INNOVATION May-June 2014

The potential use for this new technol- ogy is broad, says Skene, since it can be applicable to any biological wastewater treatment plant that produces waste sludge for disposal. Homogenizing Sludge Cells The idea for the MicroSludge technology started more than a decade ago in the UBC lab of 1993 chemistry Nobel Prize winner Dr. Michael Smith. High-pressure homoge- nizers—a device that uses a pump to break down material into uniform pieces—were being used to break down animal cell cultures so researchers could extract their contents for use in cancer research. The UBC lab’s researcher, Dr. Rob Stephenson, discovered the potential of us- ing a homogenizer to break down sludge mi- crobe cells. Dr. Stephenson and Paradigm’s engineering team would transform the homogenizer into a cell disrupter and make it commercially viable and robust enough to work in a wastewater treatment plant. Dr. Stephenson notes that the idea of us- ing a homogenizer to treat sludge was new. They did exist for the food industry, such as was needed for homogenizing milk, but the

Scott Laliberte, Engineering Manager, in front of the cell disrupter.

question was whether the homogenizer could be adapted to stand up to rigorous industrial and municipal uses. Neill came on board Paradigm’s engineering team five years ago to address this question. His portfolio included developing units that were rigorous enough to withstand industrial and municipal applications and reliable enough to yield projected results. This involved examining the mechanical process by which sludge is pushed through a small valve at a high pressure of 10,000 psi. “There is a lot of abrasive material in the sludge resulting in mechanical wear,” Neill says. As well, sludge is also not as uniform as feed stocks found in the food industry where homogeniz- ers are more commonly used. Neill’s team revamped nearly every part of the existing homogenizer unit. “It was challenging to identify root causes of problems and to address them due to the multivariable process conditions,” he says. Even the task of forcing material through a small valve came with major challenges to determine the optimum valve diametre combined with pressure to create the maximum cell carnage. Neill says that further refinements took place once the unit went into the field. An alpha test was carried out at Chilliwack where MicroSludge was installed at the municipality’s wastewater treatment plant. Not only did the team want to ensure that the mechanism was durable, but they also wanted the opportunity to capture field data on the system’s effectiveness. “We wanted to better understand what sort of results the system would deliver,” Dr. Stephenson says, adding that there can be a vast difference between laboratory testing and actual field trials. Since the alpha testing site, Neill says there have been continued refinements to MicroSludge to bring it to its current model now to be used by Metro Vancouver. Paradigm’s Closing the Loop system serves as a means of further reducing WAS, Dr. Stephenson says, as recycling all of the treated sludge back to the aero- bic treatment plant is unheard of in the industry. “We were told we could not do that,” he says, “But, there was no logical explanation why it should not be done. So, we tried it and it worked.”

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