Innovative, creative, and simple ways to can water good enough to drink!!
The use of solar is becoming increasingly poplar as a source of energy. By capturing this technology and manipulating it to treat water is rather simple. It has been used since the 1800’s when it was invented to deliver drinking water to miners using a high nitrate brackish influent. Since then, solar distillation is increasingly becoming a common method for supplying clean drinking water.
The method is really simple: solar heat increases water temperature to where it is evaporated into the atmosphere, captured and collected. It is basically creating a man-made cloud and making it rain. This ‘collected rain’ will be free from salt and microbes, making it then, safe to consume.
Dirty water is put into a container or basin that has a blacked out bottom. Then it is covered with glass that is at an angle, allowing the clean water to collect or drain. The sun heats the water causing evaporation and condensation to collect on the glass. Since it is covered at an angle the condensed water moves down the angle cover to collect in a separate container. Water in the feed should be added in order to clean out the basin.
The size of these systems can be large or small, however their production is somewhat limited. A system set up for a family can create up to 3 gallons a day. This is a great option for those communities that suffer from drought because these areas tend to have a hot climate great for distilling salt contaminated water sources. In some areas the contaminated water source has a built structure directly on the source to create a greenhouse-like effect.
The technology is remarkably simple and somewhat inexpensive. The basin where the feed water is located should be shallow and of a dark color such as black in order to absorb the heat. Choosing a cover such as glass allows for the solar energy to go through without becoming the same temperature as the basin, hence the creation of condensation.
There is a possibility of recontamination in the catchment system, so it is recommended using a PVC plastic piping made specifically for water systems. The reason being that some PVC pipes degrade in time thus releasing various chemicals which can be dangerous to consume. There are pipes made specifically for water systems and are manufactured to avoid this danger and would be clearly identified at any hardware store. Another way to minimize contamination is to leave the materials to build the solar distiller in the sun for approximately a week so that any chemicals will be ‘burned’ off and released without it entering into the water system. Also, a disadvantage of this process is that the gathered water is tasteless. By adding a small amount of chlorine (5 drop per liter) or by allowing the water to flow through marble to obtain some lost minerals. Both of these methods will make the water taste better.
The United Nations states that the cost of solar distilled water is $3-6 per 1,000 gallons. This is less than buying bottled water, but a bit more expensive than the average municipal supplied water. However, although it is a little more expensive, there is more guarantee of cleanliness in the context of variations of municipal drinking water quality around the world.
According to the University of Central Florida, who specializes in solar distillation research, ‘if it costs about $40-60 per square meter to build the still and it is worth roughly $15 USD per 1,000 gallons, the still should pay for itself in 2,500 to 4,000 days or 7-11 years.” This is a great idea as the prices of water rise and the valuable resource becomes scarcer.
Distillation by solar energy has been used for a rather long time and is widely accepted by both water quality engineers and those communities/families/persons who use and maintain these systems. This choice for obtaining clean drinking water is most effective where somewhat clean water is difficult to come by or where there is a shortage in water supply. This is because it may be most beneficial to pump and purify where water is more plentiful.
The simplicity of this method and the result of quality drinking water is ideal in humanitarian assistance and natural disaster emergencies. It is worthy of being a viable option to increase clean water consumption.
UV treatment for drinking water is a technology that dates back to 1916. It’s one of the most popular means of treatment for drinking water and is used in a lot of RO plants. What it does is use UV-B waves of 280-315 nm to put water into the ‘germicidal zone.’ Some UV-C of 200-280 nm is used with a little longer exposure times, but these two UV types are most efficient at deactivating bacteria, viruses, and protozoa.
Now, the deactivation is what is so unique about this type of treatment, it doesn’t kill anything, instead it rips the DNA and RNA proteins and bonds rendering these microorganisms inactivated. Basically, meaning they are prevented from reproducing. The UV light damages the DNA and RNA and when a microorganism cannot reproduce, it cannot infect. BUT, microorganisms are highly evolved sneaky little guys that also have the ability to repair the bond breaks caused by UV light. To enhance the effectiveness of the treatment, adding some type of chemical usually chlorine to further disinfect is used or you can drink it quickly before these bonds are repaired usually within a few hours or days.
