Insights into the retention behavior of betamethasone by nanofiltration - An alternative for decentralized drinking water treatment

Betamethasone (BET) has been found in surface and wastewater around the world. The pharmaceutical is prescribed to human and veterinary use due to its anti-inflammatory, anti-allergic and immunosuppressive properties. As a result of its recalcitrant character and resistance to biological degradation processes, BET is not retained by wastewater treatment plant, nor in drinking water treatment plants. However, it is necessary to invest in techniques that allow BET to be removed from aqueous matrices in view of its adverse effect on human health and the environment. In this sense, nanofiltration (NF) stands out as a promising alternative. Thus, in this study, the DK NF membrane was applied under different transmembrane pressure (TMP; 4-10 bar) and feed flow rates (0.8-3.2 L/min) for surface water treatment, aiming for a higher permeate flux, as well as the higher BET retention. Increasing TMP lead to higher permeate flux (47.44 L/m(2).h) and lower flux decline (J/J(0) = 0.95). The increase in feed flow rates besides lead to a high permeate flux also contributed to a high membrane rejection (BET retention of 98.8%), but implies a higher specific energy consumption. The NF Opex was estimated in 0.43 US$/m(3), which demonstrates that NF could be a feasible alternative to remove BET from drinking water with high desalination capacity.

Automated summary

Betamethasone is commonly found in surface and wastewater, posing a threat to human health and the environment. Nanofiltration has shown to be a promising method for removing BET, achieving a balance between high permeate flux and high BET retention rate.