Simulation of a full-scale activated sludge reactor: an approach to airflow rate optimization

The most challenging issue for existing large WWTPs (>100,000 PE) in Poland will be achievement of the new effluent standards for total nitrogen. Consequently, reliable and accurate information concerning the dimensioning of anoxic compartments is necessary. This study focused on validating to what extent the denitrification rates determined from batch tests were comparable with the rates calculated based on a mass balance over a full-scale activated sludge reactor. The experiments were conducted at two large WWTPs in northern Poland: “Wschod” in Gdansk and “Debogorze” in Gdynia. Two types of batch tests were used to determine the denitrification capability of activated sludge. Lower nitrate utilization rates observed during the full-scale experiments could potentially result from the local disturbances such as nitrate limitation (“Wschod” WWTP) or oxygen penetration to the anoxic zone (“Debogorze” WWTP). These factors should be taken into consideration during the design phase of the anoxic compartments.

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Respirometry for determination of the influents SS-concentration

Water Science & Technology ◽

10.2166/wst.1996.0031 ◽

1996 ◽

Vol 33 (1) ◽

pp. 311-323 ◽

Cited By ~ 2

Author(s):

A. Witteborg ◽

A. van der Last ◽

R. Hamming ◽

I. Hemmers

Keyword(s):

Experimental Design ◽

Activated Sludge ◽

Substrate Concentration ◽

Full Scale ◽

Activated Sludge Process ◽

Respiration Rates ◽

On Line ◽

Large Measurement ◽

Set Up

A method is presented for determining influent readily biodegradable substrate concentration (SS). The method is based on three different respiration rates, which can be measured with a continuous respiration meter which is operated in a cyclic way. Within the respiration meter nitrification is inhibited through the addition of ATU. Simulations were used to develop the respirometry set-up and decide upon the experimental design. The method was tested as part of a large measurement programme executed at a full-scale plant. The proposed respirometry set-up has been shown to be suitable for a semi-on-line determination of an influent SS which is fully based on the IAWQ #1 vision of the activated sludge process. The YH and the KS play a major role in the principle, and should be measured directly from the process.

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Evaluating the treatment performance of a full scale Activated Sludge Plant in Islamabad, Pakistan

Water Practice & Technology ◽

10.2166/wpt.2012.016 ◽

2012 ◽

Vol 7 (1) ◽

Cited By ~ 1

Author(s):

S. S. Fatima ◽

S. Jamal Khan

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Wastewater Treatment Plant ◽

Suspended Solids ◽

Treatment Plant ◽

Oxygen Demand ◽

Full Scale ◽

Operational Parameter ◽

Mixed Liquor ◽

Treatment Performance

In this study, the performance of wastewater treatment plant located at sector I-9 Islamabad, Pakistan, was evaluated. This full scale domestic wastewater treatment plant is based on conventional activated sludge process. The parameters which were monitored regularly included total suspended solids (TSS), mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), biological oxygen demand (BOD), and chemical oxygen demand (COD). It was found that the biological degradation efficiency of the plant was below the desired levels in terms of COD and BOD. Also the plant operators were not maintaining consistent sludge retention time (SRT). Abrupt discharge of MLSS through the Surplus Activated sludge (SAS) pump was the main reason for the low MLSS in the aeration tank and consequently low treatment performance. In this study the SRT was optimized based on desired MLSS concentration between 3,000–3,500 mg/L and required performance in terms of BOD, COD and TSS. This study revealed that SRT is a very important operational parameter and its knowledge and correct implementation by the plant operators should be mandatory.

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Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies

Water Science & Technology ◽

10.2166/wst.2017.522 ◽

2017 ◽

Vol 77 (1) ◽

pp. 70-78 ◽

Cited By ~ 4

Author(s):

Yanjun Mao ◽

Xie Quan ◽

Huimin Zhao ◽

Yaobin Zhang ◽

Shuo Chen ◽

...

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Removal Efficiency ◽

Nitrogen Removal ◽

Treatment Plant ◽

Oxygen Demand ◽

Pilot Scale ◽

Full Scale ◽

Nitrification And Denitrification ◽

Dyestuff Wastewater

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.

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