Top IPC subclasses
1
|
C02F
|
2
|
Treatment of water, waste water, sewage, or sludge
|
2
|
B01D
|
1
|
Separation
|
3
|
B09B
|
1
|
disposal of solid waste
|
4
|
C01G
|
1
|
Compounds containing metals not covered by subclasses C01D or C01F
|
5
|
C12F
|
1
|
recovery of by-products of fermented solutionsdenaturing of, or denatured, alcohol
|