CAJ | 학술논문

长期以来，研究者在探讨土壤中多环芳烃（PAHs）的降解及修复过程中，缺乏简便有效的手段对化合物的降解动态进行定量研究。前人尝试用投加实验、对比采用降解措施前后污染物的浓度变化、模型计算等方法研究PAHs的降解过程，其结果常互相矛盾，或不能真实反映复杂的实际环境。本文应用单体碳同位素分析技术对农田土壤中PAHs的植物降解过程进行定量表征，采集了某地农田表土作为供试土壤，选择玉米作为供试作物，开展了作物对土壤中PAHs降解及消除过程的研究。气相色谱－质谱分析结果表明，培养所用的玉米原始土及分4批收集的空白土、根际土、非根际土样品中16种PAHs的浓度总和（∑PAHs）平均分别为380．8 ng／g、（281．5±34．7）ng／g、（272．2±1 1．6）ng／g和（299．8±37．9）ng／g；玉米生长期间，各土壤样品的∑PAHs均比原始土壤有所下降，但除3环以下化合物（萘、苊烯、苊、芴、菲、蒽）外，其他化合物并未随玉米的生长表现出显著趋势。与玉米根、叶倾向于富集低环PAHs化合物相对应，可以判断植物对土壤中的低环化合物去除作用最为显著。各采样时期玉米根际土、非根际土和空白土壤样品中PAHs单体化合物的碳同位素分馏值（δ13C）在－34．31‰～－23．95‰之间，且除芘外的其他化合物的δ13C值随时间呈现逐步变轻的趋势，波动值位于－9．0‰～－0．6‰之间；本文对于PAHs单体化合物，尤其是4、5环化合物，在玉米降解过程中的碳同位素分馏与浓度变化之间未发现明显关系。考虑3环以下的PAHs化合物更倾向于被降解和清除，且其碳、氢同位素分馏情况更容易被观察到，因此稳定同位素分析技术更有助于探明该类单体PAHs污染物在环境中的迁移、转化规律。
장기이래，연구자재탐토토양중다배방경（PAHs）적강해급수복과정중，결핍간편유효적수단대화합물적강해동태진행정량연구。전인상시용투가실험、대비채용강해조시전후오염물적농도변화、모형계산등방법연구PAHs적강해과정，기결과상호상모순，혹불능진실반영복잡적실제배경。본문응용단체탄동위소분석기술대농전토양중PAHs적식물강해과정진행정량표정，채집료모지농전표토작위공시토양，선택옥미작위공시작물，개전료작물대토양중PAHs강해급소제과정적연구。기상색보－질보분석결과표명，배양소용적옥미원시토급분4비수집적공백토、근제토、비근제토양품중16충PAHs적농도총화（∑PAHs）평균분별위380．8 ng／g、（281．5±34．7）ng／g、（272．2±1 1．6）ng／g화（299．8±37．9）ng／g；옥미생장기간，각토양양품적∑PAHs균비원시토양유소하강，단제3배이하화합물（내、액희、액、물、비、은）외，기타화합물병미수옥미적생장표현출현저추세。여옥미근、협경향우부집저배PAHs화합물상대응，가이판단식물대토양중적저배화합물거제작용최위현저。각채양시기옥미근제토、비근제토화공백토양양품중PAHs단체화합물적탄동위소분류치（δ13C）재－34．31‰～－23．95‰지간，차제비외적기타화합물적δ13C치수시간정현축보변경적추세，파동치위우－9．0‰～－0．6‰지간；본문대우PAHs단체화합물，우기시4、5배화합물，재옥미강해과정중적탄동위소분류여농도변화지간미발현명현관계。고필3배이하적PAHs화합물경경향우피강해화청제，차기탄、경동위소분류정황경용역피관찰도，인차은정동위소분석기술경유조우탐명해류단체PAHs오염물재배경중적천이、전화규률。
For the research on degradation and remediation of soil polycyclic aromatic hydrocarbons (PAHs ) pollutants,researchers have been trying to find an effective method to quantitate the dynamic processes.Many approaches have been designed,such as spiked experiment,concentrations comparison before and after the degradation,and modeling calculations.However,all of this culminates in contradictory results and lack of corroboration of the actual environment.Compound-Specific Isotope Analysis (CSIA)technique is used in this study to investigate the phytodegradation process of soil PAHs with maize as the testing plant.Total concentrations of 1 6 PAHs in the blank soil,rhizosphere soil and the controlled soil samples were (299.8 ±37.9)ng/g,(272.2 ±1 1 .6)ng/g,and (281 .5 ±34.7)ng/g,respectively,all lower than the original cultivating soil (380.8 ng/g). The soil PAHs concentrations did not show significant decline tendency during the maize growing period,except for PAHs compounds below 3-ring which was consistent with the accumulation effect of the 3-ring PAHs in maize roots and leaves.The δ13C value of 6 PAHs compounds ranged from -34.31‰to -23.95‰with fluctuations between-9.0‰ --0.6‰,and all δ13 C values turned lighter with maize plants growing except that of pyrene.No significant correlation between δ1 3 C and the concentration of 4-,5-ring PAHs was observed during the maize cultivating process. Most research indicates that PAHs and other macromolecular compounds strongly resist phytodegradation,which illustrates less obvious carbon isotope fractionation.PAHs compounds below 3-ring would degrade more easily and the isotope fractionate more significantly than those of other macromolecular compounds, thus maing CSIA technique more advantageous for understanding the transportation pathway of these compounds.