菲、芘在单一和复合污染条件下不同老化阶段的提取率及其生物有效性

Effects of Aging on Extractability and Bioavailability of Phenanthrene and Pyrene Under Single and Co-Contaminant Conditions

研究了土壤中多环芳烃菲、芘在单一和复合污染条件下的老化过程,150天内观察到菲、芘的提取率随时间延长而逐渐减少,下降速率呈现初始较快、而后减慢的趋势;菲、芘的环糊精提取法的提取率随老化时间延长而下降的趋势要比索氏提取法明显。老化过程中复合污染土壤中芘的索氏法提取率略低于单一污染土壤中芘的提取率。在老化的后期,复合污染土壤中菲的环糊精法提取率略高于单一污染土壤中菲的提取率。利用蚯蚓作为测试生物,研究两种污染物的老化过程对其生物有效性的影响,发现表征其生物有效性的蚯蚓吸收率、生物富集系数(BCF)均随老化时间的延长而下降,此外,老化过程中复合污染条件下菲的生物有效性总是大于菲作为单一污染源时的生物有效性。对污染物的环糊精法提取率和蚯蚓吸收率作相关分析发现,单一污染土壤中菲和芘的环糊精提取法的提取率与蚯蚓吸收率均呈显著正相关。

Study was conducted on the aging process ofphenanthrene（PHE） and pyrene （PYE） under single and co-contaminant conditions. Results indicated that the extractable PHE and PYE decreased as their contact time with soil increased during 150 days. The aging rates of PHE and PYE in soil were rather high at the initial stage, and then slowed down with time, besides, the decreasing trend of extractability by using hydroxypropyl-β-cyclodextrin （HPCD） extraction was more obvious than using soxhlet extraction as time passed. The extractability of PYE by soxhlet extraction in co-contaminated soil was a bit lower than that in single contaminated soil in aging process. At the later stage of aging, HPCD extractability of PHE in co-contaminated soil was slightly higher than that in single contaminated soil. Earthworms were used as test organisms to reveal the aging effect on the bioavailability of two pollutants, and it was found that earthworm uptake and bioconcentration （BCF） of pollutants decreased in aging process. The PHE in co-contaminated soil was more available than that in single contaminated soil during aging. Correlation analyses showed that earthworm uptake of PHE and PYE in single contaminated soil were significantly correlated with their extractability in HPCD extraction.