Most small systems find that disinfection using chlorine, especially when added in hypochlorite form, to be the best method of disinfection of their water supply.
The U.S. Environmental Protection Agency (EPA) allows drinking water treatment plants to use chloramine and chlorine to disinfect drinking water. Research shows that chloramine and chlorine both have benefits and drawbacks. Chlorine is a highly effective method of disinfection.
Hypochlorite. Hypochlorites are the most commonly used chlorine disinfectants. Sodium Hypochlorite is commercially available as household bleach. This EPA-registered chemical is stable and fast acting.
Some of the most commonly used disinfectants for decentralized applications include chlorine, iodine, and ultraviolet (UV) radiation. Wastewater must be adequately treated prior to disinfection in order for any disinfectant to be effective.
Chlorine is effective in oxidizing certain organic and inorganic compounds. Chlorination has flexible dosing control. Chlorine can eliminate certain noxious odors during disinfection. The chlorine residual, even at low concentrations, is toxic to aquatic life and may require dechlorination.
70% isopropyl alcohol is by far better at killing bacteria and viruses than 99% isopropyl alcohol. As a disinfectant, 70% concentration of alcohol is the most effective at killing pathogens. Any higher or lower percentage will be less effective.
* Free available chlorine is the more active form of chlorine that kills germs.
A common and relatively inexpensive method of disinfecting water is chlorination, where a solution of chlorine or hypochlorite is added to the water. The method kills disease-causing microorganisms including bacteria and certain viruses but does not kill the protozoa Cryptosporidium, Giardia, and some others.
The final disinfection is carried out in the source of infection after isolation of the patient or batsylonosiya. The goal – the complete disinfection of objects that may be contaminated with infectious agents. Preventive disinfection is ongoing, regardless of the source of infection.
Other chemical disinfectants, such as iodine and chlorine dioxide, can also be effective for disinfecting water. Using or drinking water with small amounts of chlorine, iodine, or chlorine dioxide does not cause harmful health effects and provides protection against waterborne disease outbreaks.
Hydrogen peroxide and sodium hypochlorite disinfectants are more effective against Staphylococcus aureus and Pseudomonas aeruginosa biofilms than quaternary ammonium compounds.
Glutaraldehyde is a saturated dialdehyde that has gained wide acceptance as a high-level disinfectant and chemical sterilant 107. Aqueous solutions of glutaraldehyde are acidic and generally in this state are not sporicidal.
Peracetic acid–hydrogen peroxide solutions.
Peracetic acid solutions have strong microbial effects and a broad spectrum of activity and can be used for HLD and sterilization applications.
Chlorination is a cheaper source than UV or ozone disinfection methods used to treat water. It is very effective against a wide range of pathogenic microorganisms. Dosing rates are controlled easily as they are flexible.
Water disinfection methods that can be applied in the field include use of heat, clarification, filtration, chemical disinfection, and ultraviolet radiation (UVR).
Lemon juice as a natural biocide for disinfecting drinking water.
Sterilization describes a process that destroys or eliminates all forms of microbial life and is carried out in health-care facilities by physical or chemical methods.
Autoclave, the process of sterilization by the use of heated steam under pressure to kill vegetative microorganisms and directly exposed spores. Common temperature and pressure for being effective is 121°C (250°F) at 15 psi (pounds per square inch) over pressure for 15 minutes.
Chlorine is most commonly used as disinfectant because it is powerful and remains in water for a long time.
Among all oxidizing biocides, ozone is the most effective chemical disinfectant against Cryptosporidium. Both Ozone and Chlorine are highly effective at removing bacteria and viruses; however, Ozone has much lower CT values than Chlorine. Both are very effective at controlling the growth of biofilm.
The three most common chlorine-containing substances used in water treatment are chlorine gas, sodium hypochlorite, and calcium hypochlorite. The choice of the chlorine type to be used often depends on cost, on the available storage options and on the pH conditions required.
Recommended rates for using hydrogen peroxide
The recommended concentration of hydrogen peroxide for water disinfection varies depending on the intended use and the level of contamination present. For drinking water, the EPA recommends a concentration of at 25 to 50 ppm of residual hydrogen peroxide.
Here's how to do it: Combine 1 1/2 cups rubbing alcohol with 3/4 cups water and 15 drops each of lavender and lemon essential oil in a metal or glass spray bottle.
70% denatured alcohol penetrate the cell wall more completely which permeates the entire cell, coagulates all proteins, and therefore the microorganism dies. Extra water content slows evaporation, therefore increasing surface contact time and enhancing effectiveness.