环境科学研究
環境科學研究
배경과학연구
RSEARCH OF ENUIRONMENTAL SCIENCES
2010年
1期
20-25
,共6页
重金属%沉积物%竞争吸附%热力学和动力学%pH
重金屬%沉積物%競爭吸附%熱力學和動力學%pH
중금속%침적물%경쟁흡부%열역학화동역학%pH
heavy metals%sediment%competitive adsorption%thermodynamic and dynamic%pH
研究了复合污染的重金属体系(多元体系)中松花江沉积物吸附Hg~(2+),Cu~(2+),Pb~(2+),Zn~(2+)和Cd~(2+)的热力学和动力学特征,以及pH对重金属吸附量的影响.结果表明:Langmuir吸附等温线可以很好地描述多元体系中沉积物吸附重金属的热力学过程,沉积物吸附5种重金属离子能力的顺序为Hg~(2+)>Cu~(2+)>Pb~(2+)>>Zn~(2+)> Cd~(2+).在相同的条件下,与单一体系相比,多元体系中Pb~(2+),Zn~(2+)和Cd~(2+)吸附量减小的程度远远大于Hg~(2+)和Cu~(2+),Pb~(2+),Zn~(2+)和Cd~(2+)的吸附量分别减少了31.9%,32.1%和68.1%.一级动力学方程和Langmuir动力学方程可以较好地描述沉积物吸附Hg~(2+),Cu~(2+),Pb~(2+),Zn~(2+)和Cd~(2+)的动力学过程.沉积物对5种重金属的吸附速率为Cd~(2+)>Zn~(2+)>Pb~(2+)>Cu~(2+)>Hg~(2+).沉积物对Cu~(2+),Pb~(2+),Zn~(2+)和Cd~2(+)的吸附能力随pH的降低而减小,pH的降低造成锰氧化物的溶解,可能在一定程度上影响沉积物对重金属的吸附能力.
研究瞭複閤汙染的重金屬體繫(多元體繫)中鬆花江沉積物吸附Hg~(2+),Cu~(2+),Pb~(2+),Zn~(2+)和Cd~(2+)的熱力學和動力學特徵,以及pH對重金屬吸附量的影響.結果錶明:Langmuir吸附等溫線可以很好地描述多元體繫中沉積物吸附重金屬的熱力學過程,沉積物吸附5種重金屬離子能力的順序為Hg~(2+)>Cu~(2+)>Pb~(2+)>>Zn~(2+)> Cd~(2+).在相同的條件下,與單一體繫相比,多元體繫中Pb~(2+),Zn~(2+)和Cd~(2+)吸附量減小的程度遠遠大于Hg~(2+)和Cu~(2+),Pb~(2+),Zn~(2+)和Cd~(2+)的吸附量分彆減少瞭31.9%,32.1%和68.1%.一級動力學方程和Langmuir動力學方程可以較好地描述沉積物吸附Hg~(2+),Cu~(2+),Pb~(2+),Zn~(2+)和Cd~(2+)的動力學過程.沉積物對5種重金屬的吸附速率為Cd~(2+)>Zn~(2+)>Pb~(2+)>Cu~(2+)>Hg~(2+).沉積物對Cu~(2+),Pb~(2+),Zn~(2+)和Cd~2(+)的吸附能力隨pH的降低而減小,pH的降低造成錳氧化物的溶解,可能在一定程度上影響沉積物對重金屬的吸附能力.
연구료복합오염적중금속체계(다원체계)중송화강침적물흡부Hg~(2+),Cu~(2+),Pb~(2+),Zn~(2+)화Cd~(2+)적열역학화동역학특정,이급pH대중금속흡부량적영향.결과표명:Langmuir흡부등온선가이흔호지묘술다원체계중침적물흡부중금속적열역학과정,침적물흡부5충중금속리자능력적순서위Hg~(2+)>Cu~(2+)>Pb~(2+)>>Zn~(2+)> Cd~(2+).재상동적조건하,여단일체계상비,다원체계중Pb~(2+),Zn~(2+)화Cd~(2+)흡부량감소적정도원원대우Hg~(2+)화Cu~(2+),Pb~(2+),Zn~(2+)화Cd~(2+)적흡부량분별감소료31.9%,32.1%화68.1%.일급동역학방정화Langmuir동역학방정가이교호지묘술침적물흡부Hg~(2+),Cu~(2+),Pb~(2+),Zn~(2+)화Cd~(2+)적동역학과정.침적물대5충중금속적흡부속솔위Cd~(2+)>Zn~(2+)>Pb~(2+)>Cu~(2+)>Hg~(2+).침적물대Cu~(2+),Pb~(2+),Zn~(2+)화Cd~2(+)적흡부능력수pH적강저이감소,pH적강저조성맹양화물적용해,가능재일정정도상영향침적물대중금속적흡부능력.
Thermodynamic and dynamic characteristics of Hg~(2+),Cu~(2+),Pb~(2+),Zn~(2+)and Cd~(2+) adsorption to sediments in the Songhua River in the multi-metal system were investigated, and the effect of pH on the adsorption capacity was also analyzed.The results indicated that the Langmuir adsorption isotherm could be used to describe well the adsorption thermodynamics of heavy metals in the multi-metal system.Heavy metal adsorbability to sediments decreased in the order of Hg~(2+)>Cu~(2+)>Pb~(2+)>>Zn~(2+)>Cd~(2+).Compared with the single metal system, the adsorption capacity of Pb~(2+), Zn~(2+) and Cd~(2+) to sediments decreased 31.9%, 32.1% and 68.1% respectively under the same conditions in the multi-metal system, higher than the reductions of Hg~(2+) and Cu~(2+).The Langmuir kinetic equation and first-order kinetic equation could well describe adsorption dynamics of these five heavy metals to sediments.The heavy metals adsorption rate increased in the order of Cd~(2+)>Zn~(2+)>Pb~(2+)>Cu~(2+)>Hg~(2+).Cu~(2+), Pb~(2+), Zn~(2+) and Cd~(2+) adsorbability to sediments decreased with pH decrease.The dissolution of Mn~(2+) oxide due to pH decrease could affect the adsorbability of heavy metals to sediments to some extent.
