“…On the other hand, Nikoo, Kerachian and Niksokhan (2012), Mahjouri and Bizhani-Manzar (2013), Cho and Lee (2014), Lei et al (2015), Ashtiani, Niksokhan and Jamshidi (2015), Nikoo, Beiglou and Mahjouri (2016), Valory, Reis and Mendonça (2016) and Fantin, Reis and Mendonça (2017) works, in addition to minimizing treatment costs, incorporated into the wastewater management problem the "Polluter Pays Principle", which, in turn, expresses the notion that as greater the responsibility for pollution, greater should be the amount paid by the polluter. Thus, these studies considered costs distribution fairness principles, either in the search for water courses self-purification capacities adequate apportionment, or in the search for adequate costs distribution, also through water quality modeling and optimization techniques.…”