The removal of Zn2+, Pb2+, and As(V) ions by lime activated fly ash and valorization of the exhausted adsorbent

•Lime activated fly ash (MFA) was used as a low cost adsorbent.•The removal of Zn2+, Pb2+ and As(V), was 33.13, 26.06, and 29.70 mg g−1.•The exhausted adsorbents were (re)use as an additive for construction material.•Construction material MFA/As(V)/Ca(OH)2 was inert and safe for the environment.•The new concept of “Two-in-one” – reuse of the MFA was applied.