What are potential advantages and disadvantages? (Thought you would never ask!)
A disadvantage is that UV depends on a constant energy source, inaccurate measures of dose, and a lack of residual after treatment. If UV treated water is to be stored, then chemicals should be added as a disinfectant in order to prevent the reactivation I just mentioned. Another disadvantage is if using the mercury lamps, they must be disposed of properly due to the toxicity (not likely in a HA/DR situation) and therefore further investment into UVLED lamps is recommended although not as affordable. There are also potential risks for UV treatment, exposure to mercury again if using a mercury lamp, formation of disinfection by-products, and exposure to UV light from the device, all of which are considered to be minimal and doesn’t really happen, so moving on…
The advantages are using a physical method over chemical, which does not leave any by-products, extremely effective against protozoa, inexpensive and quick process to drinking water treatment. UV is easy to install and requires low maintenance costs. There is not any kind of chemical taste or smell and is not all that sensitive to pH or temperature. It does not take any minerals out of the water, improves taste because it kills some organics, requires little contact time, has no smell, has no volatile organic compound emissions, and is recently acknowledged in water treatment journals as a Cryptosporidium control.
UV technology is highly accepted in conjunction with another form of disinfection. It is mostly used on a large-scale community level and can be found all over North America and Europe.The design and instillation of large-scale water treatment projects in other countries also adopt this technology as part of their process. In a household, this method is not seen as often, but it is also great for humanitarian assistance and disaster relief applications. It is rather common to see UV as a treatment process during times of disaster and crisis due to the effectiveness of the treatment and the quick contact time, this method is remarkably efficient in delivering clean drinking water quickly. They are also portable and lightweight, which makes these systems even easier in times of need.
Costs vary from US$0.02/m3 to $US2.35/m3 for operating and maintenance of the system. It is affordable for low-income residences and communities, and environments with minimal electrical and water infrastructure. The initial investment of US$41 estimates for a household level and up to US$244,419 for the most up to date technology measuring high volumes (found in large treatment plants). The average for a community size UV treatment is between $300-900 USD.
So, to UV or not to UV? Is there even a question?
Kinda looks like the lightsaber of water treatment. Off to fight the Darth virus!
Activated Carbon is basically charcoal that has been heated up in order to increase the absorption of hundreds of different types of compounds that cause a discoloration or odor in water. Charcoal is highly porous, I’m sure you have noticed when you BBQ and pour lighter fluid to start the fire, it’s quickly absorbed. In water treatment that absorption works to take out organics and a catalytic reduction attaches negative ion contaminants to the positive ions of activated carbon. With these two processes working together it removes thousands of organic compounds and chemicals like chlorine, pesticides, herbicides, radon, VOC’s, and benzene. However, nitrates and salts slip right through. It soaks up almost everything, but there is a limit. These bonding sites DO have an expiration. Once all the spots of the activated carbon are filled it no longer works. This is why it is important to replace your water filters at home.
Chlorine is added during the treatment process in order to kill bacteria and viruses that can make you sick, however there are by-products such as THMs and HAAs that are carcinogens and found in almost every tap in the U.S. From using an activated carbon system, these traces will be removed. When you turn on your tap and drink water you are not only drinking what has been treated, but also what the water has picked up from traveling miles in various pipe systems that are usually 30-40 years old. My point is, overall it’s not going to hurt you to just drink tap water in the U.S., but you can make the water you intake healthier.
Ideally, water that is the best for the human body is a little bit alkaline meaning needs some Mg2+ and Ca2+. This is where the term hard water and soft water are commonly used, because we don’t want an excess of either. This balance is best achieved with filtering your water through an activated carbon system giving your water the little bit of the alkalinity you need. Overall, with the things I have seen in my travels with water, nothing you drink in the U.S. is going to hurt you, but when you are able to see what other people are drinking, our water is beyond incredible. However, if you have the time to replace the filters every 1-3 months and can afford it, then it will be better for you and your family.
Just do NOT forget to REPLACE the filter otherwise you wait a long time for the water to trickle through a maxed out activated carbon system for a glass of water that is the same thing as the tap.