The submitted Master’s thesis was carried out within the framework of the double-degree programme between Brno University of Technology and RPTU Kaiserslautern-Landau, in collaboration with THOR GmbH, a global specialty chemical manufacturer, best known for producing high-performance additives and preservatives. The work addresses the treatment and potential reuse of industrial container-cleaning wastewater through the experimental evaluation of different pretreatment strategies and membrane-based treatment processes. Overall, the experimental programme was comprehensive and successfully addressed the objectives of the thesis.

From the perspective of supervision, I was very satisfied with Raha’s work throughout the project. As the experimental part of the thesis was conducted at THOR GmbH while my supervision was entirely remotely, regular and effective communication was particularly important. Throughout the entire project, Raha maintained very good communication, regularly discussed the progress of her work and any difficulties encountered, and was always receptive to feedback and recommendations.

I particularly appreciated her ability to work independently and to address problems as they arose. During the project, she encountered challenges both in the experimental work and later in the interpretation and presentation of the results and preparation of the thesis. She approached these issues responsibly, actively sought solutions, and made effective use of our consultations. Feedback provided during supervision was carefully considered and consistently incorporated into her work, including during the final stages of thesis preparation.

Raha was reliable, collaborative and engaged throughout the supervision process. She demonstrated persistence and a constructive attitude towards critical feedback, while progressively developing her ability to interpret her results and present them within the broader context of the research question.

Overall, I consider the thesis to be a very good piece of work addressing an industrially relevant research question through substantial experimental investigation. Raha successfully fulfilled the objectives of the thesis and demonstrated independence, responsibility, good problem-solving skills, and an excellent approach to supervision and collaboration. I recommend the submitted Master’s thesis for defence and propose the grade A – excellent.

This diploma thesis addresses the highly topical issue of industrial wastewater reuse within the framework of the circular economy and sustainable waste management. Wastewater from the cleaning of transport containers (IBC containers and drums) in the chemical industry poses a significant technological challenge due to its high and variable organic load, the presence of surfactants, and residues of biocidal substances.
The main objective of this study was to characterize five wastewater streams at the company THOR GmbH plant in Speyer, Germany, to evaluate the effectiveness of various pretreatment methods (coagulation/flocculation, adsorption on activated carbon), and to verify a cascade membrane system (Microfiltration – Activated Carbon Filtration – Ultrafiltration – Reverse Osmosis) for internal water recycling. The objectives set are clearly defined, scientifically sound, and have direct application potential in industrial practice.
The thesis is clearly structured into theoretical and experimental sections, supplemented by extensive appendix documentation.
The discussion of the results is of a high standard; the author compares the results with the scientific literature and correctly identifies the limitations of her research (shorter testing period, absence of blind tests for adsorption, limitations of analytical detection limits).
The thesis is written in English at a very good level, with a minimum of typos and grammatical errors. The graphic design, process flow diagrams (e.g., Figs. 2.1, 3.1, 3.3), and data visualizations in the graphs are clear and professional. The thesis meets all the requirements for doiploma’s theses at Brno University of Technology.
The graduate, Raha Khakpournezhad, has demonstrated the ability to conduct independent scientific and research work, critical thinking, and the systematic evaluation of experimental data. The thesis provides valuable insights for a specific industrial application at company THOR GmbH.
I recommend this diploma thesis for defense and propose that it be graded “Excellent” (A). Topics for thesis defence:

1. Your results show that coagulation–flocculation with FeCl₃ and alum effectively reduced turbidity (up to 64–80%), but achieved only minimal removal of COD and TOC. Why did chemical destabilization fail to significantly remove organic pollutants in the container-cleaning wastewater, and what alternative coagulants or process modifications (e.g., pH adjustment, electrocoagulation) could potentially target this dissolved organic fraction?
2. When evaluating activated carbon, GAC achieved up to 75–78% COD/TOC reduction, whereas PAC showed much lower efficiency. Since PAC and GAC were tested under different dosage ranges and contact times, how comparable are these results? Furthermore, how might the absence of a carbon-only blank (control sample) have influenced the observed TOC and turbidity values at high GAC dosages?"
3. The study tracked specific active ingredients (MIT, CIT, phenoxyethanol) and found that lower-pressure stages (MF, ACF, UF) achieved negligible removal, while RO served as the main barrier (83–95% removal). How do solute properties such as molecular weight, charge, and polarity dictate this retention profile across the cascade?"
4. During the laboratory experiments, membranes were only flushed with tap water after each run and no chemical cleaning was applied. In a real industrial plant, what chemical cleaning strategy (e.g., CIP – Cleaning-in-Place) would be necessary to maintain flux over longer periods?"