ENVIRONMENTAL-IMPACT ASSESSMENT OF GROUNDWATER TREATMENT WITH NANOFILTRATION

Environmental life-cycle assessment (LCA) is one of the instruments fo r analyzing the effects of activities on the environment. A LCA was ca rried out to compare two groundwater treatment schemes for removing ha rdness and colour. One is a conventional treatment, using pellet softe ning and granular activated carbon (GAC), the other using nanofiltrati on. From an environmental point of view, there is no significant diffe rence between the two alternatives. This is striking because the gener al impression is that membrane filtration has more energy. The main im pact for both treatment schemes was caused by the on-site use of energ y. Also GAC filtration contributes substantially to the total score fo r the conventinal scenario. A very interesting and efficient way to im prove nanofiltration environmentally is the use of low-pressure membra nes and ''green'' energy.