What if I told you that I used to managed a high-purity water treatment system for a semiconductor company for about 4 years in a location where there's no proper technical expertise readily available?

The way you're typing out the entire post is so dramatic which is unnecessary. And not completely correct either. Are you out to scare people out of RO water?

Meh, busy at work. Maybe when I have free time tonite or during lunch hour. This is going to be an extremely long post.

Haiya, even copy and paste, you could have selected a more neutral article. The guy is partially right but mostly wrong interpretation. He doesn't have the water industry knowledge that I do.

I didn't continue because I changed jobs but still in the same company. Went to special projects and now to Environmental, Health and Safety. So some of the health and safety stuff, I know because it's part of the job. The technical aspect is because I took up Chemical Engineering for studies.

NEWater is definitely interesting. I know one of the researcher in Singapore who was developing it. Nice chap.

Hmm...I think I have to give a bit of history about water and the problems around the world.

Water is an expensive commodity yes although probably not traded as petroleum is, it is still very precious. All around the world, everyone is concern about water shortage. These shortages are as a resulted of overuse, pollution or just that there's limited supply due to the natural environment e.g. desert.

In the US, because of how big the land is, a lot of people has water treatment systems at home and they use groundwater for their daily use. Now in some areas, the groundwater is badly polluted from past industrial activities or historical pollution e.g. tanning of hides, the tannery would simply dump the waste into the river as it's so convenient, including chemicals used to tanning the hides to make leather. A very good example is California, USA. The groundwater in California in certain areas are badly polluted from the 1950s and 1960s due to jetplane manufacturing waste (mostly solvents) as environmental control wasn't as strong as it is now. Other heavy industries have polluted the water cachement areas quite significantly that drinking groundwater is impossible and so, they buy bottled water to drink at home.

Water purification technologies developed over time, mostly as a result of the need for clean water for manufacturing processes. However, some of these technologies are developed to treat drinking water. Depending on the water content in a specific location, the drinking water treatment plant can be technologically advances (huge RO units for desalination in the Middle East, UV light to remove organic pollution in the water) or they can extremely simple with a few processes.

Is RO water good for you? It depends. Not all RO water gives the same result as it changes according to water pressure and chlorine. Some RO membranes are sensitive to chlorine fluctuations and will be destroyed by it. It's either thin-film cellulaste or polyamide : try to google and let me know. RO drinking water quality may not be too bad tbh because depending on the configuration of the system, the water purity may be different. Depends on the number of modules and configuration (single stage, double stage). RO membranes also have a lifetime i.e. they degrade over time so their overall efficiency will decrease.

I wouldn't buy it for home though because maintaining it may be more costly than expected. There is a little clause in the WHO drinking water guidelines about chlorine dosage that in the event of epidemics, the chlorine dosage can increase. Some folks say that an activated carbon filter upfront will help but even that carbon filter will be used up in no time. Also, with RO systems, you are using more water because there is a stream of concentrated "salt" water. I suppose that "salt" water can be used for gardening, if you did have a garden but if you're living in a condominium, it's probalby going to end down the drain unless you have plants.

The author is also generalizing about the big water companies. They are big reputable companies but they don't necessarily make the RO membranes and neither do they hold the patents for the process configuration. GE bought a small Canadian outfit called Glegg and just revamped the website to include free material about water technologies on their website (previously Glegg material and now updated as well). DOW is a chemical company that makes a lot of things, including RO membranes. Their competitor is Hydranautics. But these are big names and they don't make the small RO units that you guys see on the market. At least, I don't recall but I could be wrong.

The leaching of minerals from the body comes from the fact that pure water is acidic. It's known that acidic water will leach out the minerals, be it from the body or in the natural environment. What is not so well-known to the general public is that at a certain purity, the measurment of the acidity in the water is not accurate. pH of the water just cannot be measured. But it's usually of a purer form than is allowable as drinking water.

Carbonated drinks are acidic. Those in science classes should know. Blow a straw into water for awhile and measure the pH and it's slightly acidic. CO2 dissolves slightly in the water and forms a weak carbonic acid.

Hmm...think I'll stop here. Maybe better if you post up a question that you need an answer to about RO and I can help answer. I can't provided the final answer but some direction should be ok. Take it with a pinch of salt.

This post has been edited by myremi: Mar 24 2009, 10:33 PM

Hard to say xavi5567. The thing with activated carbon is that it does 2 things mostly :
-remove chlorine
-remove organics

It's not known to remove bacteria in the water industry. It can remove dead bacterial though i.e. those that died from the chlorine dosing but usually, the dosing is added before the inlet.

Activate carbon is a haven for bacteria though. Because of the organics "trapped" in the carbon and the reduce chlorine amount, the bacteria nearest to the outlet will have more bacteria count than at the inlet (where the chlorine content is higher).

Not sure about 3 weeks. There are test kits for bacteria though but I don't know what is the acceptable limit. But it's probably not that bad as long as the water is not stagnant for too long. If it's internally circulating, 3 weeks should be fine I think. If not, well, drinking unboiled water in Petaling Street is equally bad. You'll get bad diarrhoa but usually, that's it.

There is a minimum flow that is used a guideline with pure water to prevent bacteria growth. But that only works with very pure water though.

As for TDS testing system, that is pretty old thinking. Nowadays, water industry tech folks go by specific ions. I think the field test kit strips are pretty cheap. Call up companies in yellow pages. Should be ok.

