State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
Chemosphere. 2020 Sep;255:126970. doi: 10.1016/j.chemosphere.2020.126970. Epub 2020 May 4.
In this work, a CuO-CoO/Ti composite was prepared via the coating-calcination method and employed as a cathode for the NO-N reduction to increase the removal efficiency of total nitrogen (TN). SEM, EDS, and XRD characterization results indicated that CuO and CoO were successfully introduced to the surface of Ti. The CuO-CoO/Ti electrode eventually removed NO-N with the main products of N, NH-N and NO-N. In comparison to the CoO/Ti electrode, the better hydrogen evolution properties of the CuO-CoO/Ti electrode resulted in pH increase and NH gas release, so the TN removal for CuO-CoO/Ti electrode was improved approximately 20%. The presence of Cl with the concentration up to 1000 mg L greatly promoted the removal of TN from 40.1% to 94.0%, as a result of NH-N oxidation with free chlorine produced from the anode. Furthermore, the CuO-CoO/Ti electrode was applied to conduct three types of actual wastewater (biological effluent of municipal wastewater and industrial wastewater, and a regeneration concentrate from an anion exchange process) for nitrate removal. The highest TN removal efficiency (78.5%) and current efficiency (54.5%), and the lowest energy consumption (2 × 10 kWh mg TN) were obtained for the regeneration concentrate, suggesting the feasibility of the CuO-CoO/Ti electrode to the water with high conductivity and high Cl concentration for removing TN by the reduction of nitrate.
在这项工作中，通过涂层-煅烧法制备了 CuO-CoO/Ti 复合材料，并将其用作阴极用于 NO-N 还原，以提高总氮 (TN) 的去除效率。SEM、EDS 和 XRD 表征结果表明，CuO 和 CoO 成功引入到 Ti 的表面。CuO-CoO/Ti 电极最终以 N、NH-N 和 NO-N 作为主要产物去除 NO-N。与 CoO/Ti 电极相比，CuO-CoO/Ti 电极具有更好的析氢性能，导致 pH 值升高和 NH 气体释放，因此 TN 去除率提高了约 20%。当 Cl 的浓度高达 1000 mg/L 时，由于阳极产生的游离氯氧化 NH-N，大大促进了 TN 的去除，从 40.1%提高到 94.0%。此外，CuO-CoO/Ti 电极应用于三种实际废水（城市废水和工业废水的生物出水，以及阴离子交换过程的再生浓缩液）进行硝酸盐去除。对于再生浓缩液，获得了最高的 TN 去除效率（78.5%）和电流效率（54.5%），以及最低的能耗（2×10 kWh mg TN），表明 CuO-CoO/Ti 电极对于高电导率和高 Cl 浓度的水通过还原硝酸盐去除 TN 的可行性。
