ABSTRACT
\nActivated carbon is a readily available material that can be added to fertilizers or manures to
\nreduce nitrate nitrogen (NO3-N) contamination of surface and near-surface groundwater. To test
\nthe nitrate adsorption performance of activated carbon, its absorbance was compared to that of
\nused wall board (gypsum), sand, carbon, iron filings, wheat litter, wood litter, coffee grounds,
\nbauxite residue and vermiculite using a nitrate ion selective electrode. Of these adsorbent
\ncandidates, only activated carbon exhibited a significant nitrate adsorption capacity.
\nA linear adsorption isotherm was observed (r2 = 0.975) over the dosing range 0.77-6.1 mg NO3-
\nN\/g activated carbon using nitrate standards. The adsorption capacity observed using neat
\nstandards was 0.69 mg NO3-N\/g carbon. The performance of activated carbon for adsorbing
\nnitrate under simulated runoff conditions was evaluated for 10, 20, 30, 40 and 50 weight %
\nmixtures of activated carbon with cow manure. The nitrate adsorption capacity observed for
\nmixtures of activated carbon and cow manure was 0.47 mg NO3-N\/g carbon, which is 68% of the
\nideal adsorption capacity observed using neat standards. This shows that activated carbon can be
\nadded to cow manure to significantly reduce NO3-N runoff to water supplies and create an
\nenvironmentally friendly manure-based fertilizer.<\/p>\n
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