Adsorption and Fenton-like Degradation of Ciprofloxacin Using Corncob Biochar-Based Magnetic Iron–Copper Bimetallic Nanomaterial in Aqueous Solutions

Abstract

An economical corncob biochar-based magnetic iron–copper bimetallic nanomaterial (marked as MBC) was successfully synthesized and optimized through a co-precipitation and pyrolysis method. It was successfully used to activate H2O2 to remove ciprofloxacin (CIP) from aqueous solutions. This material had high catalytic activity and structural stability. Additionally, it had good magnetic properties, which can be easily separated from solutions. In MBC/H2O2, the removal efficiency of CIP was 93.6% within 360 min at optimal reaction conditions. The conversion of total organic carbon (TOC) reached 51.0% under the same situation. The desorption experiments concluded that adsorption and catalytic oxidation accounted for 34% and 66% on the removal efficiency of CIP, respectively. The influences of several reaction parameters were systematically evaluated on the catalytic activity of MBC. OH was proved to play a significant role in the removal of CIP through electron paramagnetic resonance (EPR) analysis and a free radical quenching experiment. Additionally, such outstanding removal efficiency can be attributed to the excellent electronic conductivity of MBC, as well as the redox cycle reaction between iron and copper ions, which achieved the continuous generation of hydroxyl radicals. Integrating HPLC-MS, ion chromatography and density functional theory (DFT) calculation results, and possible degradation of the pathways of the removal of CIP were also thoroughly discussed. These results provided a theoretical basis and technical support for the removal of CIP in water.

Green synthesis of ZnFe2O4@BC nanocrystals using pomelo peel waste for photo‐Fenton degradation of dye under visible light

“…It was observed that the removal efficiency of MB gradually decreased as the initial pollutant concentration increased. This decline in removal efficiency may be attributed to the occupation of active sites on the ZnFe 2 O 4 @BC catalyst at high MB concentrations [37] …”

“…This decline in removal efficiency may be attributed to the occupation of active sites on the ZnFe 2 O 4 @BC catalyst at high MB concentrations. [37] The impact of H 2 O 2 concentration on MB degradation was investigated within the range of 5 mM to 11 mM, as shown in Figure 2g. The results indicated that the degradation efficiency of MB initially increased with higher H 2 O 2 concentration, followed by a decrease.…”

Coactivation of Hydrogen Peroxide Using Pyrogenic Carbon and Magnetite for Sustainable Oxidation of Organic Pollutants

“…29−31 The supporting effect of carbon, such as dispersion of magnetic nanoparticles and/or enriching pollutants to the interfacial reaction sites, has been focused in the previous studies. 32,33 Co-activation of H 2 O 2 using pyrogenic carbon and iron sources together provides a novel solution for the sustainable oxidation of organic pollutants, because pyrogenic carbon can mediate microbial reduction of Fe(III) 34−36 and may facilitate the regeneration of Fe(II) in Fenton reaction (eq 1). Thus, the enhanced oxidation efficiency of pollutants by coactivation of H 2 O 2 using biochar and aqueous iron (Fe(III) been observed in our previous studies.…”

“…In addition to being a capable adsorbent of pollutant, , pyrogenic carbon can mediate electron transfer in redox reactions. − For example, biochar alone can activate H 2 O 2 , and persulfates , to produce ROS for oxidation of pollutants. However, the yield of • OH from H 2 O 2 decomposition in the biochar-activated system was less than 10% while H 2 O and O 2 are the dominant products. , Thus, pyrogenic carbon was more often used as the supporting material of other active ingredients (e.g., iron nanoparticles) to enhance the performance of AOPs. − The supporting effect of carbon, such as dispersion of magnetic nanoparticles and/or enriching pollutants to the interfacial reaction sites, has been focused in the previous studies. , Co-activation of H 2 O 2 using pyrogenic carbon and iron sources together provides a novel solution for the sustainable oxidation of organic pollutants, because pyrogenic carbon can mediate microbial reduction of Fe­(III) − and may facilitate the regeneration of Fe­(II) in Fenton reaction (eq ). Thus, the enhanced oxidation efficiency of pollutants by coactivation of H 2 O 2 using biochar and aqueous iron (Fe­(III) or Fe­(II)) has been observed in our previous studies. , However, little is known about the performance of pyrogenic carbon on coactivation of H 2 O 2 with magnetite, although magnetite has been reported to be a reactive iron mineral to catalyze Fenton reaction.…”

Surface Treatment of Biochar: Methods, Surface Analysis and Potential Applications. A Comprehensive Review

“…The most important applications of biochar concern soil amendment and agriculture [1][2][3] , but recently much has been achieved in the design of biochar-supported nanocatalysts for water treatment consisting in total mineralization of organic pollutants such as dyes and drugs 4,5 . Other applications concern the use of biochar as fillers in composite materials [6][7][8] , electrode materials 9,10 and for the developments of novel engineered biochar for the treatment of neglected tropical diseases (NTDs) 11,12 , to name but these applications.…”