Aerobic domestic waste water treatment in a pilot plant with complete sludge retention by cross-flow filtration

Müller, Elisabeth; Stouthamer, A. H.; Verseveld, Henk W. van; Eikelboom, Dick H.

doi:10.1016/0043-1354(94)00267-b

Cited by 228 publications

(84 citation statements)

References 13 publications

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“…These results agree with Fig. 7: Effect of flow rate on sludge age those of Muller et al [16] who showed that a very low biomass production could be achieved when a very high influent flow rate is applied. Figure 7 shows that increasing the flow rate will decrease the sludge age in the reactor, hence, the removal efficiency of the aeration basin decreases.…”

Section: Effect Of Influent Flow Ratesupporting

confidence: 83%

Heterogeneous Modeling, Identification and Simulation of Activated Sludge Processes

Mustafa¹,

Ibrahim²,

Elkamel³

et al. 2009

American J. of Environmental Sciences

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Problem statement:The activated sludge system is a complex dynamic process and must account for a large number of reactions between large numbers of components. There is necessity for simulation models which describe the dynamic behavior of the activated sludge process. The application of the models in most treatment plants is limited due to lack of appropriate data acquisition and parameters identification studies. To realize this, an improvement of the operating strategies of Waste-Water Treatment Plants (WWTP) is required. The objectives of this study were to: (i) To build a process model considering mass transfer limitations and simulate an existing plant (Helwan WWTP) and validate the results using data from another existing plant with (Zenine WWTP). (ii) To adjust the model kinetic parameters of the biochemical reactions under the effect of mass transfer conditions to be prepared for simulation purposes. (iii) Study the effect of the operating conditions on the removal efficiency of both substrate and ammonia. Approach: A process model of the process was built considering mass transfer limitations and the three growth processes: Carbon oxidation, nitrification and denitrification. Helwan WWTP was used in order to extract the suitable stoichiometric and kinetic parameters to be used for the simulation. Helwan WWTP was used through the simulation results of the substrate (BOD) and ammonia. Egyptian Zenine WWTP was used for the testing and validation of the process model through predicting the response of substrate. Results: The average error of the removal efficiency in Helwan WWTP reached 3.3% for the substrate and 12.5% for the ammonia while the average error of the removal efficiency in Zenine WWTP of substrate reached 4.6%. The effects of recycle ratio, flow rate and influent substrate concentrations on the removal efficiency of the aeration tank were studied. It was found that the removal efficiency of substrate and ammonia was increased by increasing the recycle ratio, influent substrate concentrations and also increased by decreasing influent flow rates. It was found also that the sludge age increased by increasing the recycle ratio and decreased by decreasing the influent flow rates. Conclusion: The heterogeneous process model was able to describe the characteristics and reflects the real phenomena existing in activated sludge processes.

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Section: Effect Of Influent Flow Ratesupporting

confidence: 83%

Heterogeneous Modeling, Identification and Simulation of Activated Sludge Processes

Mustafa¹,

Ibrahim²,

Elkamel³

et al. 2009

American J. of Environmental Sciences

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“…However, complete sludge retention had little impact on wastewater treatment performance. The content of polluting trace elements were similar to that of a conventional treatment plant, though the fraction of inorganic compounds in sludge increased to 23.5% from 21.6% [80]. The low sludge production (0.002-0.032 kg/d) was observed in a pilot submerged MBR operating for one year without sludge discharge (Table 3) [81].…”

Section: Membrane Bioreactormentioning

confidence: 90%

“…Zero sludge production could be achieved at high sludge concentration (15-23 g/l) and F=M ratios as low as about 0.07 Kg COD (kg MLSS) À1 d À1 in a pilot submerged MBR with complete sludge retention [82,83]. Their investigations showed that the sludge reduction in MBR systems by higher organisms (protozoa/metazoa) was ruled out, and bacteria maintenance metabolism caused little/zero sludge production [80][81][82][83][84][85]. The absence of protozoa and metazoa in MBR systems occurred in their observations, but no reason was given to explain it.…”

