Settling of both influent primary solids and biological solids grown during secondary treatment is a normal part of aerated stabilization basin operation and sludge accumulation is a normal part of a basin’s life cycle that typically last 10 to 15 years. But wastewater treatment system performance, specifically removal of biodegradable organics coming from pulp and paper production, is dependent on adequate treatment time (HRT) for bacterial growth.
Even though new aerated lagoons are designed with extra volume to provide adequate treatment time as sludge is deposited over time, eventually the loss of volume and HRT limits performance. Treatment volume and residence time must be restored by removal of sludge deposits. Sludge removal by dredging and dewatering is a very expensive process, in the range of $200/dry ton of solids if mechanical dewatering is employed, not including costs for final disposal in a landfill or by some other option.
Proper aeration and mixing can play a critical role by controlling where solids deposition occurs and by ensuring hydraulic short circuiting is minimized so that available liquid volume better utilized to maximize HRT. Aerated lagoon sludge accumulation is a significant current problem in the pulp and paper industry, as many aerated stabilization basins have significant sludge deposits that are impacting performance. With a variety of solutions, Aeration Industries can help manage your sludge accumulation. Contact a Pulp & Paper expert today to learn more.
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