation led to detoxification of CIRY 174 dye.

摘要

染料是优先污染物，通常在纺织废水中浓度很高。废水中染料的存在会对水生生物和人类造成严重的问题。因此，从废水中去除染料很重要，以尽量减少它们对环境的危害。通过使用细菌菌株进行冷双功能活性染料即 CI Reactive Yellow 174 (CI RY 174) 批量降解研究，从分离的细菌种群中选择了用于此类应用的最佳微生物物种。最适宜的菌种是少动鞘氨醇单胞菌、恶臭假单胞菌和嗜酸乳杆菌。. 使用响应面方法 (RSM) 并在最佳条件下优化工艺参数（例如，接种量为 10%（OD _600nm = 1），温度为 35 °C，150 ppm，时间为 5 天）。当使用间歇反应器用 750 ppm 染料进行测试时，发现最大 COD 和颜色去除效率分别为 86% 和 90%。我们的结果表明细菌具有很高的脱色能力。高回归系数值（预测R ² = 83.65%）证实预测值与实验值一致，暗示所采用的回归模型的适当性。通过不同的描述性统计，即回归、残差、F和p 来验证模型的充分性值。紫外-可见光和 FTIR 光谱分析证实了 CI RY 174 的生物降解。使用植物毒性终点，研究了 CIRY 174 生物降解前后的毒理学研究。毒性试验证明生物降解导致 CI​​RY 174 染料解毒。