超声活化过硫酸盐降解甲基橙的影响因素研究

利用频率为40 kHz的超声（US）活化过硫酸盐（PS）氧化降解甲基橙.系统研究了超声（US）声强、过硫酸盐（PS）浓度对US/PS组合工艺降解甲基橙的影响.采用单独超声（US）或单独过硫酸盐（PS）时,甲基橙的降解率随US声强和PS浓度的增加而增大.在PS浓度为0.5~3 mmol·L^-1和US声强为0.22~0.54 W·cm^-2条件下,60 min时甲基橙的最大降解率分别为52.22%和16.7%.采用US/PS高级氧化工艺时,甲基橙的降解率也随PS浓度和US声强的增加而增大,60 min时甲基橙的最大降解率高达87.38%,比单独US和PS提高70.68%和35.16%.同种条件下,TOC的降解率小于甲基橙的降解率.甲醇和叔丁醇（自由基抑制剂）的加入降低甲基橙的降解率,且甲醇对甲基橙降解的抑制程度更明显.US/PS高级氧化工艺对甲基橙的降解主要依靠硫酸根自由基.

Influencing factors of methyl orange degradation by ultrasound activated persulfate

Persulfate(PS) activated by ultrasound(US) with a frequency of 40 kHz was used to degrade methyl orange. Effects of ultrasound(US) intensities and various concentrations of persulfate(PS) on methyl orange degradation by US/PS combined process were systematically investigated. Using ultrasound(US) or persulfate(PS) alone, the degradation rates of methyl orange increased with the US intensities and PS concentrations. Under the conditions of PS concentrations (0.5~3 mmol·L^-1) and US intensities(0.22~0.54 W·cm^-2), the maximum degradation rates of methyl orange at 60 min increased to 52.22% and 16.7%, respectively. Using the US/PS combined process, the degradation of methyl orange was also enhanced with the increase of PS concentrations and US intensities, and the maximum degradation rates of methyl orange at 60 min increased to 87.38%, which were 70.68% and 35.16% higher than those for US and PS alone. Under the same conditions, the degradation rate of TOC was lower than that of methyl orange. The addition of radical scavenger for methanol and tert-butanol reduced the degradation rate of methyl orange, and the effect of methanol was more obvious than that of tert-butanol on methyl orange. The degradation of methyl orange was mainly caused by sulfate radicals in the combined US/PS process.