Water & Wastewater Treatment

6 | APRIL 2016 | WWT | www.wwtonline.co.uk Comment W hether it is communications and telemetry, pipe condition assessment technology or instrumentation for saving energy and chemicals in the treatment process, there is no shortage of innovative ideas out there for making the water industry better. Many of these innovations have acquired valuable water company advocates as well as enjoying a high profile in the pages of WWT or on conference platforms; others are still fighting to win the attention of industry stakeholders and prove that they are effective or viable. The extent to which each UK water utility is open to innovation, and the extent to which regulatory incentives and procurement frameworks allow them to be, is open to some debate. However, one set of obstacles which could be removed to make innovative progress easier surrounds the trial Testing times process which each water company typically imposes on new technology before it can be adopted on a wider scale. Impartial trials with verifiable evidence are an essential part of building confidence around a new technology, but a-er the major hurdles of a first successful trial and business win are negotiated, the uninitiated might be surprised to find that rather than entering into an inner circle of proven technologies where life becomes easier, they are required to go through a similarly lengthy trial with each potential customer. As time passes and costs mount up, perfectly effective solutions can end up not being implemented because the frustrations of these hurdles mean that business backers lose patience. As Alastair Moseley, chair of the Innovation and Development Group at the Future Water Association, says in this month's Industry Leader interview (see p14) there is surely a case for a centralised testing and accredited trials centre which water companies up and down the land could trust and take information from. This model existed in the past through the Water Research Centre (now WRc) and could be resurrected with James brockett eDItor JamesBrockett@fav-house.com Twitter: @wwtmag the right leadership in the industry. Scottish Water recently opened its first full-scale centralised test facility for Scotland as part of its 'Hydro Nation' strategy to boost water's contribution to its economy; while that was a simpler undertaking in a part of the UK with a single water utility, it would not take too much imagination to envisage a similar facility south of the border. With a commodity as precious as drinking water, and the environment and public health at stake, a certain degree of caution is understandable before spending customers' money on new technologies. However, if the sector is serious about innovation then streamlining and removing red tape is essential. The advent of more competition in the water sector might make it less rather than more likely that water companies will be driven to work together in this way; however, this would be a pity and a missed opportunity. Collaboration is just as much of a buzzword in the industry as innovation (I have even heard the term 'collabovation' used, although the term doesn't seem to have caught on) and it is when these two intersect that the industry can be at its best. Industry view sponsored by kieran Healey, technical manager, Veolia Water technologies The UK Technical Advisory Group (UKTAG) reckons that the phosphorus standards for catchments set in 2009 were not sufficiently stringent to reduce eutrophication and has proposed new standards as low as 13µg/l for low alkalinity upland rivers. Since one of the main routes by which phosphorus gets into the aquatic environment is via sewage works discharges, this will have the knock-on effect of lowering phosphorus consents in AMP7. In particular vulnerable catchments, consents may be as low as 0.1mg/l P. This means that several hundred sewage works across the UK, including small, unmanned works in remote areas, will need to retrofit phosphorus removal, and many larger Where next for P removal? works will need to improve phosphorus residuals. Biological phosphorus removal alone will not hit low enough phosphorus concentrations for the future so, inevitably, these works will have to retrofit chemical precipitation. But even then, meeting a 0.1mg/l consent will be a challenge because many of the common solid-liquid separation technologies are just not up to the job. One way of improving performance is to provide tertiary phosphorus removal and, to this end, Veolia has previously conducted pilot trials at three different sewage treatment works using our Hydrotech Discfilters and Actiflo® technologies to compare performance. The Veolia Hydrotech Discfilter process combines coagulation, polymer enhanced flocculation and filtration. In the tests, alum was dosed at a mol ratio about 5-7 Al3+:P and polyelectrolyte at 0.07- 0.1 mg/mg SS, followed by filtration to 10µm using Veolia's well proven Hydrotech® Discfilter, which is already used as tertiary filtration by a number of UK water companies. This coagulant dose is in the same range as is used for technologies like deep-bed sand filtration and ultrafiltration, and the results showed that the combination of coagulant and polymer consistently achieved filtrate phosphorus residuals below 0.1 mg /l and turbidities below 2NTU – significantly better than current tertiary treatment technologies. Tests at some other sites have demonstrated that if the coagulation and flocculation is incorporated into an Actiflo® sand ballasted, high rate clarifier upstream of the Discfilter then the process can achieve phosphorus residuals as low as 0.03mg/l P. Since the success of these trials and subsequent demonstrations, there are now approximately 90 installations globally comprising either our Actiflo® or Hydrotech® Discfilter technologies achieving required treated water phosphorous guarantees down to levels below 0.1mg/l. www.veoliawatertechnologies.co.uk

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