▎ 摘　　要

NOVELTY - Four-columns water filter system has three filtering bed in each column. The three filtering bed comprises filter I or first filter bed-made-up of functionalized graphene on cotton bed, filter II or second filter bed-made-up of cotton supported bed on which neutral powdered egg shell membrane is distributed in uniform thickness of 0.5 cm, and filter III or third filter bed-made-up of reduced egg-shell membrane rest on cotton bed. USE - Four-columns water filter system. ADVANTAGE - The system has low cost, high efficiency, minimization of chemical and biological sludge, no additional nutrient requirement and regeneration of sorbent, and possibility of metal recovery.