In this work, a novel method for complete Cr(Ⅵ) removal was achieved in a single-chamber cell with titanium (Ti) as anode via simultaneous indirect electro-reduction of Cr(Ⅵ) and in-situ precipitation of Cr(Ⅲ). The Cr(Ⅵ) and total Cr removal, and electric energy consumption were optimized as a function of electrochemical reactor, current density, initial Cr(Ⅵ) and chloride (Cl⁻) concentration, and initial solution pH. The maximum Cr(Ⅵ) and total Cr removal efficiency reached 80.5 and 79.4% respectively within 12 h at current density of 10 mA cm⁻² as initial Cr(Ⅵ) concentration was 0.078 mM. Decreasing the initial solution pH was beneficial to Cr(Ⅵ) reduction, but Cr(Ⅲ) precipitation was inhibited, resulting in the poor total Cr removal. The suitable Cl⁻ concentration guaranteed sufficient reducing agents (Ti³⁺ and Ti²⁺) for Cr(Ⅵ) removal. The reaction mechanism demonstrated that Ti anode could be corroded to produce Ti³⁺ and Ti²⁺, which provided the electrons for reduction of Cr(Ⅵ) to Cr(Ⅲ). Simultaneously, the solid products (${\text{Ti}}_2{\text{O}}_{(6\text{x}-\text{y}-\text{z}+\frac{5}{2})}{\text{Cl}}_{2\text{y}}{\text{Cr}}_{2\text{x}}{\left(\text{OH}\right)}_{2\text{z}}\left(\text{s}\right)$) were in-situ formed and precipitated from the solution due to the continuous generation of hydroxyl ion (OH⁻) from cathode. This study might provide a new electrochemical method with non-precious metal as the electrode for complete Cr(Ⅵ) removal from aqueous media.

在这项工作中，通过同时间接电解还原Cr（Ⅵ）和原位沉淀Cr（Ⅲ），在以钛（Ti）为阳极的单室电池中实现了一种完全去除Cr（Ⅵ）的新方法。 。的铬（Ⅵ）和总铬去除，以及电能消耗进行了优化作为电化学反应器，电流密度，初始的Cr（Ⅵ）和氯化（CL的函数^- ）浓度和初始溶液的pH值。当初始Cr（Ⅵ）浓度为0.078 mM时，电流密度为10 mA cm ^-2时，在12 h内最大Cr（Ⅵ）和总Cr去除效率分别达到80.5％和79.4％。降低初始溶液的pH值有利于Cr（Ⅵ）的还原，但抑制了Cr（Ⅲ）的沉淀，导致总的Cr去除率较差。合适的氯^-浓度可确保有足够的还原剂（Ti ³⁺和Ti ²⁺）用于去除Cr（Ⅵ）。反应机理表明，Ti阳极可被腐蚀而产生Ti ³⁺和Ti ²⁺，从而提供了将Cr（Ⅵ）还原为Cr（Ⅲ）的电子。同时，固体产品（${\text{钛}}_2{\text{Ø}}_{（6\text{X}-\text{ÿ}-\text{ž}+\frac{5}{2}）}{\text{氯}}_{2\text{ÿ}}{\text{铬}}_{2\text{X}}{（\text{哦}）}_{2\text{ž}}（\text{s}）$）为原位形成，并从溶液中沉淀由于连续生成氢氧根离子（OH的^- ）从阴极。这项研究可能提供一种新的电化学方法，以非贵金属为电极，可从水性介质中完全去除Cr（Ⅵ）。