Manganese Greensand + Carbon mix in same tank?
I'm in the process of researching and buying a filter to remove dissolved iron from well water as it goes into my house. Right now the water flows out completely clear, but when it sits in the presence of oxygen, say overnight, it gets a strong orange tint. I live in Thailand in the countryside and my filter dealer options are limited, but the most knowledgeable dealer I have met is suggesting that I use a MIX of manganese greensand and carbon TOGETHER in one large filtration tube. Does mixing these two filter agents together sound sensible?
I have read many references to manganese greensand filtration for the dissolved iron problem, and I'm familiar with carbon from the twin (separated) carbon/resin filter at my old house, but do manganese and carbon belong together in the same tank? Will I run into trouble when I regenerate the manganese? Will the regeneration liquid hitting the carbon cause problems?
Thanks much for any information on this.
I have never heard of this mixture. Worse yet, greensand is regenerated with potassium permanganate which is not recommended for carbon. Also, greensand is very heavy and carbon light in weight. Backwashing flow rate would either be inadequate to lift greensand, or too much and piston the carbon to the top of the tank.
Originally Posted by H2Obuffalo
My advice, avoid that mix. Softeners are not common in Thailand but that would be the choice. Where do you live in Thailand?
Andy Christensen, CWS-II
Thanks for your post. I live an hour outside Ubon Ratchathani city. I have been talking with the owner of the biggest (of very few) filter shops here in Ubon.
Sorry for this newbie question, but by softener, do you mean resin? Because my limited understanding is that I should not run water containing dissolved iron through resin or it will quickly and completely ruin the resin as the iron solidifies and coats the resin beads. Do you mean a different kind of softening agent/procedure?
To my current knowledge, the only filtering media readily available in Ubon are carbon, resin, and manganese (greensand). Plus rinky-dink replaceable cartridge filters for sink-top use. So, my (probably frustrating) question is how best to use these three agents. I'm not in a financial position to have anything flown in on a special charter flight. :- ) The 8,000 baht (about US$ 250.00) for the currently proposed 35 liter manganese/carbon tank will already be a strain, but doable.
About the potassium permanganate, I tried to ask about this, but the English name did not ring a bell with "my guy". He said there is a chemical used locally that I can buy very cheap at any drugstore to regenerate the manganese. Unfortunately I did not write down the Thai name right away, so I need to ask him again exactly what chemical he was referring to. I understood (we're speaking Thai) that locally the chemical is used for cleaning vegetables. I definitely have to get back to him on what it is.
Another filter shop owner in town (who does not seem as knowledgable) said I can just backwash the manganese with the same groundwater I'm trying to filter, without using any regenerating agent. That sounded dubious to me, but this is all new for me, beside what I have dug up on the internet.
Finally, a more practical issue: The other possiblity is to put the manganese and carbon into two separate 18 liter tanks, so that they don't mix, and then run the wellwater through both of them. This will cost me 10,000 baht (US$ 320), but if it seems a better choice to knowledgable people here, I can still afford that.
I already have a modest (smaller) size twin chamber carbon/resin filter from my old place that I'm planning on running the final water through before use to get rid of possible tannins, which have cropped up here before.
This post is getting windy. :- ) And I hope I'm not appearing uncooperative. But could you consider it a puzzle? What would be the best way to arrange manganese, carbon, and resin (and maybe a physical straining filter) to optimize chances of success?
As far as I know that's all I have to work with here. :- )
Thanks much again for any advice and info!
Last edited by H2Obuffalo; 08-06-2010 at 01:55 AM.
From what I can gather, you have available only tank or cartridge type filters and not backwashable/reusable types, right? In other words, once the filter is finished, it is replaced. If that is the case, then yes, resins will clog and become useless.
A water softener uses resins and has an automatic valve that cleanses the resins using salt and then resumes its duties in removing iron, manganese and hardness minerals. this process repeates itself over and over for many years providing much improved water. It is not a water "purifier" meant to create drinkng water, though.
As far as backwashing with the source water, there can be some value to this and what is being washed out has accummulated and what is in the backwashing rinse is minimal. This is not ideal--like washing off caked on mud with the baby bath water...not rerally clean, but better than before.
Tannins also use a resin (different type) and it too needs to regenerate using salt.
Carbon is an excellent media and has a wide range of water improvement, but it also has limitations and can harbor/colonize bacteria reversing its effectiveness.
You have a real challenge. I know that materials, tools and equipment are hard to find in Thailand (I lived in Bangkok and Lampang) and water treatment is not common. Bottled water is very common and even new houses show signs of hard water damage.
Can you take pictures of the types of equipment you have available?
Are you teaching there? With an organization? Temporary stay or fairly permanent?
Take care, Andy
"Can you take pictures of the types of equipment you have available?"
