Work

Introducing a dual approach to industrial wastewater reclamation and microalgae harvesting by filamentous fungus

Year: 2025

Type: article

Abstract: Fungal-assisted bioflocculation offers a promising and economical method for harvesting microalgae , although there is a lack of studies on fungi and microalgae co-cultivation in real/unsterilized wastewater without additional carbon sources. In this study, the capability of fungus ( Aspergillus oryzae ) for the simultaneous purposes of microalgae ( Chlorella sorokiniana ) harvesting, purification of pretreated fish processing wastewater (FPWW) (free from oils and fats) and recycling of algal/fungus pellets was investigated. A. oryzae was successfully produced in pellet form at pH 4–5 and used first in harvesting a pure C. sorokiniana suspension. The highest harvesting efficiency (98 %) within 6 h was obtained under optimised conditions of an initial pH of 9, 150 rpm, and a fungus:algal biomass ratio of 2.5:1. SEM analysis showed that successful fungus-microalgae symbiosis was established by integrating A. oryzae hyphae with C. sorokiniana cells. The formed algal/fungus pellets were further used to purify FPWW. The results showed that both microalgae monoculture and co-culture had high total nitrogen (TN) (89.6 %, 93.4 %), total phosphorus (TP) (95.4 %, 92.9 %) and chemical oxygen demand (COD) (67.9 %, 69.4 %) removal efficiency. A. oryzae pellets showed potential for use as a bioflocculant in harvesting microalgae and FPWW suspension, with harvesting efficiency of 99 %. Also, algal/fungal pellets show potential for recycling, although more investigation is needed to assess their long-term effects. These findings suggest a possible advance in microalgae harvesting and nutrient removal with algal/fungus pellets, offering a cost-effective solution to enhance sustainability and productivity in algal-based treatment systems.

Source: Journal of environmental chemical engineering

DOI: 10.1016/j.jece.2025.116035

Authors: Saba Khalatbari, Ville-Hermanni Sotaniemi, Tiina Leiviskä

Institution: University of Oulu

Language: English

Topic: Algal biology and biofuel production

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production

Open Access status: hybrid

Estimated APC paid: $3,350