基于高级氧化技术的公路隧道排水系统水质净化

Highway Tunnel Drainage System Water Purificationbased on Advanced Oxidation Technology

公路隧道排水系统水质中残存的有机物具有水环境危害大、易造成淤堵等特点,对水生物生命与隧道安全造成严重威胁。传统的净化方法对公路隧道排水系统水质中的有机物去除效率较低,需要开发新的水质净化技术。采用超声/过硫酸盐/Fe_(3)O_(4)体系即US/PMS/Fe_(3)O_(4)对公路隧道排水系统的水质进行净化。通过单因素实验,探讨了Fe_(3)O_(4)投加量、PMS投加量、超声功率、初始pH值对水质COD去除的影响。结果表明,US/PMS/Fe_(3)O_(4)对COD的去除作用效果最优,强于PMS/Fe_(3)O_(4)、US/PMS体系;超声与PMS/Fe_(3)O_(4)之间有较好的协同作用,显著增强了COD的去除。超声的空化作用能持续腐蚀Fe_(3)O_(4)表层,促使其持续产生Fe^(2+)释放到溶液中,进而激活过硫酸盐产生大量的硫酸根自由基,高效去除COD。此外,采用自由基捕获实验证实了US/PMS/Fe_(3)O_(4)体系中存在硫酸根自由基、羟基自由基和超氧自由基,其中:硫酸根自由基的贡献率为52.6%、羟基自由基的贡献率为27.8%,硫酸根自由基的贡献较显著。

The residual organic matter in the water of highway tunnel drainage system has the characteristics of strong biological toxicity,great harm to the water environment and being easy to cause siltation,which have become serious threats to the life of aquatic organisms and the safety of the tunnel.The traditional purification methods have low efficiency in removing organic matter from tunnel drainage system water,so more efficient water purification technologies need to be developed.In this study,the degradation and removal effect and efficiency of tunnel drainage system water have been investigated by using the ultrasound/peroxymonosulfate/Fe_(3)O_(4) system,i.e.US/PMS/Fe_(3)O_(4).The effects of single factor experiment such as Fe_(3)O_(4) dosage,PMS dosage,ultrasonic power and pH on the COD removal of tunnel drainage system water have been investigated.The results have shown that the COD removal effect by US/PMS/Fe_(3)O_(4) is excellent and better than that of PMS/Fe_(3)O_(4) and US/PMS systems.The removal efficiency of COD is significantly enhanced by the good synergistic effect between US and PMS/Fe_(3)O_(4).The cavitation effect of US can continuously corrode the surface layer of Fe_(3)O_(4),prompting it to continuously produce Fe^(2+)for release into the solution,which in turn activates the PMS to produce a large number of sulfate radicals for efficient COD removal of tunnel drainage system water.In addition,free radical capture experiments have determined that the US/PMS/Fe_(3)O_(4) system contains sulphate radicals,hydroxyl radicals and superoxide radicals.The largest contribution of sulphate radicals is 52.6%,while the contribution of hydroxyl radicals is 27.8%.