Showing papers on "Trickling filter published in 1982"

Unit Operations and Processes in Environmental Engineering

Abstract: 1. Chemical Concepts 2. Biological Concepts 3. Mass Balances, Flow Models, and Reactors 4. Water Quantities and Water Quality 5. Wastewater Quantities and Wastewater Quality 6. Water and Wastewater Treatment Plants 7. Preliminary Unit Operations and Processes 8. Coagulation and Flocculation 9. Sedimentation 10. Filtration 11. Ammonia Removal 12. Adsorption 13. Ion Exchange 14. Membrane Processes 15. Activated Sludge 16. Oxygen Transfer and Mixing 17. Trickling Filters and Rotary Biological Contactors 18. Stabilization Ponds and Aerated Lagoons 19. Anaerobic Digestion 20. Aerobic Digestion 21. Solids Handling 22. Land Treatment of Municipal Wastewater and Sludges 23. Other Unit Operations and Processes 24. Disinfection Appendices / Glossary / Answers to Selected problems / Index

The theory and design of aerobic biological treatment.

Abstract: The processing of numerous experimental data shows that the high-level and rough treatments of multicomponent sewage water follow different laws. In the case of rough treatment, the classical Monod's model is fairly adequate to the experiment. High concentrations of a pollutant "saturate" the complex of microorganisms (activated sludge or biofilm) and the general oxidation process follows a zero order for the substrate. In the case of high-level treatment, the model of an n order (n > 1) for the substrate is adequate to the experiment. Generalized models of aerobic treatment, independent of the reactor type (an aeration tank, trickling filter, rotating disk), are proposed.

Nitrification Kinetics and Its RBC Application

Abstract: The surface reaction model for the mechanism of mass transfer-metabolism in the fixed-film nitrification process is investigated and discussed for the design of trickling filter systems and rotating biological contactor (RBC) systems. Two experimental studies are performed. The first study, using a stationary fixed-film reactor to simulate the trickling filter process, reveals that the surface reaction kinetics follow a pseudo-homogeneous model. The second study, using a bench-scale RBC unit, indicates that the pseudo-homogeneous model is also applicable to the rotating fixed-film process. The effective slime thickness of an RBC system can be estimated from this model by locating the optimum NH3-N removal rotating speed and finding the corresponding liquid film thickness at that rotating speed.

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.

The Hydrodynamic Evaluation of a Fixed Media Biological Process

Abstract: : TWo basic classifications of flow models for biological processes are presently accepted, plug or piston flow and complete mixing. The trickling filter can be modelled as a plug flow system and the activated sludge process can be designed as a complete mixed system. If a trickling filter and a complete mixed activated sludge system are combined together in a tank, then an interesting question arises on how the mixing characteristics will be changed. A hydrodynamic evaluation was made to characterize the flow patterns and the mean detention time changes inherent to such a system. Tracer analyses were used during the course of the development of a fixed media process which utilized plastic tower packing, but unlike a trickling filter system, the packing was completely submerged. A surface aerator supplied oxygen to the system and provided mixing in the system by pumping action through a draft tube.

Models and Design of Aerobic Biological Treatment Processes

Abstract: Various models, applied to the design of aeration tanks, trickling filters and rotating discs, are compared. The adequacy of the models is established from the minimal mean square deviation of the measured and calculated values of the effluent concentration of a pollutant. It is shown that at the oxidation of simple substrates of the glucose type Moser's model is an adequate model and Monod's model is a particular case of this model. If a single substrate has a large concentration, activated sludge or biofilm become “saturated” and the oxidation kinetics follows the zero order. As the processing of the results of some experiments showed, the classical Monod model and its extreme case—the first-order equation of a reaction—are not adequate to the processes of the oxidation of multicomponent municipal sewage water. Equations for reactions of higher orders are true for them. The rate constant of the first-order reaction correlates well with the effluent concentration-influent concentration ratio, i.e., it is variable and depends on the treatment conditions and, above all, it is inversely proportional to the level of treatment.

Method and device for biological nitrification and denitrification of waste water

Abstract: PURPOSE:To improve treatment efficiency of a trickling filter by constituting a denitrifying section having a raw water inflow section as an immersion filter maintaining an anaerobic state, and a nitrifying section having a treated water outflow section as a trickling filter maintaining an aerobic state. CONSTITUTION:Raw water 21 contg. BOD and ammonia nitrogen flows into a denitrifying section 22 by an anaerobic immersion filter. Gravel, plastic modules and the like are usable for filter media 23, and it is important to immerse the media 23 under the water surface. Besides the raw water 21, nitrified water 24 flows into the section 22, and the NO2-N and the like in this are reduced away to gaseous nitrogen 33' by the denitrifying gers stuck on the media 23. Denitrified water 25 is sprayed from the spray nozzles 18 of a nitrifying section 27, and flows down in a filter bed 29. At this time, the NH4-N in the water 25 is effetively nitrified by the nitrifying germs existing on the filter medium surfaces of the filter bed 29.