Section: Membrane Bioreactormentioning

confidence: 99%

Minimization of excess sludge production for biological wastewater treatment

Wei

Houten²,

Borger³

et al. 2003

Water Research

618

278

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Excess sludge treatment and disposal currently represents a rising challenge for wastewater treatment plants (WWTPs) due to economic, environmental and regulation factors. There is therefore considerable impetus to explore and develop strategies and technologies for reducing excess sludge production in biological wastewater treatment processes. This paper reviews current strategies for reducing sludge production based on these mechanisms: lysis-cryptic growth, uncoupling metabolism, maintenance metabolism, and predation on bacteria. The strategies for sludge reduction should be evaluated and chosen for practical application using costs analysis and assessment of environmental impact. High costs still limit technologies of sludge ozonation-cryptic growth and membrane bioreactor from spreading application in full-scale WWTPs. Bioacclimation and harmful to environment are major bottlenecks for chemical uncoupler in practical application. Sludge reduction induced by oligochaetes may present a cost-effective way for WWTPs if unstable worm growth is solved. Employing any strategy for reducing sludge production may have an impact on microbial community in biological wastewater treatment processes. This impact may influence the sludge characteristics and the quality of effluent. r

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“…Considering the strong aeration condition (50 m 3 m −2 h −1 ) in the bioreactor, it is difficult to think that oxygen supply might be the problem. However, oxygen transfer limitations might occur inside the floes of activated sludge due to the increase of EPSs (Lübbeke et al, 1995;Muller et al, 1995). So, the increase of menaquinones from 8 to 14% with the prolongation of operational period, except for period 2, in the nitrification system was probably related with the existence of nitrate/nitrite respiration because of the limitation of oxygen transfer.…”

Section: Quinone Profilesmentioning

confidence: 99%

Nitrification performance and microbial community dynamics in a submerged membrane bioreactor with complete sludge retention

Yang

Zhang

et al. 2006

Journal of Biotechnology

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A submerged membrane bioreactor (MBR) supplied with inorganic ammonium-bearing wastewater (NH 4 + -N, 500 mg l −1 ) was operated for 260 days without sludge purge under decreased hydraulic retention times (HRT) through six steps (from 30 to 5 h). Almost complete nitrification was obtained at a volumetric loading rate (VLR) 1.2 g NH 4 + -N l −1 day −1 . The sludge nitrification activities were evaluated at each stage. The specific ammonium oxidizing rate (SAOR) decreased from the initial 0.45 to 0.15 kg NH 4 + -N kg −1 MLSS day −1 in the last four stages, while the specific nitrate forming rate (SNFR) increased from 0.17 to 0.39 kg NO 3 − -N kg −1 MLSS day −1 at the third stage, and then decreased to below 0.1 kg NO 3from the fourth stage. Microbial population dynamics was investigated by a combination of the MPN method, fluorescence in situ hybridization (FISH) and quinone profiles. During the experiment, although the MLSS increased gradually from 4.5 to 11.5 g l −1 , the number of ammonia-oxidizing bacteria (AOB) decreased from 10 9 l −1 at the third stage to 10 7 l −1 in the last two stages, and that of nitrite-oxidizing bacteria (NOB) decreased gradually from 10 8 l −1 at the second stage (HRT of 20 h) to the final 10 5 l −1 . FISH results showed that the active cells decreased gradually with time from about 60 to 20% in the last two stages, and most of sludge was inert cells. The sum of nitrifiers occupied only about 10% of the total bacteria number in the last stage even though only ammonium-bearing inorganic wastewater was fed in. Nitrosomonas sp. and Nitrospira sp. were confirmed by FISH as the dominant nitrifying genera responsible for ammonia and nitrite oxidation, respectively. In the mean time, a small ratio of Nitrobacter sp. also existed in the system. FISH analysis matched better with the batch activity test results than did the MPN techniques. Quinone profiles revealed that the dominant ubiquinone was ubiquinone-8 (UQ-8), ranging from 84 to 66%, followed by UQ-10 of 7-13%, UQ-7 of 3-5% and UQ-9 of 1.6-2.6%. The dominant menaquinone in the MBR was menaquinone-7 (MK-7) followed by MK-6, MK-8 and MK-8 (H 2 ). With the prolongation of operation, the percentage of menaquinones increased from 8 to 14%. The use of the polyphasic approach gave some new insight on variations of microbial community structures.

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Aerobic domestic waste water treatment in a pilot plant with complete sludge retention by cross-flow filtration

Cited by 228 publications

References 13 publications

Heterogeneous Modeling, Identification and Simulation of Activated Sludge Processes

Heterogeneous Modeling, Identification and Simulation of Activated Sludge Processes

Minimization of excess sludge production for biological wastewater treatment

Nitrification performance and microbial community dynamics in a submerged membrane bioreactor with complete sludge retention

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