TY - JOUR
T1 - Filtration of triazine herbicides by polymer-clay sorbents
T2 - Coupling an experimental mechanistic approach with empirical modeling
AU - Gardi, Ido
AU - Nir, Shlomo
AU - Mishael, Yael G.
N1 - Publisher Copyright:
© 2014 Elsevier Ltd.
PY - 2015/3/1
Y1 - 2015/3/1
N2 - Triazine herbicides detected in surface and groundwater pose environmental and health risks. Removal of triazine herbicides (simazine, atrazine and terbuthylazine) by polymer-clay composites was studied and modeled. Their binding by a poly 4-vinyl pyridine co styrene-montmorillonite (HPVP-CoS-MMT) composite was especially high due to specific interactions between the herbicides and polymer, mainly hydrogen bonds and π-π stacking. The binding kinetics to the composite was in the order of simazine > atrazine > terbuthylazine, which was in accord with their equilibrium Langmuir binding coefficients; 44,000, 17,500 and 16,500M-1, respectively, which correlated with herbicide accessibility to form specific interaction with the polymer. Simazine binding kinetics to the composite was significantly faster than to granulated activated carbon (GAC), reaching 93% vs 38% of the maximal adsorption within 10min, respectively. Herbicide filtration by composite columns was adequately fitted by a model which considers convection and employs Langmuir formalism for kinetics of adsorption/desorption. Filtration of simazine (10μgL-1) by composite columns (40cm long, which included 26g composite mixed with sand 1:40 (weight ratio)), was well predicted by the model with nearly 120L purified, i.e., effluent concentrations were below regulation limit (3μgL-1). Effluent concentrations from GAC columns exceeded the limit after filtering 5L. Experimental results and model predictions suggest that while GAC has a high capacity for simazine binding, the composite has higher affinity towards the herbicide and its adsorption is faster, which yields more efficient filtration by composite columns.
AB - Triazine herbicides detected in surface and groundwater pose environmental and health risks. Removal of triazine herbicides (simazine, atrazine and terbuthylazine) by polymer-clay composites was studied and modeled. Their binding by a poly 4-vinyl pyridine co styrene-montmorillonite (HPVP-CoS-MMT) composite was especially high due to specific interactions between the herbicides and polymer, mainly hydrogen bonds and π-π stacking. The binding kinetics to the composite was in the order of simazine > atrazine > terbuthylazine, which was in accord with their equilibrium Langmuir binding coefficients; 44,000, 17,500 and 16,500M-1, respectively, which correlated with herbicide accessibility to form specific interaction with the polymer. Simazine binding kinetics to the composite was significantly faster than to granulated activated carbon (GAC), reaching 93% vs 38% of the maximal adsorption within 10min, respectively. Herbicide filtration by composite columns was adequately fitted by a model which considers convection and employs Langmuir formalism for kinetics of adsorption/desorption. Filtration of simazine (10μgL-1) by composite columns (40cm long, which included 26g composite mixed with sand 1:40 (weight ratio)), was well predicted by the model with nearly 120L purified, i.e., effluent concentrations were below regulation limit (3μgL-1). Effluent concentrations from GAC columns exceeded the limit after filtering 5L. Experimental results and model predictions suggest that while GAC has a high capacity for simazine binding, the composite has higher affinity towards the herbicide and its adsorption is faster, which yields more efficient filtration by composite columns.
KW - Competitive adsorption
KW - Filtration
KW - Modeling
KW - Polymer-clay composites
KW - Simazine
KW - Triazine herbicides
UR - http://www.scopus.com/inward/record.url?scp=84916908761&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2014.11.032
DO - 10.1016/j.watres.2014.11.032
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
C2 - 25506764
AN - SCOPUS:84916908761
SN - 0043-1354
VL - 70
SP - 64
EP - 73
JO - Water Research
JF - Water Research
ER -