Escalating water pollution is one of the most critical global crises, jeopardizing the global supply of clean water and threatening public health on an unprecedented scale. Contaminated water, together with poor sanitation can be directly linked to transmission of various diseases such as cholera, diarrhoea and hepatitis A. Our successfully completed ERC project (CoG CABUM) has shown that cavitation (almost instantaneous growth and collapse of vapor bubbles due to a local pressure drop) destroys microorganisms by mechanical forces (shear and shockwaves) and that these effects can be enhanced by an elegant manipulation of cavitation conditions. CABUM has also revealed, that low-pressure cavitation region can be used to ignite non-thermal plasma, leading to successful disinfection.

To further evolve the technology, PureWater will develop a compact, pilot-scale device that innovatively couples cavitation and plasma (CAP) and builds on the established lab-scale prototype. The novel CAP device will have a dual purpose:

• a safe and energy efficient alternative to established disinfection technologies in public and industrial facilities that have problems with Legionella pneumophila outbursts;
• a royalty free technology for on-site drinking water treatment in most vulnerable regions of the world.

Firstly, the small-scale device will be fine-tuned and scaled up and then tested in a relevant setting, where CAP will be optimized for reliable long-term operation and high efficacy.

The phenomenon of cavitation, which enables the concentration of high energy and the enhancement of mass transfer, is one of the advanced oxidation processes in chemical and environmental engineering, particularly in water and wastewater treatment. Most current research focuses on systems with Venturi tubes or orifices and rotational generators of hydrodynamic cavitation, which require multiple recirculations of the medium to degrade pollutants effectively.

Cav-Micro project on the other hand focuses on cavitation in microchannels, allowing for intensified effects through controlled bubble manipulation. The research includes designing cavitation rmicroreactors, analyzing cavitation mechanisms, optimizing conditions, and studying differences between micro and macro cavitation. The goal is to better understand the processes of oxidant activation, radical formation, and pollutant degradation.

The project promises significant findings for further research, contributing to the field's recognition and the development of methodologies.

Cavitation – a phenomenon, in which developed extreme conditions can inactivate bacterial cells. Despite recent findings on the fundamental inactivation of bacterial cells and single microbubble, we are still not sure whether a cavitation cloud can be as effective as individual microbubble. In this project, we aim to scale up the inactivation phenomenon from a single cavitation microbubble to organized microbubble clusters and up to a cavitation cloud in a microcavitation device to determine the most efficient form of cavitation for bacterial removal. A better understanding of the correlation between the efficiency of bacterial inactivation and the cavitation cloud will allow optimization of the phenomenon to establish it as a sustainable and effective inactivation technology.

There are two faces of a phenomenon of cavitation – a formation of small vapor bubbles (cavities) inside an initially homogeneous liquid medium. Cavitation is feared of as it causes shockwaves, high temperatures, shear flows, all causing nuisances such as erosion, decrease of hydrodynamic performance, drop in machine efficiency etc.. On the other hand, these same extreme conditions, enable processes such as enhancing fluid mixing and heat and mass transfer, enhancing chemical reactions, surface cleaning, emulsification and even breaking down kidney stones and tumors.

Despite significant progress, a large gap persists between the understanding of the mechanisms that contribute to the effects of cavitation. We are still not able to answer the fundamental question: »What precisely are the mechanisms how bubbles, erode, clean, disinfect, kill bacteria and enhance chemical activity?« What makes cavitation unpredictable is its multiscale nature: nucleation of vapor bubbles heavily depends on micro- and nanoscale details; mesoscale phenomena, as bubble collapse, determine relevant macroscopic effects, e.g. cavitation damage. In addition, macroscopic flow conditions, such as turbulence, have a major impact on it.

