Tertiary treatment of dairy industry wastewater with production of Chlorella vulgaris biomass: evaluation of effluent dilution

• Main Author: Nunes, Ivan Venâncio de Oliveira
• Publication Date: 2021
• Other Authors: Inoue, Carina Harue Bastos, Rodrigues Sousa, Ana Elisa, Carvalho, João Carlos Monteiro de, Gomes, Andreia Maria da Anunciação, Matsudo, Marcelo Chuei
• Format: Article
• Language: eng
• Source: Revista Brasileira de Ciências Ambientais (Online)
• Download full: https://www.rbciamb.com.br/Publicacoes_RBCIAMB/article/view/787
• topic: microalga; biomassa; tratamento terciário de efluentes; laticínios; lipídios; microalgae; biomass; tertiary wastewater treatment; dairy industry; lipids

Secondary wastewaters from the dairy industry may cause eutrophication of water bodies when not properly treated, mainly because they contain nutrients such as phosphorus and nitrogen. Tertiary treatment using microalgae could be an adequate solution for Minas Gerais State, the largest Brazilian milk producer, contributing to the reduction of environmental impacts, as well as providing biomass for oil extraction, and obtaining active compounds and inputs (including proteins) for animal feeding. In this work, dilutions (with distilled water) of the secondary wastewater from the dairy industry were evaluated to cultivate Chlorella vulgaris in a bench-scale tubular photobioreactor. Theresults indicate the feasibility of using wastewater from the dairy industry, after secondary treatment, to cultivate microalgae, showing cell growth like that obtained in control cultures (Bold basal medium). The secondary wastewater without dilution (100% wastewater) provided the best condition for biomass production. The biomass obtained in wastewater showed no differences from the biomass obtained in the Bold basal medium (control) in terms of protein, lipid content, or fatty acid profile.