Correct

无污染

/ wú wūrǎn / 
Strokes

Example

As an Adjective

pollution-free; free of pollution/contamination

1
Wúwūrǎn
无污染
néngyuán
能源
  
/
ránliào
燃料

pollution-free energy/fuel; clean energy/fuel

2
Wúwūrǎn
无污染
gōngyì
工艺
  
/
gōngyè
工业

pollution-free technology/industry