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--- health:water-filtration [2018/06/27 07:50]
marcos [method]
+++ health:water-filtration [2021/11/16 04:03] (current)
marcos
@@ Line 1: / Line 1: @@
-==== method ====
+~~META:
+title = DIY Water Filtration
+~~
+====== Water Filtration ======
+===== motive =====
+https://www.ncbi.nlm.nih.gov/pubmed/30326398\\
+https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4050989\\
+https://www.ncbi.nlm.nih.gov/pubmed/26313703\\
+https://www.ncbi.nlm.nih.gov/pubmed/20183522
+===== method =====
 To filter tap water, you can buy tea bags and fill them with a mix of the following:\\
@@ Line 28: / Line 42: @@
 HOCl + NH2Cl « NHCl2 + H2O\\
 HOCl + NHCl2 « NCl3 + H2O\\
-Since these reactions are in equilibrium, it is possible that free chlorine will be present under certain conditions of pH, temperature and the ratio of chlorine to nitrogen. Free chlorine will degrade an ion exchange resin. This occurs primarily via decrosslinking in a cation resin and defunctionalization in an anion resin. In addition to the free chlorine that is formed when the equilibrium is shifted on these equations, the chloramines, while less oxidative than chlorine, will oxidize the anion resin functional group. Chloramines and free chlorine should be removed prior to ion exchange resin beds. Degradation products of these reactions include ammonia, hydrochloric acid, nitrogen, and in the case of anion resin oxidation - trimethylamine. The ionic species will likely be removed from the water by the downstream ion exchange resin and seldom have an impact on product water quality." [[https://dowac.custhelp.com/app/answers/detail/a_id/466/~/dow-ion-exchange-resins---chloramine | Source]]
+Since these reactions are in equilibrium, it is possible that free chlorine will be present under certain conditions of pH, temperature and the ratio of chlorine to nitrogen. Free chlorine will degrade an ion exchange resin. This occurs primarily via decrosslinking in a cation resin and defunctionalization in an anion resin. In addition to the free chlorine that is formed when the equilibrium is shifted on these equations, the chloramines, while less oxidative than chlorine, will oxidize the anion resin functional group. Chloramines and free chlorine should be removed prior to ion exchange resin beds. Degradation products of these reactions include ammonia, hydrochloric acid, nitrogen, and in the case of anion resin oxidation - trimethylamine. The ionic species will likely be removed from the water by the downstream ion exchange resin and seldom have an impact on product water quality."  [[https://water.custhelp.com/app/answers/detail/a_id/466/~/dow-ion-exchange-resins---chloramine |Source]]
 "If water is held in the carbon block for longer period, microorganisms can grow inside which results in fouling and contamination. Silver nanoparticles are excellent anti-bacterial material and they can decompose toxic halo-organic compounds such as pesticides into non-toxic organic products." [[http://link.springer.com/article/10.1007/s11051-005-7523-5|Source]]
@@ Line 73: / Line 87: @@
 " Dissolved organic solids, such as sugar, and microscopic solid particles, such as [[https://en.wikipedia.org/wiki/Colloid | colloids]], do not significantly affect the conductivity of a solution, and are not taken into account. "
-So let me conclude, by telling you one of the other reasons I'm using activated carbon: [[https://www.omicsonline.org/open-access/bpa-free-waters-essential-to-perform-laboratory-studies-2157-7064-1000295.php?aid=61493 | it helps remove plastics]].  Yet when I put a tea bag of carbon in my [[https://en.wikipedia.org/wiki/CamelBak | camelback]], the water still tastes like plastic.  I need to try and see if the [[https://www.homebrewtalk.com/forum/threads/beer-line-tests-solution-to-the-plastic-taste.60380/ | tube]] or bladder causes the most effects.  In any case, it appears that the plastic overwhelms the tea bag.  They have inline carbon filters for the hose line, that may help, but I'm going to accept some plastic on my hikes for now.
+Again, one of the other reasons I'm using activated carbon is to [[https://www.omicsonline.org/open-access/bpa-free-waters-essential-to-perform-laboratory-studies-2157-7064-1000295.php?aid=61493 |help remove plastics]].  Yet when I put a tea bag of carbon in my [[https://en.wikipedia.org/wiki/CamelBak | camelback]], the water still tastes like plastic.  I need to try and see if the [[https://www.homebrewtalk.com/forum/threads/beer-line-tests-solution-to-the-plastic-taste.60380/ | tube]] or bladder causes the most effects.  In any case, it appears that the plastic overwhelms the tea bag.  They have inline carbon filters for the hose line, that may help, but I'm going to accept some plastic on my hikes for now.  The carbon does keep the plastic taste from forming in my cycling water bottle, however.
