Khoom nta:
1. Siab filtering qhov tseeb thiab ruaj khov
2. Qhov ntau ntawm cov pa phem
3. Nws muaj cov tshuaj tiv thaiv corrosion muaj zog thiab tuaj yeem siv hauv qhov chaw muaj qhov kub thiab txias, acid, alkali thiab organic solvent
4. Cov dej ntws loj, siab porosity thiab zoo heev permeability
5. Lub zog tawv thiab yas
6. Nws tuaj yeem ntxuav los yog anti ntxuav nrog lub neej ua haujlwm ntev