https://tecnoscientifica.com/journal/tasp <p><strong><em>Tropical Aquatic and Soil Pollution (Trop. Aquat. Soil Pollut.) (ISSN 2798-3056) </em></strong><strong> </strong>with a short form of <strong>TASP </strong>is an<strong> Open Access Refereed Journal </strong>that publishes <strong>research articles, reviews, and short communication </strong>on theoretical and applied sciences related to aquatic and soil, all aspects of pollution and solution to pollution in the biosphere.</p> <p><strong>TASP </strong>is published online with a frequency of two (2) issues per year in <strong>July and December </strong>with <strong>FREE </strong>of Article Processing Charge (APCs) and Articles Submission Charges (ASCs). Besides that, special issues of TASP will be published non-periodically from time to time. </p> Tecno Scientifica Publishing en-US Tropical Aquatic and Soil Pollution 2798-3056 <p>Authors shall retain the copyright of their work and grant the Journal/Publisher rights for the first publication with the work concurrently licensed under the <a href="https://creativecommons.org/licenses/by/4.0/"><strong>Creative Commons Attribution 4.0 International License (CC BY 4.0)</strong></a>.</p> <p>Under this license, authors who submit their papers for publication by <em>Tropical Aquatic and Soil Pollution</em> agree to have the CC BY 4.0 license applied to their work, and that anyone is allowed to reuse the article or part of it free of charge for any purpose, including commercial use. As long as the author and original source is properly cited, anyone may copy, redistribute, reuse and transform the content.</p> <p>This broad license intends to facilitate free access, as well as the unrestricted use of original works of all types. This ensures that the published work is freely and openly available in perpetuity.</p> https://tecnoscientifica.com/journal/tasp/article/view/1002 <p>This experimental study investigated the solar photocatalytic degradation process for improving bathroom greywater quality using titanium dioxide nanotubes modified 2,4,6-trinitrotoluene with zeolite (TNTs/zeolite) and sought to optimize it. Organic pollutants, suspended solids, and personal care products remained in total household greywater at a proportion of 43–70% from bathroom sources. The optimization method applied was Central Composite Design (CCD) under Response Surface Methodology (RSM), in which three independent variables were considered: pH within a range of 3–10; catalyst loading expressed as the exposed surface area of 1 or 2 cm²; and irradiation time between thirty and one hundred eighty minutes under natural sunlight conditions with average irradiance values between six hundred twenty and seven hundred eighty watts per square meter. Twenty runs were carried out in triplicate. The responses tested were Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), turbidity, pH, and Dissolved Oxygen (DO). The optimum condition predicted by RSM had a pH of 6.25, an irradiation time of 180 minutes, and a catalyst loading of 1 × 1 cm². Experimental validation at this optimum condition confirmed the adequacy of the model, with removals greater than 50% for COD, BOD, TSS, and turbidity. ANOVA showed that the models were statistically significant (p &lt; 0.0001) and highly predictively reliable (R² &gt; 0.90 for most responses). The study demonstrated that TNTs/zeolite under natural sunlight represented a potential low-energy alternative for bathroom greywater treatment with practical possibilities for decentralized reuse applications.</p> Siti Nor Hidayah Arifin Paran Gani Radin Maya Saphira Radin Mohamed Adel Al-Gheethi Chin Wei Lai G. Yasni Kean Hua Ang Copyright (c) 2026 Siti Nor Hidayah Arifin, Paran Gani, Radin Maya Saphira Radin Mohamed, Adel Al-Gheethi, Chin Wei Lai, G. Yasni, Kean Hua Ang https://creativecommons.org/licenses/by/4.0 2026-03-11 2026-03-11 6 1 1 17 10.53623/tasp.v6i1.1002