Effective Removal of Arsenic in Water by Inductively Coupled Plasma Mass Spectrometry: Equilibrium and Kinetic Study

In this study, we report the ecient catalytic activity for the removal of arsenic contamination from water using L-cysteine derived iron oxide nanoparticles. The catalytic ability was checked by ICP-MS. Best optimized magnetite iron oxide nano particles at pH-10 were conrmed through different characterization techniques such as TEM, XRD, EDS, FTIR and zeta potential analyzer, respectively. TEM was conrmed the smallest particle size in the range of 5-30 nm. The application study was performed by ICP-MS instrument to check the removal eciency of arsenic by iron oxide magnetite nano catalyst rst on synthetic water prepared on laboratory was 99.8% and then checked on real water samples collected was 81.09% from arsenic contaminated sites areas of Larkana exceeded arsenic concentration from 10ug/l as compared to WHO limit, The adsorption capacity of arsenic on the prepared porous iron oxide nanoparticles was 1.96 mg/g proved that the particles having higher surface area with excellent catalytic degradation property. The adsorption dataset best ts in the Langmuir model and obeyed the pseudo-second-order model. Herein, we report the simple and greener synthesized iron oxide nano-adsorbent and their effective ability for the removal of arsenic from water source using advanced ICP-MS technique. on real water samples was 81.09% and synthetic water prepared on laboratory was 99.8% tested by Inductively couple plasma mass spectrometry (ICP-MS) instrument.

as compared to WHO limit, The adsorption capacity of arsenic on the prepared porous iron oxide nanoparticles was 1.96 mg/g proved that the particles having higher surface area with excellent catalytic degradation property. The adsorption dataset best ts in the Langmuir model and obeyed the pseudosecond-order model. Herein, we report the simple and greener synthesized iron oxide nano-adsorbent and their effective ability for the removal of arsenic from water source using advanced ICP-MS technique.

Novelty Statement
Arsenic is ever-present in the environment and its toxicity makes it lethal to all living beings. It has become a sign of danger for all over the world, especially for Asian countries. Communities in Pakistan are unable to approach the high quality of drinking water. By consuming contaminated water, people face different skin diseases as arsenic is carcinogenic too.
To fabricate a stable, highly selective nano materials using to eliminate arsenic To characterize the prepared nanoparticles To check the e ciency of fabricated nanomaterial on real water samples using advanced ICP-MS technique.