The objective of the MICKA project is to develop the lacking multiscale description of cavitation, by proposing new integrated experimental and numerical methods capable to perform quantitative predictions. The detailed and physically sound understanding of the multifaceted phenomena involved in cavitation (nucleation, bubble growth, transport, coalescence, collective collapse, shock wave emission, single bubble interaction, bubble collapse and the two-way interaction with the nearby structure in turbulent flows) fostered by MICKA project will result in new methods for designing fluid machinery, but also water treatment processes, therapies in ultrasound medicine and chemical reactors.

Cavitation structures carry a significant amount of energy and can, at their coherent collapse, emit pressure waves of magnitude of several MPa. Yet, the cavitation cloud collapse itself cannot be the direct cause of majority of cavitational effects as its energy is not concentrated enough. Currently the most widely accepted explanation of the phenomenon is that the potential energy contained in a macro cavity (cavitation cloud) is transformed into the radiation of acoustic pressure shock waves, observation of which was recently shown by the PI. Further on, the energy is transferred into the micro-scale cavitation structures or single bubbles. Understanding the mechanism through which bubbles act against structures remains vague, and the extremely fast and localized dynamics that lead to nearby structural damages has not been completely resolved.

Up until now, the above processes (cavitation inception, clustering, shedding, collective cloud collapse, shock wave emission, single bubble collapse and structural response) were investigated separately, without real consideration of the energy transfer between the scales. The MICKA project builds on the PI's preliminary research in the scope of ERC grants and employs novel experimental and numerical methodologies, to approach the phenomenon of cavitation from the inception point of attached cavitation to the collapse of a single bubble in an integral and simultaneous way, revealing the multiscale details of the process.

Cavitation is a fascinating and complex phenomenon that occurs when a liquid undergoes rapid changes in pressure, leading to the formation and implosion of vapor-filled cavities or bubbles. In engineering applications, cavitation can have both negative and beneficial effects - it can lead to damage in machinery, but it is can also be harnessed for process intensification.

Understanding cavitation is crucial for optimizing the design and performance of various systems, ensuring efficient and safe operation. One of the key aspects of research is the interaction between cavitation bubble(s) and the nearby substance. This has been rigorously investigated for the case of solid material, but much less so for other types of structures.

In the present project we will use innovative experimental and numerical methods to address the interaction of cavitation with the four states of mater: gas, liquid, solid and plasma. The outcome of the action will echo in fields of mitigation of cavitation erosion, intensification of chemical processes, in emulsification processes, in preparation of dispersions and studies of synergistic effects of abrasion and cavitation erosion and in innovative approaches to water treatment.

Hydrodynamic cavitation (HC) is known for causing damages on machines, pipelines and equipment due to the formation and implosion of tiny gas bubbles and local temperature hotspots. Controlling and utilizing these harsh micro-conditions has the potential to revolutionise process unit operations such as mixing, reactions, emulsions and particle formation for the benefit of the European process industries and global industrial community. Systematic understanding of the physicochemical phenomena occurring in HC and design of HC reactors and scale-up are missing. Now it is time to guide the research further towards game-changing implementations that utilises HC and orchestrate them in large systems that are ready for industrial deployment. Therefore, we propose the DN project CaviPRO, which aims (a) to push the current scientific boundaries and explore entirely new directions of fundamental research on controlled cavitation that is linked to state-of-the-art additive manufacturing, advanced process control and machine learning; and (b) to educate and mentor 10 curious and capable doctoral candidates to form a critical mass of fully skilled young professionals acting as multipliers to develop technologies across Europe. The network is built on synergies and complementarities between leading scientists, world-class institutions, different disciplines, and the incorporation of several industries as drivers – ranging from start-ups to SMEs to global players – from all over Europe.

The project aims to promote social innovation and entrepreneurship in water management through advanced technologies in harvesting and desalination practices. Acting4Water partners will develop educational resources and activities to raise awareness and address water scarcity through business-academia synergies. In particular, the project focuses on integrating citizen science in university courses regarding water scarcity as a means of encouraging civic engagement and advocacy.

