Removal Organic Matter and of Phosphates Using Photochemical and Biological Methods for the Treatment of Municipal Wastewater in Peru

Abstract

In this work, the percentage of removal of organic matter and phosphates from municipal wastewater of the Wastewater Treatment Plant (WWTP) Puca Puca, Ayacucho Region, Peru was determined by applying the combined method of photochemical water treatment and biological, which consists of coupling the photolysis process and the microalgae culture technique using Chlorella sp. The experience was carried out at the laboratory level using a photoreactor with an ultraviolet (UV) lamp for the photolysis process and a set of bioreactors that were illuminated with a light emitting diode (LED) lamp and continuously injected with CO2 from the air and a pure gas system during the biological process. Finally, with the application of the integrated photochemical and biological method, it was possible to reduce the organic matter of the municipal wastewater of the Puca Puca WWTP from 226 to 102.6 mg/L (54.60%) and from 93 to 55.17 mg/L (40.68%) for chemical and biochemical oxygen demand respectively; and phosphates from 6.8 to 4.1 mg/L (33.82%). A similar performance was observed in the cultivation of microalgae with wastewater without prior treatment with Photolysis. In this case, the decrease in chemical and biochemical oxygen demand was from 226 to 90.9 mg/L (59.78%) and from 93 to 48.78 mg/L (47.55%) respectively, and phosphates from 6.8 to 4 mg/L (41.18%).