Pd/Ti阳极电催化氧化处理焦化废水反渗透浓缩液的研究

Electrocatalytic oxidation of Pd/Ti anode for the treatment of reverseosmosis concentrates from coking wastewater

针对焦化废水膜浓缩过程所产浓缩液中难降解有机物浓度高、处理难度大的问题,本研究采用简便的喷涂法制备了Pd负载多孔钛的阳极,并构建了以Pd/Ti为阳极和钛网为阴极的电催化氧化装置,实现了焦化废水反渗透浓缩液中难降解有机物的高效稳定去除。在电流密度为5 mA/cm^(2)时,运行4 h后,Pd/Ti阳极对反渗透浓缩液的COD去除率为86.3%,远高于掺硼金刚石(46.7%)和铱钽电极(34.0%)。气相色谱-质谱分析结果表明,以Pd/Ti为阳极的电催化体系可将反渗透浓缩液中的难降解有机物(如1-硝基-3,5-二甲基金刚烷)转化为结构简单的降解产物(如2-戊炔-1-醇)。在28 h连续运行过程中,COD出水均低于50 mg/L以下,满足《炼焦化学工业污染物排放标准》(GB 16171—2012)中废水直接排放标准限值。以上结果表明,Pd/Ti阳极具有高效、低耗处理焦化废水反渗透浓缩液中难降解有机物的潜力。

In this study,a Pd-loaded porous titanium anode was prepared using a simple spraying method,and an electrocatalytic oxidation system was constructed with Pd/Ti as anode and titanium mesh as cathode to achieve the efficient and stable removal of refractory organic pollutants from coking wastewater reverse osmosis concentrates.At a current density of 5 mA/cm^(2),the Pd/Ti anode achieved a[JP2]COD removal of 86.3%in 4 hours which was higher than that of the BDD(46.7%)and Ir/Ta(34.0%)electrodes.Gas chromatography-mass spectrometer analysis demonstrated that the electrocatalytic system with Pd/Ti as the anode could effectively convert refractory organic pollutants(e.g.,1,2-dimethyl-5-nitroadamantane)in the reverse osmosis concentrate into simple substances(e.g.,2-pentyn-1-ol).During the 28-hour long-term operation,the COD effluent was less than 50 mg/L,meeting the limit of the standard for direct discharge of wastewater in the Emission Standard for Pollutants in Coking Chemical Industry(GB 16171—2012).These results indicated that the Pd/Ti anode had the potential for eliminating refractory organic pollutants in reverse osmosis concentrates from coking wastewater with high efficiency and low consumption.