Activation of persulfate by manganese oxide-modified sludge-derived biochar to degrade Orange G in aqueous solution

Zixi Fan,Qian Zhang,Meng Li,Wenjiao Sang,Yue Qiu,Chenfeiyang Xie

doi:10.1080/26395940.2019.1577702

Zixi Fan, Qian Zhang + Show 4 more

Open Access

https://doi.org/10.1080/26395940.2019.1577702

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Abstract

ABSTRACTManganese oxide-loaded sludge-derived biochar (Mn-SDBC) was synthesized and used to activate persulfate (PS) for Orange G (OG) degradation. X-ray fluorescence and Fourier transform infrared spectroscopy analysis indicated that the manganese oxides were successfully loaded on the SDBC. The result of batch experiments suggests that OG can be efficiently degraded by PS activated by Mn-SDBC. Metal loading rate, biochar dosage and PS concentration play a crucial role in experiments, whereas pH has a minor effect on OG removal. The free radical quenching experiment was investigated to determine the predominant radical species, and the activation mechanism was also illustrated. The as-synthesized Mn-SDBC can efficiently activate PS and removal OG under a continuous flow condition in a fixed-bed column. Our study suggests that Mn-SDBC would be a promising catalyst for the remediation of dye-contaminated wastewater.

Highlights

Advanced oxidation processes that are based on the generation of active radicals such as hydroxyl radicals and sulfate radicals derived from oxidant directly or indirectly have been given growing attention to the degradation of refractory organic pollutants in soil and water [1,2]
This strongly positive relationship between metal loading rate and degradation efficiency demonstrates that the loaded manganese oxides could significantly strengthen the PS activation and result in a higher and quicker degrade rate
The factors that controlled the degradation of Orange G (OG) by Manganese oxide-loaded sludge-derived biochar (Mn-sludge-derived biochar (SDBC)) activating PS were explored

Summary

Introduction

Advanced oxidation processes that are based on the generation of active radicals such as hydroxyl radicals and sulfate radicals derived from oxidant directly or indirectly have been given growing attention to the degradation of refractory organic pollutants in soil and water [1,2]. Finding a better means to activate PS for oxidative species generation and manipulate the oxidative properties for effective degradation of pollutant has been recognized as the main challenge. Among these initiators, transition metal catalysts have been recognized as one of the most effective activators in PS activation due to its lower consumption of both energy and chemicals. Metallic iron (Fe)based materials that can provide Fe2+ are most wildly utilized transitional metal in the environmental application Drawbacks such as excessive Fe2+ will react with as-formed SOÁ4À in a short time, which would significantly lower contaminant degradation efficiency. Theheterogeneous catalyst was recognized as more effective catalyst compared to homogeneous catalyst since in most cases, oxidative radicals are generated on the surface of catalysts [6]

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