Improvement of Final Settling Tanks Performance by Using Chemical Additions

Main Article Content

Mohamed A. E. Halawa
Hanan A. Fouad
Rehab M. Elhefny
A. F. Wail

Abstract

Biological treatment in wastewater treatment plants WWTPs consists of two main tanks, aeration tank and final settling tank. Aeration process using in return activated sludge system is very costly and it is required to operate WWTPs with low dissolved oxygen (DO) concentration in aeration process without risking poor effluent quality. To apply this study, a plant model for the addition of chemicals must be made with the necessary calibration of this model. Laboratory experiments were started between November 2017 and June 2018. This paper will discuss the impact of DO concentration on sludge properties by using a pilot plant model WWTP and find the optimum doses of Hydrogen peroxide H2O2 concentration with using low DO concentration to achieve good sedimentation.  In this study the DO set-point was changed every 3 weeks between 0.5 mg/l and 4.5 mg/l for a few months.  Experiments were carried out to The optimal ratio and dosage of H2O2 /Fe+2 was 5 as 30/6 mg/l. BOD, COD, TSS and VSS removal efficiency by using H2O2 /Fe+2 were 91%, 89% 90% & 89%, respectively with DO = 1.5 mg/l at an increased rates were 21.3%, 25.4%, 20% & 12.7%, respectively. Results of paper proves that the addition of optimum H2O2 will save 2 mg/l of DO concentration and providing a high cost of using electricity and mechanical equipment compared to the non-use of H2O2.

Keywords:
Wastewater treatment plants (WWTPs), sludge properties, chemical additions, hydrogen peroxide (H2O2), dissolved oxygen (DO) concentration

Article Details

How to Cite
Halawa, M. A. E., Fouad, H. A., Elhefny, R. M., & Wail, A. F. (2019). Improvement of Final Settling Tanks Performance by Using Chemical Additions. Journal of Engineering Research and Reports, 7(4), 1-7. https://doi.org/10.9734/jerr/2019/v7i416978
Section
Review Article

References

Mackenzie L. Davis. Microscopy and Activated Sludge Process Control. MWEA Process Seminar; 2015.

Metcalf, Eddy. Waste water engineering: Treatment, Disposal and Reuse. Mc Graw Hill, Inc, USA; 2003.

Castro E, Avellaneda A, Marc P. Combination of Advanced Oxidation Processes and Biological Treatment for the Removal of Benzidine-Derived Dyes. Environ. Prog. Sustain, Energy. 2014;33: 873–885.

Zhen G, Lu X, Su L, Kobayashi T, Kumar G, Zhou T, Zhao Y. Unraveling the catalyzing behaviors of different iron species (Fe+2 vs. Fe0 ) in activating per sulfate-based oxidation process with implications to waste activated sludge dewater ability. Water Research. 2018; 134:101e-114.
Available:https://doi.org/10.1016/j.watres.2018.01.072

Qian Zeng, Feixiang Zan, Tianwei Hao, Basanta Kumar Biswal, Sen Lin, Mark CM, van Loosdrecht, Guanghao Chen. Electrochemical pretreatment for stabilization of waste activated sludge: Simultaneously enhancing dewaterability, inactivating pathogens and mitigating hydrogen sulfide. Wastewater Treatment Laboratory, FYT Graduate School, The Hong Kong University of Science and Technology, Guangzhou, China; 2019. Available:https://doi.org/10.1016/j.watres.2019.115035

Clauss F, Helaine D, Balavoine C, Bidault A. Improving Activated Sludge Floc Structure and Aggregation for Enhanced Settling and Thickening Performance. J Wat Sci. 1998;38(8-9):35-44.

Collivignarelli MC, Bertanza G, Sordi M, Pedrazzani R. High-strength wastewater treatment in a pure oxygen thermophilic process. 11-year operation and monitoring of different plant configurations. Water Sci. Technol. 2015;71:588–596.

Jolanta Kozak, Maria Włodarczyk-Makuła. The Use of Sodium Carbonate-Hydrogen Peroxide (2/3) in the Modified Fenton Reaction to Degradation PAHs in Coke Wastewater. Presented at Innovations-Sustainability- Modernity- Openness Conference (ISMO’19), Bialystok, Poland; 2019.
[Published: 17 July 2019]

Millero FJ, Leferriere A, Fernandez M, Hubinger S, Hershey JP. Oxidation of H2S with H2O2 in natural waters. Environ. Sci. Technol.1989;23:209-213.

Hermosilla D, Merayo N, Gasco A, Blanco A. The application of advanced oxidation technologies to the treatment of effluents from the pulp and paper industry. A review. Environ. Sci. Pollut. 2015;22:168–191.

Lipczynska-Kochany E, Kochany J. Effect of humic substances on the Fenton treatment of wastewater at acidic and neutralpH. Chemosphere. 2008;73:745-750.

Kozak J, Włodarczyk-Makuła M. Comparison of the PAHs degradation effectiveness using CaO2 or H2O2 under the photo-Fenton reaction. Desalination Water Treatment. 2018;134:57–64.
DOI:10.5004/dwt.2018.22708

Namkung KC, Burgess AE, Bremner DH. A Fenton-like oxidation process using corrosion of iron metal sheet surfaces in the presence of hydrogen peroxide: a batch process study using model pollutants. Environ. Technol.2005;26:341-352.
DOI: 10.1080/09593332608618564

Metcalf, Eddy. Waste water engineering: Treatment, Disposal and Reuse. Mc Graw Hill, Inc, USA; 2003.

Pal P, Khairnar K, Paunikar WN. Causes and Remedies for filamentous foaming in Activated sludge treatment plant. Global NEST Journal. 2014;16(4):762-772.

Paul Dombrowski. Hands on State Point Training Illuminates Clarifier Operation. NEWEA Annual Conferences, Session 13-January 27; 2015.

Byeong-Cheol Jeon, Se-Yong Nam, Young-Kwon Kim. Treatment of Pharmaceutical Wastewater by Hydrogen Peroxide and Zerovalent Iron. Hankyong National University, Anseong 456-749, and Korea Environ. Eng. Res. 2014;19(1):9- 14. DOI:https://doi.org/10.4491/eer.2014.19.1.009

Sun WQ, Zhu H, Sun YJ, Chen L, Xu YH, Zheng HL. Enhancement of waste-activated sludge dewaterability using combined Fenton pre-oxidation and flocculation process. Desalination Water Treatment. 2018;126:314–323.
DOI:10.5004/dwt.2018.23076

Mamais D, Kalaitzi E, Andreadakis A. Foaming control in activated sludge treatment plants by coagulants addition. Global NEST Journal. 2001;13:237-245.

Ayers D, Kelly R. Solutions to Mitigate Effects of Microthrix Parvicella at the Meridian WWTP. PNCWA Annual Conference; 2012.

Sam Jeyanayagam. Design and Operation of Final Clarifiers. Florida Water Resources Journal; 2016.