abstract

background

blue

blur

bright

clean

clear

close

dark

drink

drip

drop

ecological

ecology

evening

fill

filter

filtration

flow

glass

illuminated

light

liquid

motion

night

nonwettability

nonwettable

plastic

pollute

polluter

pollution

potable

pour

pure

purification

safe

science

spill

spotlight

tasteless

technology

transparency

transparent

water