The Acting4Water project is structured on an innovative business-academia-society cooperation to offer a multidimensional open training programme to academic communities as well as to the general public. Acting4Water aims to enhance education related to water scarcity, and to conduct a landscape analysis of the existing training practices to identify their effectiveness and explore emerging new directions.

The Curious project focuses on studying the dynamics of cavitation bubbles in highly anisotropic environments, such as when the bubbles are placed in close proximity to boundaries. Recent research indicates that the dynamics of bubbles in such environments deviates significantly from the current understanding, leading to a discovery of new exotic phenomena with a high promise and important implications for the use of cavitation in many existing and novel applications.

The phenomena of cavitation and bubble dynamics have been extensively studied in engineering fields due to the negative consequences of cavitation, such as material erosion. In addition, cavitation has been extensively researched and used in various fields such as medicine, chemistry, environmental protection, and engineering. Despite the considerable progress, there is still a large gap between the understanding of the mechanisms contributing to the effects of cavitation and its application. Additionally, there exists a lack of understanding of how bubbles behave in extreme conditions. This is supported by the recent discoveries of new phenomena that occur when bubbles grow and collapse in highly anisotropic environments. Amongst others, this includes the formation of very fast jets that can reach supersonic speeds, fast and thin needle jets, bullet jets, and fast planar jets.

The Curious project aims to further investigate and venture beyond these recently discovered phenomena. The overall objective of the Curious project is to significantly push the current state-of-the-art by achieving a deeper understanding of the fundamental physics of fast jet formation and exploring the conditions, under which imploding cavitation bubbles form fast, possibly supersonic jets. The research will further focus on how these conditions affect the characteristics of the resulting jets, how the developed jet characteristics affect the extreme conditions during bubble implosion, and how nearby structures respond to these conditions.

There are four main objective of the Curious project, each with a designated work package: (O1) improvements of the current modeling methodology of bubble dynamics and extensive model verification and validation; (O2) experimental station setup for generation and observation of single laser-induced cavitation bubbles and fine-tuning of the experimental methodology; and investigation of bubble dynamics and fast jet formation in highly anisotropic environments, (O3) near solid boundaries and (O4) near soft matter.

The Curious project builds on the project leader’s prior research in the scope of a PhD under an ERC grant and involves novel methodologies, that allow cutting edge experimental and computational research on the topic of bubble dynamics. Advanced numerical models and experimental methodologies will be further improved and fine-tuned to the phenomena under consideration, which has direct implications in the broader scientific field of fluid dynamics. In addition, an important part of the project’s outline is dedicated towards collaboration with other researchers in order to enhance the scope and impact of the proposed research.

Studying bubble dynamics in never before explored environments and configurations has a high likelihood of leading to the discovery of new and exciting physics, along with the potential to revolutionize the use of cavitation in various applications. The results are guaranteed to significantly contribute to the understanding of these novel phenomena and pave the way towards cleaner, greener, and safer medical procedures, industrial processes, water treatment, and production of energy. The research is thus also significant because of the plethora of potential implications for both exploiting cavitation and preventing its unwanted effects.

The project objective is to establish a network of research institutions with the vision of providing young people comprehensive and up-to-date knowledge about renewable energy harvesting methods. A support to student mobility and cooperation with the industry during studies will be provided to increase young engineers competence to work in the renewable energy sector anywhere in Europe.

We will develop and practically test over two growing seasons several grapevine protection systems against harmful organisms, suitable for integrated (INT) and organic grape production (EKO), which will allow at least a 40% reduction in the consumption of conventional phytopharmaceuticals (PPP) at the expense of the use of alternative means from the category of basic substances for organic production, biostimulators and phytopharmaceuticals with low risk.

