Heavy metals in water and wastewaters are considered as a dangerous pollutant that must be removed usually up to less than ppm levels of concentration. Today, adsorption processes are recognized as one of successful methods for treating heavy metal contaminations and finding powerful, cheap and environmentally friend adsorbent is the most desirable. To meet these requirements, in this thesis, nanoparticles of calcium carbonate were suggested as the desirable adsorbent. To achieve this goal, a novel method was developed to generate calcium carbonate in colloidal gas aphron (CGA) system. As there are different morphologies and polymorphs of calcium carbonate, the effect of surfactant concentration on the morphology and crystalline structure were investigated in the first step of this study. Characterizations of generated calcium carbonate particles were analyzed by SEM, XRD and FTIR. Experimental results show that spherical vaterite particles are formed when the concentration of sodium dodecyl sulphate was 1.4 milimolar and increasing the reagents concentrations only increase the average diameter of particles from 107 to 1500 nanometers without any change in morphology and crystalline structure. However, when concentration of sodium dodecyl sulphate was 8.2 milimolar, morphology and crystalline structure was changed and calcite and vaterite plates of calcium carbonate with sizes of more than 10 micrometers were formed. There is no report about these morphology of calcites and vaterite plates in the scientific literature. XRD analysis demonstrated that in 8.2 milimolar concentration of surfactant, the population of calcite rather than vaterite crystalline increases with increasing reagents concentrations. The generated calcium carbonate nanoparticles were used for removal of Cu, Pb and Fe ions in the second step of this experimental work. As many heavy metals precipitate in basic pH, the effect of pH was the first parameter that evaluated on the removal capacity. Increasing in pH values from 2.5 to 6 resulted in 50 percent increase in removal capacity. The pH value of 5.5 was selected as the optimum value to ensure no hydroxide precipitation occur before adding nanoparticles. The investigation of metal ions concentrations on the removal capacity of CaCO 3 nanoparticles at different temperatures showed that prepared nanoparticles have a great capacity to remove heavy metals from aqueous solution. The maximum removal capacities of calcium carbonate nanoparticles were found to be 1210±30 mg/g for Pb(II), 845±7 mg/g for Fe(II) and 686±6 mg/g for Cu(II) ions, respectively. Analyzing the experimental data showed that the CaCO 3 adsorption mechanism is not just a simple monolayer adsorption and transformation of precipitation between CaCO 3 and heavy metal carbonates could be the explanation for the large removal capacity of CaCO 3 . The effect of time showed that all the experiments achieve their adsorption equilibrium within 2 hours. The reaction rate of process was found to follow the second order equation. Response surface methodology based on three variable Box-Behnken design was utilized to evaluate the effects of temperature (25-65 ?C), initial metal concentration (10-200 mg/L), and CaCO 3 dosage (0.5-1.5 g/L) on the sorption process. The results showed that the temperature has no significant effect on the removal capacity (p-value 0.05), but decreasing in CaCO 3 dosage and increasing in initial metal concentration improve the removal capacity. Key words : Calcium carbonate structures, Colloidal gas aphron, Heavy metal removal, Cadmium ion, Surface response methodology (RSM), Box-behnken method