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\documentclass[jou, 12pt, a4paper]{apa7}
\usepackage{amsmath}
\title{Bacterial Degradation of Crude oil in Petroleum Polluted Soil Enhanced by Iron oxide-Chitosan Nanocomposite for Bioremediation}
\shorttitle{Nanocomposite-Assisted Bioremediation of Petroleum-Contaminated Soil}
\leftheader{Bisht}
\authorsnames{Aman Bisht, Dr. Abdul Rasheed, Dr. Priyank Bhutiya}
\authorsaffiliations{Environmental Management Department, Gujarat Energy Research and Management Institute}
\abstract{}
\begin{document}
\maketitle
\section{Introduction}
\section{Methods and Material}
\subsection{Chitosan preparation}
Chitin was processed by cutting it into small fine flakes and then mixing it with a 50\% (v/v) sodium hydroxide solution. The mixture was then heated to 95 °C and constantly stirred for 3 h. Following this, the chitosan was filtered, washed with tap water, and dried at 70 °C in a hot-air oven. The chitosan was then kept in a desiccator overnight and subsequently used for further experiments \cite{Saad2020}.
\subsection{Synthesis of Iron oxide nanoparticles}
8 ml FeCl\textsubscript{3}·6H\textsubscript{2}O solution (1.00 mol dm\textsuperscript{-3}) was added to 8 ml NaOH aqueous solution (pH = 11), and 0.5 grams of CTAB were also added to the solution. The slurry solution was poured into a Teflon-lined hydrothermal apparatus and heated at 160 °C for 12 h. The apparatus was then cooled to room temperature, and the products were collected by centrifugation and washed with deionized distilled water and ethanol. Finally, the samples were air-dried at 60 °C for 20 h before characterization \cite{Dong2012}.
\subsection{Preparation of chitosan solution}
1 g of each grade of chitosan sample was dried in a hot-air oven at 110 °C for 1 h. After drying and further weighing, the chitosan samples were added to 100 mL of 0.1 N HCl and stirred vigorously for 2h at room temperature for complete dissolution. The freshly prepared chitosan solution made with dried chitosan for each case was used as a stock solution to complete the titration process \cite{Hossain2020}.
\subsection{Degree of deacetylation}
The deacetylation degree of chitosan was assessed using acid-base titration. A fresh 100 mL solution of 0.1 N NaOH was prepared for each titration, with the chitosan samples placed in separate conical flasks before being titrated against the NaOH solution. It is worth mentioning that every time, the same volume of chitosan solution should be used for titration. We utilized 30 mL of chitosan solution in each titration, although this amount may differ based on the specific experimental setup employed by different researchers. Subsequently, 2–3 drops of methyl orange indicator were introduced into each conical flask containing various concentrations of chitosan solution and then titrated with standard NaOH solution until reaching the endpoint. The endpoint was determined through visual examination, noting a distinct color transition from pink to yellow-orange. For prompt and comprehensive visualization, the color transition is shown in Figure 1. Finally, the volume of NaOH solution consumed was noted down. The experiment was conducted three times for each chitosan sample, and the degree of deacetylation for each sample was determined using the equation provided:
\[
\text{Percentage of DD} = \frac{(V1 - V2) * 16}{V1 * 9.94 * x} * 100
\]
\section{Results}
\section{Discussions}
\section{Conclusion}
\bibliographystyle{unsrt}
\bibliography{Research_paper}
\end{document}