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Ecological Wastewater Treatment
Ecological Wastewater Treatment is a treatment system that relies on living organisms such as plants and bacteria to break down the biological nutrients and chemicals in wastewater. The purpose is to purify wastewater using strategies that mimic naturally occurring ecosystems. These ecological design strategies include employing flora and fauna as a way to treat wastewater6. It is not only an attractive solution, but one that is less invasive and energy intensive as compared to some other water treatment mechanical systems. The exact ecological design of the wastewater treatment system is dependent on the location2.These local contexts include natural, economic, social, and religious conditions and the type of structure that the wastewater is servicing. The scale of the treatment systems can range from individual households and schools to commercial buildings and large-scale communities7.

Methods
Ecological wastewater strategies have been around since the 1980s and have been implemented in solutions across the globe. However, ecological sanitation is not based on any one system. In every ecological wastewater system strategies there is a need for holistic and closed looped systems approach11.The ecological wastewater treatment employs the same fundamental strategies as typical wastewater treatments, but use highly varied organisms. These include, algae, aquatic plants, marsh plants, worms, crustaceans, mollusks, and vertebrates—supporting the populations of bacteria that break down wastes and eliminate nutrients from the wastewater. The implementation of these organisms is meant to replicate naturally occurring ecosystems like those seen in ponds, ponds, wetlands, soil infiltration, soak pits, and nonplanted filters. 10 In nature, bacteria and other small organisms in water consume organic matter in sewage, turning it into new bacterial cells, carbon dioxide, and other by-products. The bacteria normally present in water must have oxygen to do their part in breaking down the sewage. Scientists observed that these natural processes can be contained and accelerated in systems to remove organic material from wastewater. With the addition of oxygen to wastewater, masses of microorganisms grew and quickly metabolized organic pollutants. The excess microbiological growth can be removed from the wastewater by physical processes. 13

Treatment Process
In typical wastewater treatment processes, the initial stage in the treatment of domestic wastewater is known as primary treatment. Coarse solids are removed from the wastewater in the primary stage of treatment. In some treatment plants, primary and secondary stages may be combined into one operation. At many wastewater treatment facilities, influent passes through preliminary treatment units before primary and secondary treatment begins. In a typical ecological system the following treatments occur when the raw municipal system enters the system:
 * 1) Open Aerobic Reactors – This is typically the initial step and acts like a septic tank. It is covered and below grade. The purpose here is to reduce concentrations of BODs (the amount of dissolved oxygen that must be present in water in order for microorganisms to decompose the organic matter in the water, used as a measure of the degree of pollution, also known as Biochemical Oxygen Demand)
 * 2) Clarifier(s) – These are in place to promote the growth of microorganisms while also removing a significant portion of the incoming BOD (Biochemical Oxygen Demand)
 * 3) Ecological Fluid Beds – Mixing is accomplished through aeration by course bubble diffuser. Settle biosolids from clarifiers and nitrified process water from the final open aerobic reactor – recycle back.
 * 4) Closed Aerobic Reactor – The dissolved wastewater BOD is reduced to low levels. Odorous gases are removed through nitrification. The filter is over the reactor.
 * 5) Clarifier – Promotes growth of floc-forming microorganisms.
 * 6) Constructed Wetland – A series of aerated tanks, closed aerobic reactor in design. Instead of being covered with a biofilter – the surfaces of the reactors are covered with vegetation supported by racks. The plants promote microbial growth, nutrients, insects, microorganisms, and aesthetics7.

Within the treatment process the following reactions occur: sedimentation, filtration, clarification, absorption, nitrification, denitrification, volatilization and anaerobic decomposition and aerobic decomposition16.

Benefits
Around 80% of all wastewater is disposed into the world’s waterways every day due to poor water planning and infrastructure. Over the next 20-50 years – 800,000 new urban residents will be added every week to existing and new cities around the world – which refers to wastewater production as well. Ecological Wastewater treatment solutions are favored because they are low impact and require no mechanical devices, which results in a lower energy impact8.The energy that is required is used to power the pumps and circulate air through the tanks. The Living Machine technologies specifically have found a 25% reduction in energy costs. In addition there is no need for a large-scale pipe network which results in low construction costs, convenient implementation and operation, and easy recovery and utilization of water. The operating costs included for these ecological wastewater systems are labor, energy, and chemicals. Labor costs for ecological systems are often similar to typical wastewater treatment facilities.11

Approaches and Types
There are many ways to approach recovering and treating wastewater in a closed loop system. This has resulted in various types of Ecological Wastewater Treatment Systems seen in the industry. These types have been employed in small and large scales and are continuously being changed and adapted. They all employ the same methodology as those techniques seen in ecological wastewater management, but often go by different titles. Examples of these are as follows: the Living Machine, Eco Machine, Solar Aquatic System, the Biomatrix, green walls/roofs, etcs. 6

