Biochar was made from wheat straw at 300℃for 3, 6, 8 hours respectively. The productivity, pH, ash content and C, H, N content of these biochar were compared. The surface morphology of the 300 ℃-6 h biochar was characterized, and it was used to remediate the petroleum-polluted soil of Dagang oil field. Results showed that, as the extension of pyrolisis time, the productivity of biochar decreased, pH increased, ash content increased, H/C decreased. But productivity, pH, ash content and H/C changed significantly from 3 h to 6 h, unsignifi-cantly from 6 h to 8 h. C content showed a downward trend after the first rise. After remediation of biochar for 14 and 28 days, the TPH degra-dation rate were 45.48%and 46.88%respectively, higher than control group. After 14 days remediation, content of naphthalene, acenaph-thene, Benzo [a] anthracene, chrysene, Benzo [b] fluoranthene, Benzo [k] fluoranthene, Benzo [a] pyrene, Indene and [1,2,3-CD] pyrene were decreased to various degrees, with the Benzo [a] pyrene content decreased by 98.18%, and the degradation rate of other PAH higher than con-trol group. After 28 days remediation however, content of these PAH showed a rising trend. It suggested that pyrolisis time had influence on biochar’s characteristics, and 300℃-6 h biochar could be used to remediate petroleum-polluted soil.%以小麦秸秆为原材料，在300℃下缺氧裂解3、6、8 h制备生物炭，比较了3种生物炭的产率、pH值、灰分以及C、H、N元素含量，表征了300℃、6 h生物炭的表面形态，并用其作为修复材料，对大港油田的石油污染土壤进行修复。结果表明，随裂解时间的延长，生物炭产率下降，pH值升高，灰分含量增加，H/C值下降，但产率、pH值、灰分和H/C值都是从3h到6h差异显著，6h到8h差异不显著。C元素含量先升高后下降。石油污染土壤经生物炭修复14 d和28 d后，总石油烃降解率分别为45.48％和46.88％，均显著高于对照组。修复14 d后土壤中的萘、苊、苯并[a]蒽、屈、苯并[b]荧蒽、苯并[k]荧蒽、苯并[a]芘、茚并[1,2,3-cd]芘也都有不同程度的下降，其中苯并[a]芘含量下降幅度达98.18％，其他几种PAH的降解率也都高于对照组，28 d后这些PAH的含量又有上升趋势。这说明小麦秸秆裂解时间对生物炭的性质有影响；300℃、6 h生物炭可以用来修复石油污染的土壤。
展开▼
