School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084, China.
School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084, China; Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
J Hazard Mater. 2014 Sep 15;280:644-53. doi: 10.1016/j.jhazmat.2014.09.001. Epub 2014 Sep 6.
Electrolysis and ozonation are two commonly used technologies for treating wastewaters contaminated with nitrophenol pollutants. However, they are often handicapped by their slow kinetics and low yields of total organic carbon (TOC) mineralization. To improve TOC mineralization efficiency, we combined electrolysis using a boron-doped diamond (BDD) anode with ozonation (electrolysis-O3) to treat a p-nitrophenol (PNP) aqueous solution. Up to 91% TOC was removed after 60 min of the electrolysis-O3 process. In comparison, only 20 and 44% TOC was respectively removed by individual electrolysis and ozonation treatment conducted under similar reaction conditions. The result indicates that when electrolysis and ozonation are applied simultaneously, they have a significant synergy for PNP mineralization. This synergy can be mainly attributed to (i) the rapid degradation of PNP to carboxylic acids (e.g., oxalic acid and acetic acid) by O3, which would otherwise take a much longer time by electrolysis alone, and (ii) the effective mineralization of the ozone-refractory carboxylic acids to CO2 by OH generated from multiple sources in the electrolysis-O3 system. The result suggests that combining electrolysis with ozonation can provide a simple and effective way to mutually compensate the limitations of the two processes for degradation of phenolic pollutants.
电解析氧和臭氧化是两种常用于处理含硝基酚污染物废水的技术。然而，它们通常受到动力学缓慢和总有机碳（TOC）矿化率低的限制。为了提高 TOC 矿化效率，我们将掺硼金刚石（BDD）阳极电解析氧（电解-O3）结合起来处理对硝基酚（PNP）水溶液。在电解-O3 过程 60 分钟后，TOC 去除率高达 91%。相比之下，在相同反应条件下，单独进行电解析氧和臭氧化处理时，TOC 分别去除了 20%和 44%。结果表明，当电解和臭氧化同时应用时，它们对 PNP 矿化具有显著的协同作用。这种协同作用主要归因于（i）O3 将 PNP 快速降解为羧酸（例如草酸和乙酸），而单独通过电解则需要更长的时间，以及（ii）通过电解-O3 系统中多种来源产生的 OH 将臭氧难矿化的羧酸有效矿化为 CO2。结果表明，将电解与臭氧化相结合可以为降解酚类污染物提供一种简单有效的方法，相互弥补两种工艺的局限性。
