Method for preparing multi-component organically-modified bentonite-embedded nanoscale zero-valent iron

Abstract

The invention discloses a method for preparing multi-component organically-modified bentonite-embedded nanoscale zero-valent iron. The method comprises the following steps that (1) bentonite is preprocessed; (2) 20-50 g/L of bentonite particles are added to 0.1 M of a FeCl3 solution, the bentonite particles and the solution are fully mixed and centrifuged, supernatant liquor is removed, and the process is repeated twice, so that Fe3+ saturated bentonite particles are obtained; (3) the Fe3+ saturated bentonite particles are added to deionized water, the pH is regulated to range from 2 to 3.5, NaBH4 is added to the mixture according to the molar ratio, 25-35:1, of the NaBH4 to Fe3+ under the protection of inert gas, the mixture reacts for 1-3 min at room temperature, and then bentonite-embedded zero-valent iron is obtained through high-speed centrifugation; (4) three organic cation modifying agents, namely HDTMA, TPMA and TMA are added to the deionized water mixed with the bentonite-embedded zero-valent iron, a replacement reaction is conducted for 15-30 min in an oxygen-free environment, and then the multi-component organically-modified bentonite-embedded nanoscale zero-valent iron is obtained through high-speed centrifugation. By means of the method, the clustering phenomenon of nanoscale iron in a complex heavy nonaqueous-phase environment can be relieved, and the surface hydrophobic performance is improved; through organic modification of the three components, adsorption of the bentonite and the reducing action of iron, the environmental behavior and the form of the nanoscale iron are improved, and the degradation efficiency of the nanoscale iron is improved finally.

Description

technical field [0001] The invention belongs to the technical field of groundwater environmental pollution restoration, and in particular relates to a preparation method of multi-component organically modified bentonite embedded with nanometer zero-valent iron. Background technique [0002] With the rapid development of the economy, the environmental pollution of groundwater in my country is becoming more and more serious. Among them, organic pollution in groundwater is a common and refractory pollutant. How to remove organic pollutants in groundwater economically and effectively has always been an issue of environmental pollution in groundwater. The goal pursued by the restorative world. [0003] Since it was reported in the late 1980s that zero-valent iron could in situ remediate chlorinated organics in groundwater [R.W.Gillham, A.F.O'Hannesin. Ehanced graduation of halogenated aliphatics by zero-valentiron. Ground Water, 1994,32:958-967.], using zero-valent Iron treatment...

AI Technical Summary

Problems solved by technology

[0009] However, some of the refractory organic pollutants concerned in the remediation of groundwater zero-valent iron are mainly dissociated in the heavy non-aqueous phase, which contains less water and is mainly the organic phase. The enhancement effect of the non-aqueous phase is not necessarily applicable, especially considering the complexity and diversity of the non-aqueous environment, the existing modification methods have certain limitations in the treatment of pollutants in the non-aqueous phase