PENGARUH AMONIA DALAM LARUTAN TERHADAP KAPASITAS ADSORPSI UREA DENGAN KARBON BERPORI

Urea is a primary nitrogen source for plant. Conventional urea fertilizer is made from reaction between ammonia and carbon dioxide. Wastewater of urea manufacture usually contains urea ammonia in a high concentration. They can be as high as 650-4000 ppm urea and 100 – 1300 ppm ammonia/m3 wastewater. High concentrated urea and ammonia disposal to environment may lead to eutrophication in aquatic ecosystem which cause adverse impact to aquatic organism. Therefore, treatment to take urea up from urea manufacture wastewater is of interest that give double benefits : reduce urea from wastewater to meet an environmentally safe condition and obtain a low cost urea fertilizer for plant. The purpose of this study is to determine urea adsorption capacity of porous carbon in aqueous solution contains ammonia. The porous carbon as adsorbent was made from coconut shell by pyrolisis. Oxidation treatment of carbon surface was performed using sulfuric acid (50%w) at 90oC temperature for 2 hours. The adsorption was conducted at room temperature with initial urea concentration in the range of 500-8000 ppm using urea-ammonia solution as simulation liquid. Results reveal that urea adsorption capacity increase significantly 41%.in urea-ammonia solution compare to urea solution, that is in the range of 27-444 mg/g carbon.