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Added on March 25, 2009, 12:06 amWhat is natural water? And how natural do we really need it to be?

If it's just chlorine, just buy an activate carbon filter. You can see the bacteria growth in the water just by opening the filter and seeing the brown film formation.

Boiling water comes about because of cholera and other water-borne diseases. Our tropical climate is good for them.

Taste flat? Water is suppose to be tasteless. You're probably tasting the calcium + magnesium i.e. hard water.

UV is to treat bacteria but damn expensive for home use. Plus, the light bulb has lifetime and it weakens over time. Not to mention that there's a bacteria film that may form over the quartz tube.

Germs will grow on RO filters : germs wll grow everywhere, especially if the RO is stagnant for awhile. At work, the RO modules are only idle for maybe 4 hrs then starts again. Mind you, work is different from home usage (factory needs tons of water).

You won't die lah.

This post has been edited by myremi: Mar 25 2009, 12:06 AM

I wouldn't be too obsessive about the taste. It just depends on the amount of salts in the water.

You're right about the outdoor filter. Just put a small one in the kitchen. It's good enough.

What do you mean "employ aluminium in it's purest form as storage and reflector to UV light"?

Reactivating spent carbon : only too many times you can do this because it reactivates about 75% each time. So there are 25% trapped organics / chlorine in there. Then it's another 75% of that 75%. Now maybe only 50% of the carbon is good. I'll just buy new ones. It's small quantity. Carbon is organic materials so it would decompose in the landfills too.

Too late now. Will replay tomorrow.

Just a side note. TDS can be converted to Conductivity. 5000 microSiemens/cm is the quality of brackish water (where seawater and river water meet). Typical city water is 200-500 uS/cm.

Mind you, this is an indicator only. Not the full picture. There are many analysis done on water and the Water Boards are suppose to quarantee a certain spec all along the distribution line. NOt sure about the hwole of Malaysia but in Kuching, the water quality is analysed by Jabatan Kimia daily. And the Health Ministry is the one that sets the water quality specs. Huge list.

Heading to bed. Nite2 guys.

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Added on March 26, 2009, 1:09 amConductivity is influenced by many things though. NINJAO, blow bubbles into the water and check the TDS reading again. It went up I bet.



This post has been edited by myremi: Mar 26 2009, 01:09 AM

xavi, i would suggest to goto GEWater site and try to find out where the library is and start reading there. Some of the info in your posts, a bit alang-alang lah. And I don't quite have the time to answer everything.

The water tech you mention in India. There's a lot of focus on low-tech water purification technologies around the world because of the money profits from the lower income community. But the best I've seen was a submission to the Rolex Environmental Annual Competition a few years ago. An African manufactured clay jars - 2 clay jars and you have a simple but effective water purifier.

Ok, now some of the things spoken about :

Aluminium : I guess it depends on the surface that is in contact with the water. As long as the aluminium doesn't increase the aluminium contenets in the water to alarming levels, should be fine.

UV filter : I wouldn't buy it because I don't drink unboiled water. No matter what, boiling water is still the safest way of destroying bacteria. Just dont' forget to turn off the fire. >.<

Water Quality Tests : There are a lot of them. I think the last time I saw such a report, the analysis covered 2 pages. I alwyas thought that if there was anythign wrong with the drinking water, the Health Dept would be breathing down their backs.

Water Tank Cleaning : It's a good idea to check yes. But don't just simple drain the water lah. Water the garden at least. Sayang the water just like that. And do it at an appropriate time. During dry season, not good lah.

Water tank + bacteria + chlorine : One thing about chlorine is that it is aggressive against metals if in high quantities. So maybe can get hold in water tank after a long time. I wouldn't worry too much about a filtration system unless it's really really bad. I just do end of point filter in kitchen. In the bathroom, I'm not so worried. But if you have the money to spend, go ahead and get your filters.

This post has been edited by myremi: Mar 26 2009, 12:56 PM

Pertaining to the bacteria in filter, there is a misconception in place that it's actually dirty water.

It's actually not. Filters act as bacteria traps and in the water industry, any filter that is after the activated carbon portion, will be a haven for bacteria growth. Why?

1) Activated carbon removes chlorine that acts as a biocide i.e. it kills bateria.
2) Filters have a lot of pores around where bacteria can stick on and grow. Even with fast moving water, they will still grow.

Filters are meant to be changed out, if they don't have backwashing facilities. I'd say that you probably kept your first filter for too long - 5 years is damn long.

RO systems are for ppl who can afford it. I don't use it because extra water is needed and that concentrated water is going to waste. Also, additional money cost in the form of electricity.

I wonder if I should debunk some myths here or not. But I guess it's also based on what people wants and needs are. For me, I live with my Granny and Uncle so it's not a big family. We prefer to have hot water boiled via gas because we do not need constant supply. Plus, it was easier having not to deal with scale cleaning with electrical appliances and we are fortunate that in Kuching, Sarawak, the water hardness is not an usual, unlike in KL and Selangor.

I can understand about the convenience but on the health part, water isn't the only aspect to look at. From a disease control point of view, yes, clean water source is necessary. But for long-term health and wellbeing, that comes in the form of lifestyle, nutrition and eating habits. And out of the 3, the hardest ones to come to terms with are nutrition and eating habits.