Introduction
Groundwater is considered as fundamental source of water, which can be consumed, and more than onethird of the population is almost dependent on it for drinking purposes [1,2]. Moreover, due to scarcity of surface water people rely on the groundwater, which further results in causing overexploitation. Numerous researchers investigated the condition of groundwater from the different countries of the world to know more about the contamination of the groundwater [3][4][5][6]. Arsenic is considered as one of the most lethal, toxic metalloid and carcinogenic. This word arsenic comes from the Greek word arsenikon, which means potent [7] and arsenikon is taken from a Persian word "Zarnikh", meaning yellow orpiment [8]. According to the United States Environmental Protection Agency (USEPA) and World Health Organization, the permissible limit of arsenic in the water is 10 µg/L [9,10] whereas many developing and underdeveloped countries have the limit of 50 µg/L [11,12]. Arsenic (As) is considered a ubiquitous element that circulates in different forms in the atmosphere. It is also known as "king of poisons and poisons of kings". Sometimes, local geological formations and human activities lead to higher arsenic concentrations. Arsenic is the 20th most ample element present in the earth's crust [13].
Arsenic is present in the environment in two ways either naturally or by anthropogenic activities. Naturally, arsenic can be obtained from the volcanic eruption, wild and res, geothermal activities and weathering of rock [14,15]. Anthropogenic activities which causes arsenic contamination are smelting, mining, wood preservatives, burning of coal, glass industry, pesticides, incinerators, municipal waste, manufacturing of semi-conductors, insecticides, industrial wastes, and herbicides [16][17][18]. Arsenic is found in two forms, inorganic and organic whereas inorganic is more toxic than organic arsenic. Arsenic when present by the accumulation in the food chain it can be lethal for human beings. There are various diseases associated with arsenic for example skin, bladder, lung, kidney, lung cancer, reproductive disorders, neurological disorders, cardiovascular issues, high blood pressure, diabetes and many others [19][20][21]. Fig. 1 shows the schematic diagram of arsenic contamination sources.
Thus, there is an urgency to innovate a novel product to remove arsenic from water. To address this need, researchers worldwide are working to develop constructive, cost-effective and productive technologies for the removal of organic and inorganic arsenic from water. Signi cant advances have been made in material sciences-speci cally, in material synthesis-to meet objectives that were once impossible. The establishment of many conventional adsorbents: such as titanium, aluminum, and iron have been used for arsenic removal. This application of nanotechnology using low-cost materials to cope up with environmental degradation processes and will enhance the knowledge of environmental protection agencies, government, and industries while protecting water bodies and preventing agricultural runoff.
Successful harnessing of nanotechnology to address arsenic will ultimately reduce water pollution generated by human activities and aquatic life.
Nanotechnology involves the manipulation of various materials on the atomic level; on this scale, the chemical and physical properties of numerous organic and inorganic species can be altered [22]. The study and manipulation of a material on a nanoscale permit the scienti c community to contribute and synthesize different materials to obtain speci c properties and characteristics. This enables the achievement of a wide range of technological advancements in the elds of environment, optics, health, electronics, and so on [23]. Nanomaterials have also been used widely in the environmental monitoring of water [24]. An assortment of arsenic degradation advancements exist and broad reviews of these procedures have been published [25,26]. The water treatment technology developed here in will have considerable economic bene ts achieved by reducing the cost of water analysis and treatment processes. Metal oxides promise incredible guarantee because they have a higher a nity and selectivity for heavy metal ions such as As (III) and As (V) [27,28].
Arsenic is ever-present in the environment and its toxicity makes it lethal to all living beings. It has become a sign of danger for all over the world, especially for Asian countries. Communities in Pakistan are unable to approach the high quality of drinking water. By consuming contaminated water, people face different skin diseases as arsenic is carcinogenic too.
Arsenic toxicity in water resources has become a serious public health concern in Pakistan. The problem is especially prevalent in Sindh, where about 36% of the population is at risk for arsenic contamination because it is present in surface and groundwater above the limits of the World Health Organization (WHO). High arsenic contaminated (>50 mg L -1 ) groundwater has been reported in various parts of the world [29]. It is generally accepted that inorganic compounds like arsenite [As 3+ ] and arsenate [As 5+ ] are the predominant forms of As in most environments, though organic forms (arsenobetaine and arsenocholine) could also be present [30]. This research will provide the best remedial solution for removal of arsenic contamination for local community of Sindh, Province. The poverty of the rural Sindh is obvious from the fact that this area housing almost half of the province's population contributes only 30% of the Sindh's GDP. In rural Sindh, mostly poor people are the most affected population from water impairment due to their limited means of livelihoods and low-income levels. Besides low awareness of water quality related health issues, these people cannot afford buying high quality drinking water and have to rely on whatever is available to them. In addition, when they get sick, they cannot meet the expenses of medical treatment and hospitals. The advanced treatment technology in this project is cost effective and hence affordable for the poor people of the rural Sindh. Iron oxide nanoparticles, due to their high electrical conductivity, chemical stability, biocompatibility, and magnetic behavior they have getting attention. It is reported several times that the characteristics vary with the size, crystal phase, and shape.
Magnetite nanoparticles are fabricated in various methods, but most stable and ecofriendly method is the co-precipitation to be the most frequent for magnetite nanoparticles.
In this research, we used magnetite iron oxide nanoparticles as they are non-hazardous and possess economic advantages over other nanoparticles used commonly. L-Cysteine is used as the capping agent as it plays a long-term stability role in magnetite NPs. Kishan et al. Suggested the use of amino acid as a surfactant agent, also they are less harmful and currently used as reagents in many studies. After the literature reviewed, we have found that a lot of work has been done on the Iron oxide nanoparticles all over the world even in Pakistan but none use L-Cysteine as the stabilizing/reducing agent, which is a greener chemical. This chemical enhances the removal e ciency of arsenic from the water. From the above-mentioned literature, it is clear that many studies are going on the removal, degradation, and adsorption of arsenic and other contaminants from the water. Many researchers have worked on the elimination of arsenic from the water in many ways but no study was found on the removal of arsenic using L-Cysteine capped iron oxide nanoparticles. Herein, we report the simple and greener method for the synthesis of iron oxide nanoparticles and their e cient catalytic degradation ability towards arsenic from water source.

