scispace - formally typeset
Search or ask a question

Showing papers on "Trickling filter published in 2006"


Journal ArticleDOI
TL;DR: Mass flows of the 6:2 fluorotelomer sulfonate and perfluorooctanoate were unchanged as a result of wastewater treatment, which indicates that conventional wastewater treatment is not effective for removal of these compounds.
Abstract: Fluorochemicals have widespread applications and are released into municipal wastewater treatment plants via domestic wastewater. A field study was conducted at a full-scale municipal wastewater treatment plant to determine the mass flows of selected fluorochemicals. Flow-proportional, 24 h samples of raw influent, primary effluent, trickling filter effluent, secondary effluent, and final effluent and grab samples of primary, thickened, activated, and anaerobically digested sludge were collected over 10 days and analyzed by liquid chromatography electrospray-ionization tandem mass spectrometry. Significant decreases in the mass flows of perfluorohexane sulfonate and perfluorodecanoate occurred during trickling filtration and primary clarification, while activated sludge treatment decreased the mass flow of perfluorohexanoate. Mass flows of the 6:2 fluorotelomer sulfonate and perfluorooctanoate were unchanged as a result of wastewater treatment, which indicates that conventional wastewater treatment is not...

372 citations


Journal ArticleDOI
TL;DR: The proposed biological treatment process based on a trickling filter appears as a promising pretreatment step for coping with dye manufacturing wastewaters in terms of removing a significant portion of the organic content.

268 citations


Journal ArticleDOI
TL;DR: In this article, the main mechanisms and parameters affecting the design and performance of trickling filters in aquaculture are discussed, including the relationship between nitrification rates and easily accessible process parameters, like bulk phase concentration of TAN, O2, organic matter (COD), nitrite, temperature, HCO3−, pH and hydraulic loading of the trickling filter.

220 citations


Journal ArticleDOI
TL;DR: A hydrogenotrophic denitrification reactor was designed for the removal of nitrate from aquaria and an electrochemical cell was used to generate hydrogen gas to avoid the need for storage of large volumes of hydrogen gas in aquarium or aquaculture applications.

46 citations


Journal ArticleDOI
TL;DR: The effect of rain events on effluent quality dynamics was studied at a full scale activated sludge wastewater treatment plant which has a process solution incorporating pre-denitrification inactivated sludge with post-nitrification in trickling filters.

34 citations


Journal ArticleDOI
TL;DR: In this article, an application of the back-propagation neural network to this experimental data is presented, where the performance parameters namely, elimination capacity and removal efficiency were predicted from the experimental observation by selecting the appropriate network topology.
Abstract: Experimental studies were carried out with a laboratory-scale biotrickling filter to treat a gaseous stream contaminated with benzene, toluene and xylene (BTX) operated in a continuous mode. The biotrickling filter initially acclimatised with toluene was used to treat BTX compound individually at loading rates ranging from 7.2 g/m³hr to 62.2 g/m³hr, operated in a sequential mode. The results showed removal efficiencies as high as 100% when operated with toluene as the sole carbon source. An application of the back-propagation neural network to this experimental data is presented in this paper. The performance parameters namely, elimination capacity and removal efficiency were predicted from the experimental observation by selecting the appropriate network topology. The sensitive internal parameters of the network were selected using the 2(k–1) fractional factorial design. The neural-network-based model was found to be an efficient data-driven tool to predict the performance of a biotrickling filter.

34 citations


Journal ArticleDOI
TL;DR: In this article, the effect of hydraulic retention time (HRT) in the range of 5-30 days was evaluated at influent total chemical oxygen demand (TCOD) in a laboratory stabilization pond.

21 citations


Journal ArticleDOI
TL;DR: Fine media FBBs can be designed and operated for biological removal of 99.95% of slow biodegrading refractory organic pollutants like methyl tertiary butyl ether (MTBE) in a single pass with discharge concentrations <1 ppb.

