WET News

wwtonline.co.uk | APRIL 2018 WET NEWS 21 electro-generating pH-neutral reactive reagents (metal cati- ons) and metering them directly into the process stream. The efficacy of Soneco as a method of phosphorus removal is supported by Southern Water, which rigorously evalu- ated and validated the system over a 12-month period with UKWIR. It compared the Son- eco ion electrodes with ferric salt dosing as part of the wider National Phosphorus Pro- gramme and concluded that it was the more environmentally friendly and cost-effective process. Key conclusions of this extended study highlight that Soneco efficiently and reliably treated the provided flow rate of 3.6m3hr-1 to achieve consistent Total P removal to levels below 0.5mgl-1 and achieved Ortho P as low as 0.03 mgl-1 in the treated effluent during the trial. This means that Soneco achieved invariable P removal rates of 98 per cent (Total P) and 99.7 per cent (Soluble Reactive P). The resultant efflu- ent forms a highly de-watered ferric sludge that can also be recirculated to the head of the works, adding to the treatment potential and providing a "double treatment" from the single process. The process also maintained an effluent with an iron concentration below 4mgl-1 discharge con- tent and can be optimised to remain below 3.2mgl-1. Ultrasound improves treat- ment efficiency through the generation of oxidative radi- cals and by the increase in nucleation sites, ensuring bet- ter coagulation and floccula- tion. It also acts as a cleaning- in-place (CIP) tool for the electrodes, keeping the sur- faces clean by cavitation, thereby maintaining an evenly reactive treatment surface. Soneco has been proven to be a highly cost-effective method of P removal, espe- cially at smaller works and those where alkalinity dosing is required. The system is eco- friendly and, in comparison with other methods, has a greatly reduced environmental impact and improved carbon footprint. With a small physi- cal footprint, Soneco is easily integrated or retro-fitted to existing over-loaded or under-performing works, and sludge volumes are as much as 50 per cent lower than with other methods. Following Southern Water's successful validation of Son- eco for P removal and pro- gressing until AMP7, P&W and Southern Water are now work- ing on the fully engineered solution to accommodate the full-flow treatment and P-load- ing of small and medium sized works. As Southern Water's report said: "Based on consistent removal of total and soluble reactive phosphate within the treated effluent, the results are excellent for a single stage iron dosing process followed by conventional humus settlement." The positive results and further benefits of the technol- ogy highlighted by the South- ern Water trial have not gone unnoticed; other utility com- panies have already shown great interest in Soneco, their aim being to further utilise the technology for P removal and sludge enrichment. When P&W sought cus- tomer feedback from Southern Water upon completion of the trial, Cecile Stanford, process capacity engineer integrated planning, said: "It was a pleasure to work with this innovative company. Results have been consistent and reli- able with a definite potential on small wastewater sites where the ideal solution for P removal has not yet been found. This process certainly provides an answer to be con- sidered and P&W have been very receptive to our demand." The joint UKWIR-funded initiative has seen Power & Water and Southern Water named as finalists of the Water Industry Achievement Awards in the "Most Innovative Use of an Existing Technology" category. We believe Soneco has the potential to create a para- digm-shi¥ in P removal pro- cesses and wastewater treat- ment technology. We intend to use this potential to also focus on the delivery of clean water treatment and sludge enrich- ment solutions which sees Soneco used with magnesium electrodes to recover P and treated water for re-use or dis- charge as well as creating a potentially high-grade struvite fertiliser (magnesium ammo- nium phosphate, or MAP) that can then either be re-used or sold and help to reduce reli- ance on raw materials within the supply chain. Going forward, P&W look forward to continuing our col- laborative work with Southern Water and see Soneco making an important and monuments contribution to the National Environmental Programme (NEP) during the remainder of AMP6, into AMP7 and beyond. JOIN THE CELEBRATION Network with the water industry's key players as we announce the winners of the Water Industry Awards 2018. Awards night: 21st May, 2018 at The Vox Birmingham CATEGORY SPONSORS: ASSOCIATE SPONSORS: waterindustryawards.co.uk/WIA18 Book your table at: WIA-shortlist-A4ad-vs2.indd 1 26/03/2018 09:40

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