Ability of MCM-41-based sorbents to remove and reduce hexavalent chromium from different water matrices

PEDRO MARTIN; NICOLÁS FELLENZ

Sitges

Congreso; Sixth International Conference on Multifunctional, Hybrid and Nanomaterials 2019; 2019

ELSEVIER

Chromium compounds are used in the leather tanning industry, the manufacture of catalysts, pigments and paints, fungicides, ceramic, in photography and for chrome alloy and chromium metal production, chrome plating, among others industrials uses. In aqueous environments chromium can be found mainly as hexavalent (Cr(VI)) and/or trivalent (Cr(III)). Between them, Cr(VI)-based compounds are many times more toxic than the Cr(III) species. Due to this, strategies for remediation of wastewater with high Cr(VI) levels involving a mixed mechanism of retrieval-reduction of Cr(VI) to the less toxic trivalent state, present a clear advantage versus those that only achieve separation without chemical transformation. Recently, we demonstrated that aminopropyl-modified MCM-41 systems have the ability to adsorb and reduce HCrO4- from distillated water at acidic conditions. However, seeking to develop sorbents for the treatment of aqueous waste similar to those generated in the aforementioned industries, it is necessary testing these kinds of solids for the treatment of complex aqueous matrices that contain, in addition to chromium, other chemical species. With this goal in mind, in this work we report the synthesis and characterization of an MCM-41-NH2 and its performance to remove and reduce Cr(VI) in the presence of Fe, Na, Ca and Zn salts.