Removal of emerging contaminants by pre-mixed PACl and carbonaceous materials

Abstract

In this study, pre-mixed poly aluminum chloride (PACl) and super powdered activated carbon (SPAC)/carbon nanotubes (CNT) were employed for the removal of emerging contaminants (ECs) from various water sources. Salicylic acid (SALA), ibuprofen (IBP) and diclofenac (DCF) were the targeted ECs. The synergistic effect of the combined coagulation and adsorption process as well as their individual removal performance are discussed in this paper. The results of the three ECs removal indicate that pre-mixed PACl and SPAC/CNT has a better removal ability compared with PACl or SPAC/CNT alone. The maximum adsorption capacities increase at least 5 times after the addition of PACl, attributed to the charge neutralization and adsorption on the flocs. The removal efficiency of ECs by coagulation improves with the addition of SPAC/CNT as a result of the bridging effect as well as adsorption of ECs by carbon materials. The removal efficiency for these three ECs generally exhibited the following trends: SALA (log P = 1.98) < IBP (log P = 3.84) < DCF (log P = 4.26), indicating that the hydrophobicity of the ECs plays an important role.