The Living Machine & Leachate By Laura Llewellyn

Hypothesis The living machine will successful remove contaminants from leachate while remaining a healthy environment itself. The living machine will remove the contaminants found in leachate but some of the aquatic life will die in the process. The living machine will not remove a sufficient amount of contaminants found in the leachate.

Step 1- Anaerobic Reactor Leachate drains from reactors (left) To a septic tank (right) - Leachate manually transported to tank 1 Purpose: to reduce concentrations of BOD5 and solids

Step 2- Anoxic Reactor promote growth of microorganisms Settled bio-solids from clarifier can be recycled back into anoxic reactor Aerated Vented with plant bio-filter

Step 3- Closed Aerobic Reactor reduce BOD5, odors, and stimulate nitrification Aerated and mixed by bubble diffuser Usually covered with bio-filter

Step 4- Open Aerobic Reactor covered by vegetation Further reduce BOD5 and nitrification

More Open Aerobic Reactors size and number vary according to influent characteristics, effluent requirements, flow conditions and design Variety of plants is key

Step 5- Clarifier -settling tank for remaining solids -pumped back into closed aerobic reactor or removed

Step 6- Ecological Fluidized Bed inner and outer tank with growth medium inside the inner tank Water flows in circular motion from the outer to the inner tank Circulation periodically reversed by air pump to prevent sludge build up

Water Quality Tests over 5 week period Week 1 no leachate in system Leachate added during week 2 & 3 System design changed week 4

pH concentration of Hydrogen ions pH scale 1 (acidic)… 6.5-8.2 (aquatic life flourishes) 14 (alkaline/basic)

Dissolved Oxygen (DO) quantity of oxygen being used by water High DO- slow uptake by microorganisms Low DO- high demand from microorganisms DO increases with temperature

Specific Conductance = measured conductance (uS) 1+.019(field temp. - 25) - affected by presence of inorganic dissolved solids such as chloride and phosphate

Chloride Content - chloride contents doubled when leachate was added to the system

Nitrate Content nitrate can stimulate algae growth thus cause low levels DO Other Living Machines have goals <5 mg/L

Sulfate Content Potentiometric titration of pure leachate revealed .6 mg/L sulfide Sulfide is converted into sulfate Sulfate decreases around system

Conclusion The living machine is capable of handling the leachate. Improvements on design will increase the machine’s capabilities… Better flow of water around the system Less rocks where sludge can collect More diversity of plant life