2 steps to clean up floodwater.

Do not carry out disinfection simultaneously with alum treatment because alum neutralizes the disinfecting effect of chlorine. (In the photo: Health officials instruct residents on cleaning drinking water after floods and storms - Illustration: Ha Tinh Department of Health)

The Department of Preventive Medicine (Ministry of Health) provides guidance on ensuring safe drinking water after floods, safeguarding health, and preventing outbreaks of disease by using a two-step water purification method.

Step 1: Clean the water

There are many ways to make it domestically, the simplest being using alum or filtering through a clean cloth.

- Clarifying with alum: Use alum at a dosage of 1g of alum for every 20 liters of water.

Scoop a ladleful of water, dissolve an equal amount of alum in the water until completely dissolved, pour it into the container holding the water and stir well. Wait about 30 minutes for the sediment to settle to the bottom, then pour off the clear water.

- If alum is unavailable, you can use a clean cloth to filter the water, retaining the impurities. Repeat this process several times until the water is clear (note that the filter cloth should be made of cotton to allow water to pass through, and the cloth should be replaced when there is a lot of sediment on it).

Step 2: Disinfect the water

After the water has been clarified, it needs to be disinfected, which can be done using chemicals or by boiling the water.

Water disinfection using chemicals: For households, water is usually disinfected using Chloramine B.

Currently, the most popular options are Chloramine B 0.25g tablets or Aquatabs 67mg tablets, which are very convenient for disinfecting small volumes of water such as jars, pots, buckets, basins, or small water tanks.

For Chloramine B 0.25g tablets: Add 1 Chloramine B 0.25g tablet to a container of 25 liters of clarified water, stir well, cover, and wait 30 minutes before using the water for household purposes.

For Aquatabs 67mg tablets: add 1 Aquatabs 67mg tablet to a container of 20 liters of clarified water, stir well, cover and wait 30 minutes before use.

Note that disinfected water can be used for household purposes. However, it must still be boiled before drinking directly. Disinfection should not be carried out simultaneously with alum treatment, as alum neutralizes the disinfecting effect of chlorine.

After disinfection, you should smell chlorine to indicate that the disinfection is effective. If you accidentally add too much chlorine, open the lid and wait another half hour or an hour for the strong smell to dissipate.

The Department of Preventive Medicine also recommends using only boiled water for direct consumption. Boiled water should not be left for too long; it is advisable to boil fresh water daily for drinking.

In addition to the water treatment methods mentioned above, households can also use water filters to treat their water. The effectiveness of the water filter depends on the quality of the incoming water, the filtration technology, the condition and quality of the filter, and the usage time.

Please note that the input water for water filtration devices must be purified water; do not use surface water directly from rivers, streams, or canals to avoid clogging the filtration equipment.

Source: https://tuoitre.vn/2-buoc-lam-sach-nuoc-sau-lu-20240916221526966.htm