Showing papers on "Trickling filter published in 2003"

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.

Diversity of microbial communities correlated to physiochemical parameters in a digestion basin of a zero-discharge mariculture system

Abstract: Bacterial community structure and physiochemical parameters were examined in a sedimentation basin of a zero-discharge mariculture system. The system consisted of an intensively stocked fish basin from which water was recirculated through two separate treatment loops. Surface water from the basin was pumped over a trickling filter in one loop while bottom-water was recirculated through a sedimentation basin followed by a fluidized bed reactor in the other. Ammonia oxidation to nitrate in the trickling filter and organic matter digestion together with nitrate reduction in the sedimentation basin and fluidized bed reactor, allowed zero-discharge operation of the system. Relatively high concentrations of oxygen, nitrate, sulphate and organic matter detected simultaneously in the digestion basin suggested the potential for a wide range of microbially-mediated transformation processes. In this study, physiochemical parameters were correlated to bacterial diversity and distribution in horizontal and vertical profiles within this basin in an effort to obtain a basic understanding of the chemical and microbial processes in this system. Chemical activity and microbial diversity, the latter measured by denaturing gradient gel electrophoresis (DGGE) analysis of polymerase chain reaction (PCR) amplified 16S rDNA fragments, were higher in the sludge layer than in the overlying aqueous layer of the basin. Chemical parameters in sludge samples close to the basin inlet suggested enhanced microbial activity relative to other sampling areas with evidence of both nitrate and sulphate reduction. Four of the nine DGGE bands identified in this zone were affiliated with the Bacteroidetes phylum. Detected sequences closely related to sequences of organisms involved in the sulphur cycle included Desulfovibrio, Dethiosulfovibrio and apparent sulphur oxidizers from the gamma-proteobacteria. In addition, a number of sequences from the beta and alpha-proteobacteria were identified.

Trickling filters and biofilm modelling

Abstract: Tricking filters are biofilm reactors commonly used for biological removal of nitrogen and organic matter. A review of published and unpublished material on the function, microbiology, design and operation of trickling filters is given. This is followed by more general dynamic biofilm reactor modelling, i.e. models for rotating biological contactors, different types of biofilters, moving beds as well as trickling filters.

19 – Fixed film processes

Abstract: This chapter discusses the various fixed film technologies for wastewater treatment. The fixed film processes are based on the capacity of different microorganisms to grow on surfaces. There are certain conditions that are important for the sloughing off to occur and are used technologically to control the biofilm. The hydraulic erosion acts continually on the surface of the biofilm and leads to a steady sloughing off on the outer side. The degradation of bacteria in the endogenous phase at the bottom of the biofilm may cause a weakening of the adhesion. Gas formation within the biofilm may destroy the adhesion. Development of a bacterial biofilm for substrate degradation is a complex phenomenon that is influenced by factors such as wastewater characteristics (nature of substrate, nutrients ratio and environmental conditions), operational factors (inoculation, organic loading rate, hydrodynamics), and the support medium. The various fixed film techniques include the trickling filter (TF), the rotating biological contactors (RBC), the biological aerated filters (BAF), and the suspended growth processes such as the activated sludge.

Operational and Design Considerations of a Trickling Filter for Ammonia Removal from Potable Water

Abstract: We studied the steady-state behavior of a mathematical model of a nitrifying trickling filter. In particular, we studied the effect of the operating conditions of the filter on the complete and safe nitrification. We presented the results with the help of the operating diagram of the system and we determined the range of operating conditions resulting in optimal operation. We also computed biofilm thickness along the filter depth and concentration profiles inside the biofilm, and compared them with experimental results found in the literature. The comparison shows very good qualitative agreement between model predictions and experimental data.

Techno-Economic Assessment Of Biological Treatment And Water Reuse Of Effluent From The Food Industries

Abstract: Treatment of high strength wastewater generated by food plants requires a development of cost effective wastewater treatment schemes and exploration of viable means for treated water reuse. This paper addresses the techno-economic aspects of a combined biological treatment scheme comprising anaerobic digestion and aerobic biological filters. Advanced water treatment for reuse includes multimedia filtration, activated carbon adsorption and membrane separation. Analysis of the results of the combined performance of the anaerobic/aerobic treatment indicates that treating high strength wastewater could be achieved by an upflow anaerobic sludge blanket (UASB) reactor and high rate trickling filter. Typical biological treatment capital and operating costs are about 1.3 million dollars and 131,000 dollars, respectively, for a treatment facility of about 4000 v m 3 /day to produce effluents of COD about 30 v mg/l. Water reuse costs ranged from US$ 0.034 to US$ 0.38/m 3 based on the salt content and residual disso...

