Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, No. 18, Shuangqing Rd, Beijing, 100085, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, No. 18, Shuangqing Rd, Beijing, 100085, China; School of Textiles, Nantong University, Nantong, 226019, China.
Chemosphere. 2020 Jun;249:126129. doi: 10.1016/j.chemosphere.2020.126129. Epub 2020 Feb 6.
A novel coagulant poly-ferric-titanium-silicate-sulfate (PFTS) was synthesized and employed to treat two typical kinds of dye wastewaters-disperse blue and reactive yellow. The results indicated that PFTS with a Si/Fe molar ratio of 0.02 exhibited superior coagulation performance, especially under alkaline condition. The residual turbidity after coagulation by PFTS was only half of that after coagulation by poly-ferric-titanium sulfate (T-PSF). The sludge volume index was also reduced by PFTS compared to T-PSF in reactive dye treatment. Through the structure and morphology investigation of PFTS, it was found that new bonds of Si-O-Fe, Si-O-Ti and Fe-OH (Si-OH) were formed, and multi-branched structures and expanded surface area were generated. Additionally, compared with T-PSF, the floc strength and the floc size were also enhanced by PFTS, which was attributed to the polymerization between polysilicic acid and Fe/Ti which formed multi-branched structures, and finally adsorption and bridging ability of the coagulant was improved. Furthermore, the floc formed in reactive yellow wastewater treatment was larger and looser than that formed in disperse blue wastewater, with poorer strength and recovery ability, which can also interpret the better coagulation efficiency in disperse dye water treatment. From the results of coagulant characterization, zeta potential and flocs properties, it can be inferred that charge neutralization by the positive charged hydrolysate of coagulant was identified as the critical effect in disperse dyes removal, while the sweep and adsorption of metal hydroxyl compound formed during the hydrolysis of coagulants were considered to play a key role in reactive dye removal.
一种新型的聚合硫酸铁钛硅（PFTS）被合成并用于处理两种典型的染料废水——分散蓝和活性黄。结果表明，具有 Si/Fe 摩尔比为 0.02 的 PFTS 表现出优异的混凝性能，特别是在碱性条件下。PFTS 混凝后的残余浊度仅为聚硫酸铁钛（T-PSF）混凝后的一半。与 T-PSF 相比，PFTS 处理活性染料时的污泥体积指数也有所降低。通过对 PFTS 的结构和形态进行研究，发现形成了 Si-O-Fe、Si-O-Ti 和 Fe-OH（Si-OH）等新键，生成了多分支结构和扩展的表面积。此外，与 T-PSF 相比，PFTS 还增强了絮体强度和絮体尺寸，这归因于聚合硅酸与 Fe/Ti 的聚合形成了多分支结构，最终提高了混凝剂的吸附架桥能力。此外，在活性黄废水处理中形成的絮体比在分散蓝废水中形成的更大、更疏松，强度和恢复能力较差，这也可以解释在分散染料水处理中更好的混凝效率。从混凝剂的特性、ζ 电位和絮体性质的结果可以推断，带正电荷的混凝剂水解产物的电中和被认为是去除分散染料的关键作用，而混凝剂水解过程中形成的金属氢氧化物的扫集和吸附则被认为是去除活性染料的关键作用。