Chemicals and Reagents
Precursors used in this study are ferric chloride hexahydrate (FeCl 3 ·6H 2 O), ferrous chloride tetrahydrate (FeCl 2 ·4H 2 O). Sodium hydroxide (NaOH) is used as a reducing agent while L-Cysteine is used as a capping agent and was purchased by Daejung Chemicals & Materials Co. Ltd. Nitric acid of 70% was used to dissolve L-Cysteine.

Preparation of stock solution
The arsenic stock solution was prepared by standard solution of 1000 ppm (1 million ppb) purchased from VWR Chemicals, USA. It was then diluted in the desired concentration for the experiment. All the preparation was done in the volumetric ask to avoid errors. The pH of Deionized water was checked before the dilution and ve different concentrations were made by diluting to 10 ppm (1 ppm, 0.5 ppm, 0.1 ppm, 0.05 ppm and 0.001 ppm). The formula used for the dilution is: The glass bottles were washed from HNOs and liquid detergent solution.

Synthesis of iron oxide (Fe 3 O 4 ) nanoparticles in aqueous solution
The aqueous Iron oxide solution was prepared by the salts i-e FeCl 3 . 6H 2 O and FeCL 2 .4H 2 O with a concentration of 0.2 M and 0.1 M, respectively. Ferric chloride hexahydrate was diluted in 100 ml of deionized water and kept on a magnetic stirrer hot plate for 10 minutes. After the mixing, ferrous chloride tetrahydrate was diluted in 100 ml of DI and mixed to the solution at a magnetic stirrer for 30 minutes. On the other hand, L-Cysteine of 0.1 M was prepared using nitric acid and then added to the solution for the prevention of agglomeration. After 10 minutes, Sodium hydroxide (NaOH) of 0.5 M was added gradually to maintain the pH from 9-12 and allowed the mixture for vigorous mixing for 4-5 hours until the precipitates formed. The denser liquid present at the bottom due to magnetic properties was collected and passed through the lter. It was rinsed three times with ethanol and DI to remove impurities. In the end, it was kept in an oven for 4 hours at 60°C and collected for experimental purposes.

Site selection
District Larkana of Sindh province is situated by the side of the Indus River and covers ve tehsils, Ratodero, Warah, Miro Khan, Dokri and Larkana with a total land area of 7423 km 2 . It is the fourth largest city of Sindh with a population of 1.5 million (CENSUS 2017). The residents of Larkana use groundwater for drinking purposes. As reported by Ali et al. [31], investigated the cause of arsenic enrichment in the water of Larkana in 2019 and concluded that the level of arsenic is from 2 ppb to 318 ppb in the drinking water, which is above the level of WHO. This research creates enthusiasm to collect water from the sachal colony, Larkana and to test the synthesized material. Fig. 2a, there is a map, which showed the levels of arsenic present in water and in Fig. 2b, shows the area selected for the collection of water. The cause of arsenic enrichment in Larkana's water is vertical mixing with return irrigation water.

Water sampling frequency and sampling protocols
In our experimental study, we collected a small portion of water randomly from different parts of Sachal Colony, Larkana. The number of samples was eight. The volume per sample was 900 ml so that they can be tested in triplicates. They were collected in a 1-liter bottle and we did onsite water quality testing also. The basic purpose of water sampling and testing was to check the change occurred in previous studies until now.
Following are the few sampling protocols that we followed during our study: 1. Wore gloves and mask 2. Kept sample ID on the bottles 3. Sprayed ethanol of the source from which we collected the water 4. Opened faucet for 1 minute before collecting water so that the water can run 5. After lling the bottle, it was tightly capped and kept in ice-box for transportation

Sample collection and transportation
The samples were collected in the autoclaved plastic bottles of 1 liter from the Sachal Colony, District Larkana and were placed in ice-box for the transportation to US-Pakistan Center for advanced studies in water, advanced water and waste water quality control laboratory, MUET, Jamshoro. The bottles were lled until 900 ml and capped properly so that the effect of evaporation can be reduced. They were preserved in hydrochloric acid because samples having metals can be perfectly preserved with the help of acid. They were placed in the refrigerator to maintain the temperature and for further experiments.

Water sample preparation for analysis
Samples were prepared with different dosage of L-Cysteine functionalized iron oxide nanoparticles and concentration of arsenic varies. The real water samples were also kept with different dosages for 1 hour on the ask shaker so that the particles can easily be mixed. They were poured in 20ml glass bottles for the analysis of ICP-MS. The model no of ask shaker is 1220K73 and Mfr. No is 401000-2. The model no of the orbital shaker used for this study was 1165U07.

