The Project

Project title: SANIFI-COV: Sanitation of air and surfaces from the SARS-CoV-2 virus with low environmental impact methods.

Acronym: SANIFI-COV

Duration: 6 months

Emilia Romagna Region contribution: € 101,600

University of Bologna contribution: € 18,400

Scientific Responsible: Prof. Andrea Contin

 

Project objectives:

The sanitization of work surfaces is an indispensable element to allow the safe recovery of production activities and services after the lockdowns linked to the SARS-CoV-2 virus pandemic. The current methods of decontamination and sanitization that involve the use of disinfectants produce pollution causing, for example, damage to water purification systems. The goal of the SANIFI-COV project is to develop a system for heating, combined with the emission of ozone and subsequent air purification with an activated carbon filter and a UV-photocatalytic module. The solution applies to all workplaces where it is possible to maintain a temperature of about 50° C for a time that can be evaluated in less than two hours and emit ozone into the air when the premises are not occupied. The project will experimentally verify the system's ability to destroy the virus through molecular analyses. The verification will take place on different surfaces, optimizing the quantities of heat and ozone released into the premises, also for the purpose of reducing energy expenditure. The expected results from the SANIFI-COV project are the construction schemes of the sanitation system and the related application protocols.

The project proposes the development of a sanitation procedure for close spaces by combining existing technologies, adapting them for the purposes of air treatment and work surfaces for the destruction of the SARS-CoV-2 virus (also called COVID-19). The solution proposed by the SANIFI-COV project is divided into two operating modes:

  • space heating and release of ozone for the treatment of air and surfaces when the premises are not used and / or manned;
  • air treatment through continuous filtration during working hours in the presence of people.

The proposed solution applies to all closed unattended environments 24 hours a day, where it is possible to maintain a temperature of about 50 ° C for one or two hours and emit ozone into the air. Premises used for commercial activities, those intended for school and hospital buildings, industrial environments, auxiliary premises, offices and collective transport vehicles are potentially suitable. The proposed solution has a low environmental impact as it does not produce waste, does not use chemicals that are potentially dangerous for people and the environment and neutralizes residual ozone.
The technological solutions developed by the project and the application methodologies proposed, innovative with respect to current procedures (Istituto Superiore di Sanità, ISS COVID-19 Report no. 5/2020, "Interim indications for the prevention and management of indoor environments in relation to transmission of SARS-CoV-2 virus infection "), are able to reduce the risk of contamination and ensure the safety of people in the workplace.
Although there are effective methods of decontamination of surfaces that involve the use of disinfectants, it is necessary that all surfaces are reached by these substances and this is not easily achievable and / or requires the use of dedicated personnel. Furthermore, in some work environments there are instruments or electrical and electronic components that can be ruined or damaged by humidity, sodium hypochlorite, hydrogen peroxide or disinfectants, and in the case of specific production activities (for example food production companies) the use of chemicals could generate contamination problems in finished products. In addition, sodium hypochlorite is highly irritating to the mucous membranes and therefore the rooms need ventilation after sanitization. Finally, residues that end up in the sewage manifolds can cause malfunctions and overloads in biological wastewater treatment plants.
It is therefore necessary to develop alternative methods that can be applied in the absence of people in the rooms, but which allow the use of the rooms themselves in a short time after sanitization, avoiding pollution with harmful residual substances.
The innovative principles underlying SANIFI-COV are:
1. the demonstrated ability to destroy the virus when exposed to a temperature of 56 ° C for 30-90 minutes;
2. the synergistic combination of heat and ozone for sanitation.

In addition to these basic principles SANIFI-COV intends to demonstrate the sanitation of work environments through:
3. the use of a photocatalytic UV module integrated with an activated carbon filter for the removal of viruses and potential vectors such as particulates and droplets;
4. the removal of residual ozone through filters with activated carbon.

