Variability in Nutrient Dissipation in a Wastewater Treatment Plant in Patagonia: A Two-Year Overview

MANZO, LUZ MARÍA; EPELE, LUIS BELTRÁN; HORAK, CRISTINA NATALIA; ASSEF, YANINA ANDREA; MISERENDINO, MARÍA LAURA

ENVIRONMENTAL MANAGEMENT

SPRINGER

Año: 2022

0364-152X

Constr ucted wet lands are environmen tal solution s that mitiga te the impacts of urban effl uents. It is unclear how theperfor mance of these was tewater treatmen t plants (WWTP) is affect ed by climatic condition s. The dissipat ion of nutrien ts,suspen ded solids, and changes in dissolved oxygen were investig ated on a mont hly basis over two y ears (2018/ 2019) at sixsamp ling points across a WWT P located in Esquel, Pa tagonia. It was p redicted that climatic varia bles (rai n p attern and a irtempe rature) would affect the functioni ng and effi ciency of the WWT P (i.e., via nutri ent load mitiga tion and sedimentreten tion). Rainfall and tem poral patt erns diff ered mark edly betw een and throu ghout the two years, leadi ng to a clearseason ality in the transform ation of pollutant s. Nitrat e loads wer e signifi cantly higher in 2018 than in 2019 suggestin g somedegree of operat ional failure, wher eas amm onia level s in treated effl uents wer e extre mely high during both y ears, withmark ed peaks o ccurring durin g autumn 2018 and summer 2019. The W WTP was moder atel y succes sful (~36%) in reduci ngTSS contents during 2018 but was ineffi cient in 2019. Ammon ia level s in receiving waters underwent dilutio n due to rainsrathe r than due to adequat e WWT P n utrient reten tion. In terms o f nutrients , effl uent values exceeded those established bygovernm ental regul ation durin g most mont hs, but worsened durin g summer coinci ding wi th low fl ows. This lack ofpredi ctability for the values of the treated effl uent stro ngly jeopar dizes the ecolog ical integrity and biodi versity of therecei ving stream.