Turbidity and COD Removal from Municipal Wastewater Using a TiO2 Photocatalyst—A Comparative Study of UV and Visible Light
Source abstract
Abstract
Water resources are depleting, and the availability and supply of clean, potable water are a global concern. Advanced oxidation processes (AOPs) possess immense prospects in water and wastewater treatment settings. This study investigated and optimized the photocatalytic treatment of wastewater using titanium dioxide (TiO2) as the photocatalyst. The one-factor-at-a-time (OFAT) technique was employed to evaluate the effects of reaction time (20–100 min), mixing speed (20–100 rpm), and catalyst load (0.3–1.5 g/L) on pH, colour, turbidity, and chemical oxygen demand (COD) removal from actual municipal wastewater. Reaction time and catalyst load were then identified as the two key factors selected to be modeled and were optimized for turbidity and COD removal using the Central Composite Design (CCD) of response surface methodology (RSM). These statistical models were developed and used to optimize the operating conditions. The results obtained showed a desirability efficiency of 74.7% at a 95% confidence level. The RSM model predicted results at the optimum conditions and showed reasonable agreement with the experimental results obtained. The optimal responses achieved were 32.64% COD removal and 95.17% turbidity removal. A comparative study between UV light and visible light was also conducted at optimum conditions, whereby the UV light was demonstrated to be highly effective for turbidity and COD removal. The optimal responses achieved were 25.58% COD removal and 66.88% turbidity removal for visible light.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: TiO2 Photocatalysis and Solar Cells · Water Quality Monitoring and Analysis · Advanced Photocatalysis Techniques
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Green Engineering Research Group, Department of Chemical Engineering, Faculty of Engineering and the Built Environment, Durban University of Technology, Durban 4001, South Africa
Funding
South African Water Research Commission
References (45)
Show source-provided references
1. du Plessis, A. (2023). South Africa’s Water Predicament: Freshwater’s Unceasing Decline, Springer.10.1007/978-3-031-24019-5 ↗
2. Zhang, F., Wang, X., Liu, H., Liu, C., Wan, Y., Long, Y., and Cai, Z. (2019). Recent Advances and Applications of Semiconductor Photocatalytic Technology. Appl. Sci., 9.10.3390/app9122489 ↗
3. Kretzmann, S. (2023, March 06). Municipalities Are Failing to Provide Clean Water. Citizens Are Stepping in to Fix the Problem. Available online: https://www.groundup.org.za/article/water-in-two-thirds-municipalities-does-not-meet-minimum-standards/.
4. Toxopeüs, M. (2022, December 01). Understanding Water Issues and Challenges II: Municipalities and the Delivery of Water Services. Available online: https://hsf.org.za/publications/hsf-briefs/understanding-water-issues-and-challenges-ii-municipalities-and-the-delivery-of-water-services.
5. Xaba, N. (2023, March 10). The Centrality of the Water-Energy-Food Nexus in Navigating South Africa’s Power Crisis. Available online: https://www.dailymaverick.co.za/opinionista/2023-02-27-the-water-energy-food-nexus-and-south-africas-energy-crisis/.
6. Photocatalytic Oxidation of Treated Municipal Wastewaters for the Removal of Phenolic Compounds: Optimization and Modeling Using Response Surface Methodology (RSM) and Artificial Neural Networks (ANNS)10.1002/jctb.3755 ↗
7. Recent Developments in Industrial Organic Degradation Via Semiconductor Heterojunctions and the Parameters Affecting the Photocatalytic Process: A Review Study10.1016/j.jwpe.2022.102671 ↗
8. Pharmaceutical and Personal Care Products (PPCPS) as Endocrine Disrupting Contaminants (EDCS) in South African Surface Waters10.4314/wsa.v43i4.16 ↗
9. Critical Review of Advanced Oxidation Processes in Organic Wastewater Treatment10.1016/j.chemosphere.2021.130104 ↗
10. Advanced Oxidation Process: A Sustainable Technology for Treating Refractory Organic Compounds Present in Industrial Wastewater10.1007/s11356-022-19435-0 ↗
11. A Review on UV/TiO 2 Photocatalytic Oxidation Process10.1007/s11814-008-0011-8 ↗
12. Elimination of Pharmaceuticals in Sewage Treatment Plants in Finland10.1016/j.watres.2006.12.017 ↗
13. Removal of Veterinary Antibiotics from Sequencing Batch Reactor (SBR) Pretreated Swine Wastewater by Fenton’s Reagent10.1016/j.watres.2009.06.057 ↗
