Water notes
Pollution in the Apatlaco River and how to purify its water
By Leonardo Ortiz Vázquez, Claudia Constanza Garduño Rojas, Valeria Elizabeth Castellot Serna, Valeria Recio Aldrete and Andre Schleske Pérez Castro
Matter and the environment
Introduction and theoretical framework

“Purified water should be a resource that everyone has access to” (Secretary General, 2010). Sadly, the community that lives near the Apatlaco River (Mexico), gets water with possible particles of trash, water residuals, and chemicals. Achieving purification would make a healthier lifestyle for all the community, and will help to reduce the pollution in rural places, conserve a clean natural resource, and avoid diseases on all water bodies from these rivers.
According to the WHO (World Health Organization), “The ferric sulfate acts as a coagulant and aggregates suspended particulates and larger microbes. The resulting floccules then settle to the bottom of the water container. The calcium hypochlorite acts as a disinfectant” (WHO, 2014).
To get the clean water, the aggregate particles and floccules are filtered with a simple cloth due to the particles size. The Apatlaco River is one of the most polluted rivers in Mexico. This pollution is primarily attributed to the significant discharge of sewage water from industries, chemical contaminants, and various other substances being dumped into it.
Population growth has exacerbated the problem as it leads to increased wastewater production, and the mismanagement of these pollutants further complicates finding a solution. However we did find a solution in which our objective is to clean water from the river by using purification pockets so that the river can be saved and the water can still be used. We could be able to achieve this by cleaning small amounts of water at first to confirm the effectiveness of our experiment.
Research question
What’s the impact and efficiency of a powder made to clean water on the color, sanity and quality of dirty and contaminated water?
Hypothesis
Water should be cleaned with a powder made of calcium hypochlorite and ferric sulfate, and a filtration process. According to this, no matter where the water is taken from it can be turned into purified water, and avoid diseases.
FIRST PART
Variables identification
- Independent variable:
- The amount of powder used on each sample
- Dependent variable:
- pH of water.
- Color of the water
- Controlled variables:
- Amount of water used.
Experimental procedure
Materials:
- 3 samples of water:
– Natural water from water container (bottle) (2 l)
– Water from Apatlaco River (2 l)
– Natural water from carboy with 45 g of dirty and trash (2 l)
- 6 containers of 3 l (to put the water)
- 3 purification packets P&G
- 3 spatulas to stir the water with the powder
- 3 cloths (to filter the water from dirty water)
- 3 pH paper strips
- Timer
- Sheet of paper
- Pencil
- Labels
Procedure
- Put the three different samples of water on their containers, and label them with the location where the water was taken.
- Measure the pH of the water with the paper strips.
- Record results of level of pH on a sheet of paper.
- Put the purification powder to the samples at the same time.
- Stir strongly each sample for 5 minutes.
- Let it settle for 5 minutes and see which one settles first.
- Start filtering the water with the clothes and put the “clean water” on the clean containers.
- Measure the pH of each sample after the purification process.
- Record the results again and compare them with the first results.
- Check the pH of the water, and record the process of settlement of each location.
Note: Purified water pH should be of 7, to indicate that they are not contaminated particles on it.
SECOND PART
Collecting and processing data
Analysis and interpretation
The most important trend seen in this experiment is the pH of the water. In both of the experiments, the pH of the water was always lower before mixing the solution in water than it was after doing the process. We didn’t find atypical data during the experiment. The connection between the variables was depending on the amount of the solution that we placed on the water were the residuals that were seen at the bottom of the water jugs. This was because what the solution did was mixing with the polluted water and going at the bottom for having a part that is clean. The color of the water clearly changed due to pollution it had before purifying the powder into the water. By putting the powder into the water, we get to observe a type of color in a mixture of brown and yellow. All the contaminated particles went to the bottom and after sieving it got completely transparent. After doing these experiments it is clear that the pH of water does not change drastically, however the trash and contaminated particles will disappear from the water.
Conclusion
Water purification powders, often containing chemical compounds such as chlorine or iodine, are typically used to disinfect and clarify water from various sources. While this powder may be effective at disinfecting, they may not address all quality issues, and comprehensive approach to water treatment.
All the variables have something to do with water and its data, which are the amount of powder used on each sample, pH of water, color of water and the amount of water used.
The hypothesis was accepted because during the experimentation it was proved that dirty water can be purified with a powder made of calcium hypochlorite and ferric sulfate and a filtration process. Water from a dirty pond was taken, then the powder was added and after 2 minutes the mixture was filtered and clean water was the final result with a different pH. The pH was also measured before and after the experiment, there was a visible difference between the pH of water from the pond before being purified and the pH after the water was purified.
In order to make a comparison, the powder was also added to bottled water and the same process was carried out. Even though bottled water is clean enough to be drunk, after being purified it also ended up with a different pH. This experimentation can be taken in people’s daily life because it is a simple experiment that can be made with very few materials and it takes less than 5 minutes to complete it. We also proved to be effective, so if the experiment is carried out and dirty water is purified the result will be clean water.
Evaluation

Our experiment worked, as we planned, however we still could do some things better to have more precise results. Some possible mistakes could have been avoided, by using a coffee filter since the beginning. Straining the water of the pond with the wrong materials, could have given us a wrong result of the pH level. Another part where we could do it better, could be the quantity of water that is used, since each package of purifier uses 10 liters of water. We used only 2 liters and poured half of the package approximately. If we had poured exactly the quantity for 2 liters of water, it would also be a way to have a lower possibility of getting a fake result. Measuring and using the correct materials for each step is clearly the tool to get exact and correct results.
References
Breton-Deval L, Sanchez-Reyes A, Sanchez-Flores A, Juárez K, Salinas-Peralta I, Mussali-Galante P. (2004). Water reuse in the Apatlaco River Basin (México): A feasibility study. National Library of Medicine. Recovered from https://pubmed.ncbi.nlm.nih.gov/
Nunez, C. (2021, May 3). Water pollution is a rising global crisis. Here’s what you need to know. Environment. Recovered from https://www.nationalgeographic.com
Secretary General. (2010, September 22). “Everyone Should Have Access to Water and Sanitation Services That We in This Room Take for Granted”, says Secretary-General on Persistent, Pressing Challenge. United Nations: Meetings Coverage and Press Releases. Recovered from https://press.un.org
WHO, World Health Organization. (2014, March, 12). WHO International Scheme to Evaluate Household Water Treatment Technologies. Recovered from https://cdn.who.int/