High Rate Air Activated Sludge Operation at the City of Los Angeles Hyperion Wastewater Treatment Plant

1992 ◽  
Vol 25 (4-5) ◽  
pp. 75-87 ◽  
Author(s):  
Y. J. Shao ◽  
J. Crosse ◽  
E. Keller ◽  
D. Jenkins
Keyword(s):  
Los Angeles ◽  
Activated Sludge ◽  
Treatment Plant ◽  
High Rate ◽  
Secondary Effluent ◽  
Biological Phosphorus Removal ◽  
Anaerobic Digesters ◽  
Effluent Quality ◽  
The City ◽  
Biological Phosphorus

The City of Los Angeles USA Hyperion Treatment Plant (HTP) implemented high rate air activated sludge operations in November 1989. Using this process, the secondary treatment organic loading (F/M) was increased from 0.5 to 1.0 kg BOD/kg MLVSS/day and the MCRT reduced from 3.1 days to 1.5 days, thereby enabling the secondary treated flow to be increased from 150 mgd to 200mgd (6.6 to 8.8 m3/s). Excellent secondary effluent quality (BOD5 = 15 mg/l, carbonaceous BOD5 = 6 mg/l, SS = 6 mg/l) is currently obtained using rectangular secondary clarifiers operated at surface overflow rates of 1,100 gal/day/ft2 (43 m3/m2/day) and low MLSS concentrations (950 mg/l). The enhanced biological phosphorus removal that was obtained when operating at a 3 day MCRT was eliminated in the change to high rate operation and struvite (MgNH4PO4(c)) build-up in the anaerobic digesters has been eliminated. Nocardia scum formation, with its odor generating potential and other associated operating problems, has also been eliminated by high rate operation.

Effects of MCRT on Enhanced Biological Phosphorus Removal

1992 ◽  
Vol 26 (5-6) ◽  
pp. 967-976 ◽  
Author(s):  
Y. J. Shao ◽  
F. Wada ◽  
V. Abkian ◽  
J. Crosse ◽  
B. Horenstein ◽  
...  
Keyword(s):  
Los Angeles ◽  
Treatment Plant ◽  
Phosphate Removal ◽  
High Rate ◽  
Experimental Investigations ◽  
Secondary Effluent ◽  
Biological Phosphorus Removal ◽  
Anaerobic Digesters ◽  
Phosphate Release ◽  
Standard Rate

This paper presents the results of full scale experimental investigations into the fate of phosphorus in the Hyperion Treatment Plant, City of Los Angeles, CA, USA. For almost three decades, the activated sludge process, operated at standard rate has exhibited enhanced biological phosphate removal accompanied by initial anaerobic phosphate release and subsequent aerobic phosphate uptake. In 1989 when high rate treatment was initiated the enhanced phosphate removal and accompanying initial anaerobic phosphate release decreased and finally was eliminated. Phosphorus in the secondary effluent increased from 0.4 to 3.1 mg/l as the MCRT decreased from 3.1 to 1.5 days. Of added interest was the accompanying decrease in struvite (MgNH4PO4.6H2O(s)) build-up in the sludge dewatering processes downstream of the anaerobic digesters.

Solving fecal coliform growth/reactivation in biosolids during full-scale post-digestion processes

2005 ◽  
Vol 52 (1-2) ◽  
pp. 283-288 ◽  
Author(s):  
R. Iranpour ◽  
R. Palacios ◽  
H.H.J. Cox ◽  
V. Abkian
Keyword(s):  
Los Angeles ◽  
Fecal Coliform ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Full Scale ◽  
Fecal Coliforms ◽  
Anaerobic Digesters ◽  
Plant Conversion ◽  
Thermophilic Anaerobic Digestion ◽  
The City

Fecal coliform recurrence has been observed at the City of Los Angeles Hyperion Treatment Plant during pilot-scale experiments with a designated thermophilic battery of six anaerobic digesters, while other digesters were still at a mesophilic temperature. Several lab and full-scale experiments indicated the following possible causes of the growth/reactivation of fecal coliforms in post-digestion: a) contamination of thermophilically digested biosolids with mesophilically digested biosolids; b) a large drop in the biosolids temperature between the centrifuges and silos, which could have allowed the reactivation and/or growth of fecal coliforms. These were resolved by the full plant conversion to thermophilic anaerobic digestion and design modifications of the post-digestion train.

Petro® concept: a tentative approach to biological phosphorus removal incorporating waste stabilisation ponds

2000 ◽  
Vol 42 (10-11) ◽  
pp. 223-229 ◽  
Author(s):  
O. V. Shipin ◽  
P. G. Meiring ◽  
J. R. Hoffmann
Keyword(s):  
Activated Sludge ◽  
High Rate ◽  
Biological Nutrient Removal ◽  
Biological Phosphorus Removal ◽  
Waste Stabilisation Ponds ◽  
Biological Removal ◽  
Activated Sludge Reactor ◽  
Calcium Magnesium ◽  
Additional Process ◽  
Biological Phosphorus

Ponding which is usually considered a low tech process can be successfully integrated with downstream Biological Nutrient Removal (BNR) facility. The PETRO system incorporating ponds and downstream trickling filter (TF) or activated sludge process (ASP) is a technology which offers simplicity of O and M combined with biological removal of P and N. It is feasible to produce in a primary facultative pond with a deep fermentation pit quantities of readily biodegradable substrates sufficient to meet the requirements of phosphate accumulating organisms (PAO) in a downstream BNR facility. Malodorous conditions are dealt with by high rate recirculation. This novel low tech approach is a step towards a more straightforward BNR process. PETRO concept features phenomenon of algae-assisted chemical P-removal in activated sludge reactor. The process results in precipitation of inorganic phosphates apparently in a form of calcium/magnesium salts. Possible mechanism of this additional process which removes up to several milligrams per litre of inorganic P is discussed.

