Assessing the combined roles of natural organic matter and black carbon as sorbents in sediments
Assessing the combined roles of natural organic matter and black carbon as sorbents in sediments
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DOI：
10.1021/es010953c
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发表时间：
2002-01-01
影响因子：
11.4
通讯作者：
Gschwend, PM
中科院分区：
文献类型：
--
作者：
Accardi-Dey, A;Gschwend, PM
我们假设，两种机制，吸收到天然有机物和吸附到燃烧衍生的黑碳（BC），平行的行为，绑定多环芳烃（PAHs）波士顿港沉积物。为了研究BC的吸附，我们在空气中375 ℃下燃烧海岸附近的沉积物24 h，除去非BC部分，留下约100%的BC。减少了16%的碳。芘在燃烧沉积物上的吸附等温线是非线性的，Freundlich指数为0.62 +/- 0.12，BC归一化分配系数（mug/kg（BC））/（mug/L）（n）为10（6.25+/-0.14）。未处理沉积物对芘的吸附可用K-d = f（oc）10进行合理估算（4.7）+/- f（BC）10（6.25）C-W（（0.62-1））其中f（oc）是非BC有机碳含量，1043是芘的有机碳标准化吸收系数（L/kg（oc）），f（BC）是BC含量，C1是溶解的芘浓度（μ g/L）。C/H/N比表明，我们的环境BC与NIST柴油机烟尘有很大不同，可能是由于包含了来自近源大气沉降物和城市径流的较大BC颗粒。BIG对多环芳烃总吸附的影响可以解释报告的非线性等温线，K-OC值的多环芳烃，超过各自的K-低值，平面和非平面山梨酸酯之间的生物利用度的差异。
We hypothesized that two mechanisms, absorption into natural organic matter and adsorption onto combustion-derived black carbon (BC), act in parallel to bind polycyclic aromatic hydrocarbons (PAHs)to Boston Harbor sediments. To focus on BC-adsorption, we removed the non-BC fraction by combusting near shore sediments at 375degreesC for 24 h under air, leaving ca. 16% of the reduced carbon. The isotherm for pyrene sorption onto our combusted sediment was nonlinear with a Freundlich exponent of 0.62 +/- 0.12 and a BC-normalized distribution coefficient (mug/kg(BC))/(mug/L)(n) of 10(6.25+/-0.14). Pyrene sorption to untreated sediment was reasonably estimated using K-d = f(oc) 10(4.7) +/- f(BC) 10(6.25) C-W((0.62-1)) where f(oc) was the non-BC organic carbon content, 1043 was the organic carbon-normalized absorption coefficient for pyrene (L/kg(oc)), f(BC) was the BC content, and C, was the dissolved pyrene concentration (mug/L). C/H/N ratios indicated that our environmental BC differed substantially from NIST diesel soot, possibly due to inclusion of larger BC particles from near source atmospheric fallout and urban runoff. The impact of BIG on total PAH sorption may explain reports of nonlinear isotherms, K-oc values for PAHs that exceed their respective K-ow values, and discrepancies in bioavailability between planar and nonplanar sorbates.