Point 1 refers to the studies on the SARS virus in 2003 (Duan et al. Stability of SARS Coronavirus in Human Specimens and Environment and Its Sensitivity to Heating and UV Irradiation (2003), Biomedical and Environmental Sciences 16, 246-255 ) and recent studies on SARS-CoV-2 (Yang, P., Wang, X. COVID-19: a new challenge for human beings. Cell Mol Immunol (2020), doi: 10.1038 / s41423-020-0407-x ), which confirm that the most commonly used method in the laboratory to inactivate SARS-CoV-2 is the exposure of the surfaces on which the virus is present to a temperature of 56 ° C for a time between 30 and 90 minutes.
The heat generation system consists of one or more electric unit heaters, depending on the electrical power required on the basis of the volumes involved. The use of a filtering unit using activated carbon, associated with the air heater, allows the removal of the particulate on which the virus can adhere. The filter unit can also be used during working hours and is disinfected during the room heating phase. In any case it can be easily replaced, disposed of and / or regenerated.
In addition to the use of heat, SANIFI-COV intends to use gaseous ozone to reduce the viral and bacterial load as the gas diffuses reaching every point of the environment. 

As for heat, it is a sanitation technology to be used in the absence of people in the treated environment, due to ozone concentrations not compatible with the exposure of workers / users of the facility. Ozone is introduced into the rooms before the heating phase and then removed, using the activated carbon filter. The use of ozone has the purpose of limiting, on the one hand, the need to raise the air temperature in the treated rooms, while limiting the use of ozone compared to systems based solely on the latter.
With the aim of testing a further improvement in sanitization performance, a photocatalytic UV module will also be integrated into the system to verify the inactivation of the virus (Han W, et al (2004) Biochem Biophys 31 (11): 982– 985) and the destruction of particulates / aerosols. In fact, in the workplace, any viral contamination could persist in suspended particulate matter and droplets (Setti L, et al. 2020 Position Paper - Report on the effect of airborne particulate pollution and the spread of viruses in the population).
The project therefore aims to create a synergy between heat, ozone, activated carbon and UV-photocatalysis integrated in a system that has affordable costs and can be proposed as a solution that can be purchased or rented by the end user or that can be proposed by companies specialized in operations of disinfection. The synergy between these systems is to be understood both as a cumulative sanitizing effect against the virus, and as interoperability of the systems that can allow different operating modes. In fact, UV-photocatalysis and activated carbon systems can operate even when people are present in the workplace and capture and / or inactivate particulate matter and droplets, while the disinfection of surfaces by ozone and heat can take place through automated procedures in the absence. of people exposed.
The effectiveness of the sanitation strategies used will be tested using molecular analyzes for the detection of viruses / test strains with swabs carried out on the surfaces before and after treatment or from environmental air samples. In particular, the following will be used:

  1. High-yield massive sequencing (Next Generation Sequencing, NGS), which allows sequencing of the entire population of nucleic acids present in the tested sample, generating a global photograph of the microorganisms present. Molecular protocols and probes are already available and extensively tested (Rampelli et al., Retrospective Search for SARS-CoV-2 in Human Faecal Metagenomes (March 19, 2020).
  2. Quantitative real time PCR, which is the current method of analysis for health surveillance and is considered the most reliable method for detecting even very low concentrations of viral RNA because it allows specific detection by means of amplification and quantification of the presence of marker genes that characterize the genome of the virus. For example, for SARS-CoV-2 four genes characterize the genome: 3 genes encoding 3 nucleocapsid proteins (N1-3) and one gene encoding an envelope protein (E). The methodology and protocols used are those indicated by WHO (WHO, 2019. https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical- guidance / laboratory-guidance) and already used for analysis of environmental samples (Medema G, et al. Presence of SARS-Coronavirus-2 in sewage. medRxiv 2020.03.29.20045880).

The expected results from the SANIFI-COV project are the constructive schemes of the sanitation system and the application protocols in terms of: a) quantity of ozone to be used; b) times for reaching the temperature in the rooms to be sanitized; c) duration of the heating time in the absence of active personnel on the premises; d) filtering capacity necessary for the elimination of ozone; e) filtering capacity required with the presence of active personnel on the premises.
The inactivation / destruction performed by heat combined with the targeted use of ozone is potentially a technique that involves very low operational risks, very low purchase and operating costs and intervention times limited to a few hours.
The project provides for an activity for the transfer of results by adapting existing products and technologies for a quick introduction into commercial channels. It is possible to assume that this type of sanitization is performed, as a fixed installation, or, alternatively, at optimal time intervals by specialized companies as is currently the case in mills and pasta factories that require the intervention of external companies.

Contact

Andrea Contin

Professor
Physics and Astronomy Dept.

Via Sant'Alberto 163, I-48123 Ravenna, Italy

+39 0544937333

+39 0544937401

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