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biodigester

Biodigestion in Action

Over the course of the last several weeks, Island School students spent time kayaking, experienced a hurricane, explored the majority of the island, and additionally, were able to gain intimate knowledge of many of the systems that make the campus run. Most notably, aquaponics, aquaculture, permaculture, and biodigestion were featured as Human Ecology modules during the kayak rotation. During the students' time learning about biodigestion, they were asked to take a look at the ways Island School falls short of its goals of self sustainability and try to find some solutions. In doing so, students' learned about the systems that support human life on campus, where waste comes from, how humans get energy, and how we can improve as a community. The focus of their work was mainly turning waste to energy, which led to some hands on work with the biodigestion system. Students learned about the anaerobic process, how biodigestion mimics natural systems, how renewable energy is generated by microbes, and eventually how to put that energy to use. After dinner circle on Wednesday, students ventured to the biodigester to check out some of the applications of biogas. They observed running the gas through a conventional burner system and explored possibilities for how this campus system could develop into the future. [slideshow]

Building Bridges Abroad: Bradley and Garneisha Return From Training in China

[slideshow] The Island School and The Embassy for the People’s Republic of China celebrated a growing partnership this summer as the Embassy welcomed Bahamian Environmental Steward Scholar alumni (BESS) and Island School alumni Garneisha Pinder (F'10) and Bradley Watson (F'08). Pinder a rising sophomore at The College of The Bahamas and Watson a rising senior at College of Charleston, attended the Training Course on Bio-gas Technology for Developing Countries on May 15th - July 9th. You can hear more about their experiences on our previous blogs about biodigestion, genetic engineering, and making biogas from straw.

The focus of the training was how to effectively create and utilize bio-gas—a process which takes organic wastes like sewage and agricultural runoff and converts them into methane gas, a clean-burning fuel with many applications, such as cooking and heating. This end product is a renewable energy source for both urban and rural areas of China and can be applied anywhere else in the world.

The partnership between the The Embassy for the People’s Republic of China and The the Island School has continued to grow since a visit to campus by the His Excellency Hu Shan last April. During the visit, His Excellency Hu Shan helped open the Cape Eleuthera Institute's Hallig House and toured the school's pilot first-in-The-Bahamas biodigester and biodiesel facilities. The school plans to use both human and pig waste to generate enough energy for cooking food and heating biodiesel. Seeing the work being done at the Island School prompted the Ambassador to offer scholarships to two Bahamian students for the 56-day training course.

The students' aim of the program is to share and implement the renewable energy technologies that they they learned in China in their local communities and throughout The Bahamas. Both Pinder and Watson were exceedingly grateful for the opportunity and experience. "We learned so much about sustainable energy production, with applications for right here in The Bahamas, and I'm excited to put it into practise,  Development in industry, and agriculture should not compromise the environment and I can see biodigestion technology playing a part in reducing the negative impact such development can have on countries like the Bahamas." said Watson.

Growing Power!

Last week The Island School orchard received its first dose of steroids from the biodigester. The Island School biodigester uses naturally occurring bacteria to generate renewable energy and sterilize our septic waste. The outcome? Highly nutrient rich, liquid fertilizer that has the potential to increase crop yields substantially. In some cases, certain crops have increased their yields by up to sixty percent with the addition of biodigestion effluent. A resource such as this could work wonders for both CEI and Island School as we are always seeking more local food sources and readily available, healthy snacks. With a bit of sunshine to go with these nutrients, we could eventually put the marina store out of business. Coming into season right now are sour oranges, guava, mango, sugar apples, cherries, coconuts, sapodillas, and passion fruit. Pick your poison. The next questions to ask are how much food can we make and how fast? What does it take to ween ourselves of imported fruits and vegetables? A large part of the answer is our biodigestion system that is already producing for us on a daily basis. [slideshow]

Water Quality Testing and the Biodigestion Process

Water is the most important resource available to CEI and Island School. We drink it, we bathe in it, we cook with it, and it all comes from the rain. Although we can never know what the weather may bring us, we can always be ready to take advantage of what does come our way as weather patterns shift. To that end, we use solar panels, and wind turbines, but most importantly, we catch rain water. Of late, one of the most important issues we've been tackling is how to make our water last and how to maximize it's potential. If we catch water once, how many times can we use it before it's gone? Last week we took a significant step towards increasing the usefulness of our water. This spring CEI and Island School put biodigestion on the map for The Bahamas. We've found a way to treat our waste and generate more renewable energy, in addition to getting added utility from our water. The process of biodigestion  generates energy while simultaneously eliminating odors and pathogens from organic waste streams; we ran some tests last week to find out just how well our newest system was working. Through applying some basic laboratory tests, we found that our biodigester has successfully eliminated all harmful bacteria from our waste water, including E. coli. Knowing that our water is safe for human contact applications, we can now apply the effluent from our biodigestion system to food producing trees and crops in the orchard and around campus. With the luck of some good weather, we can begin making more food more quickly, closing the loop between ample waste management and food production.

[slideshow]

Update from Bradley Watson and Garniesha Pinder in China: Turning Straw into Bio-Gas

Yesterday we visited a Bio-Gas plant that processed mostly straw into Bio-Gas. Just as straw is more difficult to process for animals than grains, it is also harder to produce Bio-Gas from than manure or sugar filled waste water from breweries. The molecules that make straw stiff also make the energy contained in the straw difficult for the bacteria in a Bio-Digester to access and convert to methane gas and carbon dioxide. This plant takes the straw and grinds it into a fine powder and then mixes this powder with warm water before feeding the mixture into a 500 cubic meter Bio-Digester. Grinding the straw makes it easier for the bacteria in the digester to break it down. The other unique thing about this plant is that they recycle the water used in the digester. The digested straw powder is separated from the water mechanically and the water is recycled through the system. This also maintains a steady population of bacteria in the system and eliminates the need for mixing of the digester contents. [slideshow]

This project’s startup was subsidized by the government and encourages farmers in this semi- rural community to transport their waste straw to the plant instead of burning it by offering them bio- gas at production cost. This production cost is very low because the system only requires two people to run it. On the other hand customers who do not contribute straw to the system must purchase Bio-Gas from this plant at a price slightly less than what they would pay for Natural Gas. Customers access the biogas they purchase through a distribution grid for use as cooking fuel etc.

Another note about this community is that it is near the airport and farmers used to burn their straw, which could be considered a post-harvest crop residue, instead of trucking it away. Another option they had was to truck the straw to a paper mill that would purchase it at a relatively low price. The competition between the biogas plant and the paper mill has increased the price of straw in the three years since the plant began gas production. The result is far less air pollution from burning straw and farmers can earn more money for their crops. The digested straw also serves as a good fertilizer and farmers can pick it up at a lower cost.

As countries develop and industrialize people tend to leave rural areas for urban ones in search of a better quality of life. Sadly these first generations of urbanites are often subjected to discrimination when the reach the city due them speaking a different dialect or lacking the quality or level of education a city dweller may have. They may lack the social support network they need in this new home as they search for work and raise children, and many are forced to leave their children behind. Considering this I can truly appreciate the benefits of Bio-Gas production and any other means of improving the quality of life of the rural population. Visiting rural areas has been one of the highlights of this trip for me, the air is fresh, the roads aren’t as hectic, and the people take the time to smile and try to get to know you if you make the first step.

Much Love,

Bradley