Table 2 The EDS results for the three ozone adsorbents before and after the ozone adsorption.

From: Evaluation of Ozone Removal by Spent Coffee Grounds

AdsorbentOzone AdsorptionCarbon (wt. %)Oxygen (wt. %)
Fresh CoffeeBefore52.116.0
Percent Change+1.9%+20%
Spent Coffee GroundsBefore62.111.8
Percent Change+2.1%+14.4%
Activated CarbonBefore83.82.9
Percent Change+1.1%+34.5%
  1. The percent change is calculated by (Xafter − Xbefore)/Xbefore × 100%, where X represents the percent weight of carbon or oxygen.