The fast development of the population and industrialization cause many environmental problems due to the increase of carcinogenic compounds and heavy metals in the environment. In this regard, many studies have been conducted to remove these compounds from the water, air, and soil. The Layered double hydroxide is one of the adsorbents which have attracted great attention in recent years owing to its ease of preparation, costeffectiveness, environmental compatibility, and non-toxicity. Consequently, in this study, magnetic nanoparticles of Fe@Mg-Al layered double hydroxide have been modified with ammonium pyrrolidine dithiocarbamate (APDC) and then used as an adsorbent to form a complex with cadmium ions and removing them. Based on the absorption properties of synthesized magnetic nanoparticles, an easy, practical, economical and repeatable method has been developed to remove contaminants from water, including heavy metal ions. Cadmium ion has been studied by floating in an aqueous medium by these nanoparticles. Also, the optimal values of effective factors such as pH, amount of magnetic nanoparticles, contact time, temperature and sample volume and ligand concentration were 7, 0.045 g, 30 min, 35 ˚C, 25 mL and 1.7 mg L-1 , respectively. The isotherm equations have been also investigated to evaluate the absorption quality. The thermodynamic parameters as well as the effects of interfering ions have been investigated as well. A flame atomic absorption spectrometer (FAAS) has been applied to detect Cd ions.

In this study, the superparamagnetic adsorbent as Fe@Mg‐Al LDH was synthesised by different methods with two steps for the removal of heavy metal ions from water samples. An easy, practical, economical, and replicable method was introduced to remove water contaminants, including heavy ions from aquatic environments. Moreover, the structure of superparamagnetic adsorbent was investigated by various methods including Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and vibrating sample magnetometer. For better separation, ethylenediaminetetraacetic acid ligand was used, forming a complex with antimony ions to create suitable conditions for the removal of these ions. Cadmium and antimony ions were studied by floatation in aqueous environments with this superparamagnetic adsorbent owing to effective factors such as pH, amount of superparamagnetic adsorbent, contact time, sample temperature, volume, and ligand concentration. The model of Freundlich, Langmuir, and Temkin isotherms was studied to qualitatively evaluate the adsorption of antimony ions by the superparamagnetic adsorbent. The value of loaded antimony metal ions with Fe@Mg‐Al LDH was resulted at 160.15 mg/g. The standard deviation value in this procedure was found at 7.92%. The desorption volume of antimony metal ions by the adsorbent was found to be 25 ml. The thermodynamic parameters as well as the effect of interfering ions were investigated by graphite furnace atomic absorption spectrometry.