Iona Island Wastewater Treatment Plant in Richmond, B.C. provides primary treatment to wastewater for over 600,000 residents in Vancouver and parts of Burnaby and Richmond. The plant opened in 1963 and has been expanded six times to accommodate population growth and treatments upgrades. The current upgrade began in October 2015 and is scheduled for completion in February 2019.
Primary treatment uses various mechanical processes to remove materials that settle or float. It removes 50 to 60 per cent of the total suspended solids (TSS) and 30 to 50 per cent of the biochemical oxygen demand (BOD). The plant produces about 9,500 bulk tonnes of bio solids every year. Once treated, the wastewater is discharged back into the Strait of Georgia.
The Solids Handling Upgrade requires construction of 4 digester mixing pump buildings that include a primary sludge screening and degritting facility, a primary sludge thickener and pump building, and odor control system. Upgrades of the existing wastewater treatment plant are to be done while the facility is still in operation.
Primary treatment facilities experience large volumes of fluid borne erosion through the mechanical process beginning with screening, where wastewater is screened to remove wood, stones, plastics and other large debris. Then on to pumping where wastewater is pumped to a higher elevation, so gravity can move it through the treatment process. Grit removal uses pumped air to keep organic materials suspended while forcing grit – sand and gravel – to settle and be removed. The process of removing solids occurs in the sedimentation tanks where the heavier ‘sludge’ settles to the bottom and lighter ‘scum’ floats to the top.
All of these primary treatment processes expose the concrete tanks to extreme erosive wear because water with large particles is consistently pumped through. Hard-Cem is the only concrete hardener that can be used in vertical and horizontal applications to withstand the abrasive-erosive streams these tanks are exposed to. Hard-Cem’s versatility allowed for Hard-Cem shotcrete to be placed in the primary treatment screening tanks, providing the tank bottoms and walls with highly erosion resistant concrete surfaces. Additionally, Hard-Cem was utilized in the facility cast-in-place flatwork in key areas subject to mechanical abrasion.
Hard-Cem is an Integral Hardening Admixture used to increase Abrasion and Erosion resistance of concrete. Hard-Cem is added to the concrete at the time of batching to increase the hardness of the concrete and extend concrete wear life. It outperforms and overcomes deficiencies of labor intensive surface applied hardeners, and can be used to enhance...