Nano-TiO2 membrane adsorption reactor (MAR) for virus removal in drinking water

• Nano-TiO2 was an excellent adsorbent for virus removal in drinking water.
• The adsorption followed Freundlich isotherm and pseudo second-order rate equation.
• The PAN (0.05 μm) membrane had higher removal efficiency than PVDF (0.20 μm).
• The coupling system (nano-TiO2-membrane) increased the removal efficiency of virus.
• Coupling system can achieve the effective separation and recycle of nano-particles.

In order to improve the removal efficiency of virus in drinking water, phage F2, which is similar to human enteric pathogenic virus, was used as the model virus to study the removal efficiency of virus in the water using nano-TiO2-membrane coupling system. The results showed that the adsorption of phage F2 by nanosized TiO2 could reach the adsorption equilibrium in 60 min, and the process could follow the Freundlich isotherm (qe = 27.4·ce1.24), which is assigned to multilayer adsorption. The kinetic studies showed that the pseudo second-order rate equation could fit the experimental data well. The chemical adsorption was the main mechanism, and the intra particle diffusion was the control step. As for the membrane systems, two different flat membranes PVDF (0.20 μm) and PAN (0.05 μm) were used, and the removal efficiency of phage F2 was 1.88–2.56 log and 4.78–5.95 log, respectively. As for the coupling systems of nanosized TiO2 and membrane (nano-TiO2-membrane adsorption reactor), the removal efficiency of phage F2 was 3.88 log and 6.40 log, respectively, which was mainly due to the adsorption of nanosized TiO2 and the effective filter cake layer formed on the surface of membrane during operation. The nano-TiO2-membrane adsorption reactor (MAR) achieved not only the high removal efficiency of virus, but also the effective separation and recycle of nanoparticles.