Pilot Evaluation Of Floating Media Biological Aerated Filters (BAFs) To Achieve Stringent Effluent Nutrient Discharge Requirements

2006 ◽  
Vol 1 (4) ◽  
Author(s):  
H. Zhao ◽  
C. Woods ◽  
J. Parker ◽  
S.-N. Hong
Keyword(s):  
High Rate ◽  
Activated Sludge Process ◽  
Mass Ratio ◽  
Tertiary Treatment ◽  
Biological Growth ◽  
Loading Rates ◽  
Conventional Activated Sludge ◽  
Nutrient Discharge ◽  
Two Stages ◽  
Control Water

This paper presents the results of a two-year pilot evaluation of floating media biological aerated filters (BAFs). The pilot consists of two stages - tertiary nitrification (N) filter followed by post denitrification (DN) filter. The focus of the pilot study was to determine the BAFs’ capacity to meet stringent tertiary treatment requirements in treating the effluent from a conventional activated sludge process. It was demonstrated that the two-stage BAF system, on a 30-day average basis, is capable of achieving 1) a total nitrogen (TN) requirement less than 3 mg/L, 2) a total phosphorus (TP) requirement less than 0.3 mg/L with chemical addition, 3) a zero net COD increase under methanol addition conditions, and 4) a TSS concentration less than 5 mg/L. Biological growth in the DN stage was not limited with an influent ortho-P less than 0.3 mg/L. Complete nitrification was achieved at loading rates up to 2.0 kg/m3/d with an oxygen-to-ammonia mass ratio of 30 g/g or above. High rate denitrification was observed at methanol-to-NOx ratios between 2.8 to 3.0 g/g. Methanol dosages greater than 3.4 g/g resulted in increased effluent NOx concentrations, and the increase probably resulted from unstable methanol dosing control. Water temperature down to 80C was shown to minimally affect both nitrification and denitrification performance.

High rate and compact single sludge pre-denitrification process for retrofit

1994 ◽  
Vol 30 (6) ◽  
pp. 31-40 ◽  
Author(s):  
Hiroyshi Emori ◽  
Hiroki Nakamura ◽  
Tatsuo Sumino ◽  
Tadashi Takeshima ◽  
Katsuzo Motegi ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
High Rate ◽  
Activated Sludge Process ◽  
Nitrogen And Phosphorus ◽  
Conventional Activated Sludge ◽  
Treatment Techniques ◽  
Conventional Activated Sludge Process ◽  
Denitrification Process

For the sewage treatment plants near rivers and closed water bodies in urbanized areas in Japan and European countries, there is a growing demand for introduction of advanced treatment processes for nitrogen and phosphorus from the viewpoints of water quality conservation and environmental protection. In order to remove nitrogen by the conventional biological treatment techniques, it is necessary to make a substantial expansion of the facility as compared with the conventional activated sludge process. In such urbanized districts, it is difficult to secure a site and much capital is required to expand the existing treatment plant. To solve these problems, a compact single sludge pre-denitrification process using immobilized nitrifiers was developed. Dosing the pellets, which are suitable for nitrifiers growth and physically durable, into the nitrification tank of single sludge pre-denitrification process made it possible to perform simultaneous removal of BOD and nitrogen in a retention time equal to that in the conventional activated sludge process even at the low water temperature of about 10 °C. The 3,000 m3/d full-scale conventional activated sludge plant was retrofitted and has been successfully operated.

Removal of organics and nitrogen in sewage treatment using anoxic-aerobic recirculated filter

2002 ◽  
Vol 46 (9) ◽  
pp. 309-314
Author(s):  
S. Tanaka ◽  
A. Suzuki
Keyword(s):  
Sulfate Reduction ◽  
Nitrogen Removal ◽  
Methane Production ◽  
Hydraulic Retention Time ◽  
Sewage Treatment ◽  
Cod Removal ◽  
Municipal Sewage ◽  
Activated Sludge Process ◽  
Loading Rates ◽  
Conventional Activated Sludge