+Update: I spent a week in Somersworth, NH, and the tap water quality is horrible, in terms of a TDS reading of 150ppm, compared with nyc 40ppm.  A single tea bag filter (working with the pump) was only good for purifying 6 liters of water to 1ppm.  After that, the next 6 liters went no lower than 82ppm.  I continued filtration with an unused filter.
+Update: If you want to remove flouride, a TDS meter will not be that helpful, because flouride is added to water at 1ppm.  The TDS meter does not have enough resolution to estimate the percentage of flouride that is removed by your filter.
 \\
 \\
+===== consumer products =====
+==== zero water filter ====
+" The problem with the Zero unit, you see, is that pure water seeks to become contaminated. It will hungrily absorb CO2 from the atmosphere, forming carbonic acid, as well as any contaminants in the air. More dangerous is the fact that the Zero Water Filter removes 100% of the chlorine form the water. If your municipality did that, your community would suffer another yellow fever, legionella or other bacterial/viral disease outbreak.
-==== demineralization controversy ====
+Bacteria will grow in water that has no chlorine in it. If you use the Zero Water Filter remember that the filtered water is chlorine free. Also remember, ion-exchange resin is also a great medium for growing bacteria. The TDS meter on this device measures electrical resistivity or conductivity. It has no capacity to measure algae, fungi and microorganisms in your water.
+The purification technology in this unit itself is sound, but the product has no technology to keep the water pure once it is made so. In water treatment science it is more expensive to keep water pure than it is to make it pure. I am willing to bet that if you do not sterilize your pitcher daily, you have bacteria growing in the system. " [[http://wateristhenewgold.com/zero-water-filters-danger-will-robinson |source]]
+==== bacterial load ====
+In order to reduce the bacterial load on a filter cartridge, it's best to have a large family that will use up its filtering capacity quickly (so that the water filter gets replaced frequently).
+Comparing the "zero water filter" with the "ion-exchange + carbon tea bag" (see section "method" above):\\
+Since you will more often discard a tea bag than a larger filter cartridge, maintaining sanitation of the filter media is easier with tea bags.  A glass jar is also easier to maintain sanitary, compared to a plastic carafe.  The only weakness in filtering with a tea bag is the need for a small water pump.
+\\
+\\
+===== maintaining water purity after filtration =====
+Pure water will strongly attract any impurity, including contaminants in the air.  In order to keep purified water pure, after being transferred out of the filter, you should continue to keep it in a glass container with a sealed lid.  Another option is to dirty the water so it is no longer pure!  Add some lemon juice, tea, cinnamon sticks or cloves.
+==== boiling pure water ====
+It's not advisable to boil pure water, because it will become contaminated quickly.  If you must, you can use a stainless steel tea kettle to boil the water, as stainless steel is [[https://www.quora.com/How-do-metals-react-with-distilled-water |highly unreactive]].
+\\
+\\
+===== demineralization controversy =====
 Demineralized water has been claimed to have negative health effects because of a reduction in beneficial minerals.
@@ Line 121: / Line 167: @@
 \\
-==== fluoride controversy ====
+===== fluoride controversy =====
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3491930\\
@@ Line 239: / Line 285: @@
 \\
-==== water pH ====
+===== water pH =====
+Should drinking water be at a certain pH?  Well, I'm taking the pH out and making it completely neutral with the ion exchange resins.  There is some marketing fad to sell alkaline water.  If it's supposed to be basic, then I've got that covered because I brush my teeth with baking soda.  The food you eat will have so much more ions in it than the trace amounts in water.  Does it matter that it goes in with the wrong pH, if it quickly gets mixed up with the food in your belly?
-Should drinking water be at a certain pH?  Well, I'm taking the pH out and making it completely neutral with the ion exchange resins.  If it's supposed to be basic, then I've got that covered because I brush my teeth with baking soda.  The food you eat will have so much more ions in it than the trace amounts in water.  Does it matter that it goes in with the wrong pH, if it quickly gets mixed up with the food in your belly?  If you know better, let me know, but I'm not going to look into it.
+Related article: [[https://www.healthline.com/health/food-nutrition/alkaline-water-benefits-risks |Alkaline Water: Benefits and Risks, healthline.com 20190530]]

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