超声波协同零价铁降解活性艳红X-3B

通过比较超声波、零价铁单独作用及其联用对X-3B的降解效果,探讨了超声波-零价铁体系降解X-3B的协同效应,考察了溶液pH、超声功率、超声时间等因素对协同效应的影响.结果表明,X-3B难以被超声波直接降解,在实验条件下获得的最高去除率仅为7.75%;在pH为5.0、7.0、9.0时,超声波与零价铁在降解X-3B时发生协同效应,相对两者单独作用对X-3B的去除率的简单加和,协同体系对X-3B的去除率分别提高1.68、1.76、1.67倍.在pH7.0时,协同处理25min后X-3B的去除率可达99.42%.在pH3.0时,零价铁直接还原X-3B的速率大于协同体系,但两者降解机理明显不同,前者仅把X-3B分解成小分子中间体,而后者可使X-3B彻底分解.研究认为,在pH5.0～7.0及超声功率为400～600W时,超声波-零价铁协同体系可有效地降解X-3B.

Degradation of Reactive Red X-3B by Ultra Sound Synergized with Zero-Valent Iron

The synergistic effects of ultra sound and zero-valent iron were studied by measuring the degradation of X-3B in zero-valent reduction, ultra sound degradation and synergistic systems. The effects of pH, ultra sound power and irradiation time on the synergistic system were explored. The results show that the X-3B is degraded difficultly by ultra sound and the total removal rate is less than 7.75% after 25min ultrasonic irradiation. When pH is 5.0, 7.0 and 9.0, the degradation rate of X-3B in synergistic system is about 1.68, 1.76 and 1.67 times, respectively, than the total removal rate of zero-valent iron reduction plus ultrasound degradatiorr After 25min ultrasonic irradiation in synergistic system, 99.42% of X-3B is removed at pH7.0. However, the degradation rate of X-3B in zero-valent iron reduction system is much higher than that of synergistic system at pH3,0. The degradation mechanism of X-3B in zero-valent iron reduction system is different from that of synergistic system. The X-3B is degraded into intermediate pollutants in the former, but is degraded completely in the latter. Accordingly, the X-3B can be degraded effectively in the synergistic system of zero-valent iron and ultra sound, when pH is 5.0-7.0 and the power of ultra sound is 400-600W.