Development of Nanoporous Carbon Materials from Asphalt for the Adsorption of Radioactive Metal Ions in Water and Persistent Organic Pollutants

Water is an essential and important part of life and has a significant place in the working of the ecosystem of Earth. Fast-paced industrialization, domestic uses, and farming activities all have huge requirement for clean water. In this proposal, we are aiming to develop a technology to prepare high surface area activated carbons from Asphalt. The preparation method of the porous carbons proposed in this is cost-effective as the starting material, asphalt, is very inexpensive and widely accessible. Asphalt is heavy crude oil fraction obtained after all boiling fractions have been removed and there is no scope to upgrade further. Asphalt contains highest portion of carbon (85-90%) with approximately 10-12% of hydrogen, therefore, economically not much useful fractions except is being used in roads and roofs. The performance of asphalt activated carbons and oxidatively modified nanoporous materials will be tested as nanoporous filters to remove radioactive metal ions and polynuclear aromatic hydrocarbons (PAHs) from water. The proposal will be executed in the following steps: [1] activation of asphalt with alkaline bases (particularly NaOH and KOH), testing the valuable activation conditions by tunning the base/carbon source ratios, mixing procedures of bases and carbon sources, temperature and time. [2] Characterization of porous activated carbons in their composition, porosity, and stability using TGA/DSC, EDX, BET, SEM and FTIR. [3] Further oxidation of nanoporous carbon surfaces in order to enrich the pore surfaces with oxygen containing functional groups that can bind efficiently heavy metal ions. To this end common oxidants such as KMnO4 or H2O2 will be used; [4] performance of nanoporous carbons as a filter to remove radioactive metal ions and PAHs will be studied, monitored and evaluated by several parameters i.e. effect of time duration, pH, concentration of metals, doses of carbon nanoporous materials and temperatures. Langmuir, Freundlich and other models. The proposed study will include but not limited to the removal of Cs, Sr, Ni, Co as substitutes for radioactive isotopes and Uranium (IV)), Thorium (IV) also if available. Many of the PAHs compounds are ubiquitous and suspected to cause carcinogenic and mutagenic effects in humans. Therefore, effective removals of radioactive metal ions and PAHs from polluted water is very important step in right direction. The results will strengthen the concept of using asphalt as an alternative, efficient and low-cost tool for adsorption processes that will have significant implications in oil industry of Kingdom of Saudi Arabia.