Wood-Biochar-Supported Magnetite Nanoparticles for Remediation of PAH-Contaminated Estuary Sediment

Abstract

Abstract:In this study, we investigated the ability of a magnetic wood biochar (WB)-based composite catalyst (Fe 3 O 4 -WB) to catalyze sodium persulfate (PS) for the remediation of estuary sediment contaminated with polycyclic aromatic hydrocarbons (PAHs). The effects of various critical parameters, including the catalyst dose and initial pH, were investigated. The degradation of the PAHs was found to be related to the number of rings in their structure. The results showed that Fe 3 O 4 -WB is an efficient catalyst for the removal of high-ring PAHs (HPAHs), with the highest degradation rates for the 6-, 5-, and 4-ringed PAHs being 90%, 84%, and 87%, respectively, for a PS concentration of 2 × 10 −5 M, catalyst concentration of 3.33 g/L, and pH of 3.0. That the reduction rate of the HPAHs was greater than that of the low-ring PAHs can be attributed to the strong affinity of the HPAHs for biochar derived from wood biomass. Overall, this study revealed that the WB-mediated electron transfer catalysis of the surface functional groups in a wide range of pH in the Fe 3 O 4 -WB/PS system and potentially application in the remediation of sediments contaminated with PAHs.

Optimization of Micro-Pollutants’ Removal from Wastewater Using Agricultural Waste-Derived Sustainable Adsorbent

“…The associated reasoning for this might be the repellent forces between the adsorbed pollutants and the free pollutants in the solution [65]. In addition, as the contact time increases after equilibrium, some of the adsorbed pollutants might be released into the solution [65]. A similar trend was reported by Sofia and colleagues regarding contact time [66].…”

“…A decrease in PAH and COD removal after 180 min of reaction time showed the possibility of physical attachment of organic pollutants with the surface or saturation of active sites by chemical adsorption. The associated reasoning for this might be the repellent forces between the adsorbed pollutants and the free pollutants in the solution [65]. In addition, as the contact time increases after equilibrium, some of the adsorbed pollutants might be released into the solution [65].…”

Nanoparticles Used for Extraction of Polycyclic Aromatic Hydrocarbons

“…Also, another green method used for the reduction of PAHs in marine sediment was enhanced by using magnetic bamboo biochar [137]. Wood biochar supported by magnetite NPs (Fe 3 O 4 -WB) was found as an efficient catalyst for the removal of high-ring PAHs with the highest degradation rates for the 6-, 5-, and 4-ringed PAHs being 90, 84, and 87%, respectively [138]. Polydopamine coated Fe 3 O 4 NPs (Fe 3 O 4 / PDA) has been successfully used as an adsorbent for determination of trace PAHs in environmental samples.…”

Novel nanocomposite of biochar‐zerovalent copper for lead adsorption

“…The four deconvoluted peaks of C1s (Figure 4b) are for C–H/C–C at 284.6 eV, C=C at 284.8 eV, hydroxyl/epoxy (C–O) at 286.8 eV and carboxylate (O=C–O) at 288.8 eV (Vuong Hoan et al, 2016; Yang et al, 2018; Zhang, Wu, & Fan, 2019). The deconvoluted oxygen peaks (Figure 4c) shows presence of C–O (531.1 eV) and OH −1 (532.3 eV) indicating electron capture by oxygen in the empty spaces of biochar surface (Briggs & Beamson, 1993; Dong, Chen, Kao, Chien, & Hung, 2018; Miyakoshi, Ueno, & Ichikawa, 2001). Figure 4d shows the presence of zerovalent form together with the +2 oxidation state of copper.…”