Trickling filter

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

Dynamic mathematical model for the biodegradation of VOCs in a biofilter: Biomass accumulation study

Abstract: Although biofiltration is a firmly established technology for the control of emissions of volatile organic compound (VOCs), more fundamental research is still needed. This work uses a mathematical model describing the dynamic physical and biological processes occurring in a packed trickle-bed air biofilter to analyze the relationship between biofilter performance, biomass accumulation in the reactor, and mathematical description of the packed bed porous media. In this study a biofilter packed with pelletized support media was used to treat toluene achieving removal efficiencies over 99% and 97% for 4.1 and 6.2 kg COD/m{sup 3} day toluene loading, respectively. Experimental results showed that as biomass accumulates in the reactor, the available area for the contaminant to diffuse into the biofilm decreases causing a drop in removal efficiency. This effect is specially important for biofilters where there is a high degree of biomass accumulation that significantly affects biofilter performance. In response to these observations, a new approach for the calculation of the biofilm specific surface area of the reactor as a function of biomass growth was developed. Three models of the reactor porous medium were analyzed. The medium was represented as a bed of equivalent spheres in the first model, as an equivalentmore » set of parallel pipes in the second model, and as an equivalent set of flat parallel plates in the third model. The first two models, spheres and pipes, were proven superior in their ability to explain the system performance. The effect of contaminant solubility on biofilter performance was also analyzed.« less

Removal of alcohol ethoxylates, alkyl ethoxylate sulfates, and linear alkylbenzene sulfonates in wastewater treatment

Abstract: An environmental monitoring study was conducted to assess the removal of alkyl ethoxylate sulfates (AESs), alcohol ethoxylates (AEs), and linear alkylbenzene sulfonates (LASs) during wastewater treatment. Samples were obtained from six trickling filter and four activated sludge treatment plants located in the midwestern United States. The average removal rates for AESs, AEs, and LASs in activated sludge treatment were 98, 97, and >99%, respectively. Lower and more variable removal rates were observed at trickling filter treatment plants with average values of 83, 90, and 82% for AESs, AEs, and LASs, respectively. Using average influent concentrations and removal rates, the predicted exposure concentrations for these surfactants in U.S. receiving waters immediately below treatment plant outfalls were less than their corresponding biological predicted no-effect concentrations in greater than 98% of the locations under low-flow conditions.

Sulfur dioxide treatment from flue gases using a biotrickling filter-bioreactor system.

Abstract: Complete treatment of sulfur dioxide (SO2) from flue gases in a two-stage process consisting of a biotrickling filter followed by biological post-treatment unit was investigated. The biotrickling filter could remove 100% of influent SO2 from simulated flue gas at an empty bed residence time of 6 s for a concentration range of 300-1000 ppm(v). All the absorbed SO2 was recovered in the biotrickling filter liquid effluent as sulfite (a product of chemical reaction of SO2) and sulfate (product of biological oxidation of sulfite). The biotrickling filter liquid effluent was further processed biologically in a single post-treatment unit consisting of a combined anaerobic and microaerophilic reactor for the simultaneous reduction of sulfate and sulfite to sulfide and oxidation of sulfide to elemental sulfur. The post-treatment unit could effectively treat the biotrickling filter effluent and produce elemental sulfur. The sulfur production efficiency of the reactor reached about 80% of the SO2 treated. This new biological treatment system seems to be a promising alternative for flue gas desulfurization.