## 1 Introduction  
In a water treatment plant, it is a necessity to remove contaminants, such as organic and inorganic materials, which can act as precursors for the production of disinfection by-products. Various types of activated carbon are widely used for the treatment of contaminants in many environmental applications by an adsorption process because of the high specific surface area; the high degree of surface reactivity [1, 2]; and the existence of specific surface chemistry, such as the presence of heteroatoms, including oxygen, nitrogen, hydrogen, sulfur and phosphorous- [3] and nitrogen-containing groups [4]. However, it is widely known that powdered activated carbon is extremely difficult to handle and separate from water and wastewater treatment plants. Recently, magnetic particles and magnetic nanosorbents were used to adsorb pollutants from water and air [5], but their applications are limited due to their small surface area and morphology structures. A magnetic field has previously been used to separate the adsorbent from aqueous solutions after the adsorption process [6]. Many researchers have used magnetite (Fe\({}_{3}\)O\({}_{4}\)) for adsorption from air and wastewater because magnetite has good performance and biocompatibility [7]. However, magnetite or magnetic particles can remove about 60% of natural organic matter from the water [8]. Magnetite can be combined with amorphous carbon (activated carbon) by an impregnation process to enhance the adsorption of various pollutants in an aqueous solution. For instance, [PERSON] and [PERSON] [9] studied and characterized a composite of activated carbon and iron oxide applied for the removal of p-nitrophenol from aqueous solutions. Moreover, [PERSON] and [PERSON] [10] developed a magnetic nanosorbent when removing strontium ions from aqueous solutions. [PERSON] et al. modified magnetic nanosorbent prepared from macadamia nut shell for the removal of basic dye [11]. The results indicated that the magnetic nanosorbent was suitable for specific water and wastewater treatment application using the advanced software tools of OriginPro and MATLAB in the interpretation of the adsorption isotherm models. Artificial dyes are being utilized in various applications such as food, paper, printing industries, cosmetics, textiles and dye houses in order to color products [12]. In general, dyes are synthetic organic pollutants composed of complex aromatic structures [13]. The discharge of colored wastewater causes significant harmful effects downstream, increasing the toxicity and chemical oxygen demand (COD) [12]. Methylene blue (MB) is considered to be one of the basic dyes that is commonly soluble in water and used by textile industries, which can cause eye and skin irritation; vomiting; nausea; and sympathetic effects, including blood changes [14]. The literature shows that patterns of the evacuation of contaminant dyes in water bodies and the development of outcome measure limitations have resulted in the utilization of adsorption processes amongst other suitable techniques [15; 16]. Minitab and Sigma Plot. Even though advanced program software tools are not available for built-in error functions as mentioned above, Microsoft Excel is a readily available operation that is not difficult, as isotherm functions can be built owing to the availability of computer algorithms. This research recognizes the importance of magnetic nanosorbent to deal with basic dyes in an aqueous solution. The objective of this study is to present a magnetic nanosorbent composite that increases the affinities for specific contaminants and allows the use of efficient batch reactors and resolves the challenge of separating the spent adsorbent from water using magnetic fields for the removal of basic dyes from water. Treatment performance and efficiencies were evaluated using adsorption isotherm models to clarify the involved mechanisms through the Microsoft Excel Solver spreadsheet-based program by nonlinear regression analyses to explore the theoretical assumptions.