典型石油烃组分在地下水中的自然衰减规律

Natural Attenuation of the Typical Petroleum Hydrocarbons in Aquifers

为了解石油烃类污染物在地下水中的自然衰减规律,以苯、萘、菲作为目标污染物,采用实验场地4种天然砂土作为含水层介质进行了室内模拟实验。结果表明:在单组分和混合组分溶液中,苯、萘和菲在地下含水层介质中的自然衰减均符合一级动力学方程;在不同含水层介质中,苯和萘的衰减速率大小顺序为粉砂>中砂≈粗砂>砾砂,而菲的自然衰减速率大小顺序为粉砂≈中砂≈粗砂>砾砂;微生物降解在苯和萘的自然衰减中起重要作用,而固相吸附在菲的自然衰减中起重要作用。3种物质共存时,苯和萘的自然衰减加快,菲的自然衰减减慢。

Batch experiments were carried out to catch the natural attenuation rule of the petroleum hydrocarbons such as benzene,naphthalene,and phenanthrene in silt sandy,medium sandy,coarse and gravel sandy aquifers collected from the contaminated field site,respectively.The results showed that the natural attenuation of benzene,naphthalene,and phenanthrene in above four aquifer media,both in individual and mixed solute systems,follows the first-order kinetics among the four aquifer media,benzene and naphthalene attenuates as following： the silt sand the medium sand≈the coarse sand the gravel sand.For phenanthrene,the sequence of the attenuation rate is the silt sand≈the medium sand≈the coarse sand the gravel sand.In investigated four aquifer media,the microdegradation plays an important role in the natural attenuation of benzene and naphthalene,while the adsorption onto the aquifer media is the most important for natural attenuation of phenanthrene.Besides,when the three components coexist,the natural attenuation of benzene and naphthalene gets faster while the natural attenuation of phenanthrene gets slower.