Water. desalination + reuse

projects The Vortex Centre was built adjacent to GWF to raise community awareness about water conservation and sustainable water management. Ap mill expAnsion A proposed expansion of the Australia Paper (AP) pulp and paper mill, one of GW���s principal industrial customers, provided the opportunity to implement the project near the western end of the Regional Outfall Sewer (ROS) and adjacent to the mill. The GWF treats domestic and industrial wastewater generated in the GW service area, including flows from AP, and reclaims effluent from the domestic wastewater to serve as the added water supply needed for the mill expansion. As a result, a reduced flow of highly treated effluent is discharged to the ROS, thereby prolonging the life of this asset and mitigating odor emissions from it. A sustainable water supply is provided by replacing raw water that would have to be supplied to AP while solving asset life, hydraulic capacity, and odor emission issues associated with the ROS. Reclaimed water quality provided to AP must meet the high quality of the raw water currently provided by GW to the AP raw water reservoir (Pine Gully Reservoir). The GWF is designed to receive 16,000 m3/d of domestic wastewater and reclaim it in a treatment train consisting of primary sedimentation; membrane bioreactor (MBR) activated sludge treatment incorporating biological nutrient removal (BNR), and chloramination followed by reverse osmosis (RO). This results in 8,000 m3/d of high quality reclaimed water delivered to AP at its Pine Gully raw water reservoir. By return, 19,000 m3/d of AP wastewater receives anaerobic treatment, along with domestic primary sludge and waste activated sludge prior to biological treatment in a parallel MBR. Over 70 km of transfer system and eight lift stations are used to convey wastewater to the new water factory. Phase 1: liquids was completed in January 2010; solids was completed in January 2011. A programme for Phase 2 has yet to be scheduled. stAges of gWf In Stage 1 of the GWF, treated AP wastewater, along with domestic RO reject and the portion of municipal MBR effluent which is not reclaimed, is diverted to the ROS. In Stage 2, the AP MBR effluent will be reclaimed using nanofiltration and RO, with the reject diverted to the ROS. The ROS conveys only treated effluent to the ocean, 90 km southeast of the facility. Separate treatment of the domestic wastewater was selected because reclamation of domestic wastewater by RO is well established, and AP wastewater is highly colored, which makes reclamation challenging. MBR treatment of domestic | 18 | Desalination & Water Reuse | February-March 2012 wastewater is considered well established including for nutrient removal. RO treatment of domestic MBR effluent has also been demonstrated. Extensive bench- and pilot-scale testing was conducted to develop the AP wastewater treatment train. One of the objectives of the GWF was to produce near-potable quality water that could be recycled to AP. A Recycled Water Quality Management Plan (RWQMP) is required for permitting of recycled water facilities in Australia. An RWQMP is an Australian regulatory mechanism to ensure schemes are managed to meet appropriate water quality objectives. The process is outlined in the Australian Guidelines for Water Recycling: Managing Health and Environmental Risks (Phase I), 2006. Each state implements the national guidelines differently, with Victoria having the most stringent requirements. The RWQMP was completed and accepted by the Victoria Department of Health in an endorsement letter dated 16 July 2010. process AnAlysis In addition to the bench-scale and pilotscale testing, the GWF process was based on extensive process analysis and a decision process based on multi-criteria analysis. The objective was to develop the most ���

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