Water Purification: the Solar Aquatics System

Meeting the needs of the people while minimizing environmental impact seems to be a theme of any excercise in the Galapagos. Perhaps the most basic of these needs is a clean water supply. Isla San Cristobal currently has traditional purification systems in place. (i.e. systems which incorporate concrete settling tanks and chemicals to remove impurities). This type of water purification system works, but Canadadian reseasrchers developed and implemented a better alternative which could be used to either supplement or replace the island's current water purification system. Their water purification method, called the Solar Aquatics System, utilizes a combination of natural biological and chemical processes to purify the water in an environmentally friendly, cost-effective, and asthetically pleasing manner.This process takes place within a greenhouse, and produces neither noise nor odor. It is currently in use in Canada, Mexico, and the United States.

A diagram of the process is as follows:


(OCETA)

"The wastewater flows through a series of biosystems where plants, algae and other organisms remove contaminants such as bacteria, organics, nutrients, pathogenic bacteria, suspended solids, and BOD." (OCETA) The final step of irradiating the effulent with UV rays kills pathogenic bacteria, and renders the water safe for surface use.

The Solar Aquatics System is extremely effective in purifying water. It has "achieved removal efficiencies of 97% BOD, 98% TSS, and 96% Ammonia Nitrogen" (OCETA). This is illustrated in the graphs below:


(OCETA - Operating data from the Ontario Science Center)

The scope of the Solar Aquatics System is well-matched to Puerto Baquerizo Moreno and San Cristobal (population ~5,000). It processes between 22 and 4500 cubic meters of water per day, which provides for roughly 100 to 20,000 people. This labor required by this method is minimal, as it consists only of tending to the plants. (Environmental Technology) It also is a tourist attraction for those interested in environmentally-friendly methods of waste management, and for those simply interested in seeing an enclosed Galapagos environment, since there is no reason why plants native to the Galapagos cannot be used for this process. (In fact, it would be illegal to import alien plants to do this, so using native plants is not only attractive - it is necessary!)

The Solar Aquatics System functions as an efficient and cost-effective water purification system, which is environmentally benign and is an effective venue for tourist attraction and education. Should San Cristobal's water purification system need to be modified, the Solar Aquatics System is the optimal solution.


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