Toxic effect of bio-oil from biomass fast pyrolysis on fresh algae

In order to determine the safety of using bio-oil from biomass fast pyrolysis, toxic effect of bio-oil on algae was investigated in an algal growth inhibition test with Scenedesmus obliquus and and Selenastrum spp., in which five alage broths with 0, 9.5, 20.7, 48.5, 81.3 mg/L concentrations of bio-oil were applied, respectively. The results show that the bio-oil has a certain inhibition effect on the growth of algae, the growth inhibition rates of S. obliquus are 0, (36.59%± 5.94%), (48.47%±2.53%), (94.83%±2.50%) and (105.25%±1.39%), respectively;the growth inhibition rates of Selenastrum spp. are 0, (45.14%±0.93%), (55.45%±1.41%), (64.07%±3.95%) and (92.58%±0.88%), respectively when the concentrations of bio-oil were 0, 9.5, 20.7, 48.5, 81.3 mg/L, respectively. It seems that the higher the concentration of bio-oil is, the greater the toxic effect is. The non-linear regression analysis of growth inhibition rate with different bio-oil concentration is conducted, according to biomass quantity, 72 h algae EC50 (median effect concentration) of bio-oil on inhibition of S. obliquus and Selenastrum spp. growth are 17.62 and 14.16 mg/L, respectively, which indicates that Selenastrum spp. is more sensitive to the bio-oil. ©, 2015, Science Press. All right reserved.