基于脉冲电晕放电技术的硫氰化物分解与氮转化

针对含高浓度硫氰酸盐的废水/废液,采用高效的物化技术实现化学转化,避免生物过程因毒性抑制所需要的稀释作用,作为预处理工艺提供厌氧氨氧化的水质条件.以配制的硫氰酸盐模拟废水作为研究对象,采用自主搭建的脉冲电晕放电(PCD)装置,从构建厌氧氨氧化适配条件的目的出发,考察了不同pH条件下含氮污染物经PCD处理随时间的动态转化规律,以及SCN~--N降解副产物(SO_4~(2-)和HCO~-_3浓度)对NH~+_4-N降解的影响,并拟合了不同条件下NH~+_4-N的降解动力学.结果表明,PCD技术利用原位产生的O_3和·OH能氧化包括SCN~--N和NH~+_4-N在内的还原态含氮化合物为NO~-_3-N,pH的增高有利于氧化反应的进行;反应过程中产生的SO_4~(2-)和HCO~-_3对NH~+_4-N的氧化具有显著的抑制作用,HCO~-_3的抑制效应要高于SO_4~(2-).研究表明,对于高SCN~-废水的处理,PCD技术可作为厌氧氨氧化工艺的预处理技术,在规避毒性抑制与构造水质特征方面表现出优越性.

Thiocyanide decomposition and nitrogen conversion based on pulsed corona discharge technology

For the treatment of wastewater containing high concentration of thiocyanate, high-efficiency physicochemical technology is used to achieve its chemical conversion to provide suitable water quality conditions for anaerobic ammonia oxidation (anammox), and to avoid any dilution operation required to protect the subsequent biological processes from toxicity inhibition. Aiming at constructing appropriate conditions for the anammox process, simulated thiocyanate wastewater was taken as the research object. Using the pulsed corona discharge (PCD) system designed by our team, the dynamic transformation of nitrogen pollutants under different pH conditions was investigated along the PCD treatment. The effects of SCN^--N degradation by-product (SO₄^2- and HCO₃^-) concentrations on the transformation of NH₄⁺-N was studied. And, the degradation kinetics of NH₄⁺-N under different conditions was studied by fitting to 0-order model. Results showed that PCD technology could effectively oxidize nitrogenous compounds including SCN^--N and NH₄⁺-N to NO₃^--N by in-situ generated O₃ and ·OH, and the increase in pH is beneficial to the oxidation reaction. SO₄^2- and HCO₃^- produced in the process of SCN^--N oxidation have significant inhibitory effects on the PCD oxidation of NH₄⁺-N. The inhibitory effects of HCO₃^- is higher than SO₄^2-. This work indicates that for the treatment of wastewater with high concentration of SCN^-, PCD technology can be used as a pretreatment technology for the anammox process, which exhibited superiority in terms of eliminating toxicity inhibition and creating suitable water quality characteristics.