One-step microwave synthesis of magnetic biochars with sorption properties

• 발행기관: 한국탄소학회
• 저자명: Anton Zubrik Marek Matik Michal Lová s Katarí na Š tefuš ová Zuzana Danková
• 간행물 정보: 『Carbon Letters』 제26권, 31~42쪽, 전체 12쪽
• 주제분류: 자연과학 > 자연과학일반
• 파일형태: PDF
• 발행일자: 2018.04.30

영문 초록

Adsorption is one of the best methods for wastewater purification. The fact that water quality is continuously decreasing requires the development of novel, effective and cost available adsorbents. Herein, a simple procedure for the preparation of a magnetic adsorbent from agricultural waste biomass and ferrofluid has been introduced. Specifically, ferrofluid mixed with wheat straw was directly pyrolyzed either by microwave irradiation (900 W, 30 min) or by conventional heating (550°C, 90 min). Magnetic biochars were characterized by X-ray powder diffraction, Mössbauer spectroscopy, textural analysis and tested as adsorbents of As(V) oxyanion and cationic methylene blue, respectively. Results showed that microwave pyrolysis produced char with high adsorption capacity of As(V) (Qm= 25.6 mg g–1 at pH 4), whereas conventional pyrolysis was not so effective. In comparison to conventional pyrolysis, one-step microwave pyrolysis produced a material with expressive microporosity, having a nine times higher value of specific surface area as well as total pore volume. We assumed that sorption properties are also caused by several iron-bearing composites identified by Mössbauer spectroscopy ([super] paramagnetic Fe2O3, α-Fe, non-stoichiometric Fe3C, γ-Fe2O3, γ-Fe) transformed from nano-maghemite presented in the ferrofluid. Methylene blue was also more easily removed by magnetic biochar prepared by microwaves (Qm=144.9 mg g–1 at pH 10.9) compared to using conventional techniques.

목차

1. Introduction

2. Materials and Method

3. Results

4. Discussions

5. Conclusions

키워드

magnetic biochar microwave pyrolysis ferrofluid adsorption arsenic