滇池、洱海水及沉积物中重金属元素的行为

Concentration Levels, Change Records and Enrichment Patterns of Heavy Metals in Waters and Sediments in Both Lake Dianchi and Lake Erhai,Yunnan Province

洱海水中重金属元素的含量不高，平均值以１０－９计算：Ｃｕ１．６，Ｐｂ０．５９，Ｚｎ９．８，Ｃｄ０．００９，Ｃｒ０．２４，水质较好；沉积物中每一样品同一元素的含量一般均趋近于平均值，以１０－６计算：Ｃｕ１１１１，Ｐｈ６０，Ｚｎ１２７，Ｃｄ０．５９１，Ｃｒ１３０。因此，洱海至今仍是一个较清洁的湖泊。滇池水质较差，内草海段水中重金属元素含量明显上升，以１０－９计算：Ｃｕ５．８，Ｐｂ０．５５，Ｚｎ３２，Ｃｄ１．６１１，Ｃｒ０．２４，但远未超过国家饮用水标准。不同湖段的沉积物已受到一些重金属元素的污染，外草海较明显，内草海较严重，表层沉积物中重金属含量以１０－６计算：Ｃｕ９２０，Ｐｂ６４７，Ｚｎ２２０８，Ｃｄ１６４．８５，Ｃｒ５５。

he heavy metals in waters of Lake Erhai, Yunnan Province, were found not at higher levels,with the following mean values calculated in ppb:Cu 1. 6, Ph 0. 59, Zn 9. 8, Cd 0. 009, and Cr0. 24, so that the water quality was assessed as abetter one. The same elements in each sample ofthe sediments form Lake Erhai generally had avalue approximate to their respective averagelevels as calculated in ppm as follows: Cu 111, Ph60, Zn 127, Cd 0. 591 and Cr 130, so that so farLake Erhai has been still a cleaner lake. LakeDianchi in the Yunnan Province was found tohave a rather worse water quality, particularly inits section of inner Caohai where there were significantly increased levels of heavy metals in wateras calculated in ppb as follows: Cu 5. 8, Ph0. 55, Zn 32, Cd 1. 611 and Cr 0. 24, which arewell below the national standards for drinkingwater. The sediments in different sections of thelake have been found to be polluted with someheavy metals, to a more significant extent in thesection of Outer Caohai and to a more serious extent in the section of Inner Caohai. The heavymetals in the top layer of sediment were calculated in ppm at the following levels:Cu 920, Ph647, Zn 2208, Cd 164. 85 and Cr 55.