Reuse of modified fly ash for treatment of dye wastewaters is a promising new technology with the potential to mitigate two waste streams currently having negative effects on the environment. In the present study, cationic fly ash adsorbent was prepared by immobilizing with poly-epichlorohydrin-dimethylamine for treating reactive dye wastewaters. Characterization analyses confirmed that poly-epichlorohydrin-dimethylamine had been immobilized onto fly ash, and this immobilization could change the Zeta potential of fly ash from negative to positive throughout the range of pH from 3 to 11, but could not alter its crystal structure. Static adsorption analyses demonstrated that dye adsorption process was spontaneous and endothermic, and the experimental data were better in accord with pseudo-second-order kinetic model. Column experiments showed that cationic fly ash displayed a dramatically high dye adsorption capacity, which was over 1.5 times more than that of commercial activated carbon. Reusability study confirmed that synthesized cationic fly ash can be used repeatedly in column. Especially, in order to avoid secondary pollution, the generated disabled cationic fly ash adsorbent can be reused to produce polymer concretes as a functional filler. The present work can provide new insight into the utilization of modified fly ash for treating wastewaters.

Graphic abstract

中文翻译：

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阳离子聚合物改性粉煤灰在印染废水处理中的应用

再利用改性粉煤灰处理染料废水是一种很有前途的新技术，有望减轻目前对环境有负面影响的两种废物流。在本研究中，通过将聚表氯醇-二甲胺固定化来制备阳离子粉煤灰吸附剂，以处理活性染料废水。表征分析证实，聚表氯醇-二甲胺已被固定在粉煤灰上，并且这种固定化可在3至11的整个pH范围内将粉煤灰的Zeta电位从负值变为正值，但不会改变其晶体结构。静态吸附分析表明，染料的吸附过程是自发的，吸热的，实验数据符合拟二级动力学模型。柱实验表明，阳离子粉煤灰显示出极高的染料吸附能力，是商业活性炭的1.5倍以上。可重用性研究证实，合成的阳离子粉煤灰可在色谱柱中重复使用。特别是，为了避免二次污染，可以将所产生的禁用的阳离子粉煤灰吸附剂再利用以生产作为功能性填料的聚合物混凝土。目前的工作可以提供新的见解，以利用改性粉煤灰处理废水。生成的禁用的阳离子粉煤灰吸附剂可以重复使用，以生产聚合物混凝土作为功能性填料。目前的工作可以提供新的见解，以利用改性粉煤灰处理废水。生成的禁用的阳离子粉煤灰吸附剂可以重复使用，以生产聚合物混凝土作为功能性填料。目前的工作可以提供新的见解，以利用改性粉煤灰处理废水。

图形摘要