The combination of hypochlorous acid and hypochlorite ions makes up what is called 'free chorine. ' Free chlorine has a high oxidation potential and is a more effective disinfectant than other forms of chlorine, such as chloramines.
Chlorine Dioxide is generally considered more effective at disinfecting water than Sodium Hypochlorite, producing fewer byproducts. The specialised ClO2 dosing equipment's initial cost may be higher than Sodium Hypochlorite's, but long-term operational costs are significantly lower.
Detailed Solution. concept: HOCl (Hypochlorous Acid): Hypochlorous acid is the most effective disinfecting form of chlorine because it is a neutral molecule that easily penetrates the cell walls of microorganisms, including bacteria, viruses, and protozoa.
It is most often added as a gas, Cl2(g). However, it also can be added as a salt, such as sodium hypochlorite (NaOCl) or bleach. Chlorine gas dissolves in water following Henry's Law. Hypochlorous acid is a weak acid that dissociates to form hypochlorite ion (OCl-).
Liquid Chlorine (Sodium Hypochlorite):
It's typically delivered to the pool in large containers and is diluted before being added. Liquid chlorine is relatively easy to handle and is effective at killing bacteria and algae.
Trichlor is the most popular choice of chlorine for regular use in home pools. It does, however, have a higher (and potentially more effective) chlorine saturation and can alter the pH of the pool slightly. However, dichlor has a neutral pH level. This means it won't affect the natural pH of the pool.
While both granular and liquid chlorine has their pros and cons, granular chlorine is more common in home pools. It's cheaper, easy to use, easy to store, and lasts a long time. More premium pools often go for liquid chlorine because of its long-lasting effect on the pool. However, there's no watertight categorisation.
Together, the hypochlorous acid and the hypochlorite ions are referred to as free chlorine. Hypchlorous acid is the more effective disinfectant, and therefore, a lower pH is preferred for disinfection.
Pools are sanitized using a variety of chlorine-based compounds including chlorine gas, sodium hypochlorite (liquid bleach), calcium hypochlorite, lithium hypochlorite and chlorinated isocyanurates.
How does chlorine disinfection work? Chlorine kills pathogens such as bacteria and viruses by breaking the chemical bonds in their molecules. Disinfectants that are used for this purpose consist of chlorine compounds which can exchange atoms with other compounds, such as enzymes in bacteria and other cells.
Hypochlorous acid is the most effective form of free chlorine residual for disinfection. Depending on pH, hypochlorous acid may break down further into a hydrogen ion and a hypochlorite ion.
Hypochlorus Acid (HOCl) is the active killing form of chlorine in water. acid and hypochlorite ion are in equilibrium with each other, which means a hydrogen ion attaches to make HOCl and detaches to make OCl- many times a second.
Hence, Trichloramine forms of chlorine has no disinfectant property.
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.
“Though bleach can be highly corrosive to surfaces, it is effective against C. diff and our goal is to help save people's lives.” As an alternative to bleach, some facilities are experiencing success in the fight against C. diff by using accelerated hydrogen peroxide (AHP) products.
Recommended Use: Trichlor is often favored for outdoor pools, especially those without a stabilizer present in the water, as it helps maintain a stable chlorine residual under sunlight exposure. Dichlor is suitable for both indoor and outdoor pools and is often used for routine pool maintenance or as a shock treatment.
Chlorine Tablets for your Pool
The time required to safely sanitize the pool with tablets alone is far greater than that of liquid chlorine. What you pay for convenience in the tablet, you ultimately sacrifice in timing should you let the pool water fall too far below recommended pH level.
Bleach is weaker, meaning you would have to add more in order to get the same results. It can also cause other problems for your pool water and system. Household bleach may work in a pinch but it should not be used as the primary means of keeping your pool safe and in balance.
Free Chlorine:
- Free chlorine refers to the chlorine that exists in the water in its most active form, available for disinfection. - It includes both hypochlorous acid (HOCl) and hypochlorite ions (OCl-) and is capable of killing microorganisms.
If your total chlorine level is higher than the free chlorine level, the difference of the two are the combined chlorine levels. To make sure your pool is sanitized, your free chlorine should remain higher than your combined chlorine.
Hydrogen peroxide, which is used in non-chlorine bleaches, does have disinfectant and sterilization effects. However, depending on the product you're using, it may not be present in high enough concentrations to effectively kill viruses and bacteria.
Is it possible to shock your pool too much? Yes—excessive shocking of your pool will keep it at an elevated chlorine level. This will cause irritation of the skin and eyes as well as excessive wear and tear on your pool filter system, including excessive corrosion of all metal parts.
Trichlor
This chemical is known for doing a great job at keeping algae out of the pool and is the most powerful of the pool shock options. Because of their strength, Trichlor tablets are a more expensive option than liquid chlorine or Cal-Hypo, but the results delivered are well worth the expense.
Biofilm or organic material in the water, such as sunscreen, leaves, or algae. Pool covers trapping chlorine and causing it to dissipate more rapidly. In some cases, your chlorine levels might be too high, and this can cause your test kit reagents to bleach out, making it look like there's no chlorine in your pool.