E-Thesis 223 views
Improving efficiency of wastewater treatment at Morfa Coke Ovens / MERGAN MUNAWA
Swansea University Author: MERGAN MUNAWA
Abstract
Production of steel through the coke making process results in the generation of highly contaminated wastewater. Currently, the Morfa coke ovens at TATA Steel Port Talbot use a conventional biological oxidation process built and designed in the 1970s to treat wastewater before discharging into the B...
| Published: |
Swansea, Wales, UK
2023
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| Institution: | Swansea University |
| Degree level: | Master of Research |
| Degree name: | MSc by Research |
| Supervisor: | Tizaoui, Chedly. and Dickinson, Paul. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa63275 |
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| Abstract: |
Production of steel through the coke making process results in the generation of highly contaminated wastewater. Currently, the Morfa coke ovens at TATA Steel Port Talbot use a conventional biological oxidation process built and designed in the 1970s to treat wastewater before discharging into the Bristol Channel via the ‘Long Sea Outfall.’ Using biological treatment alone has become an inefficient strategy to manage the wastewater produced in the coke ovens. Thus, this project evaluated other treatment techniques including ozone (O3), granular activated carbon (GAC) and advanced oxidation processes (AOPs) such as O3/GAC, O3/H2O2 to pre-treat the influent with the aim of removing organic content and enhancing biodegradability. Wastewater from the Biological Effluent Treatment (BET) plant at the Morfa coke ovens Port Talbot steelworks was used in this study and characterized by Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Total Organic Carbon (TOC) and nitrogen in the form of ammonia (NH3 – N). The influent colour was yellow brownish colour and had average =3055 −1, 3−≥500 , ≥400 −1, warm temperatures ranging 20 – 25℃ and pH range between 8 and 9. According to historic data this influent was highly polluted with a variety of compounds such as thiocyanates, ammonia, phenols, PAHs, H2S and other organic and inorganic compounds. The results indicated that increasing ozonation time had a significant impact on % COD, TOC and NH3 – N removal with 120 mins ozonation yielding 45% COD, 47% TOC and 96% NH3 – N removal. However, biodegradability significantly decreased with increase in ozonation time; 120 mins ozonation resulted to 5=0.02 as compared to 5=0.2 of the influent without ozonation. Also, treatment of BET influent with different masses of GAC alone yielded 42% COD, 88% TOC and 98% NH3 – N removal for 10g GAC in 400 mL. However, biodegradability of the influent also significantly reduced to 5=0.05 as the mass of GAC increased to 10g in 400mL wastewater sample. Additionally, when the influent was treated with AOPs, O3/GAC yielded better results for % COD, TOC and NH3 – N removal as compared to treatment using O3/H2O2. On the other hand, pre-treatment with ozone alone improved the BOD rate constant k and reduced the UBOD i.e., 120 mins ozonation resulted to =1.83 −1 & =23.18−1 whiles treatment with GAC alone improved the UBOD i.e., 5g in 400mL resulted to =0.0004 −1 & =44706.39 −1. This is possibly due to the formation of toxic substances during ozonation, or removal of key nutrients required for bacterial growth. |
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| Item Description: |
A selection of third party content is redacted or is partially redacted from this thesis due to copyright restrictions. |
| Keywords: |
Wastewater treatment, coke ovens, ozone, AOPs |
| College: |
Faculty of Science and Engineering |
| Funders: |
M2A and TATA Steel (EGR0751-100) |