Institute of Hydrodynamics of the Czech Academy of Sciences, Prague, Czech Republic.
Institute of Inorganic Chemistry of the Czech Academy of Sciences, Husinec-Rez, Czech Republic.
Environ Technol. 2023 Apr;44(9):1322-1333. doi: 10.1080/09593330.2021.2000042. Epub 2021 Dec 2.
Manganese is naturally present in water, but its increased concentration in potable water is undesirable for multiple reasons. This study investigates an alternative method of demanganization by a newly synthesized TiO-based adsorbent prepared through the transformation of titanyl sulphate monohydrate to amorphous sodium titanate. Its adsorption capacity for Mn was determined, while a range of influential factors, such as the effect of contact time, adsorbent dosage, pH value, and added ions was evaluated. The adsorbent appeared highly effective for Mn removal owing to its unique characteristics. Besides adsorption via electrostatic interactions, ion-exchange was also involved in the Mn removal. Although the Mn removal occurred within the whole investigated pH range of 4-8, the maximum was achieved at pH 7, with = 73.83 mg g. Equilibrium data revealed a good correlation with Langmuir isotherm in the absence of any ions or in the presence of monovalent co-existing ions, while the results in the presence of divalent co-existing ions showed a better fit to Freundlich isotherm. Additionally, the presence of monovalent cations (Na, K) only slightly decreased the Mn removal efficiency as compared to divalent cations (Ca, Mg) that caused a greater decrease; however, the effect of anions (Cl, SO) was insignificant. To provide insight into the adsorbent safety, the toxicity assessment was performed and showed no harmful effect on cell activity. Furthermore, the residual concentration of titanium after adsorption was always below the detection limit. The results imply that the synthesized TiO-based adsorbent is a safe promising alternative method for demanganization. The synthesis of amorphous TiO-based adsorbent was presented.The TiO-based adsorbent was found to be efficient for Mn removal.The Mn removal mechanisms were adsorption and ion-exchange.Increasing pH enhanced the efficiency of Mn removal.Divalent cations decreased the Mn removal efficiency more than monovalent cations.
锰在水中自然存在，但由于多种原因，饮用水中其浓度的增加是不理想的。本研究通过将一水硫酸氧钛转化为无定形的钛酸钠，开发了一种新的基于 TiO 的吸附剂来替代除锰方法。测定了其对 Mn 的吸附能力，并评估了一系列影响因素，如接触时间、吸附剂用量、pH 值和添加离子的影响。由于其独特的特性，该吸附剂对 Mn 的去除效果非常显著。除了通过静电相互作用进行吸附外，离子交换也参与了 Mn 的去除。虽然 Mn 的去除发生在整个研究的 pH 值范围 4-8 内，但在 pH 7 时达到最大值，吸附量为 73.83 mg g。在不存在任何离子或存在单价共存离子的情况下，平衡数据与 Langmuir 等温线很好地相关，而在存在二价共存离子的情况下，结果更符合 Freundlich 等温线。此外，与二价阳离子（Ca、Mg）相比，单价阳离子（Na、K）的存在仅略微降低了 Mn 的去除效率，而二价阳离子（Ca、Mg）的存在则导致更大的降低；然而，阴离子（Cl、SO）的影响并不显著。为了深入了解吸附剂的安全性，进行了毒性评估，结果表明该吸附剂对细胞活性没有有害影响。此外，吸附后钛的残留浓度始终低于检测限。结果表明，合成的基于 TiO 的吸附剂是一种安全、有前途的除锰替代方法。提出了无定形 TiO 基吸附剂的合成。发现基于 TiO 的吸附剂对 Mn 去除有效。Mn 的去除机制是吸附和离子交换。增加 pH 值提高了 Mn 的去除效率。二价阳离子比单价阳离子更能降低 Mn 的去除效率。
