Persulfate-activated ZnCl2-spirulina biochar for aqueous removal of phenolic & benzene-type pollutant
ZnCl2-SPI 바이오차 기반 과황산염 활성화를 통한 수중 페놀 및 벤젠계 물질 제거 연구
- 주제(키워드) microalgae biochar , persulfate activation , polymerization , redox potential
- 주제(DDC) 628
- 발행기관 아주대학교 일반대학원
- 지도교수 이창구
- 발행년도 2025
- 학위수여년월 2025. 8
- 학위명 석사
- 학과 및 전공 일반대학원 환경공학과
- 실제URI http://www.dcollection.net/handler/ajou/000000035151
- 본문언어 한국어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
In this study, biochar was manufactured from spirulina and modified with ZnCl2 to enhance its efficiency in pollutant removal. The degradation of acetaminophen (ACP), phenol (PeOH), 4-chlorophenol (4-CP), nitrobenzene (NB), and benzoic acid (BA) was investigated via persulfate activation using ZnCl2- modified spirulina biochar. ACP degradation reached 96% within 5 minutes with ZnCl2-SPI. The persulfate-to-ACP ratio significantly affected removal efficiency, with a minimum effective ratio of 5. Scavenger tests revealed that O2 •- was the dominant reactive species at low ACP concentrations (40 μM), while 1O2 prevailed at higher concentrations (200 μM), indicating that the dominant reactive oxygen species (ROS) depend on the persulfate-to-ACP ratio. At high ratios, ZnCl2-SPI activated persulfate to generate O2 •- via a radical pathway, whereas low ratios favored the formation of 1O2 through a nonradical pathway driven by direct interaction between ACP and persulfate. Electrochemical analysis confirmed a coupling reaction between ACP and persulfate, supporting the nonradical mechanism. Additionally, complete degradation of PeOH and 4-CP was observed, while BA and NB showed maximum degradation of up to 40% using SP-600. These differences were attributed to the pollutants' redox properties. Cyclic voltammetry demonstrated a strong correlation between the half-wave potential and degradation rate of four contaminants. Compounds with lower redox potential underwent more efficient degradation due to enhanced electron transfer, as supported by open-circuit potential (OCP) measurements. Scavenger tests further showed that O2 •- primarily degraded phenolic compounds, while 1O2 was responsible for benzene-type compound degradation, indicating that redox behavior influences both the degradation pathway and the type of ROS generated. Therefore, the persulfate to ACP ratio and the half- wave potential of pollutants play critical roles in determining degradation behavior in the ZnCl2-SPI/persulfate system. Keywords: Microalgae biochar, Persulfate activation, Polymerization, Redox potential
more목차
1. Introduction 1
2. Materials and Methods 5
2.1. Materials and chemicals 5
2.2. ZnCl2-SPI biochar production 5
2.3. Experiments procedure 6
2.4. Analytical method 7
2.5. Characterization 8
3. Results and Discussions 10
3.1. Acetaminophen removal by ZnCl2-SPI 10
3.1.1. ACP removal through persulfate activation with ZnCl2-SPI biochar 10
3.1.2. Effect of parameters on ACP removal efficiency 14
3.1.3. The contribution of ROS according to ACP concentration 20
3.1.4. Transformation of ACP in ZnCl2-SPI/persulfate process 26
3.1.5. Catalytic performance analysis 31
3.2. Phenol and Benzene type pollutants removal by SP-biochar 36
3.2.1. Comparison of pollutants removal under SP-biochar/PS system 36
3.2.2. Activation of PS and generation of reactive species 42
3.2.3. Physicochemical characteristics of pollutants 49
3.2.4. The role of oxidation parameters on pollutant degradation 53
4. Conclusions 66
Reference 69
국문 초록 78
