| 海河干流底泥中六氯苯残留及其释放规律 |
| 摘要点击 2324 全文点击 1293 投稿时间：2005-04-29 修订日期：2005-06-30 |
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| 中文关键词 六氯苯 底泥 释放 海河 |
| 英文关键词 HCB sediment desorption Haihe River |
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| 中文摘要 |
| 为调查海河干流底泥中六氯苯的污染程度及底泥悬浮后六氯苯的释放规律,利用Malven Mastersizer激光粒度分布仪测定海河干流5个断面底泥的粒径分布.结果表明:底泥粒径<125μm的占总质量50%左右,而>500μm只占10%左右,得出海河底泥的粒径较细,为淤泥质底泥;海河干流5断面底泥总有机碳含量在0.64%～3.40%之间;底泥中残留六氯苯浓度范围为6.8～16.7μg/kg,平均值为长江南京段底泥中六氯苯含量的2.9倍,远低于淮河底泥中六氯苯含量.考察了温度、总有机碳含量、底泥粒径以及吸附时间对六氯苯释放的影响,结果表明各因素对六氯苯的释放均有显著影响.快、慢2段一级动力学模型较好地拟合了六氯苯释放的实验数据,并得出了释放动力学参数:快速和慢速释放部分所占的质量分率Frap,Fslow分别为37.6%和62.4%;快速和慢速释放速率常数krap,kslow分别为0.066 9h-1和0.000 5h-1. |
| 英文摘要 |
| The HCB residue in sediments from Haihe River main branch and desorption rules were investigated.The particle sizes of sediments from five sections in Haihe River main branch were mensurated by Malven Mastersizer.The particles less than 125μm accounted for about 50% in mass,while more than 500μm took up about 10%.This showed those particles sizes of sediments are fine so sediments belong to silt.The TOC contents in sediments ranged from 0.64% to 3.40%.Concentrations of HCB contamination in sediments from Haihe River were 6.8～16.7μg/kg,average of which was 2.9 times higher than that in Nanjing reach of Yangtze River and far lower than that in Huaihe River.The effects of temperature,TOC,particle size of sediment and sorption time on desorption of HCB from sediments were also investigated.The results show that above all factors have remarkable influence on desorption of HCB.Experiment data of HCB desorption were simulated better by fast-slow two stage first-order kinetics model and dynamic parameters of HCB desorption were also calculated.Frap and Fslow,the fractions of contaminant present in the rapidly and slowly desorbing sediment compartment,were respectively 37.6% and 62.4%;krap and kslow,the rate constants of rapid and slow desorption,were(0.066 9)h-1 and(0.000 5)h-1,respectively. |
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