Projects / Programmes
Advanced water treatment with ultrasound and cavitation
| Code |
Science |
Field |
Subfield |
| 7.00.00 |
Interdisciplinary research |
|
|
| Code |
Science |
Field |
| T270 |
Technological sciences |
Environmental technology, pollution control |
| Code |
Science |
Field |
| 2.07 |
Engineering and Technology |
Environmental engineering
|
ultrasound, cavitation, water treatment, ultrasound cavitation, hydrodynamic cavitation, advanced oxydation processes, sonochemical reaction, algae control, water disinfection
Researchers (23)
Organisations (4)
Abstract
Presentation of the problem
The goal of biological waste-water treatment is a stepwise oxidation of organic pollutants aiming to achieve complete mineralization. Yet, numerous wastewater constituents are persistent to biodegradation or they are only subjected to minor structural changes instead of complete transformation into carbon dioxide and water. Alternatively, they may be eliminated by applying advanced abiotic treatment processes such as membrane filtration, UV degradation, ozonation, advanced oxidation processes (AOP), and potentially, also cavitation.
The goals of the study
The proposed research aims to upgrade the efficiency of wastewater treatment by integrating the cavitation. Using cavitation we aim to work in two groups: 1. We want to use extreme pressures and temperatures from cavitation collapses to disintegrate smaller organic molecules, which are otherwise harder to disintegrate by using conventional biological methods; 2. By disintegrating larger particles we wish to enlarge the specific surface and thus increase the rate of hydrolysis and biodegradation of organic pollutants. Cavitation will be combined with conventional biological treatment using activated sludge. By decreasing the amount of persistent organic pollutants in wastewater treatment plant effluent we will demonstrate the improved efficiency of treatment.
Originality of the results
In present industrial practice of waste water treatment cavitation is not present. Although some laboratory experiments exist, the methods have not been applicable to practical use. The intended research activities are therefore directed to acquire additional knowledge and experience on theoretical level and finally promote their transfer to applicative level, together with development of new technologies.
Methodology and organization of the project
In phase one we will study ultrasonic cavitation, while in phase two we will focus on hydrodynamic cavitation. Cavitation will be characterized by operating parameters such as flow rates, pressures and temperatures. The processes of cleaning and disintegration will be monitored also on a micro level with hydrophone and visualization. Cavitation will be combined with the existing pilot wastewater treatment plant with activated sludge and with a fish-pond.
The efficiency will be evaluated based on removal of selected persistent organic pollutants such as pharmaceuticals (nonsteroidal anti-inflammatory drugs, sedatives, antidepressants, hypolipidemics, etc.). Their elimination will be followed by chemical analytical method, which has already been developed by the Group for organic environmental chemistry at Jožef Stefan Institute. The analytical method involves a solid-phase extraction of analytes, their derivatization and analysis by gas chromatography hyphenated to mass spectrometry. As a measure for biodegradability we will follow biological oxygen demand (BOD-5), whereas the cavitation efficiency will also be assessed by distribution and particle size prior to and post-cavitation.
Relevance and potential impact of the results
We expect that cavitation will reduce presently necessary use of expensive chemical reagents for enhanced treatment process, which on the other hand also pose additional concerns when deposited into environment. Cavitation as physical phenomena does not introduce any new chemicals to water and also does not affect the environment after water release into environment. Finally, as nowadays great attention is put upon micropolutants such as endocrine disturbing compounds, it is expected that developed process of waste water cleaning with aid of cavitation will considerably reduce their presence in purified water. We expect that cavitation could be also used for disinfection of waste- and drinking water.
Significance for science
Results of the project show in our view, a high level of scientific relevance, since the project answered the many open issues that were identified in the state-of-the-art review. Due to the project interdisciplinarity the progress was made in all targeted research areas, namely: (1) In mechanical engineering, or. fluid mechanics, in-depth knowledge of ultrasonic and hydrodynamic cavitation and in the development of new technologies and facilities that allow such cavitation. (2) In ecological engineering the use of cavitation: (a) opened up new ways to reduce consumption of expensive and/or for the environment and people hazardous chemicals; (b) develop processes and devices for accelerated decomposition of biologically difficult degradable substances (treatment plants, biogas plants); (c) develop procedures and devices for the sanitation of water for different purposes, e.g. in aquaculture, irrigation, bathing waters, etc. (3) In public health the results of proposed research leaded to new technologies and devices for disinfection of drinking and wastewaters thus reducing the need of chemicals. (4) In the chemical analytics the results of the project contributed to the development of new analytical methods that support the identification of degradation products to be generated in our process, which will lead to a hypothesis about the possible degradation pathways of the observed priority pollutants (PP). We are also convinced that in today's world where science has become increasingly intertwined, inter-and multi-disciplinary, the results of our research will find their way into other branches of science and profession.
Significance for the country
We expect that use of cavitation will reduce presently necessary use of expensive chemical reagents for enhanced treatment process, which on the other hand also pose additional concerns when deposited into the environment. Cavitation as physical phenomena does not introduce any new chemicals to water and also does not affect the environment after water release into the environment. Finally, as nowadays great attention is put upon micropolutants such as endocrine disrupting compounds, it is expected that developed process of wastewater treatment with aid of cavitation will considerably reduce their presence in treated water. We expect that cavitation could be also used for disinfection of waste- and drinking water.
Most important scientific results
Annual report
2011,
2012,
2013,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2011,
2012,
2013,
final report,
complete report on dLib.si
