介质阻挡放电氧化降解木质素磺酸钠的动力学研究

为了有效地处理难生物降解的造纸废水，采用气相介质阻挡放电产生氧化性物质，对木质素磺酸钠进行了氧化降解研究。在不同操作条件下，对其降解动力学及矿化程度进行了研究。结果表明，介质阻挡放电能有效地降解木质素磺酸钠，其氧化降解反应遵循准一级动力学反应。当峰值电压为20 kV，被水蒸气饱和的空气为气源，流量为7 L/min时，氧化处理60 min后，木质素磺酸钠降解率达到70％。其速率常数K随峰值电压、气源、气体流量和木质素磺酸钠的初始浓度的变化而不同。气体流量越大，木质素磺酸钠的初始浓度越低，速率常数K越大，降解效果越好。随着处理时间的增加，氧化性物质能将部分木质素磺酸钠矿化使溶液TOC降低，当被水蒸气饱和的空气作为气源时，氧化处理120min，21.38%的TOC被去除。

Kinetics of sodium lignosulfonate oxidation degradation by dielectric barrier discharges

Degradation kinetics and mineralizing of sodium lignosulfonate was examined by utilizing reactive species generated from the gas phase dielectric barrier discharge (DBD) reactor. Effects of various parameters such as gas flow rate, applied voltage, gas sources and initial sodium lignosulfonate concentration on the degradation kinetics of sodium lignosulfonate were investigated. The experimental data show that the present DBD system is very effective on degradation of lignosulfonate, and the degradation reaction of sodium lignosulfonate in the plasma reactor is a pseudo first order reaction. An aqueous solution of 100 mg/L lignosulfonate is about 70% degraded following 60 min treatment at a 20 kV voltage and 7L/min gas flow rate. Applied voltage, gas flow rate, gas source and initial sodium lignosulfonate concentration were observed to affect the degradation kinetics of sodium lignosulfonate. Rate constant(K) of degradation increases with increasing the gas flow rate or decreasing the initial sodium lignosulfonate concentration. Furthermore, the higher mineralization rate is obtained when humid air (RH 100%) is used as a gas source. About 21.38% of the initial TOC can be removed only in 120 min treatment.