Background:

• The most serious challenge facing humanity in the near future will necessitate curbing energy consumption while deriving sustainable uses of its resources.
• Beyond enhanced public awareness, international agreements signed during previous summits have given rise to regulatory and behavioral modifications intended to enforce the “3 R” rule, notably within the energy and environmental fields, i.e.: reduce consumption (improved efficiency), reuse byproducts or waste products, and recycle raw materials.
• This energy transition has been applied to the sanitation field in pursuit of a double goal: develop new technologies/approaches for limiting the environmental footprint and energy consumption of treatment facilities, while continuing to ensure discharge quality compliant with standards.

Project objectives:

• The overarching objective of the CAPTURE project is to satisfy the increasing need for knowledge on how best to implement innovative processes to extract and recover the pollutants contained in wastewater in order to accompany facility operators in transitioning from wastewater treatment plants to water resource recovery plants.
• More specifically, the ultimate aim of this project is to generate knowledge on two processes tested under controlled conditions at full scale: enhanced primary sedimentation (with next-generation organic coagulants) / a high-load activated sludge process (or an “A” process).
• The characterization of these processes is performed at three levels:
  •  characterization of performance (purification, hydraulics, applicable loads, associated sedimentation)
  •  characterization of the mechanisms involved (type of coagulants, nature of the organic fraction, characterization of the extracellular polymeric substances (EPS), proteins, microorganisms present)
  • characterization of the impact of inserting these processes on downstream steps (methanogenic power of sludge, residual MO fraction, nutriment reuse, nitrogen treatment).

Approach adopted:

• In order to maximize the energy extraction and recovery of carbon matter found in wastewater, it proves useful to extract the various fractions as quickly as possible. In this manner, the rapidly biodegradable fraction is conserved (rbCOD); in other words, this fraction must not be “lost” in the bacterial metabolism. As a corollary, the soluble and relatively non-biodegradable fractions will need to be separated. Both technologies examined within the scope of CAPTURE actually enable such a dual purpose; given the impacts on downstream treatments, this project is primarily intended to study the approaches as well as their consequences on the following steps:
  • Treatment of the nutriments remaining in the water stream
  • Nutriment recovery in the digestates output from sludge stream methanizers
  • Impact on the available water masses and their reuse attributes.

Project organization:

Capture project goals:

Applied research:

• Demonstration of the underlying reliability and robustness
• Adaptability of existing systems.

Adapting the environment to the 3-m³ reactor

Verification of the device during extended aeration:

• Replace the pumping system
• Verify the blowers and aeration system
• Design an adapted sedimentation tank.