Post-hydrothermal liquefaction wastewater (PHW) nutrient recovery by Trametes versicolor mycoremediation

Post-hydrothermal liquefaction wastewater (PHW) comes from a thermal process where wet biomass is converted into biocrude oil for further biofuel production. This waste stream is potentially toxic, mainly because of the presence of aromatic and nitrogen organics as well as heavy metals. The discharge of PHW into the environment without any treatment may result in safety and health hazardous consequences. However, PHW is a nutrient-rich wastewater that can be used as fertilizer in hydroponic systems. It has been found that most of the nitrogen in PHW is in its organic form, which is not easily accessible to plants. The conversion of organic nitrogen into inorganic (i.e., ammonium and nitrate) could improve the performance of PHW as a fertilizer. In these terms, mycoremediation, the use of fungi to remove or degrade pollutants from waste streams, arises as an eco-friendly alternative to reduce PHW toxicity and increase the concentration of inorganic nitrogen in this wastewater. Fungi can perform ammonification, where small nitrogen organic molecules are metabolized, and excess nitrogen is released as ammonia/ammonium by the fungus. In addition, fungi not only possess a great sorption capacity for organic molecules and heavy metals, but also can produce extracellular enzymes that are known to degrade a range of recalcitrant organic pollutants. In this study, the white-rot fungi Trametes versicolor and Pleurotus ostreatus cultivation in 5% PHW were explored to increase inorganic nitrogen (N) and reduce the wastewater's organic N content. P. ostreatus could not grow in 5% PHW, but T. versicolor successfully grew in 5% PHW and increased the amount of ammonia/ammonium-nitrogen (NH3/NH4+-N), from 4.04 mg/L to 32.20 mg/L, and nitrate-nitrogen, from 1.84 mg/L to 30.67 mg/L, representing an increase of almost 8 and 17 times, respectively, after 3 days of PHW fungal cultivation. Additionally, the rise in NH3/NH4+-N was followed by an increase in pH from 4.29 to 7.52. Although fungal biomass growth was not observed based on dry weight measurements, laccase production by T. versicolor indicates its activity over time. Fungal cultivation in PHW resulted in a change in color of the wastewater, probably because of fungal enzymatic activity, consumption, or adsorption of color-associated organic molecules. In the first 24 hours of fungal cultivation, chemical oxygen demand decreased from 495.47 mg/L to 241.13 mg/L, a 51.33% removal. Lastly, different fungal inoculation methods were tested, and the use of matrix M and bead beater resulted in homogenous fungal pellets. Thus, the results from this study indicate T. versicolor can be a strong candidate to increase inorganic nitrogen in PHW for further use as fertilizer in hydroponic systems.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Agricultural & Biological Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2022

Author dc:creator

• Fernandes Cintra Leme, Vitoria

Contributors dc:contributor

• C. Davidson, Paul
• B. Leonelli, Laurie
• A. Conerty, Beth

• Mycoremediation
• Bioremediation
• Wastewater Valorization
• Trametes Versicolor
• Post-hydrothermal Liquefaction Wastewater (phw)

Statement dc:rights

• Copyright 2022 Vitoria Fernandes Cintra Leme

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/117579

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F117579