So by modeling our human engineered systems on their natural counterparts, we can be aligned with the natural world and experience the benefits of integrated design. Engineering science adopts a whole systems approach, which leads us to the story of Living Machines™.
The basic principles in the field of ecological engineering were first put forward by Howard T. Odum in his book Environment, Power and Society over twenty years ago. The fundamental idea is that, in addition to modeling human designed systems on nature; we can use complete ecologies to carry out useful tasks. Living Machines™ are different from "dead machines" in that the main working parts are alive. Different ecologies can be linked to handle many inputs, self manage a multitude of internal, closed-loop functions and provide a variety of outputs.
We know that the pond, marsh and meadow are capable of generating the new and decomposing the old in complex ecological cycles. John Todd set out to use the ability of these natural ecologies to handle waste streams effectively and economically. The organisms that are present naturally in the pond, marsh and meadow are harnessed along with sunlight and gravity to handle pollution. Other inputs, particularly energy requirements from fossil fuels, are minimized. The primary product is water treated to advanced wastewater treatment standards, which is then available for reuse. In addition to the application of breakdown ecologies for purifying water, nutrients are recycled and useful products are grown, such as fishes and botanicals.
Ecologically engineered systems are capable of high levels of treatment. In fact, taking the last pieces of pollution out of a waste stream is often more economical using natural systems than with conventional and chemical processes. Also the beneficial features of natural ecosystems carry over to the engineered systems, including great stability of operation due to multiple biological pathways and diversity of organisms in the system, and the ability of Living Machines™ to self-organize, self-repair and self-replicate. We find that Living Machines™ treating food processing waste streams, where there are wide variations in influent characteristics, both in flows and loadings, provide stable high quality effluent.
A typical industrial wastewater treatment Living Machine™ is the Mars facility in Wyong, Australia. This food processing plant manufactures 350 products from over 1,300 ingredients, and produces a widely varying wastewater load. First the flow is equalized in a balance tank. From there it passed to an anaerobic digester, which provides a considerable amount of treatment, without the use of energy. In fact, if the organic loading is sufficient, methane can be produced which can be used for steam generation and so on. From the anaerobic reactor, wastewater flows to a closed aerobic reactor, which is connected to a biofilter. The biofilter consists of humic material, which is mainly bark and compost. The odors are scrubbed by bacterial action as they pass from the closed tank through the humic layer. The wastewater flow then passes to a series of open aerobic reactors, with plants racked on the water surface. The plant roots provide the media for the attached growth microorganisms that break down the organic materials in the waste stream. In addition any ammonia is nitrified to nitrite and then to nitrate. As the bacteria go through their life cycles and die, they form sludge, some of which is eaten by other creatures in the system such as snails. Living Machine™ sludge volumes are low compared to other wastewater treatment technologies, because the engineered ecologies digest organic materials as part of the process, however sludge needs to be removed in the clarifier, which follows the open aerobic reactors. The final step is polishing in Ecological Fluidized Beds (EFBs). These reactors were developed and patented by Ocean Arks International. They are fixed film submerged filters with a relatively high rate of internal recirculation.
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Natural Water Treatment from Ocean Arks International
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