Characterization techniques
The prepared L-Cysteine derived iron oxide nanoparticles were characterized by using different characterization technique's such as UV- The absorption range of the incorporated L-cysteine derived iron oxide nanoparticle, were seen in the middle of the scope of 300-700nm wavelength. The colloidal Fe 3 O 4 NPs were gotten and scattered in deionized water after the sonication process (25 minutes). Reported study, shows the fabricated NPs were in the range 375 and 650 nm [32]. In our study, the peak appeared at 394 nm of the synthesized iron oxide NPs as shown in Fig. 5.

Transmission Electron Microscopy (TEM)
In material sciences, TEM is used as a powerful tool for a high-resolution image. A beam of high energy of electrons moves directly towards the sample of 0.2nm. This technology investigated the shape, size and used as chemical analysis. The crystallinity, spherical morphology and size of the synthesized Lcysteine capped iron oxide NPs were analyzed as shown in Fig. 6a. The size appeared were in the range of 5-35nm and mostly were of 15nm as shown in Fig. 6b. They showed to be in a spherical shape as shown in Fig. 6a. ImageJ software was used to analyze the sizes of the particles. Yew et al. [33], observed that most particles were ranging 10-18.

Zeta Potential Analyzer
Zeta Potential is used to know the net surface charge of the nanoparticles and is a physical property. It also con rmed the stability of the nanoparticles concerning the surface potential charge. The stability of particles can be obtained at the most optimum line between the stable and unstable nanoparticles, which are generally expressed in the range of +30mV to -30mV. This study showed that L-cysteine capped iron oxide NPs were stable with a value of -29.7mV as shown in Fig. 7. Madhavi et al. [34], showed that the nanoparticles were stable and contained a highly negative charge.

Electron Dispersion Spectrum (EDS)
EDS technique describes more about the chemical composition of the material, it also tells about the purity of the material. The spectrum at 1.73KeV at spots was examined. There were two maximum peaks of the spectrum were acquired as shown in Fig. 8. The quantitative analysis of this study revealed that there were more 68.17% weight atoms of iron are present in the synthesized Fe 3 O 4 nanoparticles as shown in Fig. 8. Radwa et al. [35], showed that the L-cysteine is used as the stabilizing agent.

X-Ray Diffraction Spectroscopy
X-ray diffraction was used to determine the phase purity and the crystalline structure of the nanoparticles.
The advantage of using this technique is that does not harm or damage the material and it provided results e ciently. The X-ray diffraction patters of synthesized L-cysteine capped nanoparticles showed the existence of the crystalline structure of the nanoparticles as shown in Fig. 9. The XRD peaks were matched with reported literature [36,37]. All peaks are matched with the characteristics of magnetite material and it proposed the core-shell structure of synthesized iron oxide NPs as shown in Fig. 9.

Fourier Transform Infrared Spectroscopy (FT-IR)
FT-IR is a useful tool for characterizing the particles. It tells more about the capping and reduction occurring within the synthesized material. As shown in Fig. 10, the different FTIR peaks were observed. A peak at 1727cm -1 shows the presence of acidic carbonyl groups (C=O). A peak at 1083cm -1 is due to carboxyethylsilanetriol (CES) (C-O) group [38]. A peak at 1337cm -1 shows the adsorption band due to CH 2 groups (bending variations). A peak at 1540cm -1 bending vibration is present [39]. A peak at 2284cm -1 shows the presence of amide groups and COO -1 .

Mechanism
Arsenic creates many acute and chronic diseases in the human body. Many various technologies have been used in the past for the removal of arsenic from the water. Iron oxide adsorbents are dominant in the eld of adsorption of arsenic because of its capacity. The adsorption of arsenic is mainly dependent on the quantity of iron present because iron adsorbent have the maximum ability to adsorb arsenic from the water. In our study, the L-cysteine was used as a stabilizing agent to prepare the desired particles. When the particles were fabricated it was then reacted with arsenic so that it can adsorb. After the reaction, the arsenic is reduced due to nanoparticles present in the solution. The following reaction shows how the arsenic was been adsorbed on the iron oxide nanoparticles.

