Efficacy and challenges of carbon nanotube in wastewater and water treatment

•CNTs outperform conventional water and wastewater treatment technologies in several ways.•CNTs have shown substantial promises in the removal of pollutants and microorganisms through adsorption, catalysis, separation, and disinfection.•They function as an efficient adsorbent with increased adsorption capacity and selectivity, and a short response time.•Water permeability, strength, and antifouling capabilities of the membrane are all improved by adding CNT.