Trickling filter method for organic waste water and apparatus therefor

Abstract: PURPOSE:To improve the quality of purified water better than that in the past, by using a floating filter, which can be easily washed in case of clogging even if it has a small particle size, as a filter forming a filter bed layer in a trickling filter vessel CONSTITUTION: A floating filter 2 having a specific gravity smaller than 10, eg small particle-sized foamed styrene, foamed PP or pearlite, is packed in a trickling filter vessel 1, to form a filter bed layer 5 Crude water 3' is sprayed to the surface part of the layer 5 from a rotary sprinkler 4, and let flow through the layer 5 The interior of the vessel 1 is ventilated by natural or forced air blow, to feed oxygen to bacteria adherent on the surface of the filter 2 The water 7' biologically purified by the layer 5 is partially returned through a circulating flow line 14, and the remainder is disposed as drain 15 With advancement of the treatment, the layer 5 is clogged by proliferation of the bacteria At this time, an effluent amount is maintained smaller than an influent amount by a control valve 9 The water head inside the vessel 1 rises, the filter 2 begins floating and finally floats as a whole, but the floatation is restricted by a member 8 Breeded bacteria and a collected SS part are stripped and removed from the filte by effects of contact, friction and swinging during the floatation After washing is completed, the valve 9 is fully opened

Trickling filter for sewage clarification - adding oxygen to circulating air and discharging min. of waste air

Abstract: Sewage is clarified in a trickling filter bed from which only a small pt. of the rising air is discharged to atmos. The major part is circulated after oxygen has been added to it to compensate for its consumption in the reaction space. A control unit automatically adjusts the discharge and the oxygen addn. (as a function of the readings of an oxygen probe). This keeps the amt. of air discharged to the environment (and thereby the bad odours) to a min.

Treatment system of waste water

Abstract: PURPOSE:To lower the COD value of waste water and to reuse purified water as industrial water, by treating steam-reforming waste in a trickling filter process, and subjecting the treated waste water to adsorption with active carbon. CONSTITUTION:Condensed water or gas-washing water containing hydrocarbon compounds discharged from a steam-reforming plant is treated in a trickling filter under the condition of a circulating ratio of 0.9-30 and a COD volume load of 0.05-5kg/m .day in a column. The treated waste water is then subjected to an adsorption treatment using active carbon under the condition of a linear flow speed of 5-10m/hr, a superficial velocity in a column of 0.5-5m /m .hr and a contact period of 10-40min. As a result, the reduction rate of COD value is improved.

Upgrading Slaughterhouse Effluent with Rotating Biological Contactors

Abstract: : The application and start-up performance of a RBC pilot plant unit for upgrading clarified trickling filter effluent has been described. Although the operational experience has been very short, the following remarks can be made from treatment of a 10 C slaughterhouse wastewater: (1) RBC process stability with respect to BOD removal was reached in approximately three weeks after start-up. The RBC-biofilm became mature relatively fast due to seeding of microorganisms from the bio-tower. (2) The hydraulic loading to the RBC was constant at 0.05 sum d whereas the organic loading varied form approximately 2 g soluble BOD sgm d to 35 g soluble BOD sgm d. A typical slaughterhouse production day organic loading is approximately 20 g soluble BOD sgm, resulting in a soluble carbonaceous BOD7 effluent concentration of approximately 35 mg/1. (3) The Sapromat analysis for soluble BOD did not require seeding or dilution of the wastewater to be tested. The nitrifiers present will therefore perform immediately if other environmental conditions are satisfactor. (4) The effect of low temperature wastewater on NH3-removal could not be verified in the short time after start-up. This will be a question to answer after prolonged RBC operation.

Removal method for phosphorus and nitrogen in water

Abstract: PURPOSE:To remove phosphorus and ammonia nitrogen effectively by subjecting the sewage contg. a small amt. of org. materials and contg. phosphorus and ammonia nitrogen beforehand to a flocculating and separating treatment then to a biological membrane treatment thereby performing nitrification and denitrification. CONSTITUTION:Sewage such as secondarily treated water of sewage and night soil or others contg. less org. materials and contg. phosphorus and ammonia nitrogen is beforehand subjected to a flocculating and separating treatment, whereby the concn. of phosphorus is reduced. This is subjected to nitrification and denitrification of ammonia nitrogen by an aerobic biological membrane treatment; at the same time, the remaining phosphorus is also removed biologically. As said biological membrane treatment, there are a granular medium living membrane method, a rotary disc method, a trickling filter method, etc., of which a stationary bed type biological membrane treatment using granular media is advantageous because it accomplishes the biological membrane treatment and filtration simultaneously. Plastics, sand, etc. are usable as the media.

The Air Force Experience in Fixed-Film Biological Processes,

Abstract: : Some 30 fixed-film biological wastewater treatment plants are located on Air Force installations. Most of the fixed-film process plants are trickling filter system, except one with the contact aeration process and two with the rotating biological contactor (RBC) process. This paper will discuss the Air Force experience in upgrading the contact aeration process plant with plastic media; the application of trickling filter to phenolic wastewater treatment plant.

Nitrification of a Municipal Trickling Filter Effluent Using Rotating Biological Contactors

Abstract: : This paper presents the results of a pilot plant investigation and design for achieving seasonal nitrification of a secondary trickling filter effluent. The municipal treatment plant in Milford, Massachusetts discharges into the headwaters of the Charles River, a class B stream. Consequently, the Commonwealth of Massachusetts has required a nitrified effluent, phosphorus removal, and effluent filtration. Table 1 lists the present and proposed discharge limitations formulated by the U.S.E.P.A. and the Massachusetts Division of Water Pollution control.

Trickling filter models: A review and evaluation

Abstract: The applicability and limitations of various trickling filter models, existing in the literature are discussed. The similarities and differences of the models are compared by examining their ability to predict the influence of several key filter variables on the overall behaviour of a trickling filter. The variables examined include hydraulic and organic loading, filter depth, influent substrate concentration, and specific surface area of the packing media.