Projects / Programmes
TiO2 nanotubes as a catalyst for removing of toxic and non-biodegradable pollutants in aqueous solutions using wet-air oxidation process
| Code |
Science |
Field |
Subfield |
| 2.02.04 |
Engineering sciences and technologies |
Chemical engineering |
Catalysis and reaction engineering |
| Code |
Science |
Field |
| T350 |
Technological sciences |
Chemical technology and engineering |
| Code |
Science |
Field |
| 2.04 |
Engineering and Technology |
Chemical engineering
|
wastewater treatment, removal of priority contaminants, advanced oxidation processes, heterogeneous catalysts, heterogeneous photocatalytic oxidation, catalytic wet-air oxidation, ecotoxicology
Researchers (1)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
28564 |
PhD Boštjan Erjavec |
Chemistry |
Head |
2013 - 2015 |
136 |
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
0104 |
National Institute of Chemistry |
Ljubljana |
5051592000 |
21,023 |
Abstract
Toxic and non-biodegradable compounds, such as endocrine disrupting compounds (EDCs), are present in the variety of industrial effluents, surface and drinking waters. In Europe, new environmental regulations are expected with tighter restrictions; thus, advanced technologies for (waste)water treatment should be available for efficient elimination of emerging pollutants in order to face the incoming challenges. The removal of priority pollutants from waters is often difficult due to their chemical resistance and low solubility, which makes the biological treatment process unsuitable.
The proposed project aims to develop innovative heterogeneous catalysts for the removal (i.e. complete oxidative degradation or mineralisation) of model EDCs (e.g. bisphenol A and 17-β estradiol) from wastewaters by means of catalytic wet-air oxidation (CWAO) process, as an example of advanced oxidation processes (AOPs). Total mineralization of dissolved organic pollutants in aqueous samples could be achieved using CWAO in trickle-bed reactors under high pressure (up to 50 bar) and temperatures (up to 250 ºC). This process is favorable due to high temperatures used in the process to ensure sufficient solubility of pollutants during the destructive degradation. The catalysts which will be used in the CWAO process are ecologically and economically acceptable, i.e. without the presence of noble metals or mixed metal oxides of Cr, Mn, Fe, Co, Ni, Cu, Zn and Mo, which are often prone to leaching. Therefore, the composition of proposed catalysts will be based only on TiO2.
A continuous-flow, three-phase trickle-bed reactor will be applied for evaluation of catalyst activity and chemical stability during CWAO as well as determination of the removal efficiency of pollutants from model aqueous samples and real effluents (e.g. landfill leachates). For comparison, the removal efficiency of refractory water pollutants with newly prepared catalysts will be tested in the AOP process of heterogeneous photocatalytic oxidation that takes place in the presence of UV, visible or solar light.
The main objectives of proposed project are as follows:
a) to synthesize new and advanced high surface area catalysts based on TiO2 (different structure, size and morphology of active particles) intended for catalytic wet-air oxidation of EDCs,
b) to characterize the catalysts before and after usage in CWAO process, with emphasis on a detailed examination of textural, structural and surface chemical properties of developed materials by a variety of advanced techniques (HRTEM, XRD, BET, TPO, TPR etc.),
c) activity tests and determination of quantitative structure–activity relationships (QSAR) of advanced catalysts in heterogeneous catalytic wet-air oxidation process,
d) to evaluate the effectiveness of CWAO process by determining conversions of model pollutants and concentrations of potential intermediates formed during the oxidative destruction (HPLC, TOC, IC, GC-MS, UV-VIS, etc.) as well as acute toxicity and estrogenicity of feed and end-product solutions. Toxic potential of initial and treated samples will be studied by toxicity tests using organisms from different taxonomic groups: (i) marine bacteria Vibrio fischeri, (ii) crustaceans water fleas Daphnia magna, (iii) unicellar green algae Desmodesmus subspicatus and (iv) zebrafish embryos Danio rerio. The potential estrogenicity of samples will be investigated by the genetically modified yeast Saccharomyces cerevisiae (YES test),
e) to compare the removal efficiency of non-biodegradable compounds with advanced TiO2 catalysts using the process of heterogeneous photocatalytic oxidation.
Significance for science
The results that we have obtained during the implementation of research project, are presented as scientific publications in leading refereed journals devoted to the environment and environmental technologies, as well as presentations at national and international scientific meetings, as well as records in international databases. On the basis of the project we have certainly enriched the knowledge on synthesis, characterization and application of advanced nanostructured catalysts and, more importantly, in the field of treatment of endocrine-disrupting compounds found in wastewaters and related toxicity and estrogenicity. The aim of the project was to use newly developed catalysts based on TiO2 and thus reduce the price CWAO process and ensure thorough removal of hazardous, non-biodegradable water pollutants, without burdening the environment. We have obtained important data, knowledge and experiences on the influence of the catalyst physico-chemical properties on the removal efficiency of organic priority pollutants. This will significantly contribute to improving the efficiency of not only CWAO process, but also of other advanced oxidation processes based on catalytic oxidation of organic pollutants.
Significance for the country
The project is based on the development and application of innovative catalysts for efficient removal of EDCs from aqueous samples by means of advanced oxidation processes. We estimate that the results and findings of the project are important and relevant for companies which are dealing with these pollutants on a regular basis. Namely, pollution control and remediation is considered as crucial and acute environmental problem. In our opinion, action through innovative approaches will have a significant impact on the conservation of natural heritage and biodiversity. Development of advanced and efficient processes for water purification is also extremely important for sustainable development of Slovenia, as well as to ensure the health and high quality of life.
Most important scientific results
Annual report
2013,
2014,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2013,
2014,
final report,
complete report on dLib.si