14. Photocatalytic Decomposition of Metronidazolein Aqueous Solutions Using Titanium Dioxide Nanoparticles
15. Photocatalytic Degradation of Methylene Blue Dye Using Ultraviolet Light Emitting Diodes10.1021/ie9012437 ↗
16. The Photocatalytic Process in the Treatment of Polluted Water
17. Recent Developments in Photocatalytic Water Treatment Technology10.1016/j.watres.2010.02.039 ↗
18. Friedmann, D. (2022). A General Overview of Heterogeneous Photocatalysis as a Remediation Technology for Wastewaters Containing Pharmaceutical Compounds. Water, 14.10.3390/w14213588 ↗
19. Heterogeneous Photocatalytic Degradation of Ibuprofen in Ultrapure Water, Municipal and Pharmaceutical Industry Wastewaters Using a TiO2/UV-LED System10.1016/j.cej.2017.10.045 ↗
20. Influence of Operating Parameters on Photocatalytic Degradation of Phenol in UV/TiO2 Process10.1016/j.cej.2007.08.002 ↗
21. New Efficient Sunlight Photocatalysts Based on Gd, Nb, V and Mn Doped Alpha-Bi2O3 Phase10.1016/j.jece.2019.103644 ↗
22. An Overview on Non-Spherical Semiconductors for Heterogeneous Photocatalytic Degradation of Organic Water Contaminants10.1016/j.chemosphere.2021.130907 ↗
23. Heterogeneous Photocatalysis: Fundamentals and Applications to the Removal of Various Types of Aqueous Pollutants10.1016/S0920-5861(99)00107-8 ↗
24. Photocatalytic Water Treatment: Solar Energy Applications10.1016/j.solener.2004.03.031 ↗
25. Photocatalytic and Photochemical Degradation of Nitrobenzene Using Artificial Ultraviolet Light10.1016/j.cej.2004.05.009 ↗
26. The Stability of Polymeric Membranes in a TiO2 Photocatalysis Process10.1016/j.memsci.2005.09.033 ↗
27. Optimisation of Degradation Conditions of 1, 8-Diazabicyclo [5.4. 0] Undec-7-Ene in Water and Reaction Kinetics Analysis Using a Cocurrent Downflow Contactor Photocatalytic Reactor10.1016/j.apcatb.2006.12.008 ↗
28. Removal of Organic Pollutants in the Municipal Sewage Water by TiO2 Based Heterogeneous Photocatalysis
29. The Photocatalytic Degradation of Methyl Green in Presence of Visible Light with Photoactive Ni0. 10: La0. 05: TiO2 Nanocomposites
30. Response Surface Methodology for Optimization of Photocatalytic Degradation of Aqueous Ammonia10.2166/aqua.2018.121 ↗
31. Kinetic Study on Photocatalytic Degradation of 4BS Azo Dye Over TiO2 in Slurry10.1089/ees.2006.23.1000 ↗
32. Goren, A.Y., Recepoğlu, Y.K., and Khataee, A. (2022). Artificial Intelligence and Data Science in Environmental Sensing, Elsevier.
33. Wastewater Treatment with the Advent of TiO2 Endowed Photocatalysts and their Reaction Kinetics with Scavenger Effect10.1016/j.molliq.2021.116479 ↗
34. Sibiya, N.P., Rathilal, S., and Kweinor Tetteh, E. (2021). Coagulation Treatment of Wastewater: Kinetics and Natural Coagulant Evaluation. Molecules, 26.10.3390/molecules26030698 ↗
35. Investigation of Epoxy Resin/Nano-TiO2 Composites in Photocatalytic Degradation of Organics Present in Oil-Produced Water10.1080/03067319.2020.1784889 ↗
36. Colour Removal in a Textile Industry Wastewater Using Coconut Coir Pith
37. Electrochemical Treatment of Endocrine-Disrupting Chemical from Aqueous Solution10.1080/19443994.2013.868834 ↗
38. UV and Solar Light Photocatalytic Removal of Organic Contaminants in Municipal Wastewater10.1080/01496395.2016.1178290 ↗
39. Photocatalytic Degradation of 2, 4, 6-Tribromophenol on Fe2O3 or FeOOH Doped ZnIn2S4 Heterostructure: Insight into Degradation Mechanism10.1016/j.apcatb.2013.09.040 ↗
40. Effect of Different Type of Scavengers on the Photocatalytic Removal of Copper and Cyanide in the Presence of TiO2 @ Yeast Hybrids10.1007/s10854-015-3229-3 ↗
41. Evaluation of Titanium Dioxide Photocatalytic Technology for the Treatment of Reactive Black 5 Dye in Synthetic and Real Greywater Effluents10.1016/j.jclepro.2014.11.014 ↗
42. Tetteh, E.K., Obotey Ezugbe, E., Rathilal, S., and Asante-Sackey, D. (2020). Removal of COD and SO42− from Oil Refinery Wastewater Using a Photo-Catalytic System—Comparing TiO2 and Zeolite Efficiencies. Water, 12.10.3390/w12010214 ↗
43. Treatment of Petroleum Industry Wastewater Using TiO2/UV Photocatalytic Process
44. Treatment of Highly Polluted Paper Mill Wastewater by Solar Photocatalytic Oxidation with Synthesized Nano TiO210.1016/j.cej.2011.01.028 ↗
45. Recent Update on Photocatalytic Degradation of Pollutants in Waste Water Using TiO2-Based Heterostructured Materials10.1016/j.rineng.2023.100920 ↗