水質浄化における抗生物質除去のための新規グラフェン酸化物系ナノコンポジットの合成

概要

九州大学学術情報リポジトリ
Kyushu University Institutional Repository

Synthesis of Novel Graphene Oxide-Based
Nanocomposite for Antibiotics Removal in Water
Purification
モハマド ファイズル イダハム ビン モハマド ズルキプリ

https://hdl.handle.net/2324/7157384
出版情報：Kyushu University, 2023, 博士（学術）, 課程博士
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（様式３）Form 3

氏

名 ：MOHD FAIZUL IDHAM BIN MOHD ZULKIPLI

Name

論 文 名 ： Synthesis of Novel Graphene Oxide-Based Nanocomposite for Antibiotics Removal in
Water Purification (水質浄化における抗生物質除去のための新規グラフェン酸化
物系ナノコンポジットの合成)
Title

区

分 ：甲

Category

論 文 内 容 の 要 旨
Thesis Summary
The metabolism of antibiotics in the human body is suboptimal, leading to the eventual release of residual
parent compounds into the environment and wastewater treatment facilities via excretion in urine and feces.
The occurrence of these compounds in aquatic ecosystems leads to significant environmental contamination
and can destabilize ecological balance by promoting the proliferation of antibiotic-resistant bacteria (ARB)
and antibiotic-resistance genes (ARG), which threaten human health. Therefore, this study addressed
antibiotic waste contamination in water using graphene oxide (GO) and GO nano zero-valent iron (nZVI/GO)
nanocomposite.
The first project aimed to optimize the chemical synthesis of GO based on time and material cost-saving
protocols in order to produce ideal GO for treating water contaminated with ciprofloxacin (CIP) and to explore
its removal conditions. The study's outcomes prove that the synthesis conditions impacted the performance
of GO produced against CIP removal. Facile GO chemical synthesis was successfully developed by
empirically optimizing each synthesis stage's parameters while considering the excellent CIP removal
performance. CIP removal condition assessment reveals that O–GO can remove a significant portion, up to
98%, of 100 mg/L CIP when administered at a dosage of 0.6 g/L with a pH range of 5-9. Interestingly, O–GO
offered the most material cost-effective of just 0.2195 ¥ for 1 mg of CIP elimination. Moreover, O–GO
exhibited an 83 % CIP desorption efficiency using 1M NaOH solution.
The second project concentrated on developing the GO-precipitated nZVI nanocomposite (nZVI/GO) and
assessing the impact of GO precursor on the nanocomposite's efficiency in removing Chloramphenicol (CAP)
from water. The finding found that the GO precursor utilized in the fabrication of nZVI/GO nanocomposite
substantially impacts its morphological characteristics and performance in CAP removal. O-GO offered a
great supporter for nZVI precipitation and improved CAP removal efficiency. The 0.25 g/L dose of nZVI/OGO nanocomposite exhibited superior removal efficiency in eliminating 100 mg/L CAP, with a maximum
removal rate of 90% at a natural pH and 91% at a pH 5. Moreover, the nZVI/O–GO nanocomposite presented
good CAP removal stability across a wide pH range and exceptional recyclability.
The doctoral thesis structure comprises five main chapters outlined as follows:
Chapter 1 begins with background information on emerging contaminants, pharmaceuticals, and global
water pollution issues due to these substances. Then this chapter also presents more specific details related
to antibiotics, including the contamination pathway of ciprofloxacin and chloramphenicol in environmental
water. In addition, this chapter explains the information regarding graphene oxide, the impact of synthesis
on GO performance, challenges, and research perspectives related to GO. Furthermore, the background of
nZVI and its suitability and limitations for water treatment application are also discussed in this chapter.

Then, chapter 1 is closed with a summary of the aims and objectives of this Ph.D. work.
Chapter 2 provides a list of the materials and chemicals used in the experiment. In addition, this chapter
thoroughly describes the methodologies for synthesizing GO and nZVI-based materials. Also described are
characterization methods and equipment for depicting the physicochemical characteristics of the materials.
The batch experiment operation under various antibiotic pollutants removal conditions and desorption batch
experiment is also covered in detail in this chapter. Moreover, the kinetic principles and thermodynamic
models for CIP and CAP removal by these GO and nZVI-based nanomaterials are also presented.
Chapter 3 presents in detail the findings of synthesis optimization in producing a practical GO for CIP
removal. This chapter systematically reports findings regarding the effect of conditions at each synthesis
stage on GO performance in CIP removal. In addition, the comparative findings of the CIP removal
performance of GO with optimized synthesis and GO manufactured conventionally are also included in this
chapter. Then this chapter also reports the results of the GO's reactivity assessment for ideal CIP removal
conditions. In addition, the results of desorption experiments performed on optimized GO are also contained
in this chapter. Moreover, several series of analyses, including kinetic, thermodynamic, and cost analyses, are
also discussed in detail in this chapter. Finally, the physicochemical properties of GO are discussed in this
chapter, such as morphology, functional element group availability, surface elemental composition, and
crystallinity.
Chapter 4 discusses the use of nZVI/GO nanocomposite for CAP removal from water by nZVI/GO
nanocomposite. The physicochemical characteristics of GO, nZVI, and nZVI/GO nanocomposite are discussed
thoroughly at the beginning of this chapter. Subsequently, the efficiencies of nZVI/GO nanocomposites in
removing CAP using various precursors, mass ratios, and dosages are presented. This chapter also addresses
the performance of the nZVI/GO nanocomposite against CAP removal under various removal conditions. In
addition, this chapter also elaborates on the findings regarding desorption analysis, the condition of the
material in the post-CAP removal phase, and the CAP removal mechanism. This chapter ends with a
discussion of results related to the stability and recyclability of nanocomposite materials and their practical
implications.
At last, Chapter 5 summarizes the essential findings of all research projects and their potential impact on
the field. In addition, this chapter provides an overview of suggestions for future studies to build upon the
current findings.

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