Screening of the dominant Chlorella pyrenoidosa for biofilm attached culture and feed production while treating swine wastewater

This research 12 microalgal species were screened for biofilm attached culture in the treatment of anaerobically digested swine wastewater (ADSW). The influence of ADSW on biomass productivity and removal efficiencies were evaluated using biofilm attached culture with the selected Chlorella pyrenoidosa. The variation of nutritional components from algal cells were further analysed to evaluate the potential applications of C. pyrenoidosa. The results showed that C. pyrenoidosa had the highest tolerance to ADSW, and the highest removal efficiencies for wastewater pollutants were reached when cultured in 5 times diluted ADSW. These test conditions resulted in an algal cell biomass composed of 57.30% proteins, 14.87% extracellular polysaccharide, 3.08% crude fibre, 5.57% crude ash, 2.85% moisture. Amino acids in proteins contained 21.73% essential amino acids and the EAA/NEAA value was 0.64. The essential amino acid score indicates that the selected C. pyrenoidosa could be a good protein source for feed addition.