Removal Of Phenolic Compounds From Aqueous Media Using Triethylamine Anchored Rice Husks

Abstract

Phenolic compounds in water are contaminants of concern even at low concentrations. They get incorporated inwater from various sources such as industrial, mining and natural sources. Natural sources of phenoliccompounds are plant saplings and aquatic plants such as green and red marine algae. This makes thesecompounds readily available from both natural and industrial sources to pollute the water. Phenolic compoundstake long to diminish and are carcinogenic. Phenolic compounds in water affects its taste and oduor of the vitalproducts. They equally affect the taste and odour of marine organisms in that water as well as the animals thatconsume it. To minimize the negative effects from these pollutants, their elimination is the only option. This papergives an account on the preparation and modification of rice husks with triethylamine and how it is used on theelimination of phenolic compounds from water by adsorption. Modification was carried out by chlorinating andanchoring with an amino group on the rice husks to form a quaternary ammonium compound. The existence ofthe functional groups that performed as the binding sites was confirmed by Fourier Transform Infrared (FT-IR)analysis. The anchoring of the amino group was confirmed by the occurrence of a signal at 3424.67cm-1. Thecarbon skeleton of the modified product resembled that of cellulose by solid-state 13C NMR. Change ofresonancefrequenciesin the modified material confirmed the chlorination and subsequent the anchoring of ethylene diaminewithin the cellulose structure. Scanning electron microscopy analysis displayed an increase in the porosity of themodified material as related to the parent material. The material was then applied for sorption experiments andit was confirmed that the optimum pH was of 5.5 for all the phenolic compounds under study. There was over90% phenolic compounds uptake in the first 2 min of contact time. The adsorption followed the Langmuirmonolayer adsorption model with correlation coefficient (R2) of 0.9895 for Naphthol. The elimination ofNaphthol with modified rice husks gave the best adsorption capacity of 0.6125 mg/g. Thus modified rice husks isan effective adsorbent material for eradication of phenolic substances originating from unsafe drinking water