Determining biota succession in a domestic wastewater pond system after treatment with a specific consortium microalgae

• Published in: Journal of environmental health science and engineering Vol. 20; no. 2; pp. 963 - 981
• Main Authors: van den Berg, M. F., Botha, A. M., Bierman, A., Oberholster, P.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 26-10-2022; BioMed Central Ltd
• Subjects: Consortia; Earth and Environmental Science; Environment; Environmental Economics; Environmental Engineering/Biotechnology; Environmental Health; Environmental Law/Policy/Ecojustice; Microbiota (Symbiotic organisms); Ponds; Purification; Quality of Life Research; Research Article; Scientific equipment and supplies industry; Sewage; Waste Management/Waste Technology; United States; South Africa; Massachusetts; Wastewater stabilization ponds; Microbiota; Microalgae; and
• ISSN: 2052-336X; 2052-336X
• DOI: 10.1007/s40201-022-00840-z

Wastewater stabilization ponds (WSPs) rely on the metabolic activities of the inhabiting microbiota to treat wastewater. A selected consortium of
Chlorella vulgaris
and
Chlorella protothecoides
were used to manipulate the natural resident microalgae assemblage to improve the treatment performance of a domestic wastewater pond treatment system in a coastal region. Since information is lacking about the resulting influence on the composition or succession of the phytoplankton or associated microbiota assemblage, the current study aimed to determine how dosing with the microalgae
C. vulgaris
and
C. protothecoides
change the efficiency of wastewater effluent treatment, as well as the composition and succession of the natural occurring phytoplankton and microbial assemblage throughout WSP system. After a year of specific microalgae inoculations, the effluent in part complied with the standards set by the Department of Water Affairs and Forestry (DWAF) and the USA, Environmental Protection Agency (EPA). The cyanobacteria
Microcystis aeruginosa
dominated the sixth (75%) and seventh pond (97%) before the inoculation with
C. vulgaris
and
C. protothecoide
commenced. After 12 inoculation events
C. vulgaris and C. protothecoides
were dominant in ponds three to seven while the dominant microbial groups were Bacteroidetes, Cyanobacteria, Firmicutes, Planctomycetes, Proteobacteria, Spirochaetes, Synergistetes and Verrucomicrobia. After the microalgae treatment, the WSP effluent were more compliant regarding to the set guidelines for effluent than prior to microalgae treatment. Based on the ability of the
C. vulgaris and C. protothecoides
to improve the effluent water quality, it was evident that the consortium of microalgae can be use improve domestic wastewater effluent in rural nutrient sensitive catchments.