Filter cake impact on the textile filtersfor wastewater treatment hydraulic capacity

Abstract

Summary. The aim of the study was to identify the filter cake hydraulic conductivity and its impact on the hydraulic capacity of textile filters for wastewater treatment. The study was carried out using septic tank effluent filtered on four types of filters of different thickness (0.9, 1.8, 3.6 and 7.2 mm). The dry biomass content was 13.45-36.7 mg TS per 1 cm 2 at organic loading rate of 0.04-0.07 mg BOD5 per 1 mg d.m. per day. The filter cake dry mass was related to filter thickness. The dry mass content of filter cake was about 9.7-19.1% of whole filter cross-sectional profile TS content in the long-term experiment. The filter cake had a significant impact on the hydraulic capacity reduction due to its high density and small porosity. The volumetric density of filter cake biomass was almost twice as high as the volumetric density of biomass inside the textile filter. The filter hydraulic conductivity of a one-layer filter without filter cake was over four orders of magnitude higher than the hydraulic conductivity of a one-layer filter with filter cake formed during the short-term experiment.