## 4 Conclusions  
This study underscores the critical need for innovative and sustainable water treatment technologies in the face of escalating challenges posed by climate change and industrial activities. With conventional treatment methods facing limitations in effectively removing contaminants such as synthetic dyes, the exploration of alternative approaches is imperative. This research investigated GO as an alternative adsorbent to the commonly used NaY and GAC for the adsorption of synthetic dyes in water and wastewater applications. This study demonstrated that GO strongly outperformed both NaY and GAC for the removal of cationic dyes in both removal efficiency and time to equilibrate under slow mixing conditions that are consistent with real-world applications. Notably, the superior performance of GO is attributed to its unique properties, including a layered structure with abundant oxygen-containing functional groups, which facilitate robust adsorption of various organic contaminants. The study's comprehensive investigation, encompassing kinetic experiments, adsorption isotherm analyses, and characterization of adsorbent structures, provides compelling evidence supporting GO as a viable alternative to conventional adsorbents in water treatment applications. Experimental results show that the multilayer adsorption behaviour of GO is consistent with the Freundlich isotherm model, and the rate-controlling step of adsorption was determined to be pseudo-second-order. GO exhibited high removal efficiencies for both large and small molecule dyes. NaY had the lowest removal efficiencies for removal of RhB, while GAC had the longest equilibrium time; the results of which are shown through isotherm analyses to be caused by limitations in their physical structures and pore sizes. In conclusion, GO has been shown to be a competitive alternative to GAC and NaY for mitigating the adverse impacts of the removal of cationic dyes with different molecular sizes and structures in small and large-scale water treatment applications. As the global community grapples with escalating environmental challenges, continued research and development in this field are essential for safeguarding water quality and ensuring the well-being of both ecosystems and human populations. Future studies that further explore the regeneration and reuse of materials are required to ensure the long-term sustainability of the material. In addition, mixtures of GO with GAC, should explore the potential for creating a robust hybrid adsorbent capable of treating a diverse set of water quality conditions. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app14219811/s1](https://www.mdpi.com/article/10.3390/app14219811/s1)]([https://www.mdpi.com/article/10.3390/app14219811/s1](https://www.mdpi.com/article/10.3390/app14219811/s1)). Pseudo first order model for removal of MB with three adsorbents (GO, GAC, and Zeolite); Figure S2. Pseudo first order model for removal of RhB with three adsorbents (GO, GAC, and Zeolite). **Author Contributions:** N.N.M. and O.D.B. conceived the research idea and designed the experiments. O.D.B. provided research supervision and guidance. N.N.M. conducted the investigation, collected data, and gave the initial data interpretation. O.D.B. and F.H.T. provided critical review, supervision, and guidance throughout the project. All authors participated in the review and revision process. All authors have read and agreed to the published version of the manuscript. **Funding:** This research project was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), Fund Number: RGPIN-2019-06645. **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** Data is contained within the article or Supplementary Materials.