Optimization of UV/H₂O₂ processes for the removal of organic micropollutants from drinking water: effect of reactor geometry and water pretreatment on E_EO values

Increasing concentrations of organic micropollutants, like pharmaceuticals, in surface water may require additional treatment for drinking water production. The UV/H₂O₂ process is very effective for this purpose, but is known for its relatively high energy demand. This energy demand may be decreased by improving the water matrix composition and/or by optimizing UV reactor geometry. Thus, operational costs of the process may be decreased. This can be visualized by calculating the Electrical Energy per Order (E_EO). By optimizing the water matrix, e.g. by pretreating the water by filtration over activated carbon or with O₃/H₂O₂, the energy demand decreased up to 70%. This is affected by the concentration and type of the natural organic matter present. By optimizing reactor geometry an additional decrease in energy demand, up to 40%, could be obtained. How efficient the process may become strongly depends on the characteristics of the micropollutants involved.