The anoxic-aerobic recirculated filter (AARF) process was investigated on removal effciencies of organics and nitrogen with regard to loading rates, recirculation ratios of nitrified liquor and contribution of methane production and sulfate reduction in the treatment of the municipal sewage. The AARF process is composed of an anoxic filter for denitrification and an aerobic filter for nitrification and some of the nitrified liquor in the aerobic filter is recirculated to the anoxic filter. The AARF process successfully removed organics and nitrogen achieving high removal rates of 88% for COD and 64-74% for nitrogen. The recirculation ratio (Re) did not affect the COD removal efficiency but did affect the nitrogen removal, which was enhanced at a higher ratio (Re = 4). The methane production was not contributive to the COD removal but the COD consumed by the sulfate reduction was equivalent to 17% of total COD removed at Re = 2. We confirmed that the AARF process was applicable to the sewage treatment including nitrogen removal at a hydraulic retention time close to that of the conventional activated sludge process.

Coarse media filtration - an alternative to settling in wastewater treatment

2003 ◽  
Vol 47 (12) ◽  
pp. 81-88 ◽  
Author(s):  
H. Ødegaard ◽  
Z. Liao ◽  
A.T. Hansen
Keyword(s):  
Separation Efficiency ◽  
Primary Treatment ◽  
Biofilm Reactor ◽  
High Rate ◽  
Tertiary Treatment ◽  
Loading Rates ◽  
Denitrification Reactor ◽  
Multi Media ◽  
Removal Efficiencies ◽  
Low Dosage

In this paper coarse media filtration has been analysed as an alternative to the traditional settling in primary, secondary and tertiary treatment of wastewater. Various filter media configurations were evaluated for enhanced primary filtration. It was found that a dual media configuration based on Kaldnes biofilm media (K1 and K2modified) were most suitable when taking both separation efficiency as well as filter run time into consideration. SS removal efficiencies of around 75% were achieved in the dual Kaldnes primary filter at around 20 m/h without any chemical addition and around 85% at low dosage (1-2 mg/l) of a high MW cationic polymer FO4440SH. In the latter case COD was removed by around 70%. Further experiments were carried out on a multi-media Kaldnes-Filtralite-Sand (KFS) filter for enhanced primary treatment as well as for secondary filtration directly downstream of a high-rate moving bed biofilm reactor, resulting in an extremely compact secondary treatment process. The secondary KFS-filter gave SS-removal efficiencies around 90% (effluent SS < 15 mg/l) and filter run times of around 24 hrs at filtration rates of 10 m/h (sludge loading rates of around 1 kg /m2h) when a small dose (2 mg/l) of polymer was used. It is also demonstrated that the primary filter may also be utilised as a pre-denitrification reactor. A denitrification rate of 1.5 kg NO3-Nequiv./m3d was achieved when the filter was operated at a filtration rate of 5 m/h.

Rehabilitation and Upgrading of the Beni Suef City Wastewater Treatment Plant

1990 ◽  
Vol 22 (7-8) ◽  
pp. 131-138
Author(s):  
Ahmed Fadel
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Primary Treatment ◽  
High Rate ◽  
Shock Load ◽  
Economic Evaluations ◽  
Activated Sludge Process ◽  
Trickling Filter

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.

Upgrading Wastewater Treatment Plants with Anaerobic Selectors

1990 ◽  
Vol 22 (7-8) ◽  
pp. 35-43
Author(s):  
K. D. Tracy ◽  
S. N. Hong
Keyword(s):  
Phosphorus Removal ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
High Rate ◽  
Nitrogen Control ◽  
Biological Phosphorus Removal ◽  
Conventional Activated Sludge ◽  
And Performance ◽  
Activated Sludge Processes ◽  
Biological Phosphorus

The anaerobic selector of the A/0™ process offers many advantages over conventional activated sludge processes with respect to process performance and operational stability. This high-rate, single-sludge process has been successfully demonstrated in full-scale operations for biological phosphorus removal and total nitrogen control in addition to BOD and TSS removal. This process can be easily utilized in upgrading existing treatment plants to meet stringent discharge limitations and to provide capacity expansion. Upgrades of two full-scale installations are described and performance data from the two facilities are presented.

Tilapia rearing with high rate algal pond effluent: ammonia surface loading rates and stocking densities effects

2018 ◽  
Vol 78 (1) ◽  
pp. 49-56
Author(s):  
I. A. Sánchez ◽  
R. K. X. Bastos ◽  
E. A. T. Lana
Keyword(s):  
Weight Gain ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
High Rate ◽  
Surface Loading ◽  
Loading Rates ◽  
Total Weight Gain ◽  
Low Weight ◽  
Total Ammonia

Abstract In two pilot-scale experiments, fingerlings and juvenile of tilapia were reared in high rate algal pond (HRAP) effluent. The combination of three different total ammonia nitrogen (TAN) surface loading rates (SLR1 = 0.6, SLR2 = 1.2; SLR3 = 2.4 kg TAN·ha−1·d−1) and two fish stocking densities (D1 = 4 and D2 = 8 fish per tank) was evaluated during two 12-week experiments. Fingerlings total weight gain varied from 4.9 to 18.9 g, with the highest value (equivalent to 0.225 g·d−1) being recorded in SLR2-D1 treatment; however, high mortality (up to 67%) was recorded, probably due to sensitivity to ammonia and wide daily temperature variations. At lower water temperatures, juvenile tilapia showed no mortality, but very low weight gain. The fish rearing tanks worked as wastewater polishing units, adding the following approximate average removal figures on top of those achieved at the HRAP: 63% of total Kjeldahl nitrogen; 54% of ammonia nitrogen; 42% of total phosphorus; 37% of chemical oxygen demand; 1.1 log units of Escherichia coli.

Determination of Nitrogen and Phosphorus Partitioning within Components of the Biomass in a High Rate Algal Pond: Significance for the Coastal Environment of the Treated Effluent Discharge

1992 ◽  
Vol 25 (12) ◽  
pp. 207-214 ◽  
Author(s):  
N. J. Cromar ◽  
N. J. Martin ◽  
N. Christofi ◽  
P. A. Read ◽  
H. J. Fallowfield
Keyword(s):  
Dry Matter ◽  
Coastal Environment ◽  
High Rate ◽  
Nutrient Input ◽  
Nitrogen And Phosphorus ◽  
Loading Rates ◽  
Effective Strategies ◽  
Treated Effluent ◽  
Algae And Bacteria

Two High-Rate Algal Ponds were operated over residence times of 4 and 6 days respectively, at three COD loading rates equivalent to 600, 350 and 100 kg ha−1d−1 from early September to late October 1991. Samples of pond N and P feed were analysed to obtain nutrient input values to the system. Pond filtrates were also analysed for soluble nutrients. The pond biomass was separated into constituent components of algae and bacteria. Following separation, the discrete fractions were analysed for dry matter, chlorophyll content, and paniculate carbon, hydrogen, nitrogen and phosphorus. Nitrogen and phosphorus balances were then calculated which were used to partition the nutrients into soluble and paniculate phases, and to further separate the paniculate phase into algal and bacterial components. The partitioning of these nutrients, responsible for eutrophication, enables the calculation of removal rates of N and P from the pond systems and makes possible more effective strategies for the removal of the nutrient-rich biomass from receiving water bodies.

Pond walls: inclined planes to improve pathogen removal in pond systems for wastewater treatment?

2018 ◽  
Vol 78 (1) ◽  
pp. 31-36 ◽  
Author(s):  
A. L. Hawley ◽  
H. J. Fallowfield
Keyword(s):  
Wastewater Treatment ◽  
Prolonged Exposure ◽  
Tap Water ◽  
Bulk Water ◽  
High Rate ◽  
Pathogen Removal ◽  
Slope Length ◽  
Loading Rates ◽  
Surface Areas ◽  
Inclined Planes

Abstract Attenuation of sunlight in wastewater treatment ponds reduces the depth of the water exposed to disinfecting irradiances. Shallow pond depth with paddlewheel rotation increases exposure of pathogens to sunlight in high rate algal ponds. Generation of thin films, using pond walls as inclined planes, may increase inactivation of pathogens by increasing sunlight exposure. The performance of a laboratory based model system incorporating an inclined plane (IP) was evaluated. F-RNA bacteriophage, in tap water or wastewater, was exposed to sunlight only on the IP with the bulk water incubated in the dark. MS2 inactivation was significantly higher when the IP was present (P < 0.05) with a 63% increase observed. Prolonged exposure increased MS2 die-off irrespective of IP presence. Versatility of the IP was also demonstrated with faster inactivation observed in both optically clear tap water and wastewaters. IPs of different surface areas produced similar inactivation rates when operated at similar hydraulic loading rates regardless of slope length.

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