Design of an adsorbent employing activated carbon fiber to remove lead

Abstract

Zorflex® activated carbon fibers (ACF), reference FM100 198B, are used before and after an oxidizing procedure with H 3 PO 4 to study the adsorption of Pb 2+. The point of zero charge was determined for the modified and unmodified fiber giving values of 2.3 and 4.3, respectively. After oxidizing the ACF, the fiber showed to have a greater Pb 2+ adsorption capacity in comparison with the unmodified fiber, which is related with the acid sites increase, where lead was mainly adsorbed. Determination of the BET area was carried out by nitrogen physisorption at 77K. ACFs presented superficial areas between 1000 and 1500 m 2 /g showing mostly, a microporous structure. The preliminary design of an adsorbent using the modified fiber is presented where the fiber superior physicochemical properties over the unmodified one are observed.

Efficiency of Leaching Tests in the Context of the Influence of the Fly Ash on the Environment

“…The difference 2at pH 6 < are too small to affect the sorption process the dominant forms of metal M 2+ (M = Cu, Zn, Pb) [Ho, et al, 2002]. This is confirmed by the data presented in Figure 6 the speciation graph of metal ions, whose curves are compatible with the data from literature [Zirino, Yamamoto, 1972, Cuppett et al 2006, Cárdenas López et al 2007, Deliyanni et al, 2007. They have been generated on the basis of the program Medusa [http://www.kemi.kth.se/medusa/].…”

Batch and Flow-Through Column Studies for Cr(VI) Sorption to Activated Carbon Fiber

“…As the pH increased, the surfaces of ACF became negatively-charged, and so the electrostatic repulsion between ACF surfaces and chromium ions (CrO 4 2-) became strong, resulting in the decrease of Cr(VI) sorption [19]. Note that the point of zero charge (pH pzc ) of ACF was reported to be 4.3 [20]. Our result agreed well with the report of Ko and Choi [14] who showed that Cr(VI) adsorption to ACF decreased from 1.3 mmol/g to near zero with increasing pH from 1.5 to 12.7.…”

Thermally modified molybdenum oxide as a potential sorbent for the removal of metal cations from aqueous solutions

“…Regarding the XRD reflections pattern, there is an apparent similarity between the commercial Fig. 4 The four main types of isotherms [41] J Radioanal Nucl Chem MoO 3 and that obtained from high temperature treatment (HTT) of AHM. However, the (0k0) reflections in the former material appear much stronger than those in the latter, a fact that suggests different morphology and orientation of the crystallites.…”

“…This pH range was selected taking into account the speciation diagrams for the investigated metal ions calculated by the computer code MEDUSA [40]. At pH values higher than 6.0, precipitation was observed in the case of lead [41]. In the case of uranium, at pH values lower than 6.0, uranyl ions UO 2 2?…”