Reducing arsenic and groundwater contaminants down to safe level for drinking purposes via Fe3+-attached hybrid column.

Abstract

Monitoring of groundwater is fundamentally important due to it has emerged as a major source of drinking water and also used for irrigation purposes in many places in the world. Arsenic contamination in surface water and groundwater resources is a major concern due to its presence at high concentration and associated adverse health effects. Thus, the remediation of As in water resources, alongside other chemical species including fluoride, lithium, vanadium aluminium and nitrate is necessary. We have designed a hybrid [polyethyleneimine (PEI)-supported Fe3+-attached poly-(HEMA-co-GMA)] column for the reduction of arsenic (III and V) and other groundwater chemicals from natural groundwater as a potential contribution to water resource management. Swelling behaviour and scanning electron microscopy (SEM) were performed for the characterization of hybrid material. For the optimization of experimental conditions, the effects of pH and initial arsenic concentrations on adsorption were studied using arsenic solutions. Maximum adsorption capacity in equilibrium was 11.44 and 5.79 mg/g polymer for As(III) and As(V), respectively at pH 7. The reduction of metalloids and other subsurface chemicals were carried out with natural groundwater samples obtained from local sources. The mean concentrations of arsenic were recorded between 44.96 and 219.04 μg/L and of which 71.3-95.4 % (0.32-1.22 mg/g) were removed. The average removals were determined as F-1 50-86%, Li+ 43.2-99.7%, Al+3 83.8-91.4%, NO3- 48.4-72.2% and V 91.3-95.7. Chemical-loaded hybrid columns were regenerated successfully 15 times with only a loss of 5% in adsorption capacity by 0.01 M NaCl- treatment for potential adaptation into water industry. No pre-oxidation of As species wasperformed for the treatment of ground water samples prior to the hybrid column testing.