Questions tagged [water-treatment]
Questions about any process which makes water more acceptable for an end use.
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What is the chemistry underlying chlorine recommendations in spa water care guides for UV/Ozone pools?
An example is here: https://alpinespas.co.nz/content/uploads/2021/01/2020-Water-Care-Guide-Spa-Supplies-SSDEC08-WEB.pdf
It recommends ignoring test strips, using a "shock dose" of chlorine ...
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Why might an ozone UV spa pool cause test strips to fail for chlorine?
My spa pool chemistry guide claims that the test strips are not accurate for measuring chlorine in a spa pool with UV and ozone. Why might that be the case? My spa pool company also sells me the ...
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I generate a waste machine coolant that contains a chelated Cd after use. Is there anything I can add to the coolant to prevent chelation of the Cd?
I have a machining process that uses a coolant. The coolant, which contains 8-12% triethanolamine, comes in contact with a low melting point alloy during use that contains Cd and Pb. When the coolant ...
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Activated charcoal for water filtration: Granules vs Pellets
NOTE:
After further investigation into the producer I found out that granules are made of 100% coconut shell whereas pellets of 100% hard coal.
This renders this question meaningless.
Apologies for ...
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Reading and adjusting pH of reverse osmosis water
I grow things for a living and regularly use pH meters + strips to read and adjust the pH of various nutrient and pesticide solutions. Oftentimes, I have a need for nearly naked water with the pH ...
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Can Adding Alcohol Create Potable Water? [closed]
I've been exploring various methods for purifying water, and I'm curious about the potential effects of adding alcohol to make it potable. Could the addition of alcohol serve as a means of purifying ...
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Ammonia (NH3) vs Ammonia Nitrogen (NH3-N)
I've been looking into chloramination (chlorine & nitrogen reactions) and noticed many papers either reference Ammonia (NH3) or Ammonia-Nitrogen (NH3-N), seemingly interchangeably.
Is the ...
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What is meant by 'as Cl2'
I feel like I'm over thinking this one, but think I need a confirmation (and quantified example) to put my confusion to bed. I'm more a mechanical than chemical background but trying my best.
I really ...
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Pressure degasser of water
Currently, I am working on a project where we are using pressure degassing. The idea is to make a test setup where we lower the pressure in a flask to 'degas' the solution. The solution is just ...
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Weight Ratio vs Molar Ratio - Chloramines
I'm working with a delicate experiment whilst trying to test corrosion of stainless-steels in a chloramine environment. I've run into various literature that discusses the formation of different types ...
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Chloramines & Nitrogen Trichloride vs Stainless Steel [closed]
We've recently experienced excessive corrosion on stainless steel within indoor pool environments. We believe this is due to chloramine (gasses) in the atmosphere. To test this, I plan to create a ...
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Are there any real dangers to using lead fishing sinkers to hold a shower curtain in place?
I am hoping someone can help me consider if there are any factors that would make the use of lead fishing sinkers such as these in the shower risky enough to stop doing it. Specifically, they are ...
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How to remove hydrofluorosilicic acid from water?
I'd like to come as close as possible to pure water. Would a KF filter remove hydrofluorosilicic acid? If not, what would?
I could not find the concentration of hydrofluorosilicic acid, but would like ...
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Is there a way to neutralize aluminum hydroxide in pool water?
Pool water sat unfiltered for 12 months with heavy leaf debris. Once manual removal was completed a variety of chemicals were introduced. In particular alum powder. This alum powder has decomposed ...
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How to make clean water from urine in a wastewater treatment plant? [closed]
Referring to a video here, describing a filter that treats wastewater, wouldn't urine in the wastewater not get filtered out because a sand filter alone does not separate urine from water? How is ...
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Is calcium hypochlorite as effective as sodium hypochlorite in sanitizing a swimming pool from algae?
Question
From this question we know that what swimming pool stores refer to as "liquid chlorine" (sold in 10 gallon jugs) is most likely sodium hypochlorite ($\ce{NaOCl}$). In the spirit of ...
