Surface-water purification using cellulose paper impregnated with silver nanoparticles

Abstract

The objective of this study is to prepare a cellulose paper that was impregnated with silver nanoparticles (AgNPs) for the purpose of water purification (disinfection and filtration). AgNP papers were prepared by chemical reduction of silver nitrate (span classCombining double low line"inline-formula"AgNO3/span) with various concentrations (0.005 span classCombining double low line"inline-formula"M/span, 0.015 span classCombining double low line"inline-formula"M/span, 0.03 span classCombining double low line"inline-formula"M/span, and 0.05 span classCombining double low line"inline-formula"M/span) using sodium borohydride (span classCombining double low line"inline-formula"NaBH4/span) as a reducing agent. Two ratios for span classCombining double low line"inline-formula"math xmlnsCombining double low line"http://www.w3.org/1998/Math/MathML" idCombining double low line"M7" displayCombining double low line"inline" overflowCombining double low line"scroll" dspmathCombining double low line"mathml"mrowmrow classCombining double low line"chem"msubmi mathvariantCombining double low line"normal"NaBH/mimn mathvariantCombining double low line"normal"4/mn/msub/mrowmo//momrow classCombining double low line"chem"msubmi mathvariantCombining double low line"normal"AgNO/mimn mathvariantCombining double low line"normal"3/mn/msub/mrow/mrow/mathspansvg:svg xmlns:svgCombining double low line"http://www.w3.org/2000/svg" widthCombining double low line"76pt" heightCombining double low line"14pt" classCombining double low line"svg-formula" dspmathCombining double low line"mathimg" md5hashCombining double low line"47e958562daf726c97fbea72d1262afe"svg:image xmlns:xlinkCombining double low line"http://www.w3.org/1999/xlink" xlink:hrefCombining double low line"dwes-14-95-2021-ie00001.svg" widthCombining double low line"76pt" heightCombining double low line"14pt" srcCombining double low line"dwes-14-95-2021-ie00001.png"//svg:svg/span/span of span classCombining double low line"inline-formula"2:1/span and span classCombining double low line"inline-formula"10:1/span were used to show the effect of reduction on the formation and removal efficiencies of AgNPs. AgNP papers were characterized using scanning electron microscopy and transmission electron microscopy. An acid digestion using HCl acid followed by analyzing the samples in an atomic absorption spectrometer (ASS) was conducted to measure the silver concentration in AgNP papers. TEM images showed that the silver nanoparticle size in the papers varied from 1.3 to 75 span classCombining double low line"inline-formula"nm/span./p pWater samples, after filtration through AgNP papers, were analyzed using ASS to measure the silver concentration in the effluent water. AgNP paper antibacterial efficiency ranged from 99 % to 100 % for both reduction ratios. The average silver content in the effluent water for the three replicates ranged from 0 to 0.082 span classCombining double low line"inline-formula"mg L-1/span, which meets the United States Environmental Protection Agency (US-EPA) guideline for drinking water of less than 0.1 span classCombining double low line"inline-formula"mg L-1/span. Turbidity tests showed that these papers can be usefully used as point-of-use filters as the turbidity reduced to less than 1 span classCombining double low line"inline-formula"NTU/span (Nephelometric Turbidity Units)./p.