Impact of biochar on sorption of polycyclic aromatic hydrocarbons in water

Biochar can be a relatively inexpensive and effective material for removing polycyclic aromatic hydrocarbons (PAHs) from aquatic environment. An evaluation of the sorptive possibilities of biochar to remove PAHs from the aquatic environment was conducted. The content of benzo(a) pyrene and the sum of four PAHs, such as benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene and indeno(1,2,3-cd)pyrene were determined in water. The sorption process was carried out for biochar doses of 25, 50 and 100 mg/L. For each biochar dose, the contact time with PAHs was: 30, 60, 90 and 120 min. The best results were obtained for a biochar dose of 100 mg/L and a contact time of 120 min. For benzo(a)pyrene, the concentration decreased up to 78%, while for the four recommended PAHs, the greatest changes were shown for benzo(g,h,i)perylene and indeno(1,2,3-cd)pyrene, whose concentrations decreased by 81%. For the remaining PAHs, greater sorption was observed for dibenzo(a,h)anthracene, the concentration of this compound decreased by 81%.