2nd Symposium on Biological Aerated Filters (BAF2) - 1996

Permanent URI for this collection

https://dspace.lib.cranfield.ac.uk/handle/1826/8614

Browse

Browsing 2nd Symposium on Biological Aerated Filters (BAF2) - 1996 by Publisher "of Water Sciences, Cranfield University"

Now showing 1 - 3 of 3
  • Thumbnail Image
    ItemOpen Access
    Aeration optimisation of Biolgical Aerated Filters
    (of Water Sciences, Cranfield University, 1996-06-12) Pearce, Peter A.
    Aeration costs account for a large proportion of the total running costs of biological aerated filters (BAFs) which are in themselves an energy intensive form of treatment process. Optimisation of oxygenation efficiency is therefore an obvious goal as small improvements in operating efficiency will yield significant savings in energy consumption. This paper will deal with the oxygen transfer characteristics of a downflow BAF using mineral media. Clean water and operational performance are compared over a range of hydraulic and organic loadings and a range of air flow rates. Alternative aeration devices and aeration procedures were also evaluated but will only be discussed in summary in this paper.
  • Thumbnail Image
    ItemOpen Access
    Experiences with BIOFOR reactors at Veas, Norway
    (of Water Sciences, Cranfield University, 1996-06-12) Sagberg, Paul; Grundness Berg, Kirsti
    Both the local situation in the inner Oslofiord and the political decisions of the countries surrounding the North Sea called for further treatment. Through 1989 and 1990, VEAS put bits and pieces of known technology together to compose a process for nitrogen and phosphorus removal to be installed in the area of the existing sedimentation tanks, only extended in depth. In addition, the process should reduce the amount of sludge considerably. A working hypothesis was presented in 1990 and later named "The VEAS Concept" by prof. H. Odegaard, Techn. Univ. of Trondheim. The status for the development is described in more detail by Sagberg et al. (1995). Figure 1. show the state of the VEAS Concept by end of 1994. Further adjustments has later been made and new will be.Introductory tests were run by VEAS with RBC from Klargester, Mechana and Envirex, with submerged Munthers media, with the Kaldnes moving bed media and with the upflow BIOFOR system from Degremont. After international pre-qualification, call for turn key tenders, which were rejected, and finally licence negotiations, the BIOFOR system was selected for full scale application.
  • Thumbnail Image
    ItemOpen Access
    Poole waste water treatment BAF plant
    (of Water Sciences, Cranfield University, 1996-06-12) Brewer, Peter
    1. The town of Poole in south east Dorset has undergone substantial development during the 1980's. Wessex Water recognised the pressure on the water services in this region and commissioned a strategy study for this region. This resulted in a proposal to extend each sewage treatment works in that area up to a standard required by the receiving watercourse. 2. The 2 main river catchments are the River Stour and River Avon. The latter flows into Christchurch harbour in the east, whilst the Stour flows into Poole Harbour. Poole WWTW discharges directly into Holes Bay in the upper reaches of Poole Harbour.This tidal estuary is of national importance in environmental terms, whilst being extensively used for recreation. 3. Consultations with the National Rivers Authority (now the Environmental Agency) led to a discharge standard of 20 mg/I BOD; 30 mg/I SS;10 mg/I Amm N on a 95 percentile basis being accepted for design of the extensions. Indications are that in the long term nutrient removal and disinfection may well become a necessity. The EA has plans to conduct extensive surveys of Poole Harbour in the next few years. 4. The extensions to Poole VWVTVV will raise the treatment capacity from a population equivalent of 129,000 to some 151,000. Dry weather flow will be 46,700 m3/d, and flow to full treatment will be 17,700 m3/d at the 12 year planning horizon. These extensions now provide a treatment plant with some 48% increase in hydraulic capacity, whilst producing a fully nitrified effluent. 5. The existing treatment plant consists of essentially two separate plants, known as eastern and western, both activated sludge plants. The site is quite close to the historical town centre, and growth in the town over the last half century has extended well beyond the works site. Consequently, the works is now completely surrounded by development fro housing to light industry. Indeed, we now have the benefit of a major supermarket on our southern boundary, some 20m from the inlet pumping station!