TOZ HALÄ°NDE Fe0 ve Al0 Ä°LE NÄ°TRATIN KÄ°MYASAL ...

ABSTRACTCHEMICAL DENITRIFICATION OF NITRATE BY Fe 0 AND Al 0 POWDERPollutant discharges form both nonpoint and point sources cause increments innitrate concentrations both in surface water and ground water resources. Nitrateconcentrations above certain concentrations harm human health, particularly tobabies. That is why if the drinking water supply is to be provided from nitratepollutedresources, this pollutant is to be removed applying appropriate treatmentmethods.In this study, some test studies concerning the nitrate removal by chemical reductionwere conducted in lab-scale studies. In this context, Al 0 and Fe 0 metal powders aswell as ferrous ion covered sand granules have been tested for their potential towardsnitrate-reduction. Since the early studies in the literature suggested that the rightconditions for reduction is provided in basic media for Al 0 and in acidic conditionsfor Fe 0 tests, this suggestion was pursued in this study. Both batch and continuousflow in fixed-bed and fluidized-bed conditions were experimented. The highestremoval of nitrate (%30) was achieved at 23 mgNO 3 - /L initial concentration test runin the presence of phosphate buffer having initial Al 0 dosage of 400 mg/L, initial pHof 9.3 and at 15°C within 2 hours contact period. The highest removal of nitrate(%81) was achieved at 21 mgNO 3 - /L initial concentration test run in the absencephosphate buffer having initial Fe 0 dosage of 3 g/L, initial pH of 2.2 and at 25°Cwithin 30 hours contact period. This study suggested that there exists a potential toreduce nitrates in water supplies by Al 0 and Fe 0 powders. However before puttingthis chemical reduction process into practice more research is needed regarding thepractical applicability of the choice.Key Words: Chemical denitrification, aluminium powder, iron powder, ferrous-ioncoated sand, batch tank, continuous-flow packed-bed column, continuous-flowfluidized bed column.