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 cm2 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 thick-ness. 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.
The study evaluates the antifeedant activity of rutin and quercetin (flavonoids of buckwheat Fagopyrum esculentum) and the extract from the leaves of black alder Alnus glutinosa on the development and the extent of damage caused by the beetles of cockchafer Melolontha melolontha in laboratory and semi−field conditions. We found increased mortality and decreased intensity of beetle feeding on the Quercus robur leaves sprayed with a solution of rutin. The treatment of Q. robur leaves with solutions of quercetin and extract from the leaves of black alder had no effect on the development of beetles and fertility of females, and did not inhibit feeding of cockchafer.