Anh
natural purification
natural self-purification
self-purification
self-treatment
Đức
Selbstreinigung
natürliche Selbstreinigung
Pháp
auto-épuration
auto-épuration naturelle
autoépuration
Selbstreinigung,natürliche Selbstreinigung /TECH/
[DE] Selbstreinigung; natürliche Selbstreinigung
[EN] natural purification; natural self-purification; self-purification; self-treatment
[FR] auto-épuration; auto-épuration naturelle; autoépuration