**2. Emerging contaminants**

Emerging contaminants (ECs), termed contaminants of emerging concern, emerging pollutants (EPs), micro-pollutants, or trace organic compounds (TrOCs) are derived from different natural as well as anthropogenic sources that extensively influence water quality [8]. They are termed as emerging not because they are new but due to enhancement in the level of concern. These contaminants are generally in small concentrations, ranging from nano-gram per liter (ng L−1) to micrograms per liter (μg L−1) in the atmosphere. United States Environmental Protection Agency (USEPA) describes ECs as new chemical compounds that have the potential to cause harmful effects on individual health and the surroundings [9]. It is essential to treat and recycle wastewater to an acceptable standard to fulfill water demands.
