新生态型聚硅酸铁锰处理染料废水的优化

为了提高混凝剂对染料废水的净化效率,本文利用硅酸钠、硫酸亚铁和高锰酸钾为原料合成了新型复配混凝剂聚硅酸铁锰(PSFM),分别以直接大红、分散蓝和活性黄染料废水为处理对象进行混凝模拟实验,研究了碱度和浊度等因素对PSFM混凝去除染料性能影响.结果表明,PSFM对直接大红和分散蓝染料废水具有较好的混凝净化效能,其色度和TOC去除率分别可达99.2%、95.4%和98.5%、93.8%,效果优于聚硅酸铁(PSF)、Al2(SO4)3和Fe Cl3等常规混凝剂,PSFM对活性黄染料废水色度和TOC去除率分别为56.3%和51.3%.浊度对PSFM混凝效能无明显影响.在碱度分别为50、0和75 mg·L~(-1)时,PSFM对直接大红、分散蓝和活性黄去除率分别达到最高.此外,利用扫描电子显微镜(SEM)、傅里叶红外(FTIR)和X射线衍射仪(XRD)等高级表征手段对PSFM进行了表征,对混凝过程中的混合液和絮体分别进行Zeta电位和絮体粒径在线监测,探索得PSFM混凝主要机制为Fe+与Mn+水解产生的带正电的多核配合物和聚硅的桥联聚合,同时还包括新生态水合二氧化锰和羟基氧化铁的吸附助凝作用.

Optimization of Dyeing Wastewater Treatment with New Eco-friendly Polysilicate Ferromanganese

To improve the efficiency of the removal of dye wastewater, a new type of coagulant "polysilicate ferromanganese (PSFM)" has been synthesized using sodium silicate, ferrous sulfate, and potassium permanganate. Three dyes (direct red, disperse blue, and active yellow) were used for the coagulation tests. The effects of the alkalinity and turbidity on the performance of PSFM were studied. The experimental results show that PSFM performs well with respect to the coagulation of the direct red and disperse blue dyes. The color and TOC removal efficiencies reach 99.2%, 95.4% and 98.5%, and 93.8%, respectively. The coagulation performance is better than that of the conventional coagulants polysilicate iron (PSF), Al₂(SO₄)₃, and FeCl₃. The color and TOC removal rates of PSFM for the active yellow dye reach 56% and 51%, respectively. Turbidity has no significant effect on the coagulation efficiency of PSFM. The purification efficiency and alkalinity depend on the amount of dye to be removed. The best alkalinity for the direct red, disperse blue, and active yellow dyes is 50 mg·L^-1, 0 mg·L^-1, and 75 mg·L^-1, respectively. In addition, PSFM has been characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The Zeta potentials of the mixed solutions and flocs during coagulation were also determined. The main indicators of PSFM coagulation are positively charged polynuclear complexes produced by hydrolysis of Fe⁺ and Mn⁺ and the bridging polymerization of polysilicon. The adsorption of hydrated manganese dioxide and hydroxyl oxide may also be included.