药品污染,个人护理产品,在二十一世纪的前三分之一,水资源中的其他新兴污染物已成为全球关注的严重新兴问题。随着社会对药品的依赖不断升级,无意中将这些物质引入水库会带来相应的环境威胁。因此,这项研究的目的是研究还原降解,特别是,关于双氯芬酸(DCF)等模型污染物的催化氢化,布洛芬(IBP),17α-炔雌醇(EE2),或双酚A(BPA),分别,在实验室规模的水溶液中。铁双金属(零价铁,ZVI,和铜,Cu,或者镍,Ni)以及零价镁(Mg,ZVM)与铑结合,Rh,或钯,Pd,作为氢化催化剂(香港),被调查了。通过各种短期批量实验进行研究,有多个样本集合,在120分钟的总范围内。结果表明,当暴露于Fe-Cu或Fe-Ni双金属(作为单一模型污染物)时,DCF的衰减超过90%。然而,当DCF与IBP一起是混合物的一部分时,EE2和BPA,Fe-Cu和Fe-Ni的衰减效率分别降至79%和23%。相反,IBP和BPA都表现出明显的低衰减水平,低于50%,都部署为单一物质或混合物。使用LC-MS无法鉴定反应(降解)产物,但有时在一定程度上可以注意到使用乙酸缓冲液时母体污染物的释放,建议对腐蚀产物如氢氧化铁和/或氧化物的吸附过程。令人惊讶的是,Mg与Rh(Rh-HK)或Pd(Pd-HK)组合显示DCF浓度显着快速降低,EE2和BPA,部分高达约100%,也就是说,在几分钟内仅部分由于氢化降解反应(相关反应产物实际上可以通过LC-MS鉴定;吸附过程在这里没有观察到)。此外,在不同温度(15°C,20°C,25°C,35°C)和不同的初始浓度(2.5mg/L,5.0mg/L,7.5mg/L,10.0mg/L)。结果表明,DCF在Rh-HK表面的降解遵循修正的一级动力学,最有可能通过催化加氢脱卤和随后的芳族部分氢化(分子氢由Mg的腐蚀提供)。从四个不同温度下确定的反应速率常数,通过Arrhenius方程估计活化能为59.6kJ/mol,这与文献中报道的类似结果非常吻合。这种结合的脱卤加氢和加氢方法可以升级为一种新的有前途的技术工艺,以一步全面去除污水厂中的此类药物和类似污染物,此外,即使与活性炭和/或臭氧化的吸附相结合,最近在瑞士和德国的一些污水处理厂已经建立了。
Contaminations by pharmaceuticals, personal care products, and other emerging pollutants in water resources have become a seriously burgeoning issue of global concern in the first third of the twenty-first century. As societal reliance on pharmaceuticals continues to escalate, the inadvertent introduction of these substances into water reservoirs poses a consequential environmental threat. Therefore, the aim of this study was to investigate reductive degradation, particularly, catalytic hydrogenation regarding model pollutants such as diclofenac (DCF), ibuprofen (IBP), 17α-ethinylestradiol (EE2), or bisphenol-A (BPA), respectively, in aqueous solutions at lab scale. Iron bimetals (zero valent iron, ZVI, and copper, Cu, or nickel, Ni) as well as zero valent magnesium (Mg, ZVM) in combination with rhodium, Rh, or palladium, Pd, as hydrogenation catalysts (HK), were investigated. Studies were executed through various short-term batch experiments, with multiple sample collections, over a total range of 120 min. The results indicated that DCF was attenuated at over 90 % when exposed to Fe-Cu or a Fe-Ni bimetal (applied as a single model pollutant). However, when DCF was part of a mixture alongside with IBP, EE2, and BPA, the attenuation efficacy decreased to 79 % with Fe-Cu and 23 % with Fe-Ni. Conversely, both IBP and BPA exhibit notably low attenuation levels with both bimetals, less than 50 %, both deployed as single substances or in mixtures. No reaction (degradation) products could be identified employing LC-MS, but sometimes a release of the parent pollutant when applying an acetic acid buffer could be noted to a certain extent, suggesting adsorption processes on corrosion products such as iron hydroxide and/or oxides. Surprisingly, Mg in combination with Rh (Rh-HK) or Pd (Pd-HK) showed a significantly rapid decrease in the concentrations of DCF, EE2, and BPA, in part up to approximately 100 %, that is, within a few minutes only in part due to hydrogenation degradation reactions (related reaction products could actually be identified by LC-MS; adsorption processes were not observed here). Moreover, kinetic modeling of the DCF degradation with Mg-Rh-HK was conducted at different temperatures (15 °C, 20 °C, 25 °C, 35 °C) and varied initial concentrations (2.5 mg/L, 5.0 mg/L, 7.5 mg/L, 10.0 mg/L). The outcomes prove that the degradation of DCF at the Rh-HK\'s surface followed a modified first-order kinetics, most probably by catalytic hydrodehalogenation and subsequent hydrogenation of the aromatic moieties (molecular hydrogen was provided by the corrosion of Mg). From the determined reaction rate constants at four different temperatures, the activation energy was estimated to be 59.6 kJ/mol by means of the Arrhenius equation what is in good agreement with similar results reported in the literature. This coupled hydrodehalogenation and hydrogenation approach may be upscaled into a new promising technical process for comprehensively removing such pharmaceuticals and similar pollutants in sewage plants in a single step, furthermore, even in combination with adsorption by activated carbon and/or ozonation which have already been established at some sewage plants in Switzerland and Germany recently.