Arsenic and total dissolved solids removal using antibacterial/antifouling nanofiltration membranes modified by...

The intrinsic hydrophilicity of metal compounds, such as copper ferrite (CuFe₂ O₄ ), and organic compounds, including graphene oxide (GO) and triethylenetetramine (TETA), make them promising adsorbents for heavy metals removal. The presence of lone pairs in these compounds is observed in modified polyethersulfone membranes used for the separation of arsenic (As) and total dissolved solids (TDS), including mono and divalent salts from aqueous solutions. The objective of this study was to investigate the performance of GO-TETA-CuFe₂ O₄ membranes for wastewater treatment applications. The membranes were characterized for their optimal mechanical strength (tensile strength) and high negative charge (zeta potential) on the surface. Separation tests were conducted at different pressures and pH levels to evaluate the membrane's effectiveness in removing contaminants. In addition, the membranes were examined for their antibacterial properties. The modified membrane exhibited superior performance compared with the control membrane, with TDS removal rates of 93.8%, As³⁺ removal rates of 81.2%, and As⁵⁺ removal rates of 87.9%. The contact angle of the modified membrane was reduced, resulting in an increase in pure water flux from 13.11 to 27.87 L/m² .h. The modified membrane also demonstrated significantly higher resistance to fouling than the control membrane, with a resistance increase from 6.78 × 10⁺¹² to 2.07 × 10⁺¹²  m^-1 . This contributed to the improved separation performance of As and TDS in a cross-flow setup. The results suggest that the GO-TETA-CuFe₂ O₄ modified membrane has great potential for use in water treatment applications. PRACTITIONER POINTS: GO-TETA-CuFe₂ O₄ was successfully used for modification of PES NF membrane structure. The efficiency of blended NF membranes with GO-TETA-CuFe₂ O₄ significantly increased. The modified membranes exhibited significant water flux and antifouling properties. The GO-TETA-CuFe₂ O₄ /PES membranes showed high rejection of heavy metal ions and TDS than PES. The GO-TETA-CuFe₂ O₄ /PES membranes exhibited desirable antibacterial activity.