Biological Fixed-Film Systems

Abstract: INTRODUCTION Overview. The work reviewed here was published during 2003 and described researches that involve biofilms treating pollutants. This review explicitly excludes research in medical biofilms, dental biofilms, biofilms causing corrosion and biofilm formation in drinking water treatment and distribution systems. Anaerobic Processes is a separate section of this issue, therefore, anaerobic biofilm treatment systems research is not reviewed here. However, denitrification in biofilm treatment systems is covered when appropriate. Similarly, biofilm systems for the treatment of air pollutants are not covered in this section (subject of the Gaseous Emissions from Wastewater Facilities section). Coverage. The references catalogued here are divided on the basis of fundamental research area or reactor types. Fundamental research into biofilms is presented in two sections, characterization/measurement and growth/modeling. The reactor types that are covered are trickling filters, rotating biological contactors, fluidized bed and airlift bioreactors, submerged bed biofilm reactors, biological granular activated carbon, membrane bioreactors, and immobilized cell reactors. Thereafter, innovative reactors that are not easily classified are presented, and an additional section on biofilms on sand, soil, and sediment is given.

Geotextiles as biofilm attachment baffles for wastewater treatment

Abstract: A bench scale pilot plant study was undertaken using geotextile baffles as biofilm attachment media for wastewater treatment. The herein named Geotextile Baffle Contact System (GBCS) removed suspended solids and hosted growth of microorganisms to absorb and decompose carbonaceous and nitrogenous pollutants. The test liquid was one sample of screened plant influent and twelve samplings of effluent from primary treatment at a Philadelphia Water Department (PWD) wastewater treatment plant that treats combined sanitary and storm sewage. The main goal was to meet secondary treatment standards, i.e., low concentrations of total suspended solids and biochemical oxygen demand in the effluent. The once-through hydraulic loading rate was similar to that used in conventional low rate trickling filters 20 gal/day-sq.ft. A second goal was reducing ammonia and nitrate to receiving water standards. It was also desired to digest excess sludge within the system. Twenty gallon glass tanks were used as reactors for the bench scale pilot plant experiments. Geotextile coupons were hung as baffles transverse to the flow in a sinuous pattern to increase path length and contact area, using elements from lamella settlers, granular depth filters and trickling filters. The first phase screened candidate geotextiles with respect to biomass attraction by immersion in wastewater. Only nonwoven needle punched geotextiles were found to host a substantial biomass. A second phase was investigating biodegradation efficiency under continuous aerated flow through the GBCS tanks with a nonwoven needle punched geotextile. Over 90% TSS and BOD5 removal occurred quickly, and over 90% conversion of NH3 to NO3 was detected after the third week. Denitrification increased steadily, producing effluent concentrations below 8 mg/l after five weeks, corresponding to the increasing biofilm thickness. The third phase used nonwoven staple fiber baffles. There was a similar performance in removing and biodegrading suspended, colloidal and dissolved organic materials. A parallel study of biomass distribution with photographs, dry solids retention, and scanning electron microscopy showed that TSS removal was a combination of sedimentation, filtration and baffle surface sorption. It was concluded that the high ratio of surface area to reactor volume supported efficient substrate and oxygen transfer.%%%%Ph.D., Environmental Engineering – Drexel University, 2003

Biological active filling material for treating water and controlling sewage and waste water

Abstract: The present invention discloses a bio-active filler for treating waster and controlling and treating sewage and waste water Said filler is made up by using natural pumice as raw material, and can bemade into the granular form with required size, and the granular density of said filler is 500-800 kg/cum perfectly, and its porosity is 40-50% perfectly Said invented filter is specially applicable to trickling filter bed, anaerobic biological filter, biological fluidized bed and other various filters

Anaerobic / aeration trickling filter device

Abstract: The utility model relates to an anaerobic/ aerobic trickling filter which is used for treating the domestic sewage in town, the organic waste water of works and lightly polluted river water into tap water; the utility model belongs to the technical field of town water supply and environmental water treatment. The utility model consists of a septic tank, a regulating basin, pacemakers, automatic aerators, a trickling filter tank, a tank before pump, a water pump and a fertilization tank. The septic tank is connected with the regulating basin by a pipe, the regulating basin is connected with the trickling filter tank by a pipe; the automatic aerators are arranged on both sides of the trickling filter tank, the top of the automatic aerators is equipped with the pacemakers; the automatic aerators are communicated with the trickling filter tank, the automatic aerators and the trickling filter tank consist of a plurality of layers; the water outlet ends of the last layer of the automatic aerators enter the tank before pump and the water inlet end of the water pump is connected with the tank before pump; the water outlet end of the water pump is connected with the fertilization tank. The utility model is characterized in that the COD is reduced to less than 100 mg/L after engineering example detecting treatment; the energy consumption is small and the operational expense is low; the utility model has no noise and is fully automatically controlled; the management is simple and the utility model has no fragile part which makes the utility model firm and durable.

