Abstract
Filamentous fungi can be used to form easily harvested pellets with microalgae (fungal-assisted algal harvesting) in order to advance the sustainability and economic feasibility of wastewater treatment using microalgae. In experiments employing the microalga Chlorella vulgaris and using the filamentous fungus Aspergillus niger for harvesting, this study investigated the effect on water quality and the quantity and quality of lipids in the biomass produced. Major reductions in the concentrations of total nitrogen, ammonium-nitrogen and total phosphorus were observed after addition of the fungal spores (day 5) and during fungal growth and entrapment of the algal cells. At harvest (day 8), the decrease in total nitrogen was 47.4% ± 18.4% of the initial value, corresponding to a reduction of 41.9 ± 17.1 mg·nitrogen·L-1. For total phosphorus, the decrease was 94.4% ± 3.2%, corresponding to a reduction of 6.4 ± 0.2 mg·phosphorus·L-1. A significant decrease in concentration of the micropollutant diclofenac was observed at harvest, to 5.1 ± 4.0 μg·L-1 compared with an initial concentration of 9.5 ± 0.6 μg·L-1. A significant decrease in total lipids in the biomass was observed after fungal-assisted algal harvesting, from 58.7 ± 2.7 μg·mg-1 at day 5 (algal biomass only) to 34.2 ± 2.7 μg·mg-1 at day 8 (fungal-algal biomass). However, because of high biomass production, the amount of lipids produced per litre of wastewater increased from 5.6 ± 0.9 mg on day 5 to 20.6 ± 4.9 mg on day 8.
Highlights
Waste streams such as municipal wastewater are currently being produced at increasing rates and quantities worldwide, due to rapid human population growth
In experiments employing the microalga Chlorella vulgaris and using the filamentous fungus Aspergillus niger for harvesting, this study investigated the effect on water quality and the quantity and quality of lipids in the biomass produced
For the algal biomass was harvested on day 5, a fivefold increase in the amount of biomass compared with the initial value on day 0 was observed in both the treatment exposed to diclofenac and the unexposed treatment
Summary
Waste streams such as municipal wastewater are currently being produced at increasing rates and quantities worldwide, due to rapid human population growth. Algae-based technologies such as high-rate algal ponds offer one possibility to achieve sustainability within the wastewater treatment sector, since these systems are well-known for removal of inorganic nutrients from wastewater [1] Another positive aspect of using microalgae for wastewater treatment is that the biomass obtained after treatment can be used within the emerging biofuel sector, with the quantity and quality of lipids produced being key factors [2]. The incentive for using microalgae for wastewater treatment and associated biofuel production is hampered by the high costs associated with the algal harvesting techniques currently in use, commonly filtration, chemical flocculation and centrifugation. The fungal-assisted algal harvesting technique may lessen the costs associated with production of microalgal biomass in wastewater and associated biofuel production [4] [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
