Hydrothermal Conversion of Triclosan—The Role of Activated Carbon as Sorbent and Reactant

Abstract

Triclosan (TCS) was treated under hydrothermal conditions at 240 °C for 4 h, either dissolved in aqueous solution or preadsorbed onto activated carbon (AC). Hydrothermal conversion of dissolved TCS led to formation of 2,8-dichlorodibenzo-p-dioxin (DCDD). Its yield was dependent on the pH of the aqueous solution increasing from 38% at pH 4 up to 67% at pH 12. Adsorption of TCS at neutral pH on three different kinds of ACs, powder, granular, and felt, changed the reactivity of the TCS molecule under hydrothermal conditions significantly. The conversion of TCS and, in particular, the formation of DCDD was inhibited in the presence of ACs. When TCS was adsorbed on powdered AC, the preferred reaction pathway was the reductive hydrodechlorination. The findings described herein may be valuable for a potential regeneration method for loaded AC based on hydrothermal treatment.

A Combination of Waste Biomass Activated Carbon and Nylon Nanofiber for Removal of Triclosan from Aqueous Solutions

“…In recent years, the adsorption process has been one of the popular methods applied to remove chemicals and dyes in water and wastewater treatments due to its advantages of having less processing procedures with less sludge being produced. Several adsorption studies to remove TCS were done using rice strawderived activated carbon [19], charcoal-based activated carbon [20], conventional activated carbon [21], civilian protective gas mask activated carbon [22], magnetic carbon composites from hydrochar [23], and wastewater biosolids-derived biochar [24]. High surface areas, micro-porous structures, and high degrees of surface reactivity cause activated carbons to become versatile adsorbents, particularly effective for the adsorption of organic and inorganic pollutants from aqueous solutions [25].…”