BIOREMEDIATION OF NITRATE CONTAMINATED AQUIFER

摘要

The invention disclosed relates to a method and apparatus for thedenitrification ofgroundwater in situ in an aquifer under substantially anaerobic conditions,the methodcomprising(a) providing a network, including an extraction well for removal ofgroundwaterfrom the aquifer and a plurality of injection wells for returning groundwaterto the aquifer, theinjection wells being arranged in a line substantially perpendicular to thedirection ofgroundwater flow, the extraction well being located downstream or upstream ofthe line ofinjection wells, and the spacing of the wells and the number of injectionwells beingdetermined by the mathematical relationshipwhere J is the cost of treatment, CP and C1 are the costs of extraction andinjectionwells, respectively; n is the number of injection wells, and W is the distanceacrossthe protected area, and wherein the water stream is evenly distributed betweeninjection wells, according to the relationship:Fi = Fc/n = constwhere F is the water flow rate (e - extraction well, i - injection well) and nis thenumber of injection wells,(b) removing groundwater from the aquifer by the extraction well,(c) adding a carbon source to the groundwater in a controlled manner,(d) returning the carbon source amended groundwater to the aquifer by theinjection wells in even distribution, the water flow rate being controlled,and(e) monitoring the nitrate concentration of the groundwater removed fromthe extraction well, a decrease in nitrate concentration being indicative ofdenitrification.