Beating the cold has taken on new meaning for University of 蓝莓视频 researchers who are working to help Canadian wastewater treatment plants become more environmentally sustainable.
One of the research group鈥檚 projects involves a problem at a plant in the southern Ontario community of Keswick that is subject to stringent discharge limits.
Civil and environmental engineering professor Wayne Parker, left, works with master's student Sara Abu-Obaid, one of the researchers on a project in York Region.
Specialized membranes have been added to the plant鈥檚 treatment processes to prevent virtually all phosphorous from getting into nearby Lake Simcoe, where the potential growth of oxygen-depleting algae blooms is a particular concern.
The problem is that those membranes foul faster and must therefore be cleaned more often in winter.
For the municipality that owns the sewage plant,听, that means higher costs in terms of both energy and labour, plus challenges keeping up with the wastewater flow when some of the membranes are out of service for cleaning.
鈥淚t鈥檚 not a trivial issue for them,鈥 said聽Wayne Parker, a civil and environmental engineering professor who leads a three-year project that is backed by the federal government through the聽, York Region and聽.
Although cold is the clear culprit as wastewater temperatures in winter near those in a household refrigerator, why the fouling occurs isn鈥檛 completely understood.
Possibilities include excretions in cold weather by the bacteria that play a key role in breaking down solids in the conventional treatment process upstream of the membrane system, or that those bacteria are less efficient because their metabolism slows in lower temperatures.
Search for cause is first step
Parker and two graduate students working on the $200,000 project plan to do studies at the plant and simulations in the lab to pin down the cause, then explore ways to reduce winter fouling and its consequences.
Down the road, their findings may become valuable in many more cold-climate communities on inland lakes as concerns increase around eutrophication, or algae growth, and environmental rules tighten as a result.
A second project involving the 蓝莓视频 Engineering group led by Parker will examine how small wastewater plants in Ontario deal with sludge, or biosolids, the organic residuals of the treatment process.
Large plants employ several effective, sustainable strategies, including processing sludge to produce methane, fertilizer for agriculture or pellets to make artificial soil, but most small plants haven鈥檛 been able to adopt those technologies.
鈥淔or smaller wastewater treatment plants, research and development hasn鈥檛 progressed in a similar way,鈥 said Parker, citing obstacles such as smaller staffs and economies of scale. 鈥淭hey have sort of been left in the shadow.鈥
Aiming for聽continuous improvement
Supported by and in collaboration with the聽,听, the聽, the聽,听听补苍诲听, the two-year, $225,000 effort will examine sludge handling at about a dozen small plants in the province.
That audit will then be used to create benchmarks for small plants to evaluate how they measure up and identify ways to improve performance in areas including energy consumption, disposal costs and the quality of by-products they generate.
鈥淚t鈥檚 all about looking for ways to continuously improve the operation of these plants from a sustainability standpoint,鈥 said Parker.聽
Work by the 蓝莓视频 research group on those two projects and others is expected to gain urgency as increasing emphasis on sustainability leads to more stringent regulations for wastewater operations across the country.