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Are liquid chlorine and super-shock chlorine the same?
To shock a swimming pool one uses either calcium hypochlorite ($\ce{Ca(ClO)2}$), commonly sold from at least one major brand in pouches,
or the more obscure "liquid chlorine".
I'm saying &...
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TV Program Said Remove Some of Chlorine in Water By Putting Hose On Fine Spray
A UK TV program suggested that some of the chlorine in tap water can be removed if you fine spray it from your hose, such as with un upside down fine sprayer.
Is this true? How effective is it?
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Why is desalination waste usually disposed back into the sea instead of converting it into chemical products?
I was reading about the desalination processes such as reverse osmosis and capacitive deionization and their alternatives. They all work on removing ions from water and disposing them back to sea/...
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I want to dechlorinate my tap water to use in an organic garden. I've purchased a product called Seachem Prime that is typically used for aquariums [closed]
I purchased a product called a seachem prime to dechlorinate my tap water so I can use it in my organic garden inside. I want to know if the product itself is safe to use on my plants and if there ...
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Can a TDS meter have a false initial reading due to some instrument artifact?
I have total dissolved solids (TDS) meter which is built in to a water purification system and this meter always reads high, around 90-100 when the machine is turned on, but over the next 30 seconds ...
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The use of far-infrared ceramics for water purification?
I am struggling to understand how exactly far infrared ceramic balls help purify the water. It is stated that active ceramic taormine balls help purify the water by forming a 2 micrometer wavelength ...
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Characteristics of metals compatible with semiconductor grade Ultra Pure Water (UPW)?
I am looking to build a water conductivity sensor for semiconductor grade Ultra Pure Water (UPW). UPW conductivity sensors already exist, but because of price and low water volume I need to fabricate ...
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Why isn't there hydrofluoric acid in fluoridated water? [closed]
From what I've read, when water is fluoridated it's done so either by $\ce{NaF}$ artificially or $\ce{CaF2}$ naturally. If this is correct, shouldn't the reaction $\ce{CaF2 + H2O -> CaO + 2HF}$ ...
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How to compute a needed volume of solution to adjust to a target pH
I am a software engineer and I would like to solve a chemistry problem. I have revised the subject a bit to understand the basics :)
My goal is to maintain a constant pH of a water tank (tap water). I ...
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Why do we clarify water with alum, but beer/cider/wine with bentonite?
My understanding of clarifying (floccing) liquids is that we add a mineral with an electric charge, which attracts suspended particles (like bacteria) which I assume have the opposite charge. The ...
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Reaction of propanoic acid with chlorine used in wastewater treatment
I'm asked in a problem to write down the equation of the reaction of propanoic acid with chlorine used in wastewater treatment: $\ce{CH3-CH2-COOH +Cl2}$. The problem also states that, in this reaction,...
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Hazardousness of Chlorothalonil & metabolites in shower water? [closed]
Recently it came out, that in some parts of Switzerland (where I live), there is Chlorothalonil & metabolites/breakdown-products of it in the drinking water. Yikes.
Problem is, chlorothalonil ...
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Total concentration conversion
when dealing with waste water and the total values of P, N, C are given in ppm units, what molecular weight is used for converting from ppm to molar?
for Example- what will be 12 ppm of P(T) in Molar ...
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Hard water filtration
Why does hard water have to pass through the cation exchange resin first followed by the anion exchange resin? Why can't it be the other way around?
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What about sodium triphosphate in drinking water?
Recently, at my place, a sort of filter for hard water was installed. They told me that it contains sodium triphosphate which is dissolved into all the water that enter home, i.e. both cold and hot ...
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Do antimicrobial abilities of copper boilers decrease over time?
As copper boilers age and develop oxide buildup, does this lessen the copper's antimicrobial abilities in killing bacteria? I was thinking since that coating would be on the copper, there would be ...
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For what chemical purpose did soldiers in WW2 carry small ion exchange resin columns in their survival kits?
My textbook [Chemistry Live, Declan Kennedy] states that ''During WW2 small ion exchange resin columns were part of a soldier's survival kit.''. I can't find any further info about this online or ...
