Modified Activated Carbon Fibers For The Adsorption Of Heavy Metal Ions And Dyes

Activated carbon fiber (ACF), as the upgrade product of activated carbon, has a good adsorption property, mainly replied on large specific surface area and small pore structure. ACF, whichcan be used for organic and inorganic pollutants removal, playing an important role in the water treatment. The adsorbent’s selective adsorption and regenaration are the two main facors of ACF, which limiting its application in wastewater treatment. Heavy metal ions wastewater and dye wastewater has always been strictly controled in China, due to its large quantity and difficulty to deal with. At present, treatment wastewater with chemical method just focused on the remove of heavy metal ions and organic matter, ignoring the recycle of heavy metal and colour standards.In this article, ACF was oxidative modificatedto improveadsorption capacity and repeated use after regeneration for many times. ACF was studied to absorb the heavy mental ions of Cu2+、Zn2+、Ni2+anddye wastewater of acid scarlet, alkaline bright red and direct scarlet. The results were summarized as follows:(1) ACFmodified by HNO3has more surface oxygen groups than H2O2. It was also proved that the ACF which oxidized by HNO3 at 60℃ for 2 hours, has the good adsorption properties, with the surface oxygen groups increased more than 3 times, carboxyl increased nearly 7 times, signed as ACF-N-2h.(2) The results showed:whenpHis 6, reaction time is 2h, ACF-N-2hhas a good adsorption properties with the Cu2+、Zn2+、Ni2+removal rate of 99.5%,90.7%, 98.9%. Langmuir and pseudo-second order adsorption kinetics models could suitable describe the adsorptionmechanism, with both correlation coefficient R2of 0.999.(3) Modified ACF do not have significantly improved of adsorption experiment of dye watert. Orthogonal test indicated thatthe factors order:pH> surface oxygen groups>reaction time. Pseudo-second order adsorption kinetics models could be suitablely described the adsorptionmechanism.(4) The actual electroplating wastewater and dye wastewater experimentshowed: when temperature is 25 ℃, pHis 6, reaction time is 2h, ACF-N-2h has a good adsorption property with the Cu2+、Zn2+、Ni2+removal rate of 99%,83%,98.3%. ACF could recycle heavy metals through regeneration. When temperature is 25 ℃, pHis 7, reaction time is 80min, decolorization rate of dye wastewater adsorpted by ACF were 97.1%, realize the colour standards.(5) The regeneration rate of ACF can reached above 98.7% with recycle used of more than five times, which indicated that ACF has a better regeneration effect.