Oil spill cleaning using engineered nanomaterials is more effective than conventional techniques; Because they lead to a better and more distinct response to conventional chemicals. The excellent performance of nanomaterials can be attributed to the increased surface area as well as higher reactivity and on-site usability. It is necessary to optimize the capture of oil impurities by magnetic nanoparticles and further removal by magnet. Despite their potential toxicity, nanomaterials have been shown to have great potential for innovative solutions to clean up oil spills through their unique structures, excellent properties, and outstanding performance. As future work in this area, materials based on ternary systems (nanosorbents, nZVI, strong oxidants, eg organic and inorganic peroxides, aerogels, oxidizers, magnetic nanoparticles) appear to be promising.
Silica aerogels have been synthesized using the drying method at ambient pressure as well as sodium silicate solution as a precursor. Silica aerogel production includes three general stages of hydrogel production, aging and drying of wet gel. In this study, inexpensive materials have been used to synthesize silica aerogels. Silica aerogels produced were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), specific surface area (BET) measurement, contact angle measurement and density determination by pycnometer. The results of FTIR showed the presence of methyl groups on the surface of silica aerogel which confirmed the hydrophobicity of silica aerogel and the desired surface modification. Based on BET analysis, the specific surface area of the sample was 822.47 m2/g. In addition, the pore volume and the mean pore size distribution were 3.76 cm3/g and 17.7nm, respectively. The SEM image showed that the pore size distributions were uniform and less than 100nm. Naphthalene was used as an organic pollutant in the effluent to investigate the adsorption performance of silica aerogel. The adsorption of naphthalene by silica aerogel is the first in this study. Among cyclic hydrocarbons, naphthalene has the highest solubility in aqueous medium. Removal of naphthalene from water has been done by various methods, and the adsorption process has received much attention due to its low cost, safety and simplicity of operating conditions [21]. The main purpose of this study was to investigate the effect of operational variables such as contact time, adsorbent concentration, solution pH and the interaction of these variables in the adsorption of naphthalene from water by silica aerogel. In the next step, to obtain the predicted model and optimal operating conditions, the surface response method (central hybrid design) was used. Based on the results obtained in the analysis of variance table, a quadratic nonlinear model was obtained to predict the removal amount of naphthalene. The variables of time, adsorbent amount, time and adsorbent interaction as well as time and pH interaction were identified as important. The accuracy of the model was confirmed by statistical variables such as characterization coefficient (0.903), adjusted characterization coefficient (0.877) and accuracy adequacy (19.23). In the kinetic study, the quasi-quadratic kinetic model showed good compatibility with the experimental results. Adsorption isotherms were obtained in the range of 10 mg/L to 34 mg/L and the results were well consistent with the Freundlich model.
The problem of oil spills is always a serious problem for the environment, especially for oil-rich countries. To solve this problem, several methods have been used that the use of suitable adsorbents has been very much considered by researchers. Therefore, it is very important to provide an environmentally friendly, low-cost, high-adsorption capacity that is operationally simple. PVA-PAN fiber airborne adsorbent was prepared and its application to recover leaked oil in seawater was investigated. In order to investigate the factors affecting the structure and properties of airgel adsorbents, experiments were designed and factors such as fiber percentage, length and percentage of PVA were investigated to determine the effect of each on the density and amount of airgel adsorbent oil adsorption. Among these, the most effective factor on the properties of aerogel adsorbent was the percentage of PVA, which changed the percentage of oil absorption to a considerable amount. After performing these experiments, the optimal conditions including 3% by weight of PAN fibers, 5 mm of PAN fiber length and 1% by weight of PVA were determined and the adsorbent made in these conditions showed the ability to absorb about 1294% of oil.