Naphthalene Removal From Water by Novel Mesoporous Carbon Nitride Adsorbent

Polycyclic aromatics hydrocarbons are chemical species with two to six fused benzene rings and are well-known toxic hazardous pollutants and highly potent carcinogens that can cause tumors in some organisms.1 In recent years, naphthalene contamination in water systems has drawn increasing attention. Naphthalene originates from natural and anthropogenic sources. Anthropogenic sources include engine exhaust, industrial processes, crude oil, urban run-off, domestic heating systems, incinerators and smoke. Natural sources include terrestrial coal deposits, volcanic eruptions and forest fires. The main sources of naphthalene in surface water are atmospheric deposition, runoff from contaminated soils and deposition from sewage discharges.2 Most naphthalenes are hydrophobic with high boiling and melting points and electrochemical stability. Therefore, they can exist and be accumulated in soils or water for a long time.3 Adsorption treatment provides a simple and universal approach to effectively removing organic pollutants from the aquatic environment. The removal of toxic organic pollutants from water is a problem, particularly when they are present in low concentrations. Several studies have focused on the fate and transport of these pollutants and the application of remedial technologies to manage them.4–10 Activated carbons present an outstanding adsorption capacity that stems from their high surface area, pore structure and surface chemical properties. These materials are effective adsorbents for priority pollutants, therefore being suitable for the decontamination of water and wastewater. These porous carbons are generally microporous and the preparation of carbon materials with well-ordered mesoporous structure would offer many application possibilities not only in the adsorption and in separation of large molecules whose molecular sizes are too large to enter micropores but also in electrical double layer capacitors, gas separation, catalysis, water and air purification and energy storage. Recently, Ryoo et al. prepared ordered mesoporous carbons from mesoporous silica templates such as MCM-48, SBA-1 and SBA-15 using sucrose as the carbon source.11–14 Adsorption plays an important role in these processes. Therefore, the interactions of such compounds with the mesoporous carbon surface must be studied in detail. The mesoporous carbon materials adsorption capacity depends on quite different factors. Obviously, it depends on the mesoporous carbon’s characteristics: texture (surface area, pore size distributions), surface chemistry (surface functional groups).15–17 It also depends on adsorptive characteristics: molecular weight, polarity, pKa, moNaphthalene Removal From Water by Novel Mesoporous Carbon Nitride Adsorbent