2. Composting and Pasteurization

Composting and Pasteurization

Overview

Our final decision was that dry composting would be the optimal system for this area of the housing redevelopment and Community Centre. The key ideas behind composting include using a form of pasteurization to assure pathogen removal. The pasteurization will be done in a low greenhouse-like, ventilated space located to absorb maximum sunlight. The drum will be placed on a stand horizontally so that the drum can be rotated and the compost aerated and watered according to testing procedures. 

System Components

  • Composting Area
    • “Greenhouse”: 1 x 1 x 10 metres with transparent roof
    • Ventilated Space
    • Limited access
  • Drum Stand
    • Allows rotation of 200L drum for mixing
    • Holds drum horizontally
    • On wheels for easy moving
  • Ventilation control
    • Direct the flow of air using carefully designed electric and passive fans


Design Considerations and Specifications

  • Frequency of Maintenance: Feces 24 Kilograms, Urine 220 Litres
  • Facility Dimensions: L-shaped building
  • Testing Space: To be determined
  • Location: Optimal for sunlight exposure


Operational Plan

  • Remove drums from composting area after testing has confirmed that the waste is safe compost
  • Put in new compost barrels when full
  • Log book for caretaker to document date each barrel starts its composting process as well as other details of composting (learn more about the caretaker’s role and data collection)
  • Assuming compost is free of pathogens, apply compost to community gardens
  • Assuming compost is not free of pathogens, plan for further pasteurization methods and consult municipal waste removal services


Experimental Research Recommendations

Testing

  • Qualify best composting method.

Examine the effect of worms, effective microorganisms and no additives on the composting process and determine which creates the best compost. Evaluate cost, complexity, ease of use, amount of carbon additive needed, composting time, and compost quality.

  • Define need for urine divergence.

Examine the effect of urine on the composting process to determine if urine helps composting. For each case evaluate amount of carbon additive needed, changes in compost time, changes in compost temperature quality of compost, and volume reduction or increase.

  • Experiment with container design

Examine the effect of container design on the composting process to determine the most effective design. Evaluate cost, compost temperature, compost quality and ease of use.

  • Qualify the ideal type and quantity of carbon source added

Examine the effect of carbon additive on the composting process to determine the correct type and quantity of carbon material to add. Evaluate availability of material, changes in compost time, quality of compost, and volume reduction or increase.

  • Define ideal volume of compost in container

Examine the effect of airspace in the composting container on the composting process to determine the ideal fill volume. Evaluate compost quality, compost time, and compost temperature.

  • Quantify ideal compost time

Examine the effects of time on compost quality to determine the ideal composting time.

  • Define ideal turning/mixing of compost

Examine the effect of turning on compost quality to determine the ideal frequency of turning/mixing. Evaluate compost quality, compost time, and compost temperature.

  • Quality of edible plants grown in human compost

Examine the quality of different plants grown in human compost to determine possibility of using for food gardens. Grow a variety of plants in compost from facility and evaluate the pathogen content in plants.

Background Research and Discussion

To learn more about the composting process, see the Gardens Team Composting Discussion.

– Toilets, Urinals, and Primary Waste Management – Composting & Pasteurization – Improved Taps – Hand Washing Station – Laundry Station – Grey Water Management Scheme– Caretaker Office – Facility Perimeter –