Effect of adsorbent dose
The adsorption of arsenic onto the L-Cysteine functionalized Iron oxide Nanoparticles are in uenced by adsorbent dose. The effect of the dose of NPs on arsenic is shown in Fig. 11. The removal percentage caused by a dose of Iron NPs of equilibrium concentrations of arsenic increases by increasing the adsorbent dose from 30 mg to 80 mg. The removal of arsenic from the aqueous solution increased from 95.4% to 99.8%. The highest removal e ciency was achieved when the maximum dose of adsorbent was added, due to the availability of maximum vacant spaces present on the surface of the adsorbent. The quantity of the adsorbent used in an experiment is directly proportional to the number of sites available for adsorption [40].

Effect of pH
The effect of pH on the adsorption is shown in Fig. 12. It is seen that the range from 5.5 to 7.5, the adsorption is higher as compared to others. At pH 6, there is maximum adsorption. The percent of removal of arsenic increases from 16% to 99.1%, as the pH increases from 4 to 8. The low adsorption rate at pH 4, which indicates that solution, becomes H + charged and that repels the molecules of the adsorbent. Moreover, as pH rises from 4 to 8 H + ions (positive) are replaced with OH -(negative) ions which makes arsenic molecules to attach onto the surface of the adsorbent. It is reported in the literature that the arsenic becomes unstable at higher pH [41] whereas Irem et al. [42], reported that the maximum adsorption of arsenic was on pH 6.

Effect of concentration
The effect of various concentrations on adsorption was studied using a range of arsenic concentrations from 0.01 ppm -1 ppm (10 ppb -1000ppb) at a xed adsorbent dose of 80 mg, using an orbital shaker speed of 150 rpm at room temperature. The batch study is shown in Fig. 13. The results depict that there was a maximum removal in the lowest concentration at 0.01 ppm (10 ppb) was 99.85% and the minimum removal was observed in the highest concentration at 1 ppm (1000 ppb) was 94.45% as shown in Fig. 14. Even at 0.5ppm (500ppb), the removal e ciency was 98.9% after one hour.

Equilibrium isotherms
For to understand the functioning of adsorbing molecule and adsorbent for the optimization process design [43]. From the experimental data, the values were put into two isotherm models. Isotherm parameters for each model was obtained from intercept and slope of model equation.

Langmuir Isotherm Model
The Langmuir isotherm model believes that the adsorption happens at certain equivalent destinations inside the adsorbent. The monolayer adsorption venture is shown as [44].
In Langmuir model, the adsorption C e /q e = 1/Q max * K L + C e /Q max -------------- (3) Where, C e = concentration of arsenic at equilibrium (mg/l) q e = equilibrium capacity of arsenic on the adsorbent (mg/g) Q max = monolayer adsorption capacity (mg/g) K L = Langmuir adsorption constant (L/mg) The values Q max and K L can be calculated from the slope and the intercept of the linear plot shown in Fig. 14. The value and constant of R 2 from the equilibrium data shown in Table 2. The important characteristic of the Langmuir isotherm can be demonstrated as the dimensionless constant separation factor R L which is shown by this equation The signi cant normal for the Langmuir isotherm can be exhibited as the dimensionless constant factor RL which is appeared by this condition [45].
Where, C o = Initial concentration (mg/l) K L = Langmuir constant (l/mg) In the Freundlich isotherm, surface adsorption occurs in multilayer or heterogeneous [46]. The Freundlich equation is follow as [47]; log q e = log K F + 1/n *(log C e ) ------------- (5) where, q e = amount of solute adsorbed per unit weight of adsorbent (mg/g) C e = equilibrium concentration (mg/L) K F = Freundlich constant indication to the relative adsorption capacity of the adsorbent (mg/g) 1/n is the adsorption intensity.
The values of K F and 1/n will be obtained from the linear plot of log q e versus log C e shown in Fig. 15.
The isotherm parameters and R 2 value are presented in Table 4.1.
In this isotherm study, it was well concluded that the Langmuir isotherm tted the best for the synthesized nanoparticles as shown in Fig. 14. The maximum adsorption capacity was calculated to be 1.96 mg/g. The parameters of both the models, Langmuir and Freundlich are mentioned in Table 2. The values are being checked by different researches and they used three isotherm models [48,49], whereas this study performed only two isotherm models.

Kinetic study
For the determination of e ciency of adsorbent in relation of solute consuming rate which can be described by adsorption kinetics. Therefore, the experimental data was shown through pseudo rst-order, pseudo second-order to describe the mass transfer process.

