|
by JETRO Los Angeles, Stefan Vos
One out of six people lack access to safe drinking water and two out of six lack access to sanitation, noted David Peterson, CEO & President of Great Circle Water, during his March 25th presentation at the JETRO LA Office. Peterson discussed water issues and his own company's role in solving them as part of JETRO's 4th Tuesday Tech Exchange series. Over 20 people attended his talked, reflective of the growing concern about water issues in Southern California.
One of the misconceptions is that there is a finite supply of water that stays constant. In reality, there is a finite supply of water that is shrinking because we are taking water out of the ground faster than it can be replenished and climate change is causing glaciers to shrink. Global water supplies are down 30% since 1970. At the same time, population in the 20th century has tripled while water use has increase six fold. Population is the main stress on water.
Irrigation accounts for the largest amount of water usage. Worldwide, 66% or water is used for irrigation. In the U.S., that number is around 80%. Only 1% of water in the U.S. goes to residential use, according to Peterson.
There are two main sources of water contamination: organic (bacteria, etc.) and inorganic (heavy metals, salts, etc.) We want drinking water to be low in both, while water used for cooling powerplants can be high in salts and water for agricultural use can be high in organic compounds.
The lowest energy method of obtaining water is from surface water, but this is available limited quantities. Water can also be obtained from pumping ground water and through desalinization, but the purification involved in each method uses more energy, desalinization being the most energy intensive. 19% of electricity use in L.A. is water-related, much of the cost coming from the fact that the water is pumped from far away.
Depletion of groundwater can lead to saltwater intrusion in areas along the coast. As the salinity of groundwater increases it forces farmers to switch to salt tolerant crops and this can have an economic impact. An example is areas in California where strawberry farmers have been forced to switch to growing less valuable artichokes to cope with increased salinity. Irrigation with high salinity water causes salt to build up in the soil and can make farmland unusable. An estimated 1-2% of irrigated land in the world is being lost because of salt building up in the soil.
Another source of contamination that was recently in the news is from drugs. Pharmaceuticals were recently found in waste streams and water supplies effecting 41 million Americans because of the amount of un-metabolized pharmaceuticals passing through the human body and entering the sewer system. While the effects of these drugs in small quantities on the human body is unknown, there have been reports of male fish developing eggs due to estrogen exposure from treated waste that has entered rivers. It seems that most human activities are the source of some form of water pollution.
Although the many water problems we face paint a bleak picture, there are solutions. The most effective and low cost solution is conservation and recycling. Unfortunately, recycled water is only 0.5% of the U.S. water supply. There is also now concern regarding drugs in recycled wastewater, which current purification processes don't remove. Desalinization, which removes salt by passing water through a membrane, and piping in water from far away are also solutions, but both are energy intensive and costly. In Peterson's view, U.S. needs to improve our recycling of water. One example of a country doing well in this area that Peterson points out is Japan, where over 70% of water for industrial use is recycled.
This brings us to the concept behind Great Circle Water. Agriculture is the largest usage of water worldwide, so finding ways of effectively providing water suitable for agriculture will go far in alleviating many of our water concerns. Currently, water that is purified for agricultural usage is cleaned to the standard of drinking water, when it doesn't need to be. In fact, plants would actually benefit from minerals and nutrients in the water that are not acceptable for drinking water. What Great Circle Water does is recycle sewage to a standard suitable for irrigation, removing pathogens while leaving in the minerals and nutrients.
There are several benefits to using recycled sewage water for agriculture. The first is that it is illegal to dump heavy metals into wastewater so these will not need to be filtered out by the system. Also, when the water is used for crops, bacteria in the soil will break down any pharmaceuticals that might be in it, so risk from that contaminant is eliminated.
Since the removal of nutrients and minerals from a water source is the most energy-intensive and difficult part, not doing so greatly reduces the cost of treating the water. Great Circle Water's system is a decentralized unit that is built into an 8'x7'x20' universal shipping container for easy transportation. The unit can generate up to 50,000 gallons of irrigation-quality water a day and it can be attached directly to a sewage line for on-site treatment, which eliminates the cost of moving the water to a centralized facility and back.
The unit does not consume chemicals or use membranes, so the cost of operation is almost entirely the cost of energy. The system uses vortex separation, expandable media filtration, gas floatation and UV disinfection to purify the water. This process also eliminates the noxious odor associated with sewage, so the end result is water that looks and smells good.
Without the complexity of membranes or the consumption of chemicals, the system has a smaller footprint than comparable systems (about 1/4 the area), it is reliable, fully automated with failsafes and it has a 40 minute throughput time, whereas other systems typically take up to 18 hours from when the water first enters the system to when the purified product comes out.
It costs about $5 and uses about 4kWh to treat 1000 gallons of sewage, which is competitive with systems dedicated to treating sewage and much less than the cost of piping in water from far away. Considered from this aspect, the irrigation water produced is just an added benefit. The portion of the sewage that is not treated gets passed along the sewage line to the centralized sewage treatment plant in a form with a greater concentration of solids that is easier for them to handle, so it reduces load on centralized facilities.
Great Circle Water is also working with a company called Microbetech to transform some of the nutrients and minerals in the water into benign byproducts. Microbetech supplies microbes that Great Circle Water uses in their holding ponds to maintain clear, odor-free water suitable for irrigation. Their first customer is the Links Golf Course in Colorado and, according to Peterson, 6 of their systems could supply water for a typical golf course.
Peterson has worked in the water industry for over 20 years and says Great Circle Water's system is the best he's seen. The company has patents in the U.S., China and Israel, with patents pending in Japan and Europe. Great Circle Water appears to solve a number of problems related to the greatest usage of water in the world and it is a great example of a company based in Southern California using innovation to solve a global crisis. With the efforts of Great Circle Water and the many other companies striving for the same goal, solving our water problems might not be so expensive as everyone thinks.
 |
Subscribe to this comment's feed