Behavior of graphitized carbon blacks in the electrodegradation and sorption of chlorophenoxyacetic acids

Abstract

This paper compares the properties of two graphitized carbon blacks in the sorption and first stage of electrodegradation (dechlorination) of chlorophenoxyacetic acids and discusses the influence of surface area on the electrochemical behavior of these carbon materials. Two carbon blacks with ten-fold different surface areas (100 and 10 m 2 /g) were used as sorbents and electrode materials as received. Two chloroorganics with various numbers of Cl atoms in the molecule, 4-chlorophenoxyacetic acid and 2,4-dichlorophenoxyacetic acid, were adsorbed on the carbon samples from neutral aqueous electrolyte solutions containing low concentrations of adsorbate. Cyclovoltammetric studies of the graphitized carbon blacks were performed using powdered electrode techniques, and the drop in organics concentration during cyclization was measured using HPLC. For carbon black with a smaller surface area, the presence of faradaic reactions was not masked by capacitive currents, and well-shaped faradaic couple peaks characteristic of a quinine/hydroquinone-like adsorbed system were observed. This indicates that these materials are active in chloroorganics electrodegradation (by dechlorination). The extent of electrodegradation (a four-fold drop in organics concentration) observed for carbon black with a larger surface area indicates the dominant role of surface (porosity) development in these processes.

A nano-carbon electrode optimized for adsorptive stripping voltammetry: Application to detection of the stimulant selegiline in authentic saliva

“…Sorbent for palladium [33] Mineral acid-modified CB Sorption Sorbent for Arsenic [34] Commercial CB Adsorption/Sorption Adsorbent for progesterone hormone [35] Commercial CB Sorption/Extraction Adsorbent for herbicides:2,4-dichlorophenoxy acetic acid and 2methyl-4-chlorophenoxy acetic acid [36] Graphitized CB Sorption and electro-degradation Adsorbent and dechlorination of chlorophenoxyacetic acids [37] 4 5…”

Efficient Removal of the Toxic Lead Ions from ContaminatedSandy Soils using Newly Engineered Carbon Black Nanoadsorbent

“…CB is receiving a great deal of attention as an adsorbent for the removal of heavy metals from wastewater, (Dong et al, 2017) because it has a form of paracrystalline structure that possesses a high surface area to volume ratio, (Sebok and Taylor, 2001) a large internal surface area, a highly developed porosity, and a remarkably high mechanical properties. (Biniak et al, 2016;Voet and Aboytes, 1971) However, adsorption properties of CB is affected by its activation process. (Brennan et al, 2002) Thus, researchers have started to modify and update its physical and chemical properties (e.g.…”