Science Behind Water Conservation and Sanitation

Unpurified drinking water can be contaminated with bacteria and viruses such as Shigella, Salmonella, Rota-virus, or protozans.[1] These bacteria can lead to water borne illnesses such as diarrhoea, cholera, dysentery, typhoid, hepatitis. There are many different types of ways to filter drinking water. The main filtering options are activated carbon filters, Ion exchange units, reverse osmosis units, and distillation units. Activated carbon filters absorb organic contaminants, by adding a special heating process to charcoal. The charcoal becomes more absorptive, and is then referred to as “activated charcoal”.[2] The gases then stick to the charcoal, absorbing most of the impurities. Reverse osmosis is another option for water filtration. The water is pushed through an ultra-fine semi-permeable membrane, here it separates the tap liquid into the pure permeate. The water stored then goes through the activated-charcoal polishing filtration stage. The only set back to this process is that it is very wasteful; it wastes two gallons of water to purify just one gallon of water. Ion exchange is the process of exchanging natural-forming mineral ions in the water with its own ions.[3] This makes the minerals neutral to their harmful effect of creating scale-buildup. Lastly and easiest is distillation, which is as simple as boiling the water. When combined with carbon 99.9% of the water purified is pure contaminate-free water.

There has been a great demand for water in the last decades. Population is growing quickly and the poverty stricken countries cannot afford to pay for the amount of clean water that their nation desperately needs. Studies show that as the population in the small countries of the Middle East and North Africa increases the access to fresh water decreases. The population in these countries has doubled between 1970 and 2001. This rose from 173 million people to 386 million people, reducing the average amount of fresh water available per capital. The growing won’t stop there, with the population expecting to double in the next 50 years. This will then in return lower the average amount of renewable fresh water to about 1,100 cubic meters per year.[4] Because these poor countries cannot afford to buy the new high-tech water filtering resources the people are finding new ways to reuse waste water and desalination and treatment.

More than 80% of water resources in some countries are consumed in agriculture. The water that is fed to these crops is reducing the availability of water to humans in these areas. The wastewater in these cities could replace to demand for fresh water. If the water was properly cleaned and handled the agriculture output would increase. The use of decentralised and semi decentralised sanitation systems is a cheaper and easier way for countries to reuse household water or rainwater. It first separates the household water into four categories. Tailored technologies are applied to treat the various wastewater fractions and the reintroduction of treatment products into the material cycle.[5] As technology advances the systems get more expensive, but the poorest countries now have a way to reuse the water that they do have so that they aren’t as scarce for water. Not only will it help the people of the country but it will help the country economically with the growth of agriculture. The nutrients in the wastewater help the vegetation which is a great contributing factor in these poorer countries’ economies.

[1] http://www.howitworks.net/how-water-filters-work.html
[2] http://www.howitworks.net/how-water-filters-work.html
[3] http://www.howitworks.net/how-water-filters-work.html
[4] http://www.prb.org/Publications/PolicyBriefs/FindingtheBalancePopulationandWaterScarcityintheMiddleEastandNorthAfrica.aspx
[5] http://www.ete.wur.nl/UK/Projects/DESAR/