Vol.:(0123456789) 1 3 Environmental Chemistry Letters https://doi.org/10.1007/s10311-020-00979-x REVIEW Nanotechnology to remove polychlorinated biphenyls and polycyclic aromatic hydrocarbons from water: a review Hadil Borji 1  · George M. Ayoub 1  · Mahmoud Al‑Hindi 2  · Lilian Malaeb 1  · Hamdan Z. Hamdan 1 Received: 14 August 2019 / Accepted: 27 February 2020 © Springer Nature Switzerland AG 2020 Abstract Persistent pollutants cause adverse efects to human and environmental health. Most polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) are toxic and stable in the environment, yet their removal is rarely targeted by conventional remediation methods. Alternatively, nanotechnology appears promising for contaminant removal. Indeed, nanomaterials have unique size-dependent properties due to their high specifc surface area. Nanomaterials also possess fast dissolution properties, strong sorption, supermagnetic characteristics and quantum confnement. This manuscript reviews the application of nanotechnologies for the removal of PCB and PAH from contaminated water sources. Keywords Carbon nanotubes · Iron oxides · Nanomaterials · Photocatalytic nanocomposites · Polychlorinated biphenyls · Polycyclic aromatic hydrocarbons Introduction As the world’s population and industrialization continue to grow, so does the demand for clean water. Expanding industrial output along with uncontrolled waste discharge, however, has led people to lose harmony with their immedi- ate environment (Al-Qodah and Al-Shannag 2017; Karataş and Karataş 2015). This has resulted in serious water con- tamination problems around the world due to the increasing amounts of pollutants that are being discharged into water bodies. Persistent pollutants are an important category of environmental pollutants given that they can remain unrec- ognized either because they are not commonly monitored or because of the limits imposed by the available detection methods (Geissen et al. 2015; Mahamadi 2019). These pol- lutants, which can be synthetic or naturally occurring chemi- cals, are of a rising concern given their potential to cause adverse ecological and/or negative human health impacts (Geissen et al. 2015). Persistent organic pollutants are extremely diverse in nature and are classifed into more than 20 classes (Geissen et al. 2015). Few of the prominent categories are: pharma- ceuticals, pesticides, disinfection by-products, and industrial chemicals (Ritter et al. 1995). Among vastly encountered pollutants are aromatic hydrocarbons which can be chlorin- ated, such as in the case of polychlorinated biphenyls and organochlorine pesticides such as dichlorodiphenyltrichlo- roethane, polybrominated diphenyl ethers, and hexachloro- cyclohexane, or non-chlorinated, such as in the case of the combustion by-products that are presented as polycyclic aro- matic hydrocarbons (Han and Currell 2017; Lammel et al. 2015). The potential serious environmental and human health risks posed by such pollutants have led to the initiation of treaties including the United Nations’ Aarhus Protocol, Stockholm Convention (UNEP 2009). These treaties were aimed at eliminating or at least restricting the production and use of such polluting chemicals. The lack of knowledge on the behavior of these pollutants in the environment and the lack of optimized analytical and sampling techniques have both entailed urgent actions at multiple levels related to water purifcation technologies (Aparicio et al. 2017; Geis- sen et al. 2015; Tobajas et al. 2017). PCB and PAH are known to be highly stable chemical compounds. Although their hydrophobicity limits their water solubility, their high toxicity is usually aggravated by the * George M. Ayoub gayoub@aub.edu.lb 1 Civil and Environmental Engineering Department, American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon 2 Chemical Engineering Department, American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon