Nitrogen and phosphorus removal from wastewater using Chlorella vulgaris and Scenedesmus
quadricauda microalgae with a batch bioreactor
摘要
The excess nutrients in the wastewater, like ammonia, nitrite, nitrate, and phosphates, are leading water bodies to eutrophication. The traditional biological treatment methods for removing nitrogen and phosphorus from wastewater are expensive, mainly because there's not enough natural material to help break them down. Microalgae hold immense potential as an environmentally sustainable resource in treatment plants for wastewater treatment. This study aims to understand how nitrogen and phosphorus pollution can be reduced in household wastewater using special types of algae called Chlorella vulgaris and Scenedesmus quadricauda in a controlled three batch bioreactor to see how they affect the organic carbon content. It has been observed that Scenedesmus quadricauda is more effective in removing ammonia nitrogen (NH3-N) (83.5%), orthophosphate (PO4−3) (57.9%), and total carbon (TC) (86.7%) from household wastewater compared to Chlorella vulgaris. On the other hand, Chlorella vulgaris shows double the efficiency in removing total nitrogen (TN) (%76.5) compared to Scenedesmus quadricauda. While both types of algae are good at removing inorganic carbon and ammonia nitrogen, they show relatively lower efficiency in removing nitrate nitrogen (NO3−-N) (%39) and orthophosphate. The kinetic modeling of Chlorella vulgaris and Scenedesmus quadricauda microalgaes are determined for optimize water treatment process. For substrate of NH3-N due to their consumption priority, µmax is 1.85 day−1, Ks is 33.3 mg/L. Besides, for Chlorella vulgaris, using the substrate of NH3-N, µmax is 1.05 day−1, Ks is 11.2 mg/L.