I can describe them better. There are *no* disposable cartridges involved, and the filter media *IS* regenerated and/or backwashed, but this is done *manually*. There is no automated, turn-it-on-and-it-will-clean-itself feature. Both the large filters that I am on the verge of buying and the smaller one that I already have at my old place for tannin removal are made from common, ubiquitous torquoise-blue PVC plumbing pipes, usually used (all over) here for standard plumbing.
These pipes have been rather ingeneously, carefully, and even attractively cut in various places and had various, numerous, smaller pipes, valves, and other plumbing-type dodads added to make a filter chamber mechanism that is very durable, reliable, and free from the danger of corrosion, because it is almost all plastic. The loose, unadorned carbon, resin, or manganese is filled directly into the chamber.
To backwash manually, one just switches the configuation of a few externally controlled valves that control how the water flows, and let the waste water flow out. To regenerate, one opens up the chamber at the top, pours the regeneration agent into the chamber, and after the required soaking period, flushes the media clean.
Here is what my questions are coming down to at this point:
In response to your advice, I will *not* mix the manganese and carbon, but instead have separate chambers for the manganese and carbon. This is what the dealer does in his own home, and he says he has even more iron in his water than me, and it works in his case. That sounds encouraging, because without a test I am guessing that my dissolved iron content is at least moderate and possibly quite high. Once the iron solidifies, there seems to be quite a lot of it.
So, as of now, the plan is to have:
1) One 15 liter chamber containing MANGANESE.
2) Another, separate 15 liter chamger containing CARBON
3) A modest physical filter of some sort. This one item only probably WILL have a disposable cartridge.
4) A smaller, twin chamber filter (about 2 liters space in each chamber), the first chamber containing more CARBON, and the second containing the tannin-removing RESIN used here.
***Is this the best order to put these components in?*** Or should the (large) carbon tank go before the (large) manganese tank? I'm also not sure of the best order for the physical filter. Is this best used after the two large tanks? There is no sediment or solidified iron in the water as it comes out of the tap. It appears completely clear and clean to the eye.
Bits and pieces:
Don't worry, I would never drink this water. It will only be for use in the (clothes) washing machine, and for washing dishes, bathing, and flushing the ceramic toilet. I always buy drinking water in the common big jugs available here.
I called the filter shop guy today, and got the Thai name of the mysterious, intriguing, vegetable-cleansing regeneration agent that he had mentioned. Then I went to a drug store and asked for it. Sure enough, they did have it. Then I asked the pharmacist if he knew the name of the substance in English, because only the Thai name was written on the vial. The pharmacist took a moment to reposition his mouth to speak in English and said carefully "Po-tass-i-um per-man-ga-nate". Ha-ha-ha!!! It is potassium permanganate afterall. The filter dealer just didn't know the English name, that's all. :- )
"Are you teaching there? With an organization? Temporary stay or fairly permanent?"
Yes, I've taught English at a college here for seven years. Been in Thailand for ten years. Only Ron knows my destiny, and he works in mysterious ways.
Okay, I'm gonna have to make a decision within about 48 hours on what to buy for the best shot. Unfortunately I urgently need to evacuate my current rented house as soon as possible, so I gotta get the water at the new place sorted out and get ready to move.
If any other advice comes to mind, please let me know very soon, okay? Specifically I don't know the best order to put the above four components in. Thanks for reading, and best regards from Ubon.
Last edited by H2Obuffalo; 08-08-2010 at 12:20 AM.
Ok, that's what I thought about the chemical. care must be taken as PotPerm is a poison and must be completely washed out of the media during the backwashing.
Your sequence of equipment is good.
Greensand is not for removing tannins as a special anion resin does that. It is usually a backwashing device as well using salt or is replaced as needed. tannins in water gove the water a tea-colored appearance. the darker the color, the more tannins there are.
I would consider a reverse osmosis for drinking water. Surely they are available there, aren't they. If not, you can get one from overseas.
I miss tom-yum goong....
Good luck and let me know how it turns out; always room to learn.
I'd just like to send a note to let people know that the manganese and carbon filters were hooked up two days ago, and yesterday when I went back to look at some of the filtered water that had been left to stand in a plastic bucket, there was... VOILA- no solidified iron! The water was still completely clear. The only odd thing I noticed was something that appeared as a *very slight* sudsiness in a couple spots. I know there wasn't any soap in the bucket. It's possible they washed out the new filters with soap before they delivered them- they were just built. Or maybe this is an effect of manganese and/or carbon that I just don't know about. Anyway, it really didn't seem like a problem at all, so everything is going well... except for the new water pump issue (described in a separate thread). Two steps forward, one step back. :- )
Many new media filters will have some bubbles come through, usually from air packets between the granuals. Once the media is fully saturated, these should disappear. I doubt they washed it out with soap unless it is some unorthodoxed method of 'building' a filter.
Pictures would be great!