UV及UV/US降解对二氯苯水溶液的研究

使用紫外光（UV）和超声波（US）降解水溶液中的对二氯苯（p-DCB）。考察了p-DCB初始浓度，初始pH、腐殖酸和H2O2的存在对p-DCB光解的影响。结果表明，较低的初始浓度或弱酸性pH有利于p-DCB降解。溶液中存在20 mg/L的腐殖酸可使p-DCB的反应速率常数提高32.6%。加入氧化剂H2O20=0.1 mmol/L，［H2O20=0.1 mmol/L，pH0=5.8，反应180 min条件下，p-DCB的降解率为95.5%。超声波对p-DCB的降解速率（14.6×10-3/min）大约是紫外光（4.3×10-3/min）的3.4倍，紫外光 超声波耦合时的降解速率（20.6×10-3/min）大于两者单独降解速率的加合。在各种实验条件下，p-DCB的降解均遵循表观一级动力学。

Photodegradation and photosonodegradation of p-dichlorobenzen in aqueous solution

The degradation of p-DCB in aqueous solution was studied by ultraviolet and ultrasonic irradiation. The effect of initial p-DCB concentration, initial pH, the presence of humic acid and H2O2 on the p-DCB photolysis was investigated. The results indicated that, lower initial concentration or weak acid condition were favorable for p-DCB degradation. The degradation rate increased by 32.6% with 20 mg/L humic aid. The degradation of p-DCB was significantly improved by adding oxidant H2O2, and the degradation efficiency was 95.5% at ［p-DCB］0=0.1 mmol/L, ［H2O2］0=0.1 mmol/L, pH0=5.8 after 180 min radiation.The rate constant of sonodegradation (14.6×10-3/min) was 4.3 times that of the photodegradation (4.3×10-3/min), and the rate constant of photosonodegradation (20.6×10-3/min) was greater than the sum of those for the two individual processes. Under various experimental conditions, the degradation of p-DCB followed the apparent first order kinetics.