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Water and wastewater technologies

“… there is no such thing as Pure or Applied science, only Good or Bad science…” -  John D. Bu´lock (editor of Biotechnology Letters)

Water is life. Water is the prime nutrient providing all living organisms with hydrogen, oxygen and a cellular solvent. Water and wastewater technologies have been developed and are still the focus of a broad and large research community. In developed nations, these technologies has been implemented as part of the basic infrastructure in modern societies to such an extent that most people in these countries take top quality drinking and recreational waters for granted. Still, according to UNEP, over 1 billion people do not have access to the minimum quality of potable water defined by the UN’s own millennium targets. In addition, 2.6 billion people lack adequate sanitation, 1.8 million people die every year from diarrhoeal diseases, including 90 % of children under the age of 5. Our programme on water and wastewater technologies aims to provide research and knowledge on optimisation of water uses and wastewater treatment technologies, and develop novel techniques for emerging water pollution problems.

Biological wastewater treatment under low temperatures is a challenge due to reduced growth rates of the microorganisms involved. Low temperature studies have been performed in laboratory, pilot and full scale in order to establish design criteria at low temperatures. This is also an important aspect when new bioreactor technologies are considered, in particular UASB (upflow anaerobic sludge bed) that involves anaerobic degradation of wastewater organics. New bioreactor developments such as UASB make it possible to treat wastewater at low temperatures and generate methane (biogas) from the wastewater organics. Compared to conventional aerobic treatment that requires energy will anaerobic treatment generate energy as methane. SBR (sequential batch reactor) is a promising technology for these new wastewater treatment processes and is a key study topic at our lab. Our most resent project under the W&WWT programme is optimisation of aerobic SBR operation for maximising biosolids production for biogas production, and minimizing energy requirement for aeration.

As oil fields in the North Sea mature, reservoir and injection water in the oil production stream increase. Produced water contains significant amounts of dissolved and dispersed hydrocarbons, and therefore represents an environmental problem when disposed of locally. On-site separation of oil from produced water requires efficient separation methods, and as the production of water increases the present technologies requires higher efficiency along with more stringent effluent criteria. Research into optimisation of oil-water separations is an ongoing activity in our group, for example optimisation of design and operation of hydrocyclones, and application of cyclonic separation technology in valve design (Typhonix). Not all wastewater fractions from the oil production and processing can be treated on site and must be transported onshore for treatment. The most appropriate treatment method is biological treatment, but the wastewater characteristics make biological treatment challenging in particularly high salinity, lack of nutrients, high organic content, complex organic compounds and high inorganic content. In aerobic biological treatment problems arise such as precipitations of nutrients (metal + P and N), high oxygen demand, presence of toxic compounds, acclimatization to various types of organic compounds etc. In cooperation with Nature Terminals we study reactor performance and operations of fixed film bioreactor systems used for oily water treatment. This is a full scale system study aimed at optimisation of treatment efficiency and appropriate pre-treatment technologies.

Contact person: Leif Ydstebø