The use of RP-HPLC–Q-TOF–MS as a powerful tool for wastewater composition profiling and selection of water pollution marker specific to wastewater contamination

Human activities that are based on water usage must generate wastewater. The United Nations Educational, Scientific and Cultural Organization (UNESCO) evaluates that the amount of sewage produced yearly is almost 1500 km 3 and it is about six times more than amount of water of rivers that run across all the world. As the general demand for water grows systematically, the quantity of sewage produced and its overall pollution load is continuously changing worldwide. It is estimated that over 80% of the world’s wastewater, and even over 95% in less developed countries, is discharged to the environment without the proper treatment [ 1 ]. Once released into water, wastewater is diluted and transported downstream and may infiltrate into groundwater, an important source of drinking water. Finally, river water containing discharged sewage contaminated with pollutants enters seas and oceans, where it may have negative impact on the marine environment [ 1 , 2 ]. Currently, wastewaters are no longer seen as an environmental problem, but rather as the part of challenging solutions that society faces today. Regarding ever-growing water demand, the sewage has gained a momentum as an alternative source of water supply (not as a source of contamination), changing the idea of wastewater management from ‘treatment and discharge’ to ‘recycle, reuse, and recovery of resources’. Wastewater can be also a cost-effective and sustainable source of organic matter, nutrients or energy. According to the United Nations World Water Assessment Programme Report 2017: Wastewater. The Untapped Resource published by UNESCO [ 1 ], the prospective advantages of acquiring these resources from sewage go well beyond human health and environmental condition and may impact on energy or food security and climate change mitigation, as well. The introduction of plan of using the partially treated wastewaters and effluents for ecosystem services may reduce freshwater abstractions and allows fisheries as well as other aquatic ecosystems to thrive by recharging depleted aquifers and minimalizing water pollution [ 1 ]. However, advance quality control and improvement of wastewater treatment systems are required. Although the use of untreated or diluted wastewater for irrigation has taken place for centuries, their composition has changed over the years. Therefore, their profiling and monitoring are of high importance and need.