Membrane desalination processes for water recovery from pre-treated brewery wastewater: Performance and fouling

Abstract

Membrane technologies for water reclamation can be effective for combating water shortages while reducing the wastewater discharge to the environment. Here, we investigated water recovery potential from biologically treated brewery wastewater using membrane distillation (MD), nanofiltration (NF), and reverse osmosis (RO). Both MD and RO achieved high organics (~97% TOC) and nutrients (>99% TN and ~100% TP) removal, whereas NF exhibited lower removal rates of TN (~64%) and TOC (~86%). A relatively lower water flux drop (~53%) was observed for MD compared to NF and RO (~98%). Significantly higher water recovery (~86%) was obtained with the MD, compared to NF (~16%) and RO (~12%). The physicochemical characterization of the fouled membranes revealed biofouling along with organic and inorganic fouling for both NF and RO membranes. However, the MD membrane was fouled primarily by organic and inorganic species, with no noticeable biofouling. Though chemical cleaning was effective for water flux recovery of MD, NF, and RO membranes, the repeated operations altered the membrane surface morphology significantly for both NF and RO membranes. Overall, the comparison study revealed that MD has the potential to be directly used for water reclamation from pre-treated brewery wastewater with minimal flux drop, and high organics and nutrient rejection, and flux recovery.