Potential of Verrucodesmus verrucosus in the removal of nitrogen and phosphorus structures from wastewater from pig farms

Abstract

Verrucodesmus verrucosus in residual water from a pig farm located in Suchiapa, Chiapas, Mexico, was evaluated as a mixotrophic culture medium. The evaluation was carried out for 40 days, under the 12:12 light / dark cycle, two growth stages were evaluated (piglet and fattening) and the 50:50 mixture of these, as well as to the residual water two pre-treatments were applied, this consisted of a filtration process using a 15 µm diameter nylon filter and a sterilization process. The microalgal species Verrucodesmus verrucosus was shown to have bioremediation potential by growing in wastewater and producing biomass, demonstrating high efficiency in removing contaminants. The maximum Chemical Oxygen Demand (COD) removal was in the Ps treatment (sterile piglet) where the removal of 96.8 % was reached, while the Biochemical Oxygen Demand (BOD) had a maximum removal of 96.7 % in the Pf treatment (filtered piglet). The removal of total nitrogen, ammonia and nitrate was demonstrated with a percentage of 85.5 %, 74 % and 91 % respectively. As for the maximum removal of phosphorus and phosphate, they reach values of 97.9 % and 82 % respectively. On the other hand, it was possible to demonstrate the antagonistic capacity of this microalga with respect to Escherichia coli, where 100 % elimination was achieved.