Sewage Treatment Plants
Since the Control of Pollution Act (1974), the ways in which we deal with the disposal of wastewater to the environment have changed significantly. Until the 1970s it was usual for properties not connected to mains drainage to be served by a septic tank but this is now generally restricted to single dwellings where an effective subsurface irrigation system can be constructed to ensure that further biological treatment takes place before the effluent joins ground or surface waters.
All Package Treatment Systems incorporate the three key stages of treatment - Primary Settlement, Biological Oxidation and Humus Settlement.
The primary settlement stage reduces the biological load passing onto the biological treatment stage through the settlement of a large quantity of insoluble solids. This requires calm conditions within the tank and sufficient storage capacity until the next desludging service. Settled sewage from the primary tank gravitates by displacement to the following carbonaceous biological treatment stage.
The treatment systems generally recommended by Soma Services use Submerged Aerated Filter technology (SAF) in the biological oxidation stage. Plastic filter media is submerged and aerated from below to provide optimum conditions for the growth of microorganisms. These microorganisms attach to the media, where they create a biofilm layer, and digest the organic compounds present in the wastewater forming carbon dioxide and water.
Effluent from the Biozone will contain small amounts of secondary solids (humus solids), which must be removed before discharge. For this reason, the effluent is passed through a final clarification stage where humus solids are settled. Settled sludge at the base of the tank are automatically removed to the inlet of the works for co-settlement within the primary tank using either a pump or air lift system
The successful long-term operation of any system will be a function of its design, quality of installation and timely maintenance. Soma Services Limited provides a comprehensive service through the stages of site assessment, supply, installation and commissioning as well as maintenance of equipment and a single point of contact is offered throughout a project when a practical cooperative approach to project management ensures that Soma Services makes it happen, on time, within budget and meeting the specified requirements.
In today’s environmentally sensitive world it is essential to apply available technology appropriately and to ensure that lines of contractual responsibility are clear. A project sold to a price will not always give a total solution although there are responsible companies who will provide a complete and reliable service which in the long term will be the lowest cost solution every time.