Pilot Scale Studies on Enhanced Phosphorus Removal in a Single-Stage Activated Sludge Treatment Plant

1985 ◽  
Vol 17 (11-12) ◽  
pp. 309-310 ◽  
Author(s):  
W. Maier ◽  
P. Kainrath ◽  
Kh Krauth ◽  
R. Wagner
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Continuous Process ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Single Stage ◽  
Biological Phosphorus Removal ◽  
Sludge Treatment ◽  
Biological Phosphorus ◽  
P Removal

Enhanced biological phosphorus removal from domestic sewage was investigated in a single-stage activated sludge treatment plant with pre-denitrification operated in a continuous process. In 10 different experimental periods the influence of varying composition of the influent, varying systems of the pilot scale unit (with and without anaerobic basin), varying retention times in the different basins and varying sludge loads were investigated. Results of the experiments can be summarized as follows: the nutrient situation and especially the P/BOD5 and N/BOD5 ratios, retention time in the final clarifier, and organic sludge load plus the desired degree of nitrification have essential influence on the process and P removal efficiency. The conclusions for the pilot scale process are discussed.

Behaviour and Modelling of NTA Degradation in Activated Sludge Systems

1989 ◽  
Vol 21 (4-5) ◽  
pp. 315-324 ◽  
Author(s):  
H. Siegrist ◽  
A. Alder ◽  
W. Gujer ◽  
W. Giger
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Water Discharge ◽  
Treatment Plant ◽  
Secondary Effluent ◽  
Biological Degradation ◽  
Q 55 ◽  
Q 14 ◽  
The City ◽  
Daily Load

The general model for single-sludge wastewater treatment systems of the IAWPRC task group (Henze et al., 1987) was extended to describe the biological degradation of NTA and adsorption of NTA onto activated sludge based on literature studies and experiments undertaken at the Glatt wastewater treatment plant (waste water discharge: Q = 55 - 60 000 m3/d, 110 000 inhabitants) for the city of Zurich. During two days, the behaviour and diurnal load variation of nitrilotriacetate (NTA), zinc, lead and copper were analyzed on one lane (volume = 1 812 m3, Q = 14 700 m3/d) of the four parallel lanes used in secondary treatment. The plant had a sludge age of about 3.6 days and was partly nitrifying (wastewater temperature = 10-11 °C). The average daily load of NTA for the investigated lane was 14 kg NTA/d, corresponding to 0.5 g NTA/person.d. The influent concentration varied between 300 and 1 500 µg NTA/l. NTA was biologically degraded up to 97 %. Between 12 am and 2 pm of the second day 17 kg NTA (120 % of the daily load of one lane) had been added to the primary effluent. During 4 to 5 hours the biological NTA degradation was saturated and four times more than the daily average of NTA was degraded. Zinc and lead did increase in the secondary effluent during the NTA shock loading.

Effects of an anaerobic zone in a textile wastewater treatment plant

1995 ◽  
Vol 32 (9-10) ◽  
pp. 133-140 ◽  
Author(s):  
G. Bortone ◽  
J. S. Cech ◽  
R. Bianchi ◽  
A. Tilche
Keyword(s):  
Activated Sludge ◽  
Treatment Plant ◽  
Textile Wastewater ◽  
Flow Sheet ◽  
Biological Phosphorus Removal ◽  
High Concentration ◽  
Biological Removal ◽  
Textile Wastewater Treatment ◽  
Biological Phosphorus ◽  
Final Effluent

High concentration of textile industries represents a serious environmental problem in the Como area in Northern Italy. The Seveso treatment plant was formerly performing biological removal of nitrogen by means of a modified Ludzack-Ettinger configuration. Being the plant overloaded, nitrification was not achieved. Therefore the plant flow sheet has been modified. The former predenitrification tank has been changed in an anaerobic compartment, since the internal recycle was stopped. The efficiency of the anaerobic reactor for COD removal, the selective pressure on the microbial community and the enhanced biological phosphorus removal were evaluated. In the anaerobic tank 40% of the influent COD was removed with a reaction time of only 45 minutes. The activated sludge showed a very high presence of Poly-P bacteria; anaerobic P release was noticed during the anaerobic phase. Sludge settleability was always good (contrary to a similar activated sludge treatment plant, also treating textile wastewater but without an anaerobic selector, that suffers heavy filamentous bulking and Nocardia foaming). The final effluent PO4-P concentration was always lower than 1 mg L−1.

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.

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.

The Implementation of Biological Phosphorus and Nitrogen Removal with the Bio-Denipho Process on a 265,000 PE Treatment Plant

1992 ◽  
Vol 25 (4-5) ◽  
pp. 161-168 ◽  
Author(s):  
J. Einfeldt
Keyword(s):  
Nitrogen Removal ◽  
Treatment Plant ◽  
First Year ◽  
In Series ◽  
Design Loads ◽  
Last Stage ◽  
Two Stages ◽  
The City ◽  
Biological Phosphorus

A process, called Bio-Denipho, for combined biological phosphorus and nitrogen removal in a combination of an anaerobic tank and two oxidation ditches is described. In this process the anaerobic tank consisting of three sections working in series is followed by two oxidation ditches. These too are working in series, but with both inlet to and outlet from the tanks changing in a cycle. The Bio-Denipho process is described specifically for the process itself and as a case study for the implementation of the process on a 265,000 pe wastewater treatment plant for the city of Aalborg in Denmark. The plant was designed and erected in two stages and the last stage was inaugurated October 31,1989. Lay-out and functions for the plant is described and design loads, plan lay-out and tank volumes are given in this paper together with performance data for the first year in operation.

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