REMOVAL OF DISINFECTION BY-PRODUCTS IN WATER BY ADSORPTION ON THIOL-FUNCTIONALIZED MESOPOROUS MATERIAL CONTAINING IN ALGINATE BEAD

Abstract

The purpose of this research was to examine adsorption mechanism of DBPs including haloacetonitrile, trihalomethane, halogenated ketone, and haloacetic acid on thiol-functionalized hexagonal mesoporous silicates based on natural rubber containing with alginate bead adsorbent (AL:NR/HMS-SH) comparing with granular activated carbon (GAC). First, NR/HMS-SH was synthesized via in-situ sol-gel method, and then was prepared into beads form in calcium chloride solution. The synthesized material was characterized the physicochemical properties by various techniques such as Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and N2 adsorption-desorption isotherm. The adsorption kinetics and adsorption isotherms were studied to examine the adsorption mechanism under batch condition. According to the kinetic study, the adsorption rate and capacity of both adsorbent exhibited the higher amount on trichloromethane (TCM) than dichloroacetonitrile (DCAN) and 1,1,1-trichloroacetone (TCA) respectively. The adsorption isotherm models including Linear, Langmiur, and Fruendlich models were estimated to examine the adsorption mechanism on adsorption isotherm study. It found that the lower water solubility DBPs which had high hydrophobicity showed higher adsorption capacity than the higher water solubility DBPs. In addition, the present of other DBPs species in the solution as mixture affected to the adsorption efficiencies of each DBP. Moreover, this research investigated the effect of natural organic matter (NOM) including hydrophilic-like (HPI) and hydrophobic-like (HPO) natural organic matter on DCAN adsorption on synthesized adsorbent. The results appeared that the adsorption of DCAN on synthesized adsorbent was affected by HPO NOM more than HPI NOM by reducing the adsorption capacity of DCAN due to the competitive adsorption on adsorbent surface. The adsorption of DCAN on fixed bed condition was investigated by varying bed depth. It revealed that the breakthrough time at breakthrough concentration increased with increasing of bed volume. This might because the higher of bed volume had more available sorption site for particle to be adsorbed.