How do viruses get into the water?
Viruses enter water when water is contaminated with urine or feces from an infected person or animal. Improperly working sewer systems, contaminated stormwater runoff and flooding increase the risk. Well water and unsterilized water sources (such as lakes and rivers) are particularly vulnerable to contamination. Virtually all untreated water sources are at risk of viral contamination, and many developing countries have suffered viral outbreaks due to a lack of clean water. Although even municipal water sources are not without risk. In the event of a flood or natural disaster, municipal disinfection procedures can fail and leave your water system vulnerable to viruses and other dangerous pathogens.
Types of Waterborne Viruses：
Hepatitis.
There are different types of human hepatitis viruses: A, B, C, D, E and G viruses. However, hepatitis A and E are the two that are transmitted only through contaminated water. All other types of viruses are transmitted through close contact, blood and injection, except for the A and E viruses, which are transmitted through the intestinal tract. To prevent the occurrence and prevalence of hepatitis A, attention should be paid to protecting water sources, managing feces, strengthening dietary hygiene management, personal hygiene, and patient excreta, eating utensils, bed linen and clothing should be carefully disinfected.
Norovirus.
Norovirus infectious diarrhea is endemic throughout the world, and infection can occur throughout the year, infecting mainly adults and school-age children, with a high incidence during the cold season. In the United States, 60-90% of all non-bacterial diarrhea outbreaks are caused by norovirus each year. Similar results have been found in developed countries such as the Netherlands, the United Kingdom, Japan, and Australia. In Chinese children under 5 years old with diarrhea, the detection rate of norovirus is about 15%, and the serum antibody level survey shows that the infection of norovirus is also very common in Chinese population.
The "norovirus" infectious diarrhea is a self-limiting disease, there is no vaccine and special drugs, the public to improve personal hygiene, food hygiene and water hygiene is the key to prevent the disease, to develop diligent hand washing, do not drink raw water, raw and cooked food separate, avoid cross-contamination and other healthy habits.
Rotavirus.
Rotavirus is one of the main pathogens causing diarrhea in infants and young children, which mainly infects the epithelial cells of the small intestine, thus causing cell damage and causing diarrhea. Rotavirus is prevalent every year in summer, autumn and winter, the route of infection is the fecal-oral route, the clinical manifestation is acute gastroenteritis, in the form of osmotic diarrhea disease, the course of the disease is generally 6-7 days, fever lasts 1-2 days, vomiting 2-3 days, diarrhea 5 days, serious symptoms of dehydration. Washing hands, maintaining good hygiene practices and avoiding potentially contaminated food and water can help prevent the spread of rotavirus.
How do you remove the virus from the water?
Water disinfection is the use of chemical and physical methods to kill pathogens in the water to prevent the transmission of disease and maintain the health of the population. Physical disinfection methods include heating and ultraviolet irradiation; chemical disinfection methods include disinfection with the addition of metal ions (such as silver and copper), alkali or acid, surface-active chemicals, and oxidants (chlorine and its compounds, bromine, iodine, ozone). Among these methods, disinfection with oxidants is the most widely used, with chlorine and its compounds being particularly versatile, followed by ozone disinfection. UV irradiation and the addition of bromine, iodine and their compounds are used for disinfection of water in small-scale water plants or special facilities (such as swimming pools).
Introduction to physical disinfection
Ultraviolet sterilizers.
The inactivation effect of UV disinfection on microorganisms in water UV disinfection has a high microbial inactivation effect, a good inactivation effect on a wide range of microorganisms in water, and a fast sterilization speed, most of which is within 1 second. In addition, UV disinfection technology has a good inactivation effect on the pathogenic microorganisms Giardia and Cryptosporidium found in recent years.
Learn more: What is an ultraviolet sterilizers? How does it work?
Introduction to chemical disinfection methods
1. Chlorine
Chlorine eliminates viruses and other pathogens from water through a chemical reaction. When chlorine is added to water, a weak acid called hypochlorite is formed, which penetrates the cell walls of viruses and bacteria, destroying them from the inside out. Chlorine is a popular choice in water treatment centers around the world because it keeps overtime water clean. However, it can leave a lingering chemical odor in tap water. If you experience this problem, an activated carbon filter is recommended to greatly improve the taste and odor of your water.
Learn more: Activated Carbon Filter
2. Ozone Generator
Ozonated water treatment removes viruses and other harmful contaminants from water through oxidation. Ozone (O3) is an oxygen compound that is one of the most powerful oxidizers in nature. In ozonated water treatment, ozone is first produced in an ozone generator. It is then injected into the water, where it oxidizes organic material on the membranes of viruses, bacteria and parasites. This weakens, breaks down and kills their cells. Ozonated water treatment not only eliminates viruses and other dangerous pathogens, but it is extremely fast and can purify water in seconds.
Learn more: What is an ozone generator and how does it work?
Does boiling water kill viruses?
Yes. Killing by boiling is the most common yet convenient and effective method. High temperatures denature and inactivate proteins and enzymes within the cells of microorganisms, thus acting as a sterilizer. Boiling directly into water for 15 minutes or more will kill the nutrients and a few of the spores or spores of bacteria or other microorganisms. It is important to note that boiling only kills the nutrients and a small percentage of the spores or spores of the bacteria or other microorganisms. Bacilli are very resistant to heat, ultraviolet light, drying, ionizing radiation and many toxic chemicals. Bacilli can survive for several hours at 120-140°C. Pressurized steam sterilization is commonly used in laboratories, and microorganisms (including bacilli) will be killed in 15-20 minutes at 121°C, while sterilization is achieved.
The bacterium has high resistance to temperature, which is a product of bacterial adaptation to the environment, enabling bacteria to resist some extreme environments, but microorganisms such as bacteria and viruses are composed of proteins, nucleic acids, lipids, etc. These substances themselves have limited tolerance to temperature, and high temperature destroys their structure, and many functions cannot be achieved.
Is COVID-19 transmitted through water?
Unlike general bacteria, viruses are microorganisms that do not have the ability to metabolize and replicate themselves in vitro. It has high environmental requirements in vitro, and generally survives longer in the presence of water. So, how long does this virus survive in water? There is no scientific research data on this, but there is research data on SARS virus, which has a high homology with the new coronavirus. 2003, the Institute of Microbial Epidemiology, Beijing Military Academy of Sciences, researched that SARS virus has a strong survival ability in tap water, which can exceed 48 hours. Then, the new coronavirus may have similar characteristics.
And the discovery a few days ago that there is a possibility of fecal-oral transmission of the new coronavirus basically confirms this conjecture. In retrospect, several major epidemic events in history were related to the lack of separation of sewerage and drinking water and drinking water contamination at the time. on February 1, the ecological environment did not issue a document on urban sewage regulation to strengthen disinfection and sterilization to prevent the spread of the new coronavirus through feces and sewage. Therefore, everyone needs to practice good personal hygiene, avoid going to crowded places, minimize the chances of being in close proximity with strangers, and pay high attention to drinking water safety.
