https://orapuh.org/ojs/index.php/orapj <p>Orapuh Journal (Orap J) is an open-access, internationally peer-reviewed online journal dedicated to oral and public health. The journal provides accessible, high-quality, peer-reviewed knowledge to oral and public health professionals, educators, consumers, and the global community.</p> <p><strong>Aim</strong><br>Orapuh Journal aims to enhance access to superior information and research in oral and public health while fostering the development of emerging researchers and authors, particularly from underserved areas within these disciplines.</p> <p><strong>Scope</strong><br>Orapuh Journal prioritises:</p> <p>1. Original research<br>2. Comprehensive and critical review articles<br>3. Evidence-based information<br>4. Interactive clinical and related content<br>5. Content contributions focused on advancing oral and public health disciplines.</p> <p><strong>Open Access Information</strong></p> <p>All articles in Orap J are open-access articles distributed under the terms of the Creative Commons Attribution Non-Commercial 4.0 International License.</p> <p>Click <a href="https://www.orapuh.org/ojs/ojs-3.1.2-4/index.php/orapj/about"><strong>here</strong></a> to read more about the Journal. Find out <a href="http://orapuh.org/ojs/ojs-3.1.2-4/index.php/orapj/why-choose">why <em>Orap J</em> is your quick access to being</a>!</p> <p><strong><a href="https://orapuh.org/the-vital-role-of-communicating-dental-and-public-health-research-findings/">Click here</a></strong>&nbsp;to read an article about the vital role of communicating oral and public health research findings to the scientific community.</p> <p><a href="http://orapuh.org/ojs/ojs-3.1.2-4/index.php/orapj/editorial-policies">Editorial Policies</a>&nbsp; | <a href="https://orapuh.org/ojs/ojs-3.1.2-4/index.php/orapj/about/editorialTeam">Editorial Team</a> | <a href="http://orapuh.org/ojs/ojs-3.1.2-4/index.php/orapj/about/submissions">Author Guidelines</a></p> en-US <p>Authors of articles published in <em>Orap J</em> are the copyright holders of their articles. When they accept our terms of use, they grant any third party the right to use, reproduce or disseminate their article freely without fiscal or registration restrictions.</p> <p>&nbsp;</p> [email protected] (Prof. V. E. Adamu) [email protected] (Editor-in-Chief) Sun, 25 Jan 2026 13:58:54 +0200 OJS 3.1.2.4 http://blogs.law.harvard.edu/tech/rss 60 https://orapuh.org/ojs/index.php/orapj/article/view/e1411 <p><strong>Introduction</strong></p> <p>Hospital effluents often contain heavy metals that pose significant environmental and public health risks, particularly in settings with limited access to advanced wastewater treatment technologies. Upflow Anaerobic Sludge Blanket (UASB) reactors represent a low-cost alternative; however, pilot-scale data on heavy metal removal remain scarce.</p> <p><strong>Purpos</strong><strong>e </strong></p> <p>This study evaluated the performance of a pilot-scale UASB reactor for heavy metal removal under optimised and non-optimised operational conditions and identified key factors influencing treatment efficiency.</p> <p><strong>Methods&nbsp; </strong></p> <p>A Plackett–Burman experimental design was used to screen critical operational parameters. The UASB reactor was operated for 12 weeks using real hospital effluent collected from the University Clinics of Kinshasa, with 36 samples analysed per monitoring point. The optimised reactor (P14) incorporated natural additives, including clay, eggshells, maize, and lime. Heavy metal concentrations were determined using atomic absorption spectrophotometry (AAS), with quality assurance and quality control procedures, calibration standards, and analytical blanks applied throughout.</p> <p><strong>Results </strong></p> <p>Under optimised conditions, substantial reductions were observed in chemical oxygen demand (COD; 620 → 150 mg/L) and heavy metal concentrations: iron (1.20 → 0.45 mg/L), copper (0.85 → 0.30 mg/L), and zinc (0.60 → 0.22 mg/L), corresponding to removal efficiencies of approximately 60–70%. Nickel and manganese concentrations also decreased but remained above World Health Organization guideline limits. Reactor performance remained stable throughout the 12-week operational period.</p> <p><strong>Conclusion</strong></p> <p>Pilot-scale UASB reactors supplemented with natural additives can significantly enhance heavy metal removal from hospital effluents. Further research is required to assess long-term operational stability, heavy metal fate, sludge management, and scalability prior to full-scale implementation.</p> Lialia Credo Mesongolo, Musibono Eyul’anki Dieudonné, Tangou Thierry Tabou , Mulaji Crispin Kyela , MAX SEKE VA, Biey Makaly Emmanuel Copyright (c) 2026 Lialia Credo Mesongolo, Musibono Eyul’anki Dieudonné, Tangou Thierry Tabou , Mulaji Crispin Kyela , MAX SEKE VA, Biey Makaly Emmanuel https://creativecommons.org/licenses/by-nc/4.0 https://orapuh.org/ojs/index.php/orapj/article/view/e1411 Sun, 25 Jan 2026 13:58:06 +0200