Water from the sky... and we are not talking about rain

I saw this article ‘Sky water' plant a boon for people of Sidlaghatta (The Hindu, 22 Mar 2010) about "a new technology that is reportedly making waves in the U.S. and European countries". Put simply, it is a big condenser that converts the water vapour in the air (aka humidity) into clean liquid water, extremely useful for rural populations with no access to safe water.

Actually, don't you think this is similar to the Dragonfly from our local brand, Hyflux, introduced a few years back? Granted, the Dragonfly is designed for a small family/office (up to 24L per day according to specs) while this sky water plant can crank out 1000L per day, about suitable for a small village. Nevertheless, the operating principles are the same.

Cost wise... sky water costs 10 paise per litre (~ SGD3 per cubic metre (m3), 1 rupee = 100 paise). Our domestic tap water costs SGD1.52 per m3 (including tariff) while newater sold to industry costs SGD1 per m3. (Desalination costs about twice that of the newater process so the price probably follows suit. Based on a ST article in 2004, desalinated water costs SGD0.78/ m3.) No, sky water is not cheap by our standards but when water stands between life and death, any price is cheap.

Incidentally, I do have some concerns about this technology, especially when applied on a large scale, say for a town or (heaven forbid) a city. When you start to draw this large amount of moisture from the atmosphere, what are the effects on the water cycle? Will we have less precipitation which leads to less water for our reservoirs, hence ending up with a zero sum game? Will less moisture in the air lead to larger fluctuations in temperature between day and night since water vapour acts as a buffer in air temperature changes? What will our neighbours say - that we are stealing water from the air which is supposed to pass over them? And I am sure there are many other unintended consequences beyond my imagination.

Figure: Water cycle (from http://cd7.e2bn.net/e2bn/leas/c99/schools/cd7/website/images/bp-watercycle2.jpg)

Though the above scenarios sound far fetched at the moment, they do somewhat mirror the process of drawing groundwater in many countries. An excessive withdrawal will lead to all sorts of problems e.g. sinking land, salt water intrusion, dried up surface soil prone to combustion.

Back to Ngee Ann Stream with Fairfield Methodist School (15 Mar 10)

This particular field trip for my advanced elective module (AEM), water quality and pollution, was reported in the Straits Times (25 Mar 10).

I have decided to post some exclusive footage not captured in the news article. (Actually, these are just routine photos I take every time I head to the field.) In addition, I have included a Google Earth file compiling all the water quality data gathered by the students on that hot and sunny morning. The students were given hands-on practice on the use of Google Earth as a means of documenting water quality data.

Figure: The 4 sampling stations displayed in Google Earth. Notice the ugly patch of cleared land. More land has since been cleared as Google Earth satellite photos are back dated. See previous post.

Aside to FMSS students in selected groups: Please use the compiled data in the Google Earth file to prepare for your case study presentation.

Figure: Group work at sampling station 2.

• The humble umbrella is immensely useful for field work as it can shield one from the rain and sun. (Try recording your data on a rain soaked piece of paper and you will know what I mean.)
• The other point to note is the highly turbid (muddy) water caused by sediments being washed down the canal from the nearby construction site. In fact, the turbidity exceeds 1000NTU which is the measurement limit of our turbidimeter (you may check the data here). This has never been observed before in this stretch of water.

Figure: Construction site - clearing of the secondary forest in progress. Note the open ground of easily eroded soil

Figure: Moving on from station 2. The canal floor was still wet from the drizzle earlier in the morning.

Figure: The customary group photo at "Graffiti Bridge" (sampling station 3). Many happy faces despite the "bedraggled" appearance

Push for Singapore students to learn from their environment and that seven-coloured thingy in the sky

Reading this Straits Times article on "Push for Singapore students to learn from their environment" pushes me to compile some random thoughts and observations into a coherent post.

The article centred on a top institution here espousing the merits of place-based education (PBE), "a learning pedagogy first introduced in the United States". PBE "emphasises learning through real-world experiences, with the local community and environment as a starting point". In short, it connects students to the real world.

Besides the term "PBE", nothing is new. Education has always been trying to get students into the real world, whether through work attachment, community service, field trips, study trips etc. However, in practice, budget and time usually closet the student in the classroom or glue him to the computer screen (online research, lessons, discussion and whatnot). I guess PBE is another repackaging exercise like PBL (problem based learning) a decade back. (Hey, don't they sound similar?!)

Nevertheless, the principles of PBE are highly relevant, so much so that I am a strong believer of PBE despite hearing about "PBE" for the first time. Besides for research purposes, my water quality monitoring (WQM) activities and courses aim to bring students (from primary level all the way to working adults) into the real world environment to experience how it fits (and contradicts) classroom theory and laboratory experiments.

Here are some anecdotes in support of PBE.
 
I once talked to a JC teacher who accounted that some of her students have never seen a rainbow in Singapore. When they had a field trip to Australia, they were awed by the first rainbow they experienced. Uh... are our students going outdoors nowadays? Not surprisingly, these students have yet to visit Bukit Timah Nature Reserve (BTNR), Sungei Buloh Wetland Reserve (SBWR) and even the highly touted Marina Barrage.
 

Figure: Marina Barrage in the foreground still under construction in 2007

When I showed my own polytechnic students bug specimens, most of them became instantly fascinated. (Of course, there were always the few who hated and feared bugs.) Why? Throughout their primary and secondary school education, the only bugs they saw were two-dimensional ones on print or screen. They would never have imagined the sizes and shapes of real bugs (albeit as specimens).
 

Figure: bug specimens

PUB is a strong supporter (financial and otherwise) of water research. A PUB staff once remarked to me about PUB having sponsored a secondary school team in developing a remote mobile WQM device. Indeed a wonderful idea and a handy gadget if successful. Yup, the kind that needs good working knowledge of mechanics and electronics. Shockingly though, the students were unsure of why WQM is necessary and how it is useful to the environment. (Perhaps they have not read this blog.)
 
Henry Peavy in his book, As if the earth matters, summed the issues up succcintly - one day, students (who will grow into the leaders of the world) can't even recognise a chicken without reading its DNA.
 
To reiterate my earlier point about students (and adults) not going out into the environment enough (shopping and movies are not counted!), I am perturbed that based on a quick poll of the primary school students in my courses, most use an email account and half write a blog. Looks like learning for them will still remain mostly in the classroom and their computers.
 
To end, I quote this from the anime, Monster (yes, television and the internet have their place in education but they should be done in moderation) - "education is to develop people useful for society". But anyone who has watched the series knows that these "educated" people ended up as psychological inepts incapable of love. Perhaps a more apt description would be "education is to develop the full potential of an individual - intellectually, physically and emotionally."