英文關鍵字
biofilters
bubble
chemical
clean
dirty
drain
ecosystem
effluent
environment
equipment
facility
factory
fluid
groundwater
handle
industrial
industry
liquid
metal
old
pipe
pipeline
plant
pollution
process
purification
recycling
rusty
separate
separation
settle
sewage
sewer
sewerage
station
steel
stopcock
storage
stream
system
tank
tap
technology
treatment
tube
valve
waste
wastewater
water