Radiotracer investigation and modeling of an activated sludge system in a pulp and paper industry

Sarkar, Metali; Sangal, Vikas Kumar; Sharma, Vijay Kumar; Samantray, J.S.; Bhunia, Haripada; Bajpai, Pratima; Kumar, Anil; Naithani, A. K.; Pant, H.J.

doi:10.1016/j.apradiso.2017.10.016

Cited by 11 publications

(3 citation statements)

References 20 publications

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“…The RTD measurement approach using radiotracers has immense potentials and thus has been used extensively to characterize flow in different industrial systems [2,[12][13][14][15][16][17][18][19]. However, data used in process calculations usually need to be precisely determined (volume of the reactor, flow rate of the stream, etc.)…”

Section: Introductionmentioning

confidence: 99%

Optimization of injected radiotracer volume for flow rate measurement in closed conduits

Pavlović

Bartl

et al. 2020

Hem Ind

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In chemical processes it is essential that the flow in the process is accurately defined. Fluid velocity measurements are important for fluid flow quality performance in flow systems. This study focuses on determination of the volumetric flow rate and its standard (relative) deviation for calibration of conventional flow meters by using a radiotracer approach. The measurements for flow meter calibration were performed at a pilot-scale flow rig using Technetium-99 m (99m Tc) as a radiotracer in the form of pertechnetate ion (99m TcO4-). The measured data were analyzed, and precision of the experimental setup was investigated under two different approaches-IAEA's RTD software and sum approximation of raw data. For the first time, the variation of standard deviation of calculated flow rate with the injection volume and activity of the radiotracer was determined. Plug flow with axial dispersion was used to simulate the measured RTD curves and investigate the flow dynamics of the flowing water. The results of the study have shown the possibility of in situ calibration of flow meters with a relative error lower than 1 %. They also revealed a slight dependency of the precision of output results on the injection volume as well as similar results for manual and specialized RTD software data processing.

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Section: Introductionmentioning

confidence: 99%

Optimization of injected radiotracer volume for flow rate measurement in closed conduits

Pavlović

Bartl

et al. 2020

Hem Ind

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“…We had an opportunity to perform industrial scale RTD experiment on a pulp and paper mill ASP [31,32]. However, it was impractical to change the operating parameters in a full-scale industrial system.…”

Section: Introductionmentioning

confidence: 99%

Hydrodynamics and parametric study of an activated sludge process using residence time distribution technique

Sarkar

Sangal

Bhunia

2019

Environmental Engineering Research

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Hydrodynamic study of Activated Sludge Process (ASP) is important to optimize the reactor performance and detect anomalies in the system. Residence time distribution (RTD) study has been performed using LiCl as tracer on a pilot scale aeration tank (AT) and ASP, treating the pulp and paper mill effluent. The hydraulic performance and treatment efficiency of the AT and ASP at different operating parameters like residence time, recycle rate was investigated. Flow anomalies were identified and based on the experimental data empirical models was suggested to interpret the hydrodynamics of the reactors using compartment modelling technique. The analysis of the RTD curves and the compartment models indicated increase in back-mixing ratio as the mean hydraulic retention time (MHRT) of the tank was increased. Bypassing stream was observed at lower MHRT. The fraction of dead zone in the tank increased by approximate 20-25% with increase in recycle rate. The fraction of the stagnant zone was found well below 5% for all performed experiments, which was under experimental error. The substrate removal of 91% for Chemical oxygen demand and 96% for Biochemical oxygen demand were observed for the ASP working at a hydraulic mean residence time 39 h MRT with a 20% recycling of activated sludge.

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“…Radiotracer experiments were conducted to study the performance and effi ciency of ASP. In an earlier study our group reported the hydrodynamics of the fi rst aeration tank and clarifi er both with perfect impulse tracer inputs [22]. This paper reports the RTD data from the second radiotracer experiment performed on the second set of an aeration tank and secondary clarifi er evaluated using the convolution of input signals.…”

Section: Introductionmentioning

confidence: 99%

Radiotracer investigation of a pulp and paper mill effluent treatment plant

et al. 2017

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The pulp and paper industry is highly dependent on water for most of its processes, producing a significant amount of wastewater that should be treated to comply with environmental standards before its discharge into surface-water reservoirs. The wastewater generated primarily consists of substantial amounts of organic, inorganic, toxic and pathogenic compounds in addition to nutrients, which are treated in an effluent treatment plant that often combines primary, secondary, tertiary and advanced treatments. However, the treatment methods vary from industry to industry according to the process utilized. The effective performance of effluent treatment plants is crucial from both environmental and economic points of view. Radiotracer techniques can be effectively used to optimize performance and detect anomalies like dead zones, bypassing, channelling, etc. in wastewater treatment plants. Experiments on the distribution of residence time were performed on the aeration tank and secondary clarifier of a full-scale pulp and paper mill to study the flow behaviour as well as locate system anomalies and hence evaluate the performance of the treatment plants using the radiotracer I-131. The convolution method was applied to model the system with an imperfect impulse radiotracer input. The aeration tank was working efficiently in the absence of any dead zones or bypassing. Various hydrodynamic models available in the literature were applied on the aeration tank and secondary clarifier to obtain the hydraulic representation of the systems.

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Radiotracer investigation and modeling of an activated sludge system in a pulp and paper industry

Cited by 11 publications

References 20 publications

Optimization of injected radiotracer volume for flow rate measurement in closed conduits

Optimization of injected radiotracer volume for flow rate measurement in closed conduits

Hydrodynamics and parametric study of an activated sludge process using residence time distribution technique

Radiotracer investigation of a pulp and paper mill effluent treatment plant

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