Aspidistra Plant : Aclk Sa L Ai Dchcsewin 9g7oap1ahvijwgjhbucbrmyababggj3zg Sig Aod64 2oocbanjef5tkp0zghlcutx4daka Adurl Ctype 5 / Wastewater treatment plants work to clean water contaminated with sewage so that it can be returned to the environment.