DESIGN

Again using the Findhorn example, the Living Machine ® is housed in a single-span greenhouse, approximately 10 Metres (M) wide by 30 M long. The flow from the Park at Findhorn has a loading of approximately 300 person equivalents. In other words about 50m3 waste water per day.

Anaerobic Primary

The first component of the treatment process is 3 anaerobic bioreactors buried outside the greenhouse. The function of this component is to reduce significantly the organic material and inorganic solids in the wastewater. During operation, no oxygen will be present in the wastewater, promoting the growth of anaerobic and facultative bacterial populations.

Closed Aerobic Reactor

Effluent from the anaerobic primary, flows into an closed aerobic tank in the greenhouse. Gases from the closed aerobic, pass through an filter system to eliminate odours.

Open Aerobic Reactors

The four aerobic tanks have diaphragm aerators and are planted with plant species with large root masses on floating plant racks. The BOD and TSS is reduced at this stage and ammonia nitrified.

The primary function of the plants is to provide favourable environments for enhanced microbial activity. Secondary functions include nutrient removal, metal sequestering, pathogen destruction and some control of gas exchanges. The main objective is to have a healthy and diverse sequence of ecosystems present. The wide variety of plant species filling ecological niches in the system is a key to the robust nature of natural treatment systems. The ecological network of species creates internal biological redundancies compared with a purely microbial system, or a monoculture duckweed system. This gives the potential for improved efficiency and greater resilience.

The Clarifiers

After the aerobic tanks, a clarifier settles solids which are returned to the anaerobic primary. In those tanks you may see tiny water creatures such as Cyclops living in the water. They perform an important part in both treatment and creating a complex food chain

The Ecological Fluidized Beds

The three Ecological Fluidized Beds in each train are filled with light rock media. For aerobic operation, air lift pumps raise the water from the bottom of the fluidized bed to the surface, where the water flows down through the bed. Recycle rates can be varied up to 100 times the flow rate through the component.

The aerobic operation provides reductions in BOD and TSS and nitrification. For the anaerobic operation of the fluidized beds for denitrification, mechanical pumps circulate water up through the bed. The fluidized beds are planted and benthic animals graze the surface.

The first fluidized beds can be run anaerobically to denitrify. The second fluidized bed is run aerobically using air lift pumps to further nitrify any remaining ammonia in the waste stream. The third and final fluidized bed is run for final denitrification and polishing.

The underlying concept behind the design, involves rapid flows of water by recycling through the media filled zones. The key attributes of an Ecological Fluidized Bed are:

The biology is managed as a balanced ecosystem. The levels of dissolved oxygen, and carbon to nitrogen ratios, as well as recycle rates and bioaugmentation, are adjusted with the overall objective of reducing levels of BOD, ammonia, total nitrogen, faecal coliform and solids.

The Greenhouse

The greenhouse is built from a galvanised steel frame, clad in high performance glazing. The walls are 10 mm polycarbonate. The roof is composed of high light transmission panels, with good thermal efficiency.

THE FINDHORN FOUNDATION LIVING MACHINE ® PROJECT

The Living Machine ® is designed to treat a maximum of 65 M3/day to tertiary standards in an aesthetically pleasing greenhouse. The scale of the components provides data and operating experience to wastewater treatment professionals and engineers, which will demonstrate that cost effective and reliable treatment can be provided by Living Machine ® technology.

This is a new means of treating domestic and industrial sewage, using biologically and environmentally sound methods to a higher standard than current EC standards. A Living Machine ® builds on the reed bed principle, but accelerates the process and uses considerably less land, as the facility is totally enclosed in a large greenhouse. As a pioneering pilot project, this facility is collecting data in order to satisfy local and national government bodies that such technology can be fully adopted in the UK. Local water and river authorities are supportive of the project.

A Living Machine ® was commissioned at the Earth Centre, Doncaster, UK in May 1998. The Findhorn Foundation is already a major educational centre which regurlarly hosts visitors from throughout the UK and overseas, therefor the establishment of such a treatment facility here will allow the technology to be seen and experienced by a wide variety of people.

Half of the funding for the project has been provided by the European Regional Development Fund, under the Highlands and Islands Objective 1 Programme (1994-1999). Funds have also been provided in grants and donations from Gaia Villages Trust, Denmark; The Paul Trust, Glasgow; The Lyndhurst Settlement, London.

There are 20 Living Machines ® currently operating and/or in design. They include:

Location - Waste - Flow (gallons per day) - Year of construction
Narragansett Bay, Rhode Island - Sewage - 16,000gpd - 1989
Paws Inc., Indiana - Sewage - 3,000 gpd - 1990
The Body Shop, Toronto - Sewage - 3,000gpd - 1993
Ballanger Creek, Maryland - Sewage - 50,000gpd - 1993
City of San Francisco, CA - Sewage - 50,000gpd - 1994
Audobon Society, Florida - Sewage - 7,500gpd - 1994
Wyong, NSW, Australia - Industrial Wastewater - 200,000gpd - 1995
Henderson Foods, Nevada - Industrial Wastewater - 32,000gpd - 1995
Findhorn, Scotland - Sewage - 18,000gpd - 1995
The Body Shop,U.K - Production Wastewater - 13,000gpd - 1996

For further information:

General Enquiries:
The Living Machine Operator,
The Findhorn Foundation,
The Park,
Forres IV36 3TZ,
Scotland, UK.
Tel: 01309 690154,
Fax 01309 691387.
E-mail: info@ecovillagefindhorn.com

If you are interested in building a natural waste water treatment system visit Living Technologies Ltd or contact:

Alex Walker,
Living Technologies Ltd.,
The Park,
Forres IV36 3TZ,
Scotland, UK.
Tel & Fax: 01309 691258.

Email : awalker@findhorn.org