Optical monitoring of activated sludge flocs in bulking and non-bulking conditions

Koivuranta, Elisa; Keskitalo, Jukka; Haapala, Antti; Stoor, Tuomas; Sarén, M.; Niinimäki, Jouko

doi:10.1080/09593330.2012.710410

Cited by 29 publications

(16 citation statements)

References 25 publications

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“…To replace a laborious, slow and subjective method to study wastewater samples manually using a microscope, a small-scale automatic optical monitoring device was designed [10] and applied to analyze the wastewater samples taken from the aeration tank of the industrial ASP. Wastewater samples were diluted with deionized water at a ratio of 1:200 and pumped through a cuvette which was imaged with a high resolution charge-coupled device (CCD) camera.…”

Section: Optical Monitoring and Image Analysismentioning

confidence: 99%

Predicting the effluent quality of an industrial wastewater treatment plant by way of optical monitoring

Tomperi

Koivuranta

Leiviskä

2017

Journal of Water Process Engineering

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Wastewater samples taken from the aeration tank of a full-scale activated sludge plant were analyzed using an automatic optical monitoring device. Five variable selection methods were utilized to find the optimal subsets of input variables to develop predictive models for the important parameters of the wastewater treatment process efficiency and the quality of the effluent, including suspended solids, biochemical oxygen demand, chemical oxygen demand, total nitrogen and total phosphorus. The dependencies between the selected variables were also inspected. The study showed that the models based solely on the optical monitoring variables can be used to predict the level of the effluent quality parameters hours before the traditional sampling and analyses. Thus, predictive modelling based on the optical monitoring variables is a potential tool to be used assistance in a process control, keeping the process in a stable operating condition and avoiding environmental risks and economic losses.

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Section: Optical Monitoring and Image Analysismentioning

confidence: 99%

Predicting the effluent quality of an industrial wastewater treatment plant by way of optical monitoring

Tomperi

Koivuranta

Leiviskä

2017

Journal of Water Process Engineering

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“…What is more, activated sludge was usually taken from one sampling point located in the aeration zone of an activated sludge system. [5,11,14] It means that the variability of sludge floc morphology along the activated sludge chamber containing zones with different oxido-reductive conditions has not been studied yet.…”

Section: Introductionmentioning

confidence: 98%

“…It was demonstrated that image analysis was a useful tool to characterize activated sludge biomass in terms of floc size and its relation to the settling properties and concentration of biomass. [8][9][10][11][12] Mesquita et al [5] proved that the image analysis methodology was adequate for a continuous examination of the morphological changes of aggregates and subsequent prediction of the sludge volume index (SVI). At the same time, image analysis combined with chemometric techniques can be applied to identify activated sludge abnormalities, namely pinpoint floc formation and filamentous and zoogleal bulking.…”

Section: Introductionmentioning

confidence: 99%

Variations of morphology of activated sludge flocs studied at full-scale wastewater treatment plants

Liwarska-Bizukojć

Klepacz-Smółka

Andrzejczak

2014

Environmental Technology

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Digital image analysis has been intensively developed over the last two decades including its application to describe morphology of activated sludge flocs. However, only few studies concerned the variation of flocs morphology with respect to the operational conditions, particularly oxido-reductive conditions, in a full-scale wastewater treatment plant (WWTP). In this work, morphology of activated sludge flocs was monitored over one year in two different full-scale WWTPs. The main aim of this study was to find the relationship between the operational parameters and morphology of sludge flocs. Simultaneously, the variations in floc size along activated sludge chamber were studied with respect to the oxido-reductive conditions. It was found that the sludge loading rate was one of the most important operational parameters influencing floc size. It was estimated that its values higher than 0.1 kg BOD5 kg TS(-1) d(-1) contributed to the decrease in floc size. Also, the oxido-reductive conditions influenced the floc size. It was statistically proved that flocs from the anaerobic zone were usually smaller than flocs from the anoxic or aerobic zones. Distribution of floc size in a full-scale WWTP usually could be described by a log-normal model.

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“…Table 4 shows the results of image analysis. All samples show the same roundness (Koivuranta et al, 2013) Table 4 Results of image analysis of SEM images, helium pycnometry and N 2 adsorption of tailing samples.…”

Section: Resultsmentioning

confidence: 99%

Aging simulation of the tailings from Stava fluorite extraction by exposure to gamma rays

et al. 2017

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Tailings storage facilities are disposal systems for storing the waste products of the mining industry consisting of a slurry mixture made of soil, rock and water that remain after the mineral values have been removed from the patent ore. Tailings dams are supposed to last forever, so after their deposition, tailings can experience aging processes with physical and chemical changes depending on the interactions between local conditions and source mineralogy. The consequences of these aging processes are increased interlocking of particles and oxidation processes, sometimes making previously safely held contaminants available and mobile. Among the long-term aging processes, the natural ionizing radiation (from radioactive isotopes of the soils, cosmic rays, and also ultraviolet rays from the sun) can be considered, as proposed in the current research. Furthermore, in many countries, tailings are beginning to be re-used as backfill, landscaping material or feedstock for cement and concrete. So if any, the long-term physical and chemical modifications could affect the hydraulic and mechanical behaviour of tailings with relevant economic consequences. For these reasons, wet and dry silty samples of tailings spilled out after the failure of the Stava tailings dam (Trentino Alto Adige, Italy) were exposed to gamma rays, as an accelerated aging technique to simulate the natural ionizing radiation, and then characterized. The modifications on physical and chemical properties were observed and, despite certain chemical stability, some physical changes were observed, particularly in terms of size particle distribution, inner porosity of the particles and specific surface.

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Optical monitoring of activated sludge flocs in bulking and non-bulking conditions

Cited by 29 publications

References 25 publications

Predicting the effluent quality of an industrial wastewater treatment plant by way of optical monitoring

Predicting the effluent quality of an industrial wastewater treatment plant by way of optical monitoring

Variations of morphology of activated sludge flocs studied at full-scale wastewater treatment plants

Aging simulation of the tailings from Stava fluorite extraction by exposure to gamma rays

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