Trickling filter

About: Trickling filter is a research topic. Over the lifetime, 1098 publications have been published within this topic receiving 20219 citations.

Hydrodynamics of plastic media trickling filters

Abstract: The hydrodynamic of plastic media trickling filters were studied. Results from clean packing and filters with biomass hold‐up are compared. Different kinds of packing were investigated and residence time distributions were obtained. Measurements of liquid hold‐up and mean residence time were performed and some correlations are presented to evaluate these parameters. Biomass hold‐up causes the liquid holdup to increase by a factor of five. Knowledge of such hydrodynamic parameters, together with appropriate kinetic models can lead to a better design and operation of trickling filters.

Substrate Removal Mechanism of Trickling Filters

Abstract: A mechanistic model was formulated for substrate removal in a trickling filter with plastic media of the film-flow type by considering the basic physical and biological processes occurring in an elemental volume of slime. It was found that the model developed could be adequately represented by an existing mathematical model. The model was verified in a study using a laboratory-scale filter reproducing the expected hydraulic regime of full-scale units and a waste with glucose as the sole carbon source. It is anticipated that the laboratory and data analysis procedures developed can be used to provide basic design and performance relationships for full scale trickling filters.

Removal Processes for Tributyltin During Municipal Wastewater Treatment

Abstract: The fate and behaviour of tributyltin (TBT) at two wastewater treatment works was examined. Both sites had two inlet streams, and each utilised high rate biological filters (biofilters) on one the streams, before treatment of the combined flows on trickling filters, with one having additional tertiary processes, installed to remove ammonia and solids. The study was designed to determine if these processes enhanced the removal of TBT. Degradation of TBT was observed in one of the biofilters, possibly as a result of temperature and hydraulic loading. At the treatment works with tertiary processes, the mass flux showed the overall removal of TBT was 68 %, predominantly due to removal with solids in the primary settlement processes. However, overall removal of 95 % was observed in the conventional trickling filter works with 94 % of this due to biodegradation in the trickling filter. The two works both removed TBT, but at different treatment stages and by different processes. Differences in the form (solubility) of TBT in the influent may have attributed to this, although further understanding of factors controlling degradation would allow for a more complete assessment of the potential of biological processes to remove hazardous compounds from wastewaters.

Full-scale trials of external nitrification on plastic media nitrifying trickling filter

Abstract: The full-scale single-stage tertiary nitrifying trickling filter (NTF) at the Citrusdal Wastewater Treatment Plant provides for external nitrification of unclarified effluent from the facultative aerobic lagoon in order to meet standard effluent ammonia concentration requirements. The apparent ammonia nitrification rate (ApANR, gN/m2 media surface·d) of the NTF was sensitive to particulate organic loading rates which were predominantly in the form of algae, and the soluble COD removal rates increased under cold climates. Installation of forced-air ventilation fans improved the nitrification efficiency from 15% to 43%. An increase in hydraulic loading rate (HLR) by effluent recirculation significantly improved the ApANR, eradicated filter flies and decreased the prevalence of worms. Maximum ApANR of ~1.0 gN/m2·d was achieved yielding an ammonia- removal efficiency of approximately 71%. Profile samples collected along the NTF media depth indicated poor media wetting at low HLR resulting in low ApANR (<0.5 gN/m2·d). Also during the cold and rainy winter period, poor biofilm activity and prevalence of motile algae were observed, and under low hydraulic loading rates and warmer temperatures, a dominance of filter flies and fly larvae were observed. In contrast, in controlled laboratory studies, ApANRs up to 1.72 gN/m2·d (22.1 mgN/l removal) were attained, which, in conformity with full-scale, was also found to be sensitive to hydraulic loading conditions.