英文關鍵字
chemical
concrete
conservation
dirty
discharge
discharging
drain
dump
ecology
effluent
environment
environmental
flow
fluid
garbage
industrial
industry
liquid
nature
old
pipe
pipeline
plant
pollution
pouring
pump
recycling
removal
sedimentation
sewage
sewer
site
slimy
sludge
smell
smelly
stink
stream
system
toxic
treatment
tube
turbid
turbidity
video
waste
wastewater
water