KMnO_(4)缓释氧化剂降解地下水中的苯酚和苯胺

Degradation of phenol and aniline in groundwater by KMnO_(4) slow-releaseoxidant

为了达到氧化剂控制释放、有效传输和高效修复的目的,采用缓释技术实现氧化剂对地下水含水层的长期高效修复。实验通过熔化成型法制备了添加活性炭的高锰酸钾(KMnO_(4))缓释材料,并通过释放动力学确定缓释材料的最佳配比和尺寸。此外,对KMnO_(4)缓释材料降解苯酚苯胺的动力学进行了研究,并考察了地下水水质对苯酚苯胺降解的影响。最后开展了二维砂槽中缓释材料降解苯酚苯胺的实验。结果表明:石蜡、高锰酸钾、活性炭以及硅砂质量比为3∶3∶2∶1的1 cm立方体的KMnO_(4)缓释氧化剂缓释效果最好。释放动力学研究显示,30 d后缓释材料的释放率为64.17%,表明其具有优异的缓释特性,并且采用一级动力学方程对实验数据拟合时相关性较好。并且缓释后的KMnO_(4)缓释材料表面出现大量孔洞和缝隙,且表面Mn、O、Si和K元素含量明显增加,说明KMnO_(4)缓释材料在水中的释放原理是以溶解扩散为主。在缓释氧化剂作用下,二维砂槽中苯酚和苯胺的浓度变化形成以缓释材料为中心的锥形修复区域,且纵向苯酚苯胺的浓度下降较快。这一实验结果为实际地下水含水层污染修复提供了理论支撑。

In order to achieve the purpose of controlled release,effective transport and efficient remediation of the oxidant,the slow-release technology is used to realize the long-term and efficient remediation of the groundwater aquifer by the oxidant.The potassium permanganate(KMnO_(4))slow-release materials with the addition of activated carbon were experimentally prepared by melt molding method,and the optimal ratios and sizes of slow-release materials were determined by release kinetics.In addition,the phenol-aniline degradation kinetics by KMnO_(4) slow-release materials and the effect of groundwater quality on phenol-aniline degradation were also investigated.Finally,an experiment was conducted on the degradation of phenol and aniline using slow-release materials in a two-dimensional sand tank.The results showed that the slow-release effect of KMnO_(4) slow-release material with a mass ratio of 3∶3∶2∶1 for paraffin,potassium permanganate,activated carbon,and silica sand,which was a 1 cm cube,was the best.The release kinetics study showed that the release rate of the sustained-release material after 30 d was 64.17%,indicating that it had excellent sustained-release properties,and the first-order kinetics equation was used to fit the experimental data with good correlation.And there were numerous holes and gaps appeared on the surface of KMnO_(4) retarded material after retardation,and the content of Mn,O,Si,and K elements on the surface increased significantly.This indicating that the release principle of KMnO_(4) slow-release material in water was mainly dissolution diffusion.Under the action of the slow-release oxidant,the concentration changes of phenol and aniline in the two-dimensional sand tank form a conical repair area centered on the slow-release material,and the concentration of phenol and aniline in the longitudinal direction decreased rapidly.This experimental result provides theoretical support for the remediation of actual groundwater aquifer pollution.