## 4 Conclusions  
The adsorption process is a dynamic phenomenon, and various factors seem to influence the remediation process synergistically. The study sets a new roadmap for the applied science by amalgamating the experimental analysis with in-depth modeling for an effective outcome. The connections among HNT as the adsorbent and DB15 color as the adsorbate displayed a test harmony (\(q_{e}\)) worth 96.00 mg g\({}^{-1}\) at pH 2, 69.00 mg g\({}^{-1}\) at a practically unbiased pH, and 112 mg g\({}^{-1}\), which was obtained via statistical optimization. To further understand the process of adsorption, nine isotherm models were studied. The adsorption follows Brouers-Sotolongo model, and the interactions between HNT and DB15 were identified to be physical in nature, following the pseudo-second-order kinetics. The contact time, dye concentration and dosage, and initial pH were the effective operating parameters influencing the adsorption. Based on the positive outcomes of the statistical optimization studies, the current work was tested at a laboratory scale for the application perspective. It was also demonstrated that the dye modified HNT has the potential to treat effluents from the textile industry. Furthermore, the current case study of the DB15 dye being adsorbed on the lucrative halloysite nanotubes sets a benchmark for remediation. Any given dye can be tested for its remediation purpose by choosing adsorbate material such as HNT. It would lead to a sustainable approach for tackling the current market demands. This study further bolsters the adsorption process by concretizing the need for modeling studies right from the laboratory scale to an industrial scale for process optimization. Thus, the work attracts researchers from various fields to address the current social/market needs by implementing green chemistry and green engineering principles for a sustainable environment.  
Conceptualization, S.J.U., M.R.S., M.N.A. and M.E.M.S.; methodology, S.J.U. and P.P.; software, S.J.U. and S.N.T.; validation, M.N.A., S.J.U. and U.T.S.; formal analysis, M.A.A. and R.A.M.; investigation, U.T.S. and R.A.M.; resources, M.I.H.S. and M.E.M.S.; data curation, M.E.M.S.; writing--original draft preparation, P.P. and S.J.U.; writing--review and editing, H.M.A. and A.E.;  
Figure 15: (1) Distilled water; (2) DB15 dye in distilled water; (3) TIE; (4) DB15 dye in TIE; (5) Nitrate after adsorption of dye on HNT after 15 min.  
support, review and editing, A.E. and E.M.E.; visualization, M.I.H.S.; supervision, M.R.S. and M.G.; project administration, M.G. and H.M.A.; and funding acquisition, A.E.A. and E.M.E. All authors have read and agreed to the published version of the manuscript.  
Deanship of Scientific Research at King Khalid University General Research Project under the grant number (R.G.P.2/138/42) and Taif University researchers supporting project number (TURSP-2020/157), Taif University, Taif, Saudi Arabia.  
Not applicable.  
The co-author [PERSON] would like to extend his appreciation to the Deanship of Scientific Research at King Khalid University for the support he received through General Research Project under the grant number (R.G.P.2/138/42). This work was supported by Taif University researchers supporting project number (TURSP-2020/157), Taif University, Taif, Saudi Arabia.  
The authors declare no conflict of interest.