Over the past decade, enough evidence has accumulated to show that pharmaceuticals are constantly entering the aquatic environment through wastewater treatment plants and affecting the receiving aquatic compartments. The problems are exacerbated when hospital wastewater containing high concentrations of various antimicrobials, including antibiotics, is discharged directly into sewage systems. In line with the EU concepts for clean and sustainable wastewater treatment, the proposed Causma project will focus on providing an alternative, environmentally friendly and economically acceptable water treatment technology. Advanced oxidation processes are a powerful tool to achieve oxidation and even mineralization of many hazardous pollutants in water matrices of different complexities, ameliorating their detrimental environmental impact. In the proposed Causma project, we will investigate the effectiveness and efficiency of two advanced oxidation processes, hydrodynamic cavitation and non-thermal plasma. The effectiveness and efficiency of the individual processes and their coupling will be investigated for the pharmaceuticals, particularly antimicrobials from the priority list: erythromycin, clarithromycin, azithromycin, amoxicillin, ciprofloxacin, sulfamethoxazole and trimethoprim.

The project will carry out an analysis of the methods and possibilities of obtaining and systematically collecting information about the plantation with an emphasis on automation using digital tools, an online platform for electronic data recording in a suitable platform with the possibility of open or closed access to the accumulated data, a database device, an orchard archive will be created and a developed computer-based system for data analysis, which will ensure faster and more professional independent decisions by the user for the implementation of agricultural practice measures.

Researchers at the UL Faculty of Mechanical Engineering have been selected for a European Research Horizon Europe project. The H- HOPE project focuses on developing innovative and sustainable power generation systems capable of extracting hidden hydropower from existing piping systems, open rivers, and open channels.

The technology is based on the use of piezoelectric materials attached to submerged bodies with deformable walls and electromagnetic devices that absorb the transverse motion of vibrating bodies within the flows. Numerical and multi-physics models will be developed in parallel to optimise the design and performance of H- HOPE devices. The resonant frequency of the coupled fluid-structure-electric generator system will be tuned to steady-state and dynamic operating conditions. Eight different case studies will be conducted on actual applications in industry and on free-floating water installations. The project will evaluate the relevant environmental and socio-economic impacts to assess the sustainability of the proposed technology.

To disseminate this knowledge and promote the results of the H- HOPE project, an open-source DIY platform will be set up and managed by the project team at the Faculty of Mechanical Engineering, University of Ljubljana, Laboratory of Water and Turbine machine LVTS. As a result, the H- HOPE platform will help reduce the negative effects of climate change, reduce CO2 emissions, and increase the EU's energy independence.

Mechanical weed control has a significant advantage over chemical control, as it leaves no pesticide residues in the soil and crops and no waiting period is required. Therefore, mechanical weed control is one of the most important agro-technical measures in organic farming, and it is also becoming increasingly important in conventional agriculture.

The aim of the project is to develop a robotic arm with an associated hoe for inter-row and inside-row hoeing, which will be installed on a smaller platform. Thus, a key element will be developed that will enable farmers to mechanically cultivate much larger production areas. With the appropriate choice of the platform (this is not part of this project) on which the arm will be installed, manual control for smaller areas will be enabled, and remote control or automatic operation, if the platform allows it. The digging arm will communicate with the platform using the ROS (Robotic Operation System) system, which will enable connectivity with many other systems, modularity, flexibility and future upgrades. In accordance with the development of the hoeing platform, the method of growing and growing vegetables will be adapted in such a way that the combination of agricultural practice and the use of the hoeing arm will enable efficient and safe work. The aim of the project is to increase productivity in organic vegetable production through better and timely hoeing, reduce weed reproduction and reduce the use of PPPs.

The results of the project are more competitive organic vegetable growers, improved sustainable use of agricultural land and reduced use of plant protection products (PPPs). This will result in the effective adaptation of agricultural production to, mitigation and adaptation to climate change.

New requirements in terms of operation and maintenance of Hydropower plants as well as co-generation of electricity with other RES needs substantial future research. As past funding of research projects was low, this new initiative should work together for a better knowledge exchange, capacity building of young researchers to meet the needs of the future. The main objective of this Action is to establish a Pan-European network for a sustainable, digitalised hydropower contributing to the Clean Energy Transition (CET), a united network of researchers, engineers, scholars, and other stakeholders, such as representatives from industry, policy and civil society, to facilitate close collaboration among European research groups through projects supporting sustainable hydropower.

