Simultaneously upgrading biogas and treating digestate using bioelectrochemical anaerobic trickling filter bed reactor

Many of Egypt's cities have existing treatment plants under operation that have been constructed before 1970. Almost all of these treatment plants now need rehabilitation and upgrading to extend their services for a longer period. One of these plants is the Beni Suef City Wastewater Treatment Plant. The Beni Suef WWTP was constructed in 1956. It has primary treatment followed by secondary treatment employing intermediate rate trickling filters. The BOD, COD, and SS concentration levels are relatively high. They are approximately 800, 1100, and 600 mg/litre, respectively. The Beni Suef city required the determination of the level of work needed for the rehabilitation and upgrading of the existing 200 l/s plant and to extend its capacity to 440 l/s at year 2000 A description of the existing units, their deficiencies and operation problems, and the required rehabilitation are presented and discussed in this paper. Major problems facing the upgrading were the lack of space for expansion and the shortage of funds. It was, therefore, necessary to study several alternative solutions and methods of treatment. The choice of alternatives was from one of the following schemes: a) changing the filter medium, its mode of operation and increasing the number of units, b) changing the trickling filter to high rate and combining it with the activated sludge process, for operation by one of several possible combinations such as: trickling filter-solids contact, roughing filter-activated sludge, and trickling filter-activated sludge process, c) dividing the flow into two parts, the first part to be treated using the existing system and the second part to be treated by activated sludge process, and d) expanding the existing system by increasing the numbers of the different process units. The selection of the alternative was based on technical, operational and economic evaluations. The different alternatives were compared on the basis of system costs, shock load handling, treatment plant operation and predicted effluent quality. The flow schemes for the alternatives are presented. The methodology of selecting the best alternative is discussed. From the study it was concluded that the first alternative is the most reliable from the point of view of costs, handling shock load, and operation.

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The Characteristics of Community Wastewater Biological Treatment Processes in Taiwan

Water Science & Technology ◽

10.2166/wst.1986.0300 ◽

1986 ◽

Vol 18 (7-8) ◽

pp. 289-296

Author(s):

C. F. Ouyang ◽

T. J. Wan

Keyword(s):

Biological Treatment ◽

Wastewater Treatment Plants ◽

Oxygen Demand ◽

Field Investigation ◽

Oxidation Ditch ◽

Trickling Filter ◽

Rotating Biological Contactor ◽

Treatment Processes ◽

Treatment Characteristics ◽

Sludge Thickening

This study investigated and compared the treatment characteristics of three different kinds of biological wastewater treatment plants (including rotating biological contactor, trickling filter and oxidation ditch) which are currently operated in Taiwan. The field investigation of this study concentrated on the following items: the performance of biological oxygen demand (BOD) and suspended solids (SS) removal; the sludge yield rate of BOD removal; the settleability of sludge solids; the properties of sludge thickening; the power consumption and land area requirement per unit volume of wastewater. Finally, based on the results of the field investigation, a comparison of the treatment characteristics of the three different biological treatment processes was evaluated.

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Denitrification of Sewage Effluents in Deep Bed Sand Filters

Water Science & Technology ◽

10.2166/wst.1993.0516 ◽

1993 ◽

Vol 27 (5-6) ◽

pp. 381-390 ◽

Cited By ~ 4

Author(s):

John Upton

Keyword(s):

Waste Water ◽

Pilot Study ◽

Water Industry ◽

Trickling Filter ◽

Sand Filters ◽

The United Kingdom ◽

The Usa ◽

Water Plants ◽

The Cost ◽

Pilot Plant Study

The European waste water industry will need to develop denitrification processes to remove nitrogen as pressures increase to reduce nutrient levels discharged in effluents. In the USA deep bed filter technology has been used extensively to provide denitrification to levels less than 5 mg/l TN. This paper describes this technology and the full scale performance at some waste water plants in Florida, USA. This paper also describes a pilot study in the United Kingdom at Severn Trent Water. The results of the pilot plant study indicate that denitrification in deep bed sand filters is a sound robust technology using methanol addition. Nitrogen removals greater than the 70% required in the EC Directive 1991 are possible at winter sewage temperatures. The process is most suitable for achieving nitrogen removal at trickling filter plants. The cost of methanol addition is calculated to be ₤10/1000m3.

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Biological removal of algae in an integrated pond system

Water Science & Technology ◽

10.2166/wst.1995.0450 ◽

1995 ◽

Vol 31 (12) ◽

pp. 21-31 ◽

Cited By ~ 4

Author(s):

P. G. J. Meiring ◽

R. A. Oellermann

Keyword(s):

Adsorptive Capacity ◽

Trickling Filter ◽

Laboratory Findings ◽

Oxidation Pond ◽

Trickling Filters ◽

Biological Removal ◽

In Series ◽

The Media ◽

Oxidation Ponds ◽

Dark Green

A system of oxidation ponds in series with a biological trickling filter is described. It was known that this arrangement was incapable of reducing effectively the levels of algae present in the pond liquid even though nitrification was effected because of autotrophic conditions prevailing in the trickling filters. This very low trophic level explained the lack of adsorptive capacity present. By shortcircuiting less than 10 percent of the effluent from a fully loaded primary facultative oxidation pond to the trickling filter, the autotrophuc nature or the film in the trickling filter was sufficiently shifted towards a heterotrophic state that had sufficient adsorptive capacity to retain the majority of the algae. It is concluded that the algae, although being absorbed, stay alive on the film and do not contribute significantly to the carbonaceous load on the trickling filter. Further more the algae, although secluded from all sunlight, actually partake in the purification process, producing an effluent which, unlike a normal humus tank effluent, is surprisingly sparkling clear. This significant observation appears to be in line with laboratory findings by others who, when they artificially immobilised certain species of algae and passed water over them, concluded that the algae retained the potential to remove certain compounds from the water. Conglomerates of biologically flocculated dark-green algae are scoured off the film (or sloughed off as part of the film) and, having been photosynthetically inactive for some days, tend not to float, but settle very rapidly. A very significantly aspect of this development is the great potential it has for practical application in developing countries. The algae sloughed off the media are easily thickened and available for ultimate recovery from the water phase without the addition of chemicals.

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Heating up trickling filters to tackle cold weather conditions

Water Science & Technology ◽

10.2166/wst.2000.0025 ◽

2000 ◽

Vol 41 (1) ◽

pp. 163-166 ◽

Cited By ~ 3

Author(s):

W. Gebert ◽

P.A. Wilderer

Keyword(s):

Waste Heat ◽

Treatment Plant ◽

Weather Conditions ◽

Pilot Scale ◽

Cold Weather ◽

Filling Material ◽

Trickling Filter ◽

Biofilm Thickness ◽

Trickling Filters ◽

Biofilm Support

The investigated effects of heating the filling material in trickling filters were carried out at the Ingolstadt wastewater treatment plant, Germany. Two pilot scale trickling filters were set up. Heat exchanger pipings were embedded in the filter media of one of these trickling filters, and the temperature in the trickling filter was raised. The other trickling filter was operated under normal temperature conditions, and was used as a control. The results clearly demonstrate that the performance of trickling filters cannot be constantly improved by heating the biofilm support media. A sustained increase of the metabolic rates did not occur. The decrease of the solubility of oxgen in water and mass transfer limitations caused by an increase of the biofilm thickness are the main reasons for that. Thus, the heating of trickling filters (e.g. by waste heat utilization) in order to increase the capacity of trickling filters under cold weather conditions cannot be recommended.

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Dynamic simulation of a low loaded trickling filter for nitrification

Water Science & Technology ◽

10.2166/wst.1999.0202 ◽

1999 ◽

Vol 39 (4) ◽

pp. 163-168 ◽

Cited By ~ 1

Author(s):

K. Seggelke ◽

F. Obenaus ◽

K.-H. Rosenwinkel

Keyword(s):

Dynamic Simulation ◽

Weather Conditions ◽

Full Scale ◽

Trickling Filter ◽

Examination Period ◽

Trickling Filters ◽

Biofilm Model ◽

Measuring Campaign

For this report, an existing biofilm model was examined in regard to its suitability for the simulation of full scale trickling filter for nitrification. The system was calibrated using the results ascertained in a measuring campaign under dry weather conditions. The verification was done using the results of a second examination period which included spells of stormwater input. It was possible for all periods to satisfactorily illustrate the degradation performance of the simulated trickling filters in regard to dynamics and quantity.

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