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Any idea why tap water goes stale overnight? [duplicate]
We have great tap water here in Hungary. My only problem that it goes stale overnight sometimes in some glasses or sometimes even the 2L water boiler has this problem too. But microbes cannot resist ...
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Is there a safe way to neutralize bleach at home [closed]
I don't want to simply replace one hazardous chemical with another. The bleach is stubbornly clinging to my shower walls and I feel its effects every time I take a shower.
Ascorbic acid seems like the ...
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Why is RO water more corrosive?
According to several articles from the American Water Works Association, permeate from RO should be stabilized in terms of pH and hardness to avoid corrosion of the distribution piping.
How does ...
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What are the properties of water in glaciers? [closed]
Does water from glaciers have many minerals (hard water) or would it be considered pure or distilled water?
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Devarda's alloy procedure
Hello dear I have a small question
I want to do kjeldahl distillation for a 100 mL sample of water after reduction with devarda's alloy to measure the concentration of nitrate nitrogen... I want to ...
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Generating hypochlorous acid for disinfecting water using HClO2
I use a product that contains $\pu{700 ppm}$ of $\ce{HClO}$ to disinfect water at $\pu{1 ml}$ per $\pu{1 l}$ and let it rest for about $\pu{2 hrs}$ before I use it so there is no $\ce{HClO}$ left ...
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How can I measure the scale in water?
I have hard water in my house. All the taps have tartar around. It generates some problems in some of my home appliances so I have bought polyphosphate salt but when I boil water I don´t get the ...
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TKN: Why are they called Missouri tablets?
When analyzing for Total Kjeldahl Nitrogen (TKN), you can make a copper sulfate digestion solution in the lab or purchase a variety of pre-prepared digesting tablets for example on VWR. My question is,...
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Heat effect on diluting concentrated NaOH solution
I am an engineer in water treatment and have a chemistry question. In water treatment we dose $32\%$ sodium hydroxide solution for $\mathrm{pH}$ adjustment and there is a concern that our dosin lines ...
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Variations in solubility of total dissolved salts in water with temperature [closed]
I want to know the solubility of "total dissolved salts" or mainly Calcium Chloride and Magnesium Chloride causing hardness of water.
Is this data published anywhere at different temperatures?
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Can Na2CO3 remove temporary hardness of water?
This was asked in my test and I remembered that all compounds that can remove permanent hardness of water can remove temporary hardness of water also. But my teacher marked it wrong and I cannot find ...
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Could the Superoxide Radical Anion Be Responsible for the Removal of Chlorine Dioxide Used to Treat Natural Waters?
Some background facts:
$\ce{ClO_2}$ is a gas that is highly soluble in water (some 8 g/L at 20 °C). However, per Wikipedia , to quote:
It does not hydrolyze when it enters water, and is usually ...
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Creating 1L of 1000 ppb stock solution of Pb2+
I’m testing on samples that require a concentration of 1000 ppb (or 1 mg/L) of Pb 2+. My first thought was to simply dissolve 1 mg of Lead nitrate in 1 L of deionized distilled water to create 1 L of ...
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Methods to quantify lead(II) concentration in water on the ppm/ppb level
While there are several ways to quantify metal concentrations in water, a lot of them are only specific to select metals. For example, there is the orthophenanthroline method for quantification of Fe(...
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Is it possible to measure light absorbance for analysis of lead concentration without photospectrophotmeter
I’m designing an experiment which requires I measure final and initial lead concentrations for the determination of aqueous lead uptake by different mediums. Because lead concentrations would be ...
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How concentrated does the analyte solution need to be in order to perform a (chelatometric) titration
I’m currently investigating a method to chemically pretreat cellulosic waste as bisorbents for enhanced uptake of lead in water. I intend to measure the initial and final concentration of water to ...
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membrane for a reverse osmosis desalination experiment
We are second year cram schoolers , we are currently working on a project tackling water desalination by reverse osmosis and are required to do an experience. During the process, we encountered some ...
