Effective removal of proteins using carbon‐based nanoadsorbent: relevancy to the application of membrane‐driven pre‐water treatment

Abstract

BACKGROUND: Protein is one of the key components of dissolved organic matter (DOM) and poses challenges in water treatment such as membrane fouling. The removal of proteins in preliminary treatment should transform wastewater treatment into a more feasible and cost-effective process by preventing membrane fouling. In this study, we chemically synthesized nanographene oxide (NGO) and explored its potential as a nanoabsorbent for adsorbing the proteins lysozyme (LYZ) and bovine serum albumin (BSA). RESULTS: Here, NGO was synthesized by incorporating some changes in a modified Hummer's method and characterized by various physicochemical methods. We demonstrated the excellent adsorption potential of NGO for the removal of LYZ and BSA from solution. We observed that the adsorption isotherm obeyed the nonlinear Langmuir model; maximal adsorption capacities of 1743.23 and 1156.54 mg g −1 were estimated for LYZ and BSA, respectively. Further, we also demonstrated the excellent regeneration efficiency of NGO whereby removal efficiency dropped by only 5-8% after repeated cycles of adsorption and desorption. Moreover, NGO demonstrated the high antibacterial potential in its protein adsorbed as well as regenerated state against both Gram-positive and -negative bacteria. CONCLUSION: Our findings revealed that carbon-based NGO might be used as nanoadsorbent for preliminary wastewater treatment before membrane treatment to overcome problems including membrane biofouling, viscosity and foaming that otherwise can cause interference and complications in membrane operation.