LAUSR

Abstract The aerobic treatment technologies such as membrane bioreactor (MBR) and sequential batch reactor (SBR) fail to address the techno-economic challenges of a small scale, household greywater (GW) treatment, therefore this research proposes a novel, amended, aerobic bioreactor design containing a macroporous nylon mesh filter (MF), submerged in aerobic bioreactor (MMBR) for the simultaneous treatment and particulate filtration of wastewater not limited to only GW. The research was focused on understanding the interplay of MF submerged depth, the orientation of MF (vertical and horizontal) and mesh pore sizes (50 μm and 100 μm) on the effluent quality and fluxes. The performance of MMBRs was mainly influenced by the MF orientation and its submerged depth in the reactors, whereas, MF pore sizes had no consequential impact on the performances. Higher rates of biofouling in horizontally positioned 100 μm MF coincided with the gradual reduction in effluent flux from 1.6 m3/m2·h to nearly 0.2 m3/m2·h, relatively lower effluent COD of 50 mg/l (90% removal) and turbidity of 29 NTU (56% reduction). In contrast, the continuous self-erosion of biofilm from the horizontally positioned 50 μm MF discharged effluent with relatively higher COD, turbidity and flux respectively. Metagenomic analysis revealed the domination of phylum Proteobacteria and several microbial communities known to degrade recalcitrant household chemical compounds (HCPs). The microbial community dynamics of MF biofilm was distinctive to the suspended microbes in its vicinity, with a comparatively lower microbial population and diversity with respect to the suspended microbes.