# Nanomaterials for the Abatement of Pharmaceuticals and Personal Care Products from Wastewater
## 1 Introduction  
Although pharmaceuticals and personal care products (PPCPs) have been used since the end of the 19 th century, only in the last two decades the concern for their (post disposal) persistence in the environment has been raised, since they are bioactive species by showing either short or long term toxicity [1; 2; 3]. Pharmaceutical products are drugs used to treat both human and animal illnesses, whereas personal care products are mainly used in cosmetics [4]. After consumption and use, low concentrations of PPCPs are continuously introduced in several ecosystems (soil, groundwater and fresh water) through sewage and waste water treatment plants (WWTPs), and finally they are found in rivers and in the surrounding environment [1; 4; 5]. Their very low concentration, ranging from a few ng L\({}^{-1}\) to \(\upmu\) L\({}^{-1}\), gives rise to a phenomenon known as micro-pollution, which makes difficult their detection, analysis and degradation in wastewater treatment plants [1]: usually, the latter are not designed and built to treat such low concentrations, mainly due to a lack in both discharge guidelines and in environmental quality standards [1; 6]. Due to the availability of new (sensible and precise) analytic techniques, including liquid and gas chromatography-mass spectroscopy [6; 7], able to measure concentrations as small as nanograms, it is now possible to detect and characterize such water micro-pollutants. The latter are also called emerging contaminants (ECs), because data concerning their transport, fate, toxicity and tolerated concentration in water bodies are not completely available [4]. ECs are essentially either naturally occurring or synthesized substances that interfere with the functioning of endocrine systems and result in unnatural responses of the organisms. For such compounds, regulations are still missing: ECs could be matter of future regulations, dependingon the results of research concerning their potential effects on human health and the availability of data on their occurrence in the environment. Some of these ECs do not need to be persistent to be (potentially) harmful, since they are continuously introduced into the environment and so, when degraded, are soon replaced. ECs include not only PPCPs and steroid hormones, but also surfactants and pesticides [1]. Among these, PPCPs can easily dissolve in water, with high persistence due to their low volatility at atmospheric temperature and pressure and low biodegradability. Moreover, their effects differ from those of other contaminants, because drugs and their metabolites are on purpose designed and synthesized to interact with cells. Therefore, when dispersed in the environment, they can more easily react with non-target organisms [7]. Especially antimicrobials, like antibiotics, are compounds that destroy or obstruct microbe proliferation. Antibiotics are used to treat infectious diseases in human beings or animals and to preserve food (under the American Food, Drug and Cosmetic Act) [8; 9]. Recently, their use in husbandry has been restricted, mainly in EU and USA, since their proliferation to prevent disease or spur growth in livestock and aquaculture has created alarms for human resistance to microbes [10; 11; 12]. All this notwithstanding, the production of antimicrobials is expected to increase up 67% by 2030, especially in developing countries, including Brazil, Russia, India, China, and South Africa (Figure 1) [2; 11; 13]. To date, several studies report the presence of pharmaceutical and endocrine disrupting compounds (EDCs) either in raw water for drinking use or in tap water for drinking use [2; 14; 15; 16; 17; 18; 19]. This review will firstly focus on the origin and fate of PPCPs (Table 1) and then on the methods envisaging the use of nanomaterials (NMs) to remove PPCPs from wastewater (Table 1). Figure 1: According to reference [2] *: Relative frequency of detection and median concentration of pharmaceuticals in receiving waters: (**a**) global; (**b**) Europe; (**c**) North America; and (**d**) Asia.