Composting is a treatment process that facilitates the decomposition of organic matter in an oxygenated environment and creates a nutrient-rich fertilizer or soil amendment. Food scraps, landscape trimmings, wood products and animal byproducts can all be composted. There are five criteria to monitor when composting:

  • Nutrient balance
  • Particle size
  • Moisture
  • Oxygen
  • Temperature

There are four types of industrial composting, each of which requires specific nutrient balances and feedstocks:

  • Vermicomposting: composting in an enclosed bin, facilitated by worms that break down the compost
  • Aerated (turned) windrow composting: composting in piled rows (“windrows”) with periodic aeration via manual or mechanical pile turning
  • Aerated static pile composting: composting in a large pile that is aerated using either/both ventilation ducting or organic bulking elements (i.e. wood chips)
  • In-vessel composting: composting in a large, enclosed container that monitors and controls the five criteria listed above. Aeration is typically managed through mechanical turning systems within the container