海绵铁感应热固定床对染料废水脱色研究

感应热固定床(IHBF)在有机废水非均相反应中,通过能量靶向作用于磁性滤料微界面,形成固液相界面高温微反应区,实现了有机废水低能耗高效降解.本文探讨了海绵铁感应热固定床处理直接紫D-BL废水的运行条件和机理.结果表明,在进水pH值6~7,水温为30 ℃,HRT为2.08min的条件下,运行30min后脱色率高达93.5%.降解溶液的UV-vis结果表明,直接紫D-BL在554nm和220nm的特征峰消失.通过SEM-EDS技术对Ni-SI降解前后的样品进行表征,结果显示,降解后Ni-SI中的Fe形成了Fe的氧化物和氢氧化物.根据降解、表征分析其反应机理,推断是直接紫D-BL首先吸附在海绵铁颗粒表面,接着铁与水反应产生的H2在Ni的催化和局部高温作用下产生大量的氢自由基,并与直接紫D-BL发生催化还原反应,使得分子中最毒性的共轭双键和苯环断开而降解.此外对酸性黑10B废水、直接大红D-GLN废水和实际染料废水分别进行试验,脱色率分别达到82%、78%、81%左右,表明海绵铁感应热固定床在染料工业废水处理中具有良好的应用潜力.

Decolorization of dye wastewater with spongy-iron induction-heating fixed bed reactor (IHFB)

For the heterogeneous reactions of organic-pollutants in wastewater, a novel reactor, the induction-heating fixed bed reactor (IHFB) realizes the targeted energy transfers on the micro-interface of catalyst particles. Due to the high temperature on the solid-liquid phase interface deriving from the ferromagnetic heating, the degradation of aqueous organic pollutants was significantly promoted with the lower energy consumption. The decolorization experiments showed that the decolorization percentage could reach 93.5% after running 30minutes in the optimal reaction conditions, i.e. influent pH 6~7and 30℃, HRT of 2.08min. The UV-vis absorption peak of direct blending purple (D-BL) at 554nm disappeared after Ni-SI react with D-BL. SEM-EDS revealed the formation of iron oxide and iron hydroxides on the surface of Ni-SI after degradation of direct blending purple (D-BL) after D-BL reaction. A degradation mechanism of direct blending purple (D-BL) was proposed. First, molecular was adsorded on the surface of modified sponge iron, then the iron nanoparticles react with water to produce hydrogen radical by the Ni catalysis and local high temperature, finally the hydrogen radical destroied the most toxic conjugated double bond and benzene ring in D-BL molecular. In addition, in the optimal operation conditions, the decolorization percentages of the acid black (10B), the direct red (D-GLN) and the real dye wastewater reached 82%, 78% and 81% respectively. The study revealed that IHBF had a tremendous application potential in dye wastewater treatment.