项目

二级标准

pH

<6.5

6.5~7.5

>7.5

Cu

≤50

≤100

≤100

As

≤40

≤30

≤25

Pb

≤250

≤300

≤350

Zn

≤200

≤250

≤300

Cr

≤150

≤200

≤250

Cd

≤0.30

≤0.60

≤0.60

Hg

≤0.30

≤0.50

≤1.0