Abstract

Chromium sulfate salt (Cr2(SO4)3) is the tanning agent used in the chrome tanning process, but during the process around 30 or 40% of the chromium is discharged as chromium III residues in the tannery's wastewater resulting in serious health and environmental problem in case of discharging to the environment without appropriate treatment. The main objective of this study is to investigate the efficiency of using solid waste materials for low-cost trivalent chromium removal from tanneries wastewater. This study was conducted in 5 phases: phase I, phase II, phase III, phase IV and phase V. In phase I, two groups of waste materials, organic and inorganic waste materials, were tested for the removal of trivalent chromium from aqueous solution and the results indicated that the group of inorganic waste materials, including marble powder (MP) and cement bypass kiln dust (CKD), showed better removal efficiency of chromium III. In phase II, the optimum mixing conditions, best removal efficiency and the energy required in the treatment process for both MP and CKD were studied. The results indicated that CKD showed better removal efficiency and lower energy consumption. In phase III, CKD was selected to carry further investigation on the treatment performance, operating conditions and the mechanisms for the removal of trivalent chromium. In phase IV, real samples wastewater was collected from a tannery in Egypt and it was tested for chromium III removal using CKD under the mixing and operating conditions obtained in phases II and III. The results recorded removal efficiency of chromium III of 99.97%. Finally, in phase V, chromium III recovery from the precipitated sludge using sulfuric acid (H2SO4) were studied. The best chromium III recovery efficiency was found to be 96.13 % using 7.75% H2SO4 solution and sludge dose of 2.5g.

Department

Environmental Engineering Program

Degree Name

MS in Environmental Engineering

Graduation Date

2-1-2020

Submission Date

September 2019

First Advisor

Ahmed El-Gendy, Salah El-Haggar

Committee Member 1

El-Haggar, Salah

Committee Member 2

El-Gendy, Ahmed

Extent

107 p.

Document Type

Master's Thesis

Rights

The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy.

Institutional Review Board (IRB) Approval

Approval has been obtained for this item

Comments

I want to express my deep thanks to everyone who helped and supported me to complete this work. Firstly, I need to give special thanks for my advisors Dr. Ahmed ElGendy and Dr. Salah Elhaggar for their unlimited help and support during this work. In addition, I want to thank the American University in Cairo for the Fellowship and research grant. Also, I need to express my thanks to Eng. Ahmed Saad, environmental engineering laboratory instructor, and Mohamed Mostafa, environmental engineering laboratory lab aide for their help and guidance during laboratory work. In addition, I need to thank Eng. Yasser Shaaban Akl from the Center of Leather Tanning Technology for helping during my visit to tanneries in Old Cairo or in Al-Robeky City. Also, my deep thanks should be given to my friend Dr. Yasmine Abdel-Maksoud for helping me in getting the CKD samples and for her technical help. In addition, I need to express my deep gratitude for my dear mother for all her endless support and help in my motherhood responsibilities during my work and for her prayers. I also need to thank my brother and sister for their help and guidance. In addition, my deep thanks should be given to my dear daughter Emy for being my strongest motivate to finish this work. Finally, I need express my deep thanks for my friends Eng. Sherif Zaher, Eng. Alaa Abbas, Eng. Israa El-Mitainy, Eng. Mohammed Osman, Manar Elnaggar, Monira Yazied, Youssef Abdel-Raouf and Amal Abul-Fetouh for all the support and help during this work.

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