机械力化学法降解十二烷基苯磺酸钠

Degradation of sodium dodecyl benzene sulfonate by mechanochemical method

考察了La_(2)O_(3)和磁性可回收的Fe_(3)O_(4)对十二烷基苯磺酸钠(SDBS)的降解性能。结果表明,在物料中外源添加剂和SDBS质量比为19∶1,球料比为40∶1,球磨转速为500 r/min,球磨4 h后,La_(2)O_(3)和Fe_(3)O_(4)对单纯SDBS的降解率分别为93.89%和85.56%。La_(2)O_(3)和Fe_(3)O_(4)对土壤中SDBS的降解率分别为75.35%和34.88%。通过紫外光谱和红外光谱分析,发现苯环结构被破坏和-SO3-被氧化,均说明球磨处理后SDBS被降解。

Sodium dodecyl benzene sulfonate(SDBS)is a widely used anionic surfactant in many industrial fields such as printing,washing,textile and building materials.The use of SDBS generates a lot of bubbles to reduce the oxygenation in water,which causes some negative effects and requires degradation treatment.Mechanochemical method is environmentally friendly and efficient for treatment of organic pollutants,which is widely used in soil remediation.At present,the ball milling method is mainly applied to the degradation of halogenated organics.The research on the treatment of surfactants has rarely been reported.In this work,the degradation properties of SDBS which was ball milled with La_(2)O_(3) and magnetic recyclable Fe_(3)O_(4) were investigated.Then the degradation of SDBS by the same method was explored in the soil.The chemical structure and properties of SDBS and the degradation products thereof were characterized by FTIR,UV-vis and LC-MS to find out the best experimental parameters.The results show that the best degradation rates of La_(2)O_(3) and Fe_(3)O_(4) to SDBS are 93.89%and 85.56%,respectively.The best experimental parameters are as follows:the mass ratio of additives to SDBS is 19∶1,the mass ratio of ball to material is 40∶1,the ball grinding speed is 500 r/min,and the ball grinding time is 4 h.When the additive is La_(2)O_(3),100%Φ5 mm ball milling beads are used,and when the additive is Fe_(3)O_(4),20%Φ10 mm,60%Φ5 mm and 20%Φ2 mm ball milling beads are used.In the soil,the degradation rates of SDBS by La_(2)O_(3) and Fe_(3)O_(4) are 75.35%and 34.88%,respectively.Through UV and IR analysis,it is found that the benzene ring structure is destroyed and-SO3-is oxidized,both indicating that SDBS has been degraded by ball milling treatment.LC-MS analysis shows that the molecular ion peaks of SDBS become weaker and many ion peaks of small organic molecules appear after ball milling,which also demonstrates that SDBS has been degraded by ball milling.