Sand filtration is a primary stage of treatment for reuse of greywater. This study aimed at assessing the volatile solid removal efficiency of a sand filter and imitating its performance using analytical simulation. This study used artificial greywater, medium sand as a filtering material, and nine PVC cylinders as filter columns. Samples of the sand were collected after 6, 14 and 21 days, with the aim of specific deposit determination. The vertical distribution of specific deposit (volatile solids) in the sand filters was typical for gravitationally operated sand filters. Relatively high removal efficiency of volatile solids (51–60%) was achieved at relatively low cumulative hydraulic load. The average removal efficiency of organic compounds (detected as chemical oxygen demand) was 26.8%. Maximum specific deposit was achieved for a cumulative hydraulic load of 363.6 m. The filter coefficient was identified empirically for application of the Iwasaki formula. The filter coefficient λ was corrected for a better fit of the modelled values with measured values.

The objective of the study was to evaluate the usefulness of novel nonwoven textile filter technology for greywater treatment. This technology had already been used on a lab scale for septic tank effluent treatment; however, this study is the first time it has been used for greywater treatment. The set-up period with septic tank effluent (STE) feeding was significantly shorter than that of greywater feeding. The average capacities of both filter types were practically the same: 1.0–1.4 cm d⁻¹. The relatively high efficiencies of chemical oxygen demand (COD_Cr) and biochemical oxygen demand (BOD₅) removal (58.8–71.6% and 56.7–79.8%, respectively) were obtained thanks to the relatively low filtration velocity and effective diffusion of atmospheric air into the greywater. The relatively high efficiency of total suspended solids (TSS) removal (67.0–88.4%) was obtained by reducing the effective pore size of the filtration layer due to high biomass concentration and accumulation of suspended solids. Thanks to hydrostatic pressure, the filters can work practically with very low energy consumption. The pollutants removal efficiencies were satisfactory in respect to simple construction and maintenance, low investment and operational costs.