黏土矿物不同腐殖质组分团聚体对苯酚的封存特征

为探讨不同腐殖质组分团聚体对苯酚封存能力的影响，应用国际腐殖酸协会推荐的方法提取腐殖质，以Ca²⁺、Al³⁺、Fe³⁺为桥键离子，制备了高岭石、蒙脱石不同腐殖质组分团聚体，并采用平衡吸附/解吸试验、应用饱和吸附量与最大解吸量差减法研究了不同腐殖质组分团聚体对苯酚的封存特征.结果表明，团聚体对苯酚的吸附等温线可用Freundlich吸附/解吸方程（R²=0.991~0.998）和Langmuir吸附/解吸方程（R²=0.993~0.999）描述.高岭石不同腐殖质组分团聚体对苯酚的封存量（Q_m^irr）排序为：富里酸团聚体（（133.71±6.14）mg·kg^-1） > 胡敏酸团聚体（（49.59±8.93）mg·kg^-1） > 胡敏素团聚体（（21.68±2.95）mg·kg^-1）；封存系数（SR）排序为：富里酸团聚体（0.53±0.04） > 胡敏酸团聚体（0.27±0.05） > 胡敏素团聚体（0.18±0.03）；蒙脱石不同腐殖质组分团聚体对苯酚的封存量（Q_m^irr）排序为：富里酸团聚体（（319.44±8.95）mg·kg^-1） > 胡敏酸团聚体（（92.96±22.10）mg·kg^-1） > 胡敏素团聚体（（36.22±6.36）mg·kg^-1）；封存系数（SR）排序为：富里酸团聚体（0.76±0.02） > 胡敏酸团聚体（0.32±0.09） > 胡敏素团聚体（0.23±0.05）.考查腐殖质团聚体对苯酚的封存能力时不但要考虑腐殖质的含量，更要考虑腐殖质的赋存形态，它也是影响团聚体对苯酚封存能力的重要因素.富里酸、胡敏酸和胡敏素与黏土矿物结合形成有机矿质复合体后，对苯酚的封存能力发生了显著改变，团聚体对苯酚的封存系数与团聚体有机碳含量和内表面积呈显著正相关（p<0.01），团聚体对苯酚的吸附/解吸分配系数（k/k_d）与团聚体有机碳含量和内表面积呈显著正相关（p<0.01），土壤/沉积物团聚体的有机碳含量和内表面积是影响对苯酚封存特征的重要因素.研究显示，不同腐殖质组分团聚体对苯酚的封存能力排序为：富里酸团聚体 > 胡敏酸团聚体 > 胡敏素团聚体.

Sequestration characteristics of phenol by aggregates with different humus fraction

To explore the effects of aggregates with different humus fraction on phenol sequestration capacity. sequestration characteristics of phenol by aggregates with different humus fraction was investigated by batch experiments of equilibrium adsorption-desorption. Results indicated that sorption/desorption isotherms for phenol on aggregates were well described by the Freundlich isotherm (R²=0.991~0.998) and Langmuir isotherm (R²=0.993~0.999). The phenol sequestration amount(Q_m^irr) on kaolinite aggregates with different humus fraction follows the order:fulvic acids aggregates((133.71±6.14) mg·kg^-1) > humic acids aggregates((49.59±8.93) mg·kg^-1) > humin aggregates((21.68±2.95) mg·kg^-1); The phenol sequestration ratio(SR) on kaolinite aggregates with different humus fraction follows the order:fulvic acids aggregates(0.53±0.04) > humic acids aggregates(0.27±0.05) > humin aggregates(0.18±0.03). Order of phenol sequestration quantity(Q_m^irr) on montmorillonite aggregates with different humus fraction was:fulvic acids aggregates((319.44±8.95) mg·kg^-1) > humic acids aggregates((92.96±22.10) mg·kg^-1) > humin aggregates((36.22±6.36) mg·kg^-1); And order of phenol sequestration ratio(SR) on montmorillonite aggregates with different humus fraction was:fulvic acids aggregates(0.76±0.02) > humic acids aggregates(0.32±0.09) > humin aggregates(0.23±0.05). Taking into account the sequestration capacity was determined by not only humic content, but also existent state of humic which was a main factor in sequestration capacity. Organo-mineral complexes play a significant role in phenol sequestration. There were significantly obvious positive correlations between sorption/desorption distribution coefficient (k/k_d) and content of organic carbon or internal specific surface area (p<0.01). and there were significantly obvious positive correlations between sequestration ratio (SR) and content of organic carbon or internal specific surface area (p<0.01). Organo-mineral complexes organic carbon content or internal specific surface area were main factor in phenol sequestration on aggregates.Order of sequestration capacity was:fulvic acids aggregates > humic acids aggregates > humin aggregates.