One of the most pressing global problems is the increasing pollution of surface and groundwater, which threatens the world's clean water supply and public health. Wastewater treatment plants, the last barrier between ever-increasing human activities and the environment, produce huge amounts, up to 13 million tonnes per year in the EU alone, of unwanted by-product - waste activated sludge. Therefore, upgrading wastewater processes with new circular economy approaches is crucial to achieve the goals of the EU Green Deal. Considering waste activated sludge as a resource rather than an unwanted end-product is the first step towards sustainable wastewater treatment. Based on the knowledge gained within the ERC- CABUM, we have developed a rotating generator for hydrodynamic cavitation - a scalable and cost-effective device that works simultaneously as a cavitation generator and a pump. With CAVIPHY, we will improve the disintegration, settleability and dewatering of waste activated sludge using this hydrodynamic cavitation generator. The synergistic result of the project will be in lower costs associated with reduced volumes of sludge and environmental burden from its disposal, while producing methane – a renewable bioenergy source.

The main purpose of the project is to answer two questions: what is the basic physical mechanics that can allow nanobubbles to remain stably suspended in liquids for a long time; and what is the potential of nanobubbles in (wastewater) treatment and surface cleaning? The goal of the project is not just academic in nature. In the long run, the results will contribute to the development of devices for the removal of particles and non-polar contamination from surfaces. To this end, UL FS researchers will investigate the real problem of removing bacteria from the distribution water supply network at the laboratory scale.

An increasing number of studies shows that there exists a great potential to utilize cavitation in various important applications in the fields of biology, chemistry, medicine, and in environmental protection. However, remarkably little is known about which or a combination of which mechanisms is important for a specific consequence of cavitation. Recent reports point towards the fact that the dynamics of microscopic cavitation bubbles differs significantly from the ones at larger scales. However, experimental investigations of the former in a precisely controlled environment are still beyond the current state of the art. To address this issue, we will develop a new facility which enables generation of microscopic cavitation bubbles. In parallel, a significantly improved observation system will be developed, which will increase both the spatial and temporal resolution of the existing experiments. The overall objective of the project is to understand and determine the fundamental physics of the interaction of microscopic cavitation bubbles. The experimental work will be complemented by numerical simulations which will enable extrapolation of the results beyond the capabilities of the experiments.

The overall eCATS objective is to improve the fundamental understanding how surface micro-/nano-topography, chemistry and wettability influence hydrodynamic cavitation incipience, development and consequently cavitation erosion. This understanding will allow us to apply advanced laser processing to control cavitation dynamics. We expect that the eCATS results will enable us to produce 3D surfaces that will lead to the development of extreme cavitation conditions behind these surfaces but will not result in their erosion.

The project will develop experimental methods for measurement of free surface topography of turbulent two phase flows, particulatly in hydraulic junctions. Measurement methods will be based primarily on laser ranging (LIDAR technology) and three-dimensional surface topography reconstruction from camera imaging data. Experimental models will be complemented by computational fluid dynamics simulations of free surface junction flows at different boundary conditions.

The project goal is to develop a new generation of household tumble dryers, featuring improved energy and functional characteristics and significantly reduced emission of fibers. The development will include research of textile degradation processes depending on mechanical and thermal loads, present during tumble drying. Based on acquired knowledge and developed models the drying operation modes will be optimized for a wide range of textiles of various composition, which will be implemented in a low emission tumble dryer prototype.

Scientific aspects of innovative technology for the treatment of waters contaminated with plant viruses will be elaborated. The viricidal properties of gaseous plasma sustained in a super-cavitation bubble will be studied. First, a device useful for sustaining a rather stable low-pressure bubble using hydrodynamic cavitation will be constructed. RT-PCR of three long fragments will assess the gaseous plasma treatment effect on the viral RNA integrity spanned almost the whole virus genome. The degradation of viruses upon the treatment will be visualized by TEM. The gaseous discharge versus cavitation parameters' properties will be measured with an oscilloscope, while the plasma parameters by VUV, UV and visible spectroscopies, electrical probes, and catalytic probes.

