Removal of 2,4-Dinitroanisole and Nitroguanidine by Membrane Filtration

NATALIA CASIS; DIANA ESTENOZ; M. SPONTON; M. MARTA FIDALGO

Cancún

Congreso; XXVI International Materials Research Congress (IMRC XXVI); 2017

Materials Research Society

The treatment of contaminated wastewaters with nitroaromatic compounds and nitramines has been investigated in the past and several technologies have been proposed. These technologies include both destructive methods such as biological (slurry phase bioreactors, constructed wetlands) [1] and chemical (advanced oxidation processes) treatments, and extractive technologies such as reverse osmosis and filtration [2]. Although membrane technologies exhibit a number of advantages, such as smaller footprint, high removal efficiency, and control over operation, there are few reports in the scientific literature about polymeric membranes being applied to this task at industrial, pilot, or bench scale. This study is the first attempt to investigate the applicability of polymeric membrane technology to the removal of nitroaromatic compounds and nitroamines from water. Two types of membranes were considered: polyamide and cellulose acetate. In particular, an extractive method based on polymeric reverse osmosis (RO) was evaluated for the removal of 2,4-Dinitroanisole (DNAN) and nitroguanidine. The work included: i) membranes characterization by SEM, FT-IR and AFM and determination of zeta potential, contact angle, and molecular weight cut off; and ii) filtration tests by cross flow system considering different transmembrane pressure, contaminants concentration and ionic strength (IS). High feed pressure yielded high recovery and more efficient filtration but more overall fouling. High IS of the feed solution increased the fouling for both membranes showing high irreversibility for high concentration of contaminant. Fouling decreased with contaminant solubility and hydrophilicity. As expected, more hydrophilic surfaces exhibitedd superior resistance to irreversible fouling. Respect to compounds rejection, experiments showed a positive correlation with contaminant hydrophobicity and membrane hydrophilicity. The results were also used to design chemical modification procedures of membranes in order to enhance the filtration capability.