Removal of Paracetamol and Cu2+ from Water by Using Porous Carbons Derived from Agrowastes

Abstract

Dende and babassu coconuts are largely used in tropical countries, namely in Brazil, for the extraction of oils from kernels. The remaining biowastes are industrially processed to produce porous carbons (PCs). PCs derived from dende and babassu biowastes and produced at an industrial scale have been characterized by textural, chemical, and ecotoxicological parameters. A commercial activated carbon (CC) of mineral origin has been used as a benchmarking material. Although the CC sample presented a higher surface area (SBET = 1083 m2/g), the PCs derived from the biowastes were richer in micropores (Vmicro = 0.25–0.26 cm3/g), while the CC carbon presented wider pore size distribution with a higher mesopore volume (Vmeso = 0.41 cm3/g). All the adsorbents used in this work have shown a non-acute ecotoxic behavior for the bacterium Vibrio fischeri (EC50-30 min > 99% v/v). The adsorbents have been tested for paracetamol and Cu2+ adsorption in mono- and bicomponent solutions. The uptake capacities of paracetamol (qe, 98–123 mg g−1) and Cu2+ (qe, 15–18 mg g−1) from monocomponent solutions were similar to the ones obtained in the bicomponent solutions, indicating no competition or cooperative effects but a site-specific adsorption. This finding represents an advantage for the removal of these adsorbates when present in the same solution as they can be adsorbed under similar rates as in the single systems. Paracetamol adsorption was related to micropore filling, π-π interactions, and H-bonding, whereas Cu2+ removal was attributed to the cation exchange mechanism and complexation to the hydroxyl groups at the carbons’ surface.

Valorization and Upcycling of Acid Mine Drainage and Plastic Waste via the Preparation of Magnetic Sorbents for Adsorption of Emerging Contaminants

“…86−88 This could be that Ferreira and coworkers used a lower pH, mass of adsorbent, high sample volume, and longer contact time, suggesting lower pH (Table 7) gave more ionic interactions and higher sample volume, which allowed more room for interactions for a longer time. 86 On the other hand, some researchers used similar pH conditions but higher sample volume and longer reaction time, which allowed for room and longer interactions between analytes and adsorbents. 87,88 However, a lower capacity obtained by Hamoudi and colleagues suggests that increased mass of adsorbent and longer reaction time did not have much influence on the adsorption capacities.…”