Characteristics and performances of microalgal-bacterial consortia in a mixture of raw piggery digestate and anoxic aerated effluent

Abstract

The piggery digestate of high ammonia was mixed with the anoxic aerated effluent of high nitrate and phosphorus, to cultivate a microalgal-bacterial consortium for simultaneous pollution removal and resource recovery. The highest removal of total inorganic nitrogen was achieved at 324.77 mg/L in 40% piggery digestate mixed with 60% anoxic aerated effluent, along with the most microalgae biomass production. The crude protein and fatty acids of C14-C20 in microalgae cells were 21.80% and 69.78%, indicating that this mixing strategy could produce abundant microalgal biomass suitable for biofuel generation and animal feed. High-throughput sequencing showed that microbial diversity increased and Paenibacillus, Thiopseudomonas and Pseudomonas were the dominant species promoting microalgal growth. Overall, these results provided a new insight of mixing two types of wastewaters for cultivating microalgal-bacterial consortia, to remove contamination and recover nutrients simultaneously.

Keywords: Anoxic aerated effluent; Bacterial community; Microalgal biomass; Microalgal-bacterial consortia; Raw piggery digestate.