Operation and Upgrading the Capacity of Wastewater Treatment Plants by Activated Sludge Method Using the Mass Flux Approach (Case Study of Wastewater Treatment Plant of Shahrak Gharb in Tehran

Document Type : Case study

Authors

1 PhD Student in Engineering and Water Resources Management, Dept. of Civil Engineering, Roudehen Branch, Islamic Azad University, Roudehen, Iran

2 Assist. Prof., Dept. of Civil Engineering, Roudehen Branch, Islamic Azad University, Roudehen, Iran

Abstract

One of the major challenges in the operation of wastewater treatment plants is the lack of experts and the lack of use of new methods in the management of this system, which has rarely been addressed in the past. Therefore, the application of new methods in exploitation is of great importance and in this regard, in the present study, using the mass flux approach, velocity and behavior of sediment particles and sludge masses in the secondary sedimentation pond by performing Settling column experiment with observance of the sludge index range between 150 and 250 mg/L, with the preparation of 6 different concentrations of raw wastewater, effluent and returned sludge continuously for more than 18 months (551 days) and in different climatic conditions were studied. By drawing graphs of height-time, concentration-velocity, concentration- mass flux, the relationships between important parameters were obtained using MATLAB software and new mathematical and experimental models that could estimate velocity in a wide range of different concentrations were presented and observed in unusual conditions. By determining the optimal operating point (sp), the capacity of wastewater treatment plants can be increased between 15 and 20% at no cost.

Keywords

References

Buratto, B., Usher, S. P., Parris, D. & Scales, P. J. 2014. Wall effects during settling in cylinders. Colloids Surfaces, A, 449, 157-169.
Bürger, R., Diehl, S., Faras, S., Nopens, I. & Torfs, E. 2013. A consistent modelling methodology for secondary settling tanks: a reliable numerical method. Water Science and Technology, 68(1), 192-208.
Clercq, D. 2003. Computational fluid dynamics of settling tanks: development of experments and rheological, settling, and scraper submodels. Ph.D Thesis, University of Gent, Applied Biological Sciences, Ghent, Belgium.
David, R., Vasel, J. L. & Wouwer, A. V. 2009b. Settler dynamic modeling and MATLAB simulation of the activated sludge process. Chemical Engineering Journal, 146(2), 174-183.
De Clercq, J., Nopens, I., Defrancq, J. & Vanrolleghem, P. A. 2008. Extending and calibrating a mechanistic hindered and compression settling model for activated sludge using in-depth batch experiments. Water Research, 42(3), 781-791.
Diehl, S. 2007. Estimation of the batch-settling flux function for an ideal suspension from only two experiments. Chemical Engineering Science, 62, 4589-4601.
Kinner, D. J. 2002. Biological solids sedimentation: a model incorating fundamental setting parameters. Ph.D. Thesis, University of Utah, Utah, USA.
Scott, K. J. 1966. Mathematical models of mechanism of thickening. Industrial and Engineering Chemistry Fundamentals, 5(1), 109-113.
Takács, I., Vanrolleghem, P. A., Wett, B., Murthy, S. 2007. Elemental balance based methodology to establish reaction stoichiometry in environmental modelling. Water Science and Technology, 56(9), 37-41.
Vesilind P. A. 1968. The influence of stirring in the thickening of biological sludge. Ph.D. Thesis, The University of North Carolina at Chapel Hill, USA.
Zhang, D., Li, Z., Lu, P., Zhang, T. & Xu, D. 2006. A method for characterizing the complete settling process of activated sludge. Water Research, 40, 2637-2644.
Journal of Water and Wastewater; Ab va Fazilab ( in persian )
Volume 32, Issue 4 - Serial Number 135
November and December 2021
Pages 21-33

Files

Share

How to cite

Statistics