Elimination of Micropollutants from Sewage Sludge Using Vermicomposting

Bayu Dume Gari

Doctoral thesis

Abstract:

Pharmaceuticals and personal care products (PPCPs) and endocrine disrupting chemicals (EDCs) are among the organic micropollutants identified in sewage sludge; however, it is unclear how earthworms influence the behaviour of these organic micropollutants. Furthermore, there is little to no evidence to explain the influence of earthworms on the removal of PPCPs and EDCs from sewage sludge during vermicomposting. Therefore, the objectives of this study were to evaluate the concentration of targeted PPCPs and EDCs during vermicomposting of sewage sludge using Eisenia andrei and in earthworm tissues to evaluate the effectiveness of earthworms in removing PPCPs and EDCs compared to conventional composting (control). The experiment was carried out for 120 days, with and without earthworms in different proportions of sewage sludge (100%, 75%, 50%, and 25% (w/w). The results revealed that the earthworms had significant removal efficiencies for triclosan (37%), and mirtazapine (14%) over non-earthworms. Venlafaxine (193%), triclosan (43%), and citalopram (37%), had the most earthworm influence efficiency of degradation. The maximum levels of vermiaccumulation for caffeine (72%), carbamazepine (65%), cetirizine (32%), citalopram (16%), diclofenac (183%), and triclosan (118%) were obtained. All PPCPs and EDCs analysed had a negative correlation with total carbon and C/N ratios; however, a positive correlation with total nitrogen (TN), except for ibuprofen, which had a negative correlation with TN. Therefore, these findings suggest that earthworms can effectively remove PPCPs and EDCs from sewage sludge during vermicomposting; however, further research is needed to optimize the process for maximum removal efficiency and confirm the effectiveness of this approach.

Keywords

Eisenia andrei, vermidegradation, Bio-waste, vermicompost, vermiaccumulation

Jazyk práce: English

Datum vytvoření / odevzdání či podání práce: 24. 8. 2023

Obhajoba závěrečné práce

• Vedúci: doc. Ing. Aleš Hanč, Ph.D.
• Oponent: Martin Dědina, externi, Radek Vurm, B.Sc., externi, Antonín Jelínek, externi

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Doctoral programme / odbor:
Agricultural Specialization / Exploitation and Conservation of Natural Resources