Removal of naphthalene from wastewaters by adsorption: a review of recent studies

Water pollution by polycyclic aromatic hydrocarbons (PAHs) has lately received considerable attention due to their wide prevalence in the environment and deleterious effects on health. Naphthalene (NP), the simplest and most common PAH, has been extensively utilized for the production of important chemicals such as phthalic anhydride and methyl anthranilate. However, owing to its health-related concerns, NP has been classified as a hazardous pollutant, mandating its removal from water systems. Adsorption has been long the preferred approach for the removal of several pollutants including NP from wastewaters. In this review, we summarize the recent research articles evaluating the removal of NP from aqueous solutions and wastewaters by a series of adsorbents (i.e., activated carbons, graphene derivatives, clay minerals, wastes/by-products, and composites). It is clear from the literature that modified materials have exhibited remarkable performance toward the removal of NP. More importantly, we highlight the potential use of adsorption integrated with other processes for the enhancement of NP removal from wastewaters. Based on the studies published in the last decade (i.e., since 2010), we pinpoint out as well the main existing shortcomings, which need to be considered in future research endeavors.