Abstract
This study investigated the applicability of iron oxide nanoparticles synthesized from Citrullus lanatus fruit waste (IONP) in the removal of some contaminants from water samples that were collected from River Jakara in Kano State Nigeria. The prepared nanoparticles was subjected to physico-chemical characteristic studies to determine the pH, moisture content, ash content, and porosity while the adsorbent surface characterizations was performed using Brunauer–Emmett–Teller (BET) surface area, Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and Thermogravimetric Analysis (TGA). The BET results revealed that IONP have large surface area and are nanometer sized particles. SEM analysis indicated that the adsorbent contain microsphere which might have facilitated the efficient purification of the river water while TGA study revealed that the adsorbent exhibited a three step decomposition process. Data obtained from XRD indicated that the synthesized adsorbent is of high purity and crystalline in nature with an average particle size of 17 nm. Results obtained after treatment of the river water with the adsorbent indicated reduced values in some physicochemical parameters confirming the high adsorption ability of the prepared nanoparticles. The percentage removal of some heavy metals in the river water by IONP was found to depend on adsorbent concentration, agitation time and pH during the batch type adsorption experiments. The highest adsorption efficiency was obtained at pH = 8, temperature = 28°C, adsorbent dosage = 200 mg/L and contact time = 100 minutes. The adsorption process of the metal ions onto the adsorbent was best described by the Langmuir isotherm model predicting monolayer adsorption and followed the pseudo second order kinetics. The regeneration stability of the adsorbent was adequate when treated with the heavy metals ions at optimum conditions. The change in the intensity of absorption as observed in the FTIR spectra of the adsorbent after treatment with the heavy metals confirms a strong interaction between the metal ions and the synthesized adsorbent. The results obtained confirm the capability of the nanoparticles synthesized from Citrullus lanatus waste as a new, low-cost, efficient and environmentally friendly alternative for treatment of contaminated water.