WHAT IS PH?HOW DOES THE INDICATOR AFFECT HEALTH?

1. pH Definition:
pH is an indicator of the chemical properties of water. The pH range is from 0 to 14; Theoretically, water with pH = 7 is neutral. At pH> 7, water is alkaline. The pH ladder is a logarithmic function. For example, pH = 5 is 10 times more acidic than pH = 6, 100 times higher than pH = 7. According to standard, the pH of water used for living is 6.0 – 8.5 and of water Drink is 6.5 – 8.5.

The pH of a water source is usually measured in order to:
– Evaluate the potential for metal corrosion on pipelines, water containers. 
Evaluate the risk of dissolved metals in water sources such as lead, copper, iron, cadmium, zinc … in water containers, in pipes. 
– Predict the impact on the accuracy of the use of water treatment measures. Processes and treatment equipment are  usually designed based on the assumed pH to be neutral (6 – 8). Therefore, it is often necessary to adjust the pH before treatment 

2.Effects of pH:

 – pH affects the taste of water. 
– Water sources with pH> 7 often contain carbonate and bicarbonate ions (flowing through many layers of rock). Water with pH <7 usually contains many acid-base ions. The most obvious evidence linking the pH and the health of the user is that it damages the enamel. 
– The pH of the water is related to the erosion of the equipment, the water piping and the water container. Especially, in the low pH environment, the ability of disinfection of chlorine will be stronger. However, when the pH is> 8.5, if chlorine is present in the water, it is easy to make the chlorine trihalomethane a cancerous compound. 
– The effect of pH on health In drinking water, pH affects health, especially affecting digestive enzymes. However, the acid (or corrosivity) of water can increase the metal ions from the container, indirectly adversely affecting health. 
– Causes for low pH water: Acidic water (low pH) is usually caused by geological causes, such as acid rain, etc. 
3. Signs of low pH
– Most commonly seen are moss green blobs on bronze objects, reddish brown spots on steel objects. Signs are harder to see than worn-out metal objects (signs of acid corrosion)
– pH test of well water: With sophisticated measuring instruments, laboratories will give the most accurate results. Observe laboratory instructions so that sampling is not distorted. Hand tools, quick test kits can only produce relative numbers. 
4. How to adjust when the pH is too low: 
– Use neutral filter:
If the pH is not too low, you can use filters that have calcite (from limestone) or magnesium (magnesium oxide) to increase pH. . This type of filter has the ability to filter residue so often need to back up, avoid causing obstruction. The material in the filter melts slowly and gradually decreases. So check regularly and add periodically.
– This method usually increases the amount of calcium and makes the water harder. Therefore, it is necessary to monitor the hardness for appropriate adjustment method. If the hardness is too high, it should be softened. For more durable materials, it is advisable to add extra roughness to the front. 
– pH adjustment with chemicals:
Large scale or when the pH is too low, often use a dosing pump to add soda or mixture of Soda and Hypochlorite. Adjustment of the pump will be calculated based on the fact, the balance between parameters: pump flow, pH, concentration of the chemical solution to ensure a sufficient increase of pH. When water is contaminated with iron or bacteria, adjusting the concentration of soda solution, hypochlorite will be more complicated. In some cases, potassium may be used to increase the pH, but must be carefully calculated so as not to adversely affect health.
Actually raising the pH using chemicals has many ways: Waste water using NaOH is the most effective. On small flow, the pH increase by LS is reached (pH = 5). 
– Manual method:
If you want to increase the pH may be mixed with some lime water here is the hydroxide that will cause the pH of the water to increase from 6.5 to 8.0. For pond water, continuous rainfall will cause the pH in ponds to lower than 6.5, so it is sprinkled with lime to adjust the pH, because lime is oxidized when added to water will form CaCO3 precipitate and Hydrochloric acid soluble in water Ca (OH) 2. Because the pH is too low, it will cause eye fish and other diseases, and calcium is also an electrolyte that is indispensable to humans as well as fish. 
– Use of grain to raise pH LS: + Chemical composition is basically CaCO3> 90% + Particle size: 1.5-2.5mm. 

+ Weight: 1,500 kg / m3 
+ White milky grain, dry, dry, angular. 
* Advantages:
– No need to use chemicals and accompanying equipment such as chemical tank, dosing pump. 
– Do not create too high pH. No membrane on the water surface. If soaked in water will produce a stable pH of about 7.5. 
– Simple operation. 
– Prices are much lower than imported materials. 
– Can be put into the filter tank is used without changing the filter tank structure. 
* Scope of application:
– pH of water input> 4.0. 
– Filter speed: 5-15 m / hour. Can be used in open filter tanks or pressure filter. 
– Filter direction: top down.
– LS no need to revert. After a period of use from 6 months to 1 year (depending on the quality of water source) need to add seeds. 
* Recommendation for use: 
– LS particles can be used in combination with ODM-2F, ODM-3F, quartz sand to increase pH, create water clarity and eliminate other pollutants, if any, in the source. country. When used in combination, LS beads should be placed on the top of the filter. 
– In addition, LS particles can be used individually in a device solely for the purpose of raising the pH. To increase the transparency of the water, the bottom of the filter should be lined with a layer of quartz sand. It should be noted, the use of LS will increase the hardness of water. 
– The LS particle thickness can be adjusted to the pH of the source water, ranging from 0.1-0.5 m to a pH of 6.0-4.0 and a filtration rate of less than 15 m / h.
– Rinsing filter: When used in combination with other filter materials , it is possible to clean the filter as in the case of conventional sand filter.