Hybrid Leachate Treatment with Date Pit Tannins and Persulfate AOP: A Statistical Approach

Shabib Al Rashdi; Nageswara Rao Lakkimsetty; Hala Ali Al Zaabi

doi:10.48084/etasr.17340

Authors

Shabib Al Rashdi Center of Excellence in Environmental Science & Technology (CEEST), National University of Science and Technology, Oman
Nageswara Rao Lakkimsetty Department of Chemical and Petroleum Engineering, School of Engineering & Computing, American University of Ras Al Khaimah, Ras al Khaimah, UAE
Hala Ali Al Zaabi Department of Mechanical and Industrial Engineering, National University of Science and Technology, Oman

Volume: 16 | Issue: 3 | Pages: 35515-35522 | June 2026 | https://doi.org/10.48084/etasr.17340

Received: 4 January 2026 | Revised: 15 February 2026, 4 March 2026, 8 March 2026, and 10 March 2026 | Accepted: 13 March 2026 | Online: 6 June 2026

Corresponding author: Nageswara Rao Lakkimsetty

Abstract

The treatment of stabilized landfill leachate using a hybrid approach combining coagulation-flocculation and Persulfