Water Exercise: Water-Use Calculator

Calculating your water usage is an important step to increasing the availability of water for others. (photo source: Sneske@gastronomic Fight Club)

Unilever and Zerofootprint.net have teamed up to come up with a one-minute water calculator. Answer a few questions and you'll know how much water a year you are using per year. You can also see what activities are your biggest "water guzzlers" and what to do about them.

I almost highlighted this as a technology, as I think that the only way to increase availability of water resources in other parts is to decrease their use in water guzzling nations like the United States, Canada, and Europe. And anything that makes us aware of our wastage works for me.

What few people realize is that there is only a finite amount of water (and drinking water) on this earth. With our continuous wastage and pollution, this precious resource is slowly ebbing away. Our hogging of water is taking away water from other areas, ones that are far more desperate than us, and where a liter of water means the difference between life and death.

Also, once you are done calculating your water usage, keep in mind that the World Health Organization (WHO) mandates a minimum of 20L (5.29 gal) of water per person per day, which means about 7300L (1931 gallons) per person per year. The reality at the moment is that most of the poor in the developing world live on far less than that.

The food crisis, climate change and the role of technology to solve it

A woman walks through a paddy field in southern India (photo credit: Meena Kadri)

Sorry to digress a bit here. There is just SO much going on, and everything is related - poverty, food, energy, water, and climate change, and the growth of technology that could change things for the better. I will have my regular post about water in addition to this.

Today there were two well-written posts, that were separately contiguous.

The first was from the google.org people. Today is World Health Day (who knew!) and the WHO has released evidence stating that Climate Change has a significant impact on food and health. They even have a map showing areas with high death rates as a result of climate change. Not surprisingly, Africa is the worst hit, with a significant region attributing 80-100 million deaths to climate change. Read the whole post here. This was something covered by Al Gore as well in his blockbuster movie An Inconvenient Truth.

The second is from Paul Krugman of the New York Times, who wrote a brilliant summary of the causes of the impending food crisis, titled Grains Gone Wild. The World Food Program (WFP), Food and Agricultural Organization (FAO), and the International Fund for Agriculture Development (IFAD) all UN agencies have stated that 854 million people are starving. Again, this starvation is primarily centered in Africa and parts of Asia, and slated to get worse with population growth. And its related to climate change.

So, the general consensus is that food and health are gravely affected by climate change. But can anything be done?? Well, obviously we (particularly those in the industrialized countries) need to be more aware of these issues and stop our own wasting. We need to stop hogging everyone else's food and messing with the rest of the world's agricultural policies. But that's an aside to my point (which has to do with this blog) about technology.

I think technology can offer a solution in the larger picture. (Please note that I believe in technology being used as an accelerator in solving a crisis; it is not the whole solution and can never be!)

Technology saved the day during the last major food crisis. Post World War II, countries all over the world were struggling with food rationing. There simply wasn't enough food produced (quite different from now, where famine is more a result of a combination of issues). Then advances in technology like pest-resistant cropping started a green revolution in many countries...the most famous of these scientists won a Nobel Prize for his work. Because climate change is such a large problem, advances in technology in every field (energy, food, road/transportation design, etc) are required to quell it. Suddenly the boundaries are blurred, and as a whole professionals and inventors in every field need to work together to solve this problem.

Technology is out there to provide a solution, but we all need to work together to make it happen. This isn't a single technological advancement needed...its a multiple technological advancement that's needed. The food crisis is just one example, one symptom in the larger issue of Climate Change.

Water 101: Decontamination, the basics

Clean drinking water - the goal of decontamination [1]

In my last post of the 101 series, we discussed how water contamination happens. In this post we'll talk about how to decontaminate water.

Decontamination really involves two main steps:

1. Figuring out what the contaminants are, and their levels of concentration:

As we talked about before, most contaminants cannot be seen by the human eye. You need to do a series of lab tests on the water to determine the types of contaminants and their concentrations. The concentration of the various contaminants is particularly important because you need to know how dangerous the water really is, and how powerful a cleaning process you need. The United States Environmental Protection Agency (US EPA), the European Union (EU), and the World Health Organization (WHO) (each country has their own such organization as well) all outline safe levels of contaminants for the human body. The thing is, many contaminants are naturally occurring in water, and they are not harmful upto a certain levels. It is beyond that level that the contaminant is dangerous for human consumption, and that's the point that a cleaning process needs to be used.


Water samples need to be lab tested to determine contaminants [2]


2. Using a series of cleaning steps or processes to remove the contaminants:

Once you have determined the nature of the contaminants and their concentrations, you need to find the right processes for each contaminant.

Decontamination generally involves the following overarching processes or a combination of processes (this is an oversimplified version, we can get into the details later):


A series of cleaning processes can get the water on the left to be clean like on the right [3]

a. Sedimentation: This is the best process for separating liquid and solids. Essentially you take the dirty water and let it sit for a while. Gravity kicks in, and all the heavier stuff will settle at the bottom (flotation, where lighter stuff floats on the top of the water and is skimmed off, is a subset of sedimentation).


Water sedimentation: notice how the heavier contaminants have settled to the bottom [4]

b. Decantation: Decantation is the process following sedimentation, where you pour the cleaner liquid (or let the liquid overflow) out, leaving behind the heavier stuff (sediments).


A Cambodian woman decants sedimented water [5]

c. Filtration: Filtration is the process where the most bad stuff gets taken out. Usually you pass the liquid through some sort of porous membrane (like cloth or other things). The bad stuff gets held back or stuck on one side of the membrane, while the cleaner water flows through to the other side. The efficacy of filtration depends on the quality of the filter, like how small the pores in the membrane are and how well it keeps the bad stuff on the other side.


Schematic diagram of a simple water filter. Water first flows through the sand, then the gravel, and finally a cloth filter. The sand and gravel take out the coarser contaminants; the cloth takes out the fine contaminants. [6]


d. Distillation: Distillation is the most effective water treatment process, but it is also the most expensive because of how much energy it uses. Essentially, you boil the water, collect the steam and cool it down. Its effective in removing metals (like arsenic, calcium and magnesium...which is why its good for your iron as it leaves no residue) and killing germs. However the removal of organic chemicals (derived from petroleum or such) have a variable removal rate. Chemicals that have boiling points lower than that of water, for example, will also vaporize with the water and contaminate it even in steamed form. For chemicals like these, advanced water cleaning processes are used.


Schematic diagram of distillation (in a lab). This can be done without the use of lab instruments as well, en masse. [7]


e. Disinfection: Disinfection is the process of killing germs. Sometimes the water is free of metals and the other grunge, and just has a bunch of germs which need to be killed. Or often, even the cleanest water that is exposed to air quickly gets contaminated by germs in the air or area surrounding the water. Disinfection is generally the last step of water treatment.


A woman disinfects her bucket of drinking water with chlorine. [8]


Photo Sources:
[1]: Tim Norris
[2]: Juvertson
[3]: http://muriellascorneronmoringa.googlepages.com/
[4]: http://www.easttennesseewildflowers.com/Teacher_Resource.php
[5]: Tom Sprague photo
[6]: http://www.blithfieldeducationcentre.co.uk/kp/waterpages/make_a_water_filter.htm
[7]: www.chemistrydaily.com
[8]: http://www.usaid.gov/press/speeches/2005/ty050915.html