Adsorption and degradation of residual pharmaceuticals in water

Thesis event information

Date and time of the thesis defence

Place of the thesis defence

TA 105, Linnanmaa campus

Topic of the dissertation

Adsorption and degradation of residual pharmaceuticals in water

Doctoral candidate

Master of Science Mahdiyeh Mohammadzadeh

Faculty and unit

University of Oulu Graduate School, Faculty of Technology, Chemical Process Engineering

Subject of study

Process and Environmental Engineering

Opponent

Professor Isabella Concina, Luleå University of Technology

Custos

Professor Tiina Leiviskä, University of Oulu

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Adsorption and degradation of residual pharmaceuticals in water

Pharmaceutical residues are an emerging environmental concern due to their widespread use and incomplete removal in conventional wastewater treatment processes. Antibiotics, in particular, can persist in water systems, posing risks to ecosystems and human health. This thesis demonstrates that low-cost biosorbents and bionanocomposites can effectively remove pharmaceutical residues from wastewater effluents. Iron-modified peat (FeP) and magnetite-pine bark (MPB) biosorbents were efficient in batch adsorption of antibiotics such as levofloxacin and trimethoprim from synthetic water and removed various pharmaceuticals from real municipal wastewater after membrane bioreactor treatment. MPB also performed well in small- and pilot-scale column tests. Small-scale column experiments showed that MPB combined with biochar (MPB+BC) is an effective, low-cost alternative to activated carbon, and in pilot-scale tests, MPB+BC efficiently removed a wide range of pharmaceuticals over four months. Biotoxicity tests using a Nitrosomonas europaea bioreporter showed that biosorbent regeneration in a pilot-scale column caused short-term toxicity, indicating the need to further optimize regeneration procedures to reduce iron release.

Cobalt–magnetite pine bark (Co-MPB) bionanocomposites were developed for the catalytic degradation of levofloxacin. Co-MPB bionanocomposites were synthesized using different cobalt and iron addition stages and varying cobalt-to-iron molar ratios to optimize performance while minimizing the use of the valuable cobalt component. Optimized materials achieved over 90% levofloxacin degradation within four hours, with hydroxyl radicals as the main reactive species. Exposure of MPB to pure culture bacteria or hospital wastewater effluent affected ciprofloxacin adsorption, with longer exposure times generally reducing removal efficiency. Microbial analysis revealed that Pseudomonas and members of the Comamonadaceae family were the dominant bacteria attached to MPB after wastewater exposure, while Geobacillus originated from the MPB biosorbent.

Overall, this research contributes to the advancement of low-cost, sustainable solutions for pharmaceutical pollution control and offers important insights to support their scale-up in wastewater treatment facilities.
Created 7.1.2026 | Updated 8.1.2026