An international network of researchers is working with policymakers and the business sector to better understand how the water-energy-food Nexus fosters policy coherence in the domains of water, energy and food, supporting the transition towards a circular and low-carbon economy in Europe. Focus is on job creation, enhancing wellbeing and care for the environment. The Nexus concept is tested at different scales (i.e. local, regional, national, European), while the international dimension is explored through the involvement of international proposers. More Nexus-compliant practices are foreseen through a knowledge sharing hub at European level and beyond. Public-private initiatives pave the path for Nexus compliant practices, building on network members’ advice. NEXUSNET will deliver examples of nexus compliant decision making, and recommendations to best achieve them, to come-up with an overview of Good Nexus Practices in Europe (policy coherence, Nexus-compliant practices and more coherent nexus evaluations).

Marmorated stink bug is a harmful bug, in Slovenia since 2017. It causes damage both in agricultural production and in the urban environment. The aim of the project is to develop and test various low-risk methods for pest control on agricultural plants, e.g. inclusion of attractive crops, use of vacuum machines for physical removal, use of biotic agents. At FS, we will develop and test a suction device with side air support, mounted in front of the tractor. The fan drive will be largely independent of the tractor engine speed.

Phosphorus is a depletable resource and essential macro-nutritional element in agriculture. It is potentially recyclable and re-usable by direct application of sludge on agricultural land and as phosphorus mineral struvite extracted and recrystallized from ash after sludge incineration. Decontamination of sludge and sludge products (digestate, pyrolysate, ash, struvite), prior to their use as phosphorus fertilizers in agriculture, by extraction of toxic metals using strong chelator ethylenediamine tetraacetate (EDTA) has gained much attention due to high metal removal efficiency. In this project we are introducing a novel EDTA-based method for sludge and sludge products decontamination. The method will be developed considering sustainability concepts to reduce the unintended environmental and economic footprint: EDTA will be recycled, no wastewater will be generated, and toxic emissions to the environment will be prevented. The hydrodynamic cavitation process will be coupled to the decontamination method. Furthermore, the feasibility of this novel method to remove LAS and LAS soluble lipophilic xenobiotics simultaneously with toxic metals will be investigated. In the end, the Life cycle assessment (LCA) will be used to analyse economic, social and environmental viability of the method.

With the help of new practices, processes and technologies we will ensure the sustainable production of grapes for wine in vineyards: demonstration of various non-chemical methods of controlling weeds in the belt under vines (without the use of herbicides), use of high-tech modern spray techniques equipped with LIDAR sensors to the effectiveness of controlling diseases and pests of vines, conservation of biodiversity in the vineyard and its surroundings (enabling biodiversity in vineyards and reducing soil erosion) and beginning of the practice of measuring grape ripening in a vineyard (allowing the production of typical grapes for the production of top quality wine).

In the scope of the proposed interdisciplinary project the team of mechanical and chemical engineers will use an advanced technique - cavitation, to perform (one of) the first experiments with microplastics. Nowadays, state of the art (SOTA) is detection of microplastics in the environment but with the proposed interdisciplinary project we will move SOTA to the level, where the potential mechanisms for microplastics degradation will be investigated. Since cavitation can only appear within the liquid, it seems an ideal technology to "attack" the microplastics litter before it enters the aquatic environment (i.e. present in WWTP influents).

The overall objective of the project is to understand and determine the fundamental physics of the interaction of cavitation bubbles with different contaminants. To address this issue, the CABUM project will investigate the physical background of cavitation from physical, biological and engineering perspective on three complexity scales: i) on single bubble level, ii) on organised and iii) on random bubble clusters, producing a progressive multidisciplinary synergetic effect.