Living Machine
The Living Machine (trademark) was conceived by Dr. John Todd, President of the non-profit organization Ocean Arks International. The Living machine is a wastewater treatment technology that uses multiple tanks that support vegetation and several other organisms with the primary goal to produce clean water. The typical Living Machine comprises six principle treatment components, after influent screening. In order these are (1) an anaerobic reactor, (2) an anoxic tank, (3) a closed aerobic reactor, (4) aerobic reactors, (5) a clarifier, and (6) “ecological fluidized beds” (EFBs). 6 The following is described of this ecological wastewater treatment20:


 * 1) Able to achieve tertiary treatment: which is defined as – the final cleaning process that improves wastewater quality before it is reused, recycled or discharged to the environment. The treatment removes remaining inorganic compounds, and substances, such as the nitrogen and phosphorus.
 * 2) Costs less to operate than standard wastewater treatment systems.
 * 3) Doesn’t require chemicals that harm the environment.

Port of Portland
The Living Machine system was integrated into the Port of Portland headquarters building in Portland, Oregon. It helps to reduce water use by 75% and is now one of the world's greenest buildings. The Living Machine technology is the “centerpiece” for the green building strategy in the Port of Portland project. The Tidal Flow Wetland Living Machine is the central design feature in the lobby and along the front walkway on the outside of the Administrative Office Building. After collection and initial treatment of the wastewater in a primary equalization tank, the water flows to the Living Machine. This system is used for secondary and tertiary wastewater treatment. It is made up of 6 tidal flow basins and one vertical flow basis. The system treats up to 5,000 gallons of wastewater a day and then uses UV light to ensure the complete deactivation of bacteria before the wastewater is pumped back up to the office to use in toilet flushing.19

Findhorn Eco Village
Findhorn Village an architectural community project based at in Moray, Scotland, near the village of Findhorn. The project's main goal was to design a sustainable development in environmental, social, and economic terms. Here, the ecovillage and ecological wastewater management techniques were employed on a large-scale community. Although many techniques were put in place to attain sustainability, one of the most important was the implementation of the Living Machine.6 Like many other solutions using the Living Machine, Findhorn uses tanks containing communities of bacteria, algae, micro-organisms, numerous species of plants and trees, snails, fish and other living creatures to treat the water. These tanks are housed in a greenhouse facility.24

Eco Machine
An eco-machine is an ecological wastewater treatment system that uses plants and microbes, and is enclosed in a greenhouse or in external constructed wetlands with aquatic cells inside a greenhouse. The concept of the eco-machine is often used interchangeably with the Living Machine technology, designed by John Todd.23

The Omega Institute for Holistic Studies
The Omega Institute is a building that services the study of holistic health, psychological inquiry, world music, art, meditation, and new forms of spiritual practice. The design team employed the Living Building Challenge strategy in the development of the building. 25

The Omega Center employed the use of an Eco Machine to return a higher quality of water back to the earth using natural systems. The building treats up to 52,000 gallons per day of wastewater using a combination of outdoor constructed wetlands and aerated aquatic cells housed within the greenhouse serving as the main space of the building. Wastewater is collected through the campus and sent to two equalization tanks that allow for the system to be constantly pumped over a wide range of flows, which is all dependent on occupancy of the building. For toilet flushing, rainwater is collected from the Omega Center’s roof. For all other water use on campus, black and graywater is sent to the Eco Machine lagoons and constructed wetlands at the Omega Center for purification. The entire system (in order of process) includes (1) Septic Tanks (2) Equalization and Anoxic Tanks, (3) Constructed Wetlands, (4) The treatment Lagoon, (5) Recirculating Sand Filter, and (6) Irrigation and Dispersal Fields. The average process from flushing a toilet to the return of the treated wastewater underground takes about 36 hours.25

Solar Aquatics
Solar Aquatics system imitate natural wetlands processes to treat natural wastewater. Unlike mechanical treatment processes, these systems can adapt to changing effluent quality better than typical mechanical and chemical systems. Solar Aquatics Systems treats effluent to advanced secondary and tertiary standards through a series of aerated tanks. The tanks during the treatment process use sunlight, oxygen, bacteria, algae, plants, and irrigation of plants. It is used on indoor planters and exterior landscapes, flushing toilets, groundwater recharge. 26

Bear River
Established in 1995 this project was a development between Annapolis County and Government of Canada. The Bear River Solar Aquatics waste treatment facility looks like a greenhouse. It is 2400 SF and has 12 solar tanks holding various organisms that process and filtrate wastewater. In the tanks there are algae, zoo plankton, phytoplankton, snails and plants. The processes involve denitrification, nutrient uptake and removal of phosphorus. The Bear River Solar Aquatics Wastewater Treatment Facility is can to process 15,000 gallons of wastewater per day.26

Biomatrix
Biomatrix Water is an ecological technology company working on ecological wastewater treatment. The company was founded in Moray, Scotland, in conjunction with the Findhorn Eco village. In addition, the founders of the company founded the Living Machine technologies.6 The Biomatrix technology uses “natural wastewater technologies” to treat water. These include Helix flow reactors, wetlands, and floating engineered products.