19 citations


Journal ArticleDOI
TL;DR: The removal of DOC by air- and O2-AS bacteria followed trends predicted by a macromolecule degradation model and a skewed distribution toward the high MWF.
Abstract: The molecular-weight distribution (MWD) of wastewater dissolved-organic carbon (DOC) was determined in samples from seven full-scale wastewater-treatment plants (WWTPs) that use different biological treatments (air activated sludge [air-AS], pure-oxygen AS [O 2 -AS], and trickling filters). The research objective was to determine how different biological treatments influenced the MWD of wastewater DOC. Primary sedimentation effluent DOC from most of the WWTPs exhibited a skewed distribution toward the low-molecular-weight fraction (MWF) (40 to 50%, 3 KDa). The removal of DOC by air- and O 2 -AS bacteria followed trends predicted by a macromolecule degradation model. Trickling-filter effluent DOC exhibited a skewed distribution toward the high MWF (50% DOC, >3 KDa).

16 citations


Journal ArticleDOI
TL;DR: Evidence is provided that the removal of organic and inorganic particulate matter in a TF bioreactor follows a first-order bioflocculation rate equation and the statistical analysis of data obtained from the pilot TF fits the dispersion model to suspended solids and PCOD remaining in the pilotTF.
Abstract: Understanding that there is a significant presence of extracellular polymeric substances at the biofilm/wastewater interface and that the primary constituent of chemical oxygen demand (COD) in domestic wastewaters is organic particulates, this research describes the kinetics of particulate removal in a pilot-scale trickling filter (TF) and the role of bioflocculation in the removal process. Recent research has described the role of bioflocculation on particulate COD (PCOD) removal in suspended growth biological wastewater treatment systems. However, no research pertaining to PCOD removal by bioflocculation in attached growth systems was identified prior to this study. For this study, experiments were conducted using both bench- and pilot-scale biofilm reactors and provided evidence that the removal of organic and inorganic particulate matter in a TF bioreactor follows a first-order bioflocculation rate equation. The statistical analysis of data obtained from the pilot TF fits the dispersion model to suspended solids and PCOD remaining in the pilot TF.

13 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated formaldehyde (HCHO) degradation in a trickling filter at three different temperature levels: 14.5, 10.0, 9.5 and 16.5.
Abstract: We investigated formaldehyde (HCHO) degradation in a trickling filter at three different temperatures. Formalin, equivalent to an initial concentration of 40 mg of formaldehyde per liter of water, was applied to a closed experimental setup that included an active trickling filter. Water samples were taken regularly over a 96-h period and analyzed for formaldehyde. Decomposition of HCHO was significantly related to water temperature; estimated half-lives were 5.0, 9.5, and 16.5 h at 14.5, 10.0, and 5.5°C, respectively. Evidence of microbial decomposition indicated that formaldehyde reduction was correlated to the available trickling-filter surface area at a removal rate of 8.3–21.3 mg formaldehyde·m−2·h−1. These findings permit the calculation of formaldehyde decomposition rates during treatments in recirculating systems and make it possible to design trickling filters with a specific decomposition capacity.

Journal ArticleDOI
TL;DR: The feasibility of combining a previously reported storage driven denitrification biofilm, where 80% of influent acetate can be converted to poly-beta-hydroxybutyrate (PHB), with a suitable nitrification reactor, either submerged or trickling filter design, to achieve complete biological nitrogen removal was tested.


Patent
17 May 2006
TL;DR: In this paper, a biological trickling filter bed for treating odorant pollutant in air is presented, which adopts new type stuffing of different grain sizes and has decreased stuffing size distribution from the bottom to the top.
Abstract: The biological trickling filter bed for treating odorant pollutant in air is one stuffing tower with spraying head in the top, air inlet in the bottom, air outlet in the top, and height/diameter ratio of 4-10. The biological trickling filter bed adopts new type stuffing of different grain sizes and has decreased stuffing size distribution from the bottom to the top. Stuffing of two different sizes, including large grain stuffing in the bottom and small grain stuffing in the top, are adopted. The present invention has high treating load, homogeneous load distribution and low pressure drop.

01 Jan 2006
TL;DR: In this article, a radial jet nozzle configuration instead of the conventional circular nozzle was used to improve the tricling filter performance by enhancing both the oxygen transfer rate and wetting percent of the media surface.
Abstract: The present study is an attempt to improve the tric kling filter performance by enhancing both the oxygen transfer rate and wetting percent of the media surface this was achieved using radial jet nozzle configuration instead of the conventional circular nozzle. The distributor-offset distance from the b ed was taken into consideration as a geometric variable parameter. Two pilot-scale tric kling filters were constructed on field to evaluate the effect of radial jet nozzle a nd offset distance on the trickling filter performance. Results indicated that the distributi on system has major effects on the trickling filter performance, and that radial jet n ozzle increased BOD removal ratio by approximately 10% higher than the conventional nozzle for fixed distributor and by approximately 7% for rotating distributor, radial j et nozzle also enhanced DO% on the filter effluent for fixed distributor but not for t he rotating one. The offset distance has approximately no effect on trickling filter perform ance. Increasing hydraulic loading rate reduced trickling filter efficiency, as the hy draulic retention time reduced.

