英文關鍵字
aerial
bacterium
basin
circle
cleaner
conservation
digital
dirty
effluent
environment
environmental
factory
graphics
industrial
industry
plant
pollution
processing
progress
purification
purified
purity
recycled
recycling
rotating
round
science
sedimentation
sewage
sewer
sludge
tank
technology
treatment
turbine
waste
wastewater
water