Removal of Cr(VI) from aqueous solution by a highly efficient chelating resin

WOS: 000400971300006The poly([(2-methacryloyloxy)ethyl]trimethylammonium chloride) [P(MOTA)] based chelating resin was synthesized by radical polymerization and employed for Cr(VI) removal. The sorption capacity of this resin was very high with a fast sorption rate for Cr(VI) obeying a pseudo-second order kinetic model. In agreement to diffusion model equations, the rate determining step was film diffusion according to the infinite solution volume (ISV) model and reacted layer in accordance with the unreacted core (UC) model. In a column-mode sorption study, the breakthrough capacity obtained was 24.3 mg Cr/mL-resin. The elution of Cr(VI) from the resin was achieved using a mixture of 1.0 mol/L NaOH and 1.0 mol/L NaCl with an elution efficiency of about 100 %. Based on FT-IR measurements, it was clearly understood that Cr(VI) was sorbed by the resin through the quaternary amine functional groups.CHILTURPOL2 (PIRSESGA Project) [269153]; FONDECYTComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)CONICYT FONDECYT [1150510]; REDOC (MINEDUC Project at University of Concepcion) [UCO1202]The authors thank the so-called CHILTURPOL2 (PIRSESGA-2009 Project, Grant Number 269153) 7FP-MC Actions Grant. We also thank FONDECYT (Grant No. 1150510), REDOC (MINEDUC Project UCO1202 at University of Concepcion) for the financial support

Role of Biofilms in Contaminant Bioaccumulation and Trophic Transfer in Aquatic Ecosystems: Current State of Knowledge and Future Challenges

International audienceIn freshwater environments, microbial assemblages attached to submerged substrates play an essential role in ecosystem processes such as primary production, supported by periphyton, or organic matter decomposition, supported by microbial communities attached to leaf litter or sediments. These microbial assemblages, also called biofilms, are not only involved in nutrients fluxes but also in contaminants dynamics. Biofilms can accumulate metals and organic contaminants transported by the water flow and/or adsorbed onto substrates. Furthermore, due to their high metabolic activity and their role in aquatic food webs, microbial biofilms are also likely to influence contaminant fate in aquatic ecosystems. In this review, we provide (1) a critical overview of the analytical methods currently in use for detecting and quantifying metals and organic micropollutants in microbial biofilms attached to benthic substrata (rocks, sediments, leaf litter); (2) a review of the distribution of those contaminants within aquatic biofilms and the role of these benthic microbial communities in contaminant fate; (3) a set of future challenges concerning the role of biofilms in contaminant accumulation and trophic transfers in the aquatic food web. This literature review highlighted that most knowledge on the interaction between biofilm and contaminants is focused on contaminants dynamics in periphyton while technical limitations are still preventing a thorough estimation of contaminants accumulation in biofilms attached to leaf litter or sediments. In addition, microbial biofilms represent an important food resource in freshwater ecosystems, yet their role in dietary contaminant exposure has been neglected for a long time, and the importance of biofilms in trophic transfer of contaminants is still understudied