Human urine has high nutrients content, containing up to 80% of the nitrogen (N) and 40% or the phosphorous (P) that end up in household wastewater, while accounting for only 1% of its volume1. Technologies aiming to recover these nutrients from urine are generally limited by the difference in the N:P ratio of urine and that of the obtained product. The cultivation of microalgae in source-separated urine is one of these technologies. The microalgae Chlorella sorokiniana can be cultivated in source-separated urine when sufficient trace elements are supplemented. Microalgae cultivation in chemostat reactors fed with source separated urine (N:P of 37:1) resulted in a simultaneous recovery of 70% and 99% of nitrogen and phosphorous, respectively. Nitrogen recovery stopped when the microalgae growth was limited by the lack of phosphorous in the medium2.
Previous studies show that the cyanobacteria strain Synechocystis PCC6803 can also be cultivated on synthetic urine giving N:P ratios up to 92:13. Based on the high N:P ratio observed in Synechocystis it is expected to achieve simultaneous recovery of nitrogen and phosphorous from urine.
After successful batch cultivation of cyanobacteria on urine in shaking flasks, we will cultivate cyanobacteria on urine in a continuous process. As a key person in the success of this project you will operate lab-scale flat panel photobioreactors (PBRs) cultivating cyanobacteria on synthetic and real urine. You will assess the performance and nutrient recovery of the process by performing experiments in the lab. This will require, among
others, studying the concentration of nutrients and biomass in the influent and effluent of the PBRs and the elemental composition of the produced biomass. You will investigate the technical feasibility of this technology.
Starting date: April/May 2022, allowance 200 euros per month.
Duration: 6 months (Either Internship or Thesis are possible within this project)