Factors affecting treatment of BTX waste-gas in bio-trickling filter

Abstract: In order to investigate the factors affecting the bio treatment of BTX (benzene, toluene and xylene) waste gas, continuous flow experiment was conducted in a novel bio trickling filter (BTF) with ZAT-2 type patent stuffing. The results showed that the gas concentration of influent, the up flow velocity of gas and the sprinkling liquid flow were three important factors affecting the removal of BTX waste gas. In order to acquire maximal removal ability, the following three aspects of the operational conditions should be satisfied: the influent gas concentrations of benzene, toluene and xylene were 2.140 mg/L, 2.026 mg/L, 2.017 mg/L respectively;the up flow velocity was 78.6 m/h and the sprinkling liquid flow rate was 25 L/h at the temperature of 12～25 ℃ and pH value of 6.3～6.9 in the reactor. Thus, the maximal removal ability of BTX waste gas can go up to 1.36 kg/(m 3·d) for benzene, 1.36 kg/(m 3·d) for toluene and 1.24 kg/(m 3·d) for xylene.

Contacting filter material consist of trickling filter

Abstract: PURPOSE: Provided is a method for fabricating a trickling filter media being capable of increasing digestion speed of substrate by using far-infrared radiation, ion exchanging and deodorizing functions. CONSTITUTION: The method comprises the steps of mixing polyolefine 60 wt%, sericite powder 25 wt%, porphyry 12 wt%, foaming agent 3 wt% such as azo-bis-formaldehyde, and extrusion molding the mixture into the form of a hollow pellet (A).

Packed-Bed Reactor for Biogas H2S Removal and for Methane-Dependent Effluent Nitrate Removal Applied to High Strength Organic Wastewater Treatment Process

Abstract: In a wastewater treatment process consisting of a UASB reactor and aerobic post treatment, excess biogas is produced during the warm season. Methane-dependent nitrate removal using a biogas scrubber would be an efficient way to utilize the excess biogas. The performance of the plastic media-filled packed-bed reactor was examined for biogas scrubbing and methane-dependent nitrate removal. A bench-scale packed-bed reactor was installed in a swine wastewater treatment plant consisting of a UASB reactor and a trickling filter. The biogas from the UASB reactor was supplied from the bottom (3.4-9.4 m d-1), and the trickling filter effluent was spread from the top (9.4-26.1m3 m-2 d-1) . The concentration of H2S dropped from 1200-2500 ppm to less than 2 ppm. The plastic media covered with biofilm were then collected from the reactor and filled into a laboratory scale packed-bed reactor. Inorganic medium containing 40 mg-N l-1 nitrate was spread from the top of this reactor (1.4 m3 m-2 d-1), and gas was supplied from the bottom (25-36.5 m d-1) . The nitrate concentration dropped significantly when CH4 (93%v/v) and O2 (7%v/v) were supplied simultaneously. In contrast, nitrate removal scarcely occurred when only CH4 or He was supplied. These results suggest that simultaneous biogas scrubbing and methane-dependent nitrate removal are possible with the packed-bed reactor.

Predicting nitrification efficiency from dissimilar wastewaters: implications for lagoon polishing

Abstract: An extended aeration sewage treatment plant on an island camp in Georgian Bay, Ontario, performed fair to well for BOD, TSS and TP removal, but was unable to nitrify ammonium to compliance levels for surface discharge. The raw sewage is from residential and kitchen sources, but is high strength (cBOD >500 mg/L and TKN >100 mg/L), and the alkalinity is low. A proposal was made to retrofit a Waterloo Biofilter absorbent trickling filter to polish the treated sewage, similar to polishing lagoon effluent. The influent mass rate to the BIOFILTERS for design purposes was 4.0 kg/d NH4-N and 0.6 kg/d cBOD (influent design peak of 160 mg/L NH4-N and 15 mg/L cBOD at 25,000 L/d). The design criteria for the effluent out of the BIOFILTERS were 0.075 kg/d NH4-N for compliance (3.0 mg/L), and 0.025 kg/d NH4-N (1.0 mg/L) as a target. Performance guarantees were requested but field experience polishing this particular wastewater type (low BOD and high NH4-N) at the required high hydraulic loading rates was not available. To predict how this technology would perform, empirical relationships of influent and effluent data of two different wastewaters were examined, with the intent to interpolate to the expected conditions at the camp and to predict performance. Existing polishing data from low-strength secondary clarifier effluent at high hydraulic rates (<1700 L/d per m 3 filter medium) indicated sustainable and complete nitrification. The same could be done with 15 m 3 filter medium at the island camp, easily placed in the limited space available. From this data, an effluent discharge of 0.015 kg/d NH4-N was predicted at peak flow, less than the target. From operational data at a second, high-strength, surface-discharge BIOFILTER, an effluent discharge of 0.0021 kg/d or 2.1 mg/L NH4-N was predicted, also within target limits. With this performance prediction, the BIOFILTERS were installed in 2002 and the results for BOD, TSS, and NH4-N were all within compliance limits and all but one month within target limits. Analysis of empirical relations from operational data from two dissimilar wastewaters such as low BOD/low NH4-N and high BOD/high TKN can