Introduction: How to Purify Muddy Water
One of the major problems we face during camping trips is finding clean water suitable for drinking and cooking. Even though you select a camping site near a water source, one can not be sure that the water is fit for consumption. Further, what can one do in the event of an unpredictable rain, muddying the entire water source...?
Do not worry. This Instructable will take you through the steps involved in cleaning and purifying the muddiest of muddy water and make it suitable for drinking and cooking.
Step 1: Chemicals Required
Aluminium Sulfate, Shortly known as Alum, when added to raw water reacts with the bicarbonate alkalinities present in water and forms a gelatinous precipitate. This floc attracts other fine particles and suspended material in raw water, and settles down at the bottom of the container. The water over this sediment is almost clean other than some fine particles dissolved in it.
Alum is in a crystallized form which you can powder and store in a clean glass container.
Bleaching Powder Solution
Bleaching powder or chlorinated lime is used to disinfect the water from bacteria. The chlorine present in the bleaching powder solution kills almost 90% of the bacteria present in water.
Bleaching powder also known as Calcium hypochlorite is in a powdered form. Add one or two teaspoons of the powder in a glass bottle, add water and mix well. Use a metal cap for the container as it may corrode plastic cap.
Both Alum and Bleaching powder are commonly available in most of the grocery stores.
Step 2: Water Sample
Look at the water collected from the source after heavy rains. It is muddy and also contains lots of floating material. Now let us see how we can convert this dirty water in to clean drinkable water.
Step 3: Treatment of Muddy Water With Alum
- Here, I have collected the muddy water in a bucket, poured more water to overflow and brushed away most of the floating material with hand.
- Using a fine cloth, filtered the muddy water into another vessel. The filtered water contains no floating material and less silt.
- Took about five liters of water in a plastic bucket and added half a teaspoon of powdered Alum (that is about 50 mg which works out to 10 mg per liter of water) and stirred well.
- This bucket of water needs to be kept still for about 6 to 7 hours so that the sediments get coagulated and settles down at the bottom.
Step 4: Draining Clean Water
Drain out Clean Water
After about seven hours, most of the dissolved particles have settled down at the bottom of the bucket. Drained out the clean water into another vessel very slowly without disturbing the sediment.
About half a liter of water is left out in the bucket with the sediments.
The water collected thus may still contain some fine dissolved particles, which can be removed by filtration. If you carry a small water filter during camping, you can fill this water after disinfection (next step) to get more pure water.
Step 5: Disinfection
The clean water we got by sedimentation still contains lots of bacteria, so it needs to be disinfected before being used. Here, I have used home bleach solution, which contains Chlorine.
The prescribed normal rate is about 2 drops of bleach solution per liter of water. So, I have added about nine drops into the water in the vessel and stirred well. This water may smell little bit of chlorine. Either keeping it open to air and intermittent stirring for about 30 minutes or using a portable filter to further purify the water will remove the chlorine smell.
The chlorination process kills almost 90% percent of the bacteria present in the water. Now I got about four and half a liters of clean water which I can use for cooking and drinking during my camping trip.
Step 6: Experiment in Plastic Bottles
I have carried out the cleaning process in a two liter water bottle. Here I have increased the Alum content to about 15 mg per liter of water. the outcome seems to be better than with 10 mg per liter of water.
Step 7: Foot Note
- The prescribed dosage of Alum varies from 5 mg per liter for a relatively clear water to 85 mg for a highly turbid waters like industrial waste. However, the normal dosage for drinking water is about 17 mg per liter.
- The dosage of bleaching solution as 2 drops per liter is suggested considering 60 to 70 percent of chlorine available in the bleaching powder. you can increase or decrease the amount by smelling the chlorinated water. More chlorine smell, add some clean water. Add a few more drops in case of no smell.
- Keeping buckets of water mixed with Alum overnight will give you enough clean water in the morning for use.
- Over-dosage of Alum may cause temporary dizziness, diarrhea and vomiting (but not dangerous). So, take care while adding alum.
- Bleaching solution is corrosive. Take care not to get your skin or cloth in contact with the solution.
So, Campers, do not forget to add a little bit of Alum and Bleaching solution to your camping kit next time. It may come in handy when you are in the middle of nowhere with only mud to drink
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Please be positive and constructive.
Hi, I am a student and I have conducted this activity. The steps are fairly simple, I appreciate that. Just that at the end, is it that easy to obtain clear water which has a turbidity that low! I tried to compare the coagulation process between Aluminium sulphate( Alum ) and ferric sulphate. In both the situations, the water has not appeared that clear. This may be due to the dosage of chemical. But how did you calculate the amount (concentration) of chemicals used to achieve the clearness of the water. Is there a formula? Or trial and error method?
Alums purify muddy water by...?
Coagulation... Please see the wiki article here (under the heading "Mechanism")