01 Jan 2006
TL;DR: In this article, a biofilter was used in three different applications with odour problems, namely restaurant, pulp mill and wastewater pumping station, and the results showed that very low concentrations of individual compounds were found (ppb-level), and very low or no removal of the targeted compounds was achieved in the biofilter.
Abstract: Biofiltration has shown its potential as an interesting treatment alternative for contaminated gas streams. Unlike conventional technologies, such as adsorption, scrubbers, and incineration, biofiltration offers effective pollution control at relatively low capital and operating costs, and without the generation of secondary pollution that may require subsequent treatment. The disadvantages of biofiltration have been the large space requirements and frequent media replacements as a result of deterioration or ageing. Extensive biofilter research and development have taken place over the past 20 years internationally, in particular laboratory experiments that address the removal of single pollutants at fairly high concentrations under constant operating conditions. In field applications, such conditions are highly unusual and the feasibility of treating complex mixtures at very low concentrations relevant to many odorous gas emissions has not received much attention. The overall objective of this thesis was to reduce the knowledge gap between laboratory studies and field conditions on the topic of biofiltration for odorous gas emissions. Various operational and process related problems, such as fluctuating flows, temperatures, and pollutant concentrations, that affected the biofilter performance by creating suboptimal living conditions for the microbes were identified. A newly designed compact pilot-scale biofilter was used in three different applications with odour problems, namely restaurant, pulp mill and wastewater pumping station. The gas streams were complex mixtures with chemically diverse contaminants whose concentrations varied significantly with time. Aldehydes were the dominant compounds in restaurant emissions, while reduced sulphur compounds, primarily dimethyl sulphide, dominated the pulp mill and wastewater emissions. Overall, very low concentrations of individual compounds were found (ppb-level), and very low or no removal of the targeted compounds was achieved in the biofilter. Limitations of the biomass density in the filter media is a plausible explanation since pollutant concentrations at the ppb-level may have been too low to build up and support the bacteria. Due to the low solubility of many identified compounds, a mass transfer limitation may also have occurred due to the prevailing short residence times. Drying of the filter medium was partly a problem, pointing to the need for an improved humidification system or using a trickling filter design. In a case study at a wastewater treatment plant, a method to evaluate odour problems was developed involving local observers in an odour panel together with operational data and weather observations. Working with an odour panel proved useful in several ways; they took an active interest in and increased their knowledge of the complexity of odour problems. However, relating the panel reports to specific events at the treatment plant proved difficult, and the reports were not always consistent with current wind directions.

Patent
15 Feb 2006
TL;DR: In this paper, the utility model provided a biological treating device for garbage-burning waste gas, which comprises a biological trickling filter, a biological filtering pond and a spraying liquid inlet with a spraying humidifying device.
Abstract: The utility model provides a biological treating device for garbage-burning waste gas, which comprises a biological trickling filter, a biological filtering pond and a spraying liquid inlet with a spraying humidifying device, wherein the top part of the cylindrical biological trickling filter is provided with the spraying liquid inlet with the spraying humidifying device and an air outlet, and the lower part of the cylindrical biological trickling filter is provided with an air inlet and a water outlet; the water outlet is connected with a water collecting device, the lower part of the cylindrical biological filtering pond is provided with an air inlet which is communicated with the air outlet, the upper part of the cylindrical biological filtering pond is provided with an air outlet, and the bottom part of the biological filtering pond is provided with the water outlet which is connected with the water collecting device; the biological filtering pond is connected with the biological trickling filter through an air pipe, and filling materials are respectively filled in the biological filtering pond and the biological trickling filter The utility model has the advantages of simple structure, flexible and convenient operation, low cost, good purifying effect, wide range for application and high treating efficiency

