聚吡咯修饰阳极在电絮凝技术处理铜铬废水过程中的研究

为进一步提高电絮凝技术处理重金属废水的效率,聚吡咯(Polypyrrole, PPy)涂层被用来修饰电絮凝阳极。采用电化学聚合法制备电絮凝PPy修饰阳极,经过表征和腐蚀测试后,将PPy修饰阳极应用于电絮凝工艺中处理电镀废水,对PPy修饰阳极的重金属离子去除效率、缓蚀效率以及电絮凝中Fe利用率进行了深入探讨,并进一步探究了PPy修饰阳极用于电絮凝处理重金属废水技术的可行性。结果表明:相比于裸钢电极,PPy修饰电极的电荷转移电阻(R_(ct))明显增加,腐蚀电流密度显著降低,证明PPy修饰电极具备出色的自我防护和防腐蚀性能;将PPy修饰阳极投入电絮凝废水处理运行中发现,极板间距为20 mm、pH值为5、反应时间为70 min、电流密度为30 mA/cm^(2)是电絮凝处理电镀铜铬废水的最佳条件,PPy修饰阳极对Cu和Cr离子的去除率可达99.9%和84.1%,且能够保证25%以上的阳极缓蚀效率;此外,通过Fe利用率分析可以观察到PPy修饰阳极能够达到更高的Fe利用率,从而提高电絮凝技术处理重金属的效率。因此,PPy修饰阳极能够达到较高的重金属去除效率以及出色的阳极保护效果。

Applying ellipsometry to studying the effect of two kinds of rare earth metal salts on anodizing aluminum alloy

The effects of rare earth metal salts (REMs), cerium(IV) salt and lanthanum (III) salt, on the property of anodized coating of LD10 aluminum alloy are studied by corrosion tests including neutral salt spray test and copper accelerated acetic acid immersion test, polarization curves measurement, energy dispersion analyzer of X-Ray(EDAX) analysis, and in situ ellipsometry. The results show that the addition of either of the two REMs in anodizing solution hardly changes the composition of an anodized coating, while increases the thickness of barrier part and reduces the porosity of porous part, which contributed to the improvement of the corrosion resistance of the anodized coating. The results also demonstrate that the effect of cerium salt was better than that of lanthanum salt.