Effect of the time and solar radiation on the floating macrophites for the reduction of the BOD of the water of the Mochica channel – Moche

Abstract

The purpose of this research work was to obtain a process that allows to reduce the biochemical oxygen demand (BOD5) of the water of the Mochica channel. An initial characterization made it possible to determine that the problem water had an average BOD5 of 198.3 mg O2 / L, which is why it was proposed to use a purification treatment with two species of floating macrophyte plants: Pistia stratiotes and Eichhornia crassipes, which are considered reducing agents of high concentrations of organic matter. The applied design was experimental factorial, being the sample used of 90 liters of water from the Mochica channel located in Trujillo in the department of La Libertad in Peru. The sample was distributed to containers with 3 L, then inserting an equal number of floating macrophytes, to evaluate the reduction process at times of 5 and 15 days both in exposure to sunlight and darkness. The obtained results allow to affirm that, the time, solar radiation and the type of floating macrophyte, exert a significant effect in the reduction of the BOD of the polluted water evaluated, also showing that, the presence of light, a greater number of days and that Eichhornia crassipes is the most effective, as it allowed to reduce the BOD5 from 198.3 mgO2 / L to 16.67 mgO2 / L in the presence of light and 15 days of treatment, reaching values very close to those established in the Standards of Environmental Quality-Water, category III, established by DS N ° 004-2017-MINAM.