The economic pretreatment of wastewater has, over the last few years, gained increasing importance within industry. Wastewater pretreatment reduces disposal charges and likewise, the operating costs of a business. At the center of attention are space saving process that can accomodate wastewater streams that vary considerably with regards to flow. Therefore, SBR has, as a pretreatment process, achieved considerable acceptance in many different application areas such as the food, dairy and brewery industries, as well as in the treatment of wastewater with high concentrations of nitrogen compounds.
Low operating costs, simple and maintenance free process technology and an ability to adapt to changing inlet and outlet requirements make SBR plants very attractive. As well as being able to achieve an economical realisation of an SBR plant, it is also possible to use existing free space. In situations where space is limited, the existing area can be optimally used by building upwards and by optimising the placement of equipment.
Over the past few years SBRs have been used as pretreatment plants for handling wastewater with high nitrogen loads, such as landfill leachate, and wastewater from fermentation plants, as well as the returns from sludge dewatering of anerobic digested sludge from municipal WWTP. In these situations the removal of the nitrogen fraction is paramount. It is possible to effecitvely deal with the nitrogen overloading of a municipal WWTP by building a plant that treats only part of the flow. This does not only help improve nitrification but can also, if necessary, contribute to total nitrogen removal.
For smaller wastewater operators there exists a financially feasible concept for expansion by applying the SBR process in a container plant. This can allow a plant to withstand overloading. At a relatively low cost, in comparison to extending the total basin volume, it is possible to increase the treatment capacity of a plant by constructing a new plant to treat part of the flow.
By using well known biological processes and equipment, further training of treatment plant operators is not required.
The SBR process, as a means of nitrogen removal, is characterised by it's extremely high operating stability. The plant can be quickly running at full capacity even after long downtimes over holidays or when the sludge is dewatered.
SBRs are also applied throughout the world for treating landfill leachate. Reduced investment and operating costs, alongside an ability of reuse existing tanks, make the SBR process extremely suitable. Should BOD5 and nitrogen removal be sufficient and the disposal requirements not too high, then SBR cannot to be beaten. SBR is also used in the treatment of wastewater from fermentation plants.
The SBR process is also interesting for the food, beverage and dairy industry, as it can not only overcome space limitations but it can also rise to the demands of a 5 day week, seasonal operation and long down times due to upgrading. It is also possible with SBR plants to operate efficiently with regards to the inlet requirements, even at partial flows. This ensures the economic operation of the plant.