Water & Wastewater Treatment

SUPPORTING ASSOCIATIONS: ORGANISED BY: sustainabilitylive.com @Suslive linkedin.com_sustainabilitylive2014 facebook.com/Sustainabilitylive OFFICIAL MEDIA PARTNERS: ● New for 2014! Top level speakers on the Keynote Stage – hear from leading experts on how the latest sustainability policy and practice will affect your business. ● Practical case-study and discussion led seminars –the latest advice, updates and best practice that you can use in your working environment ● New for 2014! Technology Pitch product showcases – your chance to see the most innovative new products ● More than 250 exhibiting companies offering the latest range of sustainable and resource effi cient solutions – fi nd the products and services to help drive your organisation forward ● Networking opportunities – with thousands of industry professionals all in one place, take the opportunity to meet your peers and make new business contacts SHOW FEATURES INCLUDE: For more information on exhibiting or sponsorship contact Rachel Lyon +44 (0)1342 332097, rachael.lyon@fav-house.com Pre-register for FREE entry now at www.sustainabilitylive.com ● WATER TREATMENT TECHNOLOGY ● WATER MANAGEMENT ● INDUSTRIAL EFFLUENT ● SusLive-VisitorAd3-WWT.indd 1 11/12/2013 16:45 TECHNICALLY SPEAKING 33 March 2014 Water & Wastewater Treatment wwtonline.co.uk T he year 1914 was a milestone. Of course, the Great War, which began on 28 July 1914, was the most significant event, but three months earlier a revolution in wastewater was announced that was to sweep the world. On 3 April 1914, at the Grand Hotel, Edward Ardern gave a paper to the Manchester section of the Society of Chemical Industry on work that he and William Lockett had been doing. It was entitled Experiments on the oxidation of sewage without the aid of filter and it marks the discovery of the activated sludge process (ASP). The activated sludge process is now one of the most widely used processes for treating wastewaters from medium to large populations worldwide. Wastewater collection and treatment including activated sludge has restored to health metropolitan rivers that were dead in the 1950s. In those days, cities turned their backs on rivers like the Aire, Irwell, Mersey, Thames, and Tyne with good reason. Today river frontage is some of the most valued real estate and lined The global impact of the activated sludge process in wastewater treatment in the century that has passed since its discovery cannot be underestimated. Nigel Horan, of University of Leeds, and Tim Evans, of Tim Evans Environment, retrace its development Activated sludge centenary – plenty to celebrate u 34 Activated sludge at Davyhulme wastewater treatment plant today Above left: Pilot plant on a cart. Image courtesy of Paul Cooper Below left: Ardern (left), Lockett (seated right) and unknown colleagues. Image courtesy of Paul Cooper with prestige apartments and offices; a river view is prized. Researchers Lockett was a research chemist working for the Manchester Corporation's Rivers Division at their Davyhulme laboratories. He was supervised by Ardern, the resident chemist. At the time, Manchester was recognised as a centre of excellence for research in sewage purification, largely because of the inspirational approach of Gilbert John Fowler of Manchester University's Chemistry Department and consulting chemist to Manchester's Rivers Division. He had been responsible for the overall direction of research at Davyhulme since 1904. Manchester University was then a centre of expertise in the application of microorganisms for industrial processes. Fowler had visited the USA in 1912 in connection with the pollution of New York Harbour. Whilst there he visited Lawrence Experiment Station, Massachusetts, and saw experiments on aerating sewage. When he returned to Davyhulme, he asked Ardern and Lockett to follow similar lines of research. Experimentation After five weeks of continuous aeration, the researchers achieved complete treatment of sewage. They then decanted off the clear supernatant and added more raw sewage without removing the sedimented sludge. This time complete treatment only took three weeks. After repeating the process a number of times they eventually achieved complete treatment in 24 hours. The researchers thought that the sludge had become "activated", actually microorganisms fit for the conditions had been selected. Scaling-up Lockett realised work at a larger scale was necessary to establish the process's economic and practical feasibility. He applied to the Worshipful Company of Grocers for one of their annual scholarships "for the encouragement of original work in sanitary science". The terms of the scholarship were that the proposed work should relate to preventing premature death. Previously, almost all scholarships had been awarded for medical- based work. However Lockett was successful with his application, and he was elected a Grocer's Fellow in July 1914; it was renewed in 1915 and in 1916. Lockett attributed his success to the fact that several eminent members of the Panel of Assessors, had also served on the Royal Commission on Sewage Disposal. Lockett constructed a full-scale continuous flow unit at Withington by converting an existing tank, to accept 1,136.5m 3 /d (250,000 gallons), about 10% of the works' total flow. Messrs Jones & Attwood, a West Midlands manufacturer of greenhouse equipment, built the air distribution equipment and it was commissioned in September 1917. Following a very successful period of operation,

• Cover