Waste Is the New Wealth – Recovering Resources From Poultry Wastewater for Multifunctional Microalgae Feedstock

Abstract

To meet the increasing demands of the growing population and to cope with the challenges of global change, both the production of biological feedstock and the recovery of recyclable natural resources play a critical role. Microalgal biomass is a promising source of renewable multifunctional feedstock, but the production is costly and requires large amounts of water. Here, we explored the potential of using wastewater as culture medium to lower the economic and environmental costs of microalgae biomass production and evaluated its valorization opportunities for animal feed production. As a proof of principle, we show that Chlorella sorokiniana can be cultivated on poultry wastewater, with a 83 and 113% increase in productivity when wastewater was first 50% diluted with tap water or standard growth medium, respectively. Wastewater sterilization before use enhanced algal growth with 36–118%, but only when wastewater was 25–50% diluted with standard medium. In contrast, it offered no additional benefits when dilutions were made with tap water or when wastewater was not diluted. At the end of the 22-days experiment, a maximum biomass of 0.8–1.9 g L−1 was reached for algae grown on wastewater. The produced biomass had a high macronutrient content, and the heavy metal content was below maximum limits for use in animal feed. Likewise, the tested pathogen groups were reduced until below safety norms for feed production after algal growth in unsterilized 50% wastewater (diluted with tap water). Overall, these findings add to our growing knowledge on the cultivation of microalgae on wastewater and its valorization opportunities, paving the way for a more sustainable use and reuse of resources.

Removal of organic matter during adaptation of Nannochloropsis oculata in livestock waste

“…Such behavior is attributed to the difference in nutrients between the wastes, since their availability plays an important role in the growth and composition of microalgae, especially nitrogen, which is crucial for the growth of microorganisms and forms a major part of vital macromolecules such as amino acids and proteins (Su et al, 2022). PWW, which is generally produced from the periodic rinsing of poultry processing plants to limit the accumulation of manure and other wastes generated in the different processes (Thoré et al, 2021), proved to be a suitable medium for the development of N. oculata, since this species was able to survive in the 3 conditions analyzed. As mentioned above, the highest cell density was obtained with 10% inoculum, with an increase from 1.2 x10 7 cells/mL on day 0, to 8.72 x10 7 cells/mL on days 14 and 15.…”

Real-Time Monitoring of Microalgal Biomass in Pilot-Scale Photobioreactors Using Nephelometry

“…Microalgae cultivation is gaining interest due to the anticipated wealth of application opportunities in a wide range of economic sectors [1,2]. Because microalgae are highly diverse, they can be cultivated in various technical systems including in open tanks and raceway ponds, or in closed (photo) bioreactors to allow for tightly controlled operating conditions [3].…”

Cultivation of Chlorella vulgaris in Membrane-Treated Industrial Distillery Wastewater: Growth and Wastewater Treatment

“…The content of suspended solids and organic matter in wastewater from food processing plants is very high (Qasim and Mane, 2013). In contrast, distilleries produce large amounts of acidic, stubborn, and colored wastewater with high organic content (Sanjay and Jamaluddin, 2018), which may lead to the destruction of the aquatic environment causing eutrophication, affecting human health and recreational activities (Sanjay and Jamaluddin, 2018;Stutter et al, 2018;Thoré et al, 2021). The alcohol industry discharges up to 0.3 billion m 3 of highconcentration wastewater each year in China (Guo et al, 2006), which has become the second largest source of organic pollution.…”