Pseudo-rst-order model
The Pseudo rst-order equation [50] can be expressed as: ln (q e -q t ) = ln q e -k 1* t ---------- (6) Where, q e = amount of arsenic adsorbed at equilibrium (mg/g) q t = amount of arsenic adsorbed at time t (mg/g) k 1 = pseudo rst order rate constant The value of k 1 and qe can be calculated from slope and intercept by plotting graph between, ln (q e -q t ) versus t as shown in Fig. 16, and the values of constants are presented in Table 3.

Pseudo-second-order model
The pseudo second-order model can be expressed as [51]; t/q t = k 2 q 2 e + t/q e ------------ (7) where, k 2 = a second-order rate equation constant and can be obtained by plotting the graph t/q e versus t, shown in Fig. 17, and the calculated values of constants are shown in Table 3.
In the current study, the kinetics of arsenic removal was studied to nd and to know the adsorption capacity and adsorption behavior. Adsorption increased with the passage of time as there are vacant spaces available on the adsorbent but after the equilibrium achieved the adsorption starts to decrease and become resistant as the vacant site are occupied. This work followed Pseudo 2 nd order and con rms the chemical adsorption as shown in Fig. 18, whereas, Pseudo 1 st order con rms physical adsorption. Rahdar et al.
[50] also performed the datasets into the kinetic study i.e., two models. In this study, Pseudo 2 nd order tted the best. The values for both kinetic orders are mentioned in Table 3.

Testing of real water samples
As discussed in methodology part, three areas were select for the site selection, sample preparation and analysis on ICP-MS of real water. The basic physical and chemical parameters of water samples as shown in Table 4.
After testing the basic parameters, we then tested arsenic presence by the arsenic kit. It con rmed the arsenic presence in the water and after then the samples were collected. Those samples were than tested on ICP-MS for further con rmation and to know the initial reading, after knowing the initial arsenic level 80mg of iron oxide NPs, were added and kept on stirrer for 30 and 60 min as shown in Fig.18.
Fluoride was also tested through spectrophotometer (DR-1900) but none of the sample had more uoride than the permissible limit. The permissible limit of uoride by WHO was reported at 1.5 ppm. In Table 5, it can be seen that the maximum removal after 30 minutes was 77.3% and when it kept for 60 minutes, the maximum adsorbed e ciency was 81.09%. Table 6 shows the comparison data of the reported and this present study.

Conclusion
In this study, Iron oxide nanoparticles were synthesized using a greener chemical named as L-Cysteine. It is protein-rich, comes in amino acid and is sold commercially as a dietary supplement. Moreover, synthesized L-Cysteine capped iron oxide nanoparticles were tested for the removal of arsenic from synthetic as well as real water samples. The synthesized iron oxide nanoparticles were characterized by different analytical techniques such as transmission electron microscope (TEM), was con rmed the smallest particle size in the range of 5-30 nm, ultraviolet-visible spectroscopy (UV-Vis) spectrum con rmed the formation with wavelength occurred at 394 nm, X-ray Diffraction (XRD) patterns showed the presence of crystalline structure, energy dispersive spectroscopy (EDS) also proved the highest elemental percent of iron as compared to other element, zeta potential analyzer con rmed the net surface potential charge and stability of the nanoparticles having -29.7 mV value and Fourier transform infrared spectroscopy (FTIR) technique determine the functionality between the interaction of metal salts with reducing/stabilizing agent. After the characterization, it is proved that the synthesized particles have the higher surface area and they were spherical. The effect of synthesized L-Cysteine capped iron oxide nanoparticles dose, concentration and pH were determined. It was observed due to the higher surface area present; the arsenic was adsorbed rapidly until the equilibrium stage was achieved. The adsorption capacity of arsenic on the prepared iron oxide nanoparticles was 1.96 mg/g and 80 mg was the maximum dose used. The adsorption dataset best ts in the Langmuir model and does not follow the Freundlich model. Hence, the adsorption was in monolayer. From the kinetic study, it can be concluded that this adsorption obeyed the pseudo-second-order model. This study showed that the fabricated nanoparticles were never used for the removal of arsenic in any study and proved to be highly e cient. They are easy to make and do not require an extensive workforce. By checking its practical application on real water samples, it can be concluded that its e ciency is better and can be further tested.

Declarations
Con ict of interests