重金属离子对生物污泥活性的抑制

研究了工业废水中常见的Cd~(2+)、Ni~(2+)、Cr~(6+)、Zn~(2+)、Cu~(2+)、Al~(3+)和Fe~(3+)七种重金属离子对生物污泥的抑制作用。发现其抑制的机理各不相同,前五种为不可逆抑制,污泥经过洗涤,活性不易恢复,而后二种为可逆抑制,污泥洗涤后,活性能基本恢复。试验还发现,几种金属离子同时存在时,抑制性比单一金属离子强。金属离子会在污泥中积聚,因此,即使废水中浓度很低,长期接触也会使生物污泥活性降低。

Inhibitory Effect of Heavy Metal Ions on Activity of Biological Sludge

Inhibitory effect of metal ions(Cd~(2+), Ni~(2+), Cr~(6+), Zn~(2+).Cu~(2+), Al~(3+) and Fe~(3+)),usually existing in industrial waste-water,on the activity of biological sludge was studied.It wasfound that the mechanism of inhibitory effect fear those ionswas different,For the first 5 type,their effect was irreversible,and the activity could not be recovered easily by rinsing.However,for the last two types,inhibitory effect was revers-ible and the activity of sludge could be recovered.Whenseveral types of metal ions existing in sludge at the sametime,inhibitory effect would be stronger than that in the caseof single type,due to metal ions could be accumulated insludge,while contacting for a long period,the activity woulddecrease even the concentration of metal ions was very lowin wastewater.