Journal ArticleDOI
TL;DR: In this article, a new design procedure is proposed based on a survey which showed that seven of eight conventional trickling filter (CTF) plants exceeded the U.S. Environmental Protection Agency secondary treatment regulatory requirements.
Abstract: Based on a survey which showed that seven of eight conventional trickling filter (CTF) plants exceeded the U.S. Environmental Protection Agency secondary treatment regulatory requirements, a new design procedure is proposed. It recognizes that bioflocculation within CTFs is poor and that most of the effluent violations seen in the survey could be related directly or indirectly to the level of effluent suspended solids. In past practice, process design focus has been on soluble or settled effluent biochemical oxygen demand ( BOD5 ) rather than the effluent suspended solids. The principal focus in CTF process design should be on predicting effluent suspended solids (SS) after secondary clarification, rather than effluent carbonaceous BOD5 . If the total organic loading (TOL) is set in the proper range, the effluent carbonaceous BOD5 is primarily determined by the effluent SS. A new design procedure has been developed that identifies the highest TOL that can be sustained without posing a constraint on efflue...

Journal Article
TL;DR: In this article, the removal experiment of odor containing hydrogen sulfide (H_2S) in lab was carried out continuously in high-efficient biological deodorization reactor packed with ceramics on which screened and cultivated bacterium were immobilized.
Abstract: The removal experiment of odor containing hydrogen sulfide(H_2S) in lab was carried out continuously in high-efficient biological deodorization reactor packed with ceramics on which screened and cultivated bacterium were immobilized.Removal efficiency can reach above 98% under following conditions: the concentration of inlet between 300 mg/m~3and 700 mg/m~3,the gas flow between 0.05 m~3/h and 0.5m~3/h.The decrease of pH did not affect the removing efficiency of hydrogen sulfide.The retention time of the reactor is long enough to treat odor efficiently.

Journal Article
TL;DR: In this article, an approach to remove low concentration SO 2 using biological trickling filter was studied, and the results of preliminary experiment show that the optimum operating conditions are as the following: the concentration of SO 2 in influent gas is 500-1?000?mg/m~3, the gas flow is 0.1?m 3/h,circulated liquid flow is 15?L/h and pH is 1.0.
Abstract: An approach to remove low concentration SO_2 using biological trickling filter was studied.The results of preliminary experiment show that the optimum operating conditions are as the following:the concentration of SO_2 in influent gas is 500—1?000?mg/m~3,the gas flow is 0.1?m~3/h,circulated liquid flow is 15?L/h and pH is 1.0.When the gas flow is changed from 100?L/h to 300?L/h,the SO_2 removal efficiency decrease,from 86.4% to 73.2%,while the concentration of SO_2 in influent gas is about 2?500?mg/m~3,the SO_2 removal efficiency can arrive to 90%.

Patent
13 Oct 2006
TL;DR: In this paper, a method for the treatment of wastewater in wastewater oxidation pond, comprises enriching the wastewater with atmospheric oxygen in a compressed air lifting device (12), supplying the wastewater into a trickling filter unit (1), obtaining the wastewater from the filter unit and reconducting the treated water into the oxidation pond.
Abstract: The method for the treatment of wastewater in wastewater oxidation pond, comprises enriching the wastewater with atmospheric oxygen in a compressed airlifting device (12), supplying the wastewater into a trickling filter unit (1), obtaining the wastewater from the filter unit and reconducting the treated water into the oxidation pond. The wastewater is brought into a partial circulation over the compressed air lifting device by the filter unit. The wastewater leaving the airlifting device flows into a collecting unit and is partly reconducted into the filter unit to ooze through. The method for the treatment of wastewater in wastewater oxidation pond, comprises enriching the wastewater with atmospheric oxygen in a compressed air lifting device (12), supplying the wastewater into a trickling filter unit (1), obtaining the wastewater from the filter unit and reconducting the treated water into the oxidation pond. The wastewater is brought into a partial circulation over the compressed airlifting device by the trickling filter unit. The wastewater leaving the compressed air lifting device flows into a collecting unit and is partly reconducted into the trickling filter unit to ooze through. The partial circulation of the wastewater is regulated before the wastewater is drained from the compressed air lifting device. Sediments are freely blown to the trickling filter by a compressed air flushing tube. An independent claim is included for a device for treatment of wastewater in wastewater oxidation pond.