• 关键词：土壤有机质  矿质结合态胡敏酸  矿质结合态胡敏素  吸附  生物降解

• 基金项目：教育部留学回国基金(No.0101234);国家高技术研究发展计划(863)项目(No.2004AA649070)

• 胡顺利
• 大连理工大学生命科学与技术学院, 大连 116024

• 贾凌云
• 大连理工大学生命科学与技术学院, 大连 116024

• 高慧鹏
• 大连理工大学生命科学与技术学院, 大连 116024

• 高波
• 大连理工大学生命科学与技术学院, 大连 116024

• 谢健
• 大连理工大学生命科学与技术学院, 大连 116024

• 徐丽
• 大连理工大学生命科学与技术学院, 大连 116024

• 摘要：为了研究不同有机质对持久性有机污染物(POPs)的吸附行为及生物可利用性的影响,从黑龙江省未被多环芳烃(PAHs)污染的农业表层土壤中提取了矿质结合态胡敏酸(MHA)、矿质结合态胡敏素(MHU),通过绘制吸附动力学曲线和吸附等温线,研究了MHA 、MHU 及全土本身对菲的吸附特性,并通过改变老化时间和吸附剂质量,研究了不同有机质成分对菲的生物降解的影响.结果表明,吸附常数(K)和非线性程度(N)均为MHU >全土>MHA .在较短的老化时间(60d)和降解时间内(48h),吸附常数(K)较小的MHA 表现出更强的对菲生物降解的抑制性,老化60d降解6h时,MHA 对吸附态菲的降解率为46.99%,而全土和MHU 分别为64.40%和59.33%.随着吸附剂质量的增加,MHA 对菲生物降解的抑制呈现增大的趋势,在老化7d降解24h条件下,MHA 剂量增加为原来的1倍和3倍时,吸附态菲的生物降解率分别为78.80%和13.90%,而MHU 剂量的增加对吸附态菲的生物降解率基本没有影响.随着老化时间的延长,吸附于MHU 上的菲的生物降解率有下降的趋势.由此推测,在较短的老化时间和生物降解时间内,MHA 将是影响土壤中持久性有机污染物生物可利用性的关键因素.

• Abstract：In order to determine the influences of different soil organic fractions on sorption characteristics and bioavailability to persistent organic pollutants (POPs),mineral-bound humic acid (MHA) and mineral-bound humin (MHU) were separated from the topsoil of Heilongjiang Province. Sorption characteristics of MHA,MHU and whole soil to phenanthrene were studied by sorption kinetics and isotherms. The influences of soil organic fractions on bioavailability were measured by changing the aging time of phenanthrene and the quantities of the adsorbents. The results showed both distribution coefficients (K) and nonlinearities were in the order MHU >whole soil>MHA . During a short aging period (60 d) and degradation time (24 h),MHA with lower distribution coefficients (K) restrained the biodegradation of phenanthrene. The degradation rates of phenanthrene,adsorbed by MHA,MHU and whole soil,were 46.99%,64.40% and 59.33% respectively,after 60 d aging and 6 h degradation. With increased amounts of sorbent,the biodegradation of phenanthrene adsorbed by MHA was significantly decreased. Phenanthrene,aged 7 d and degraded 24 h,was degraded 78.80% and 13.90%,respectively,after MHA was increased by 1 and 3 times. However,similar results were not observed by changing MHU . With prolonged aging time,the biodegradation of phenanthrene adsorbed by MHU decreased gradually. These findings suggest that MHA plays an important role in the biodegradation of POPs adsorbed by the soil in a short aging period and biodegradation time.

• Key words：soil organic matter  mineral-bound humic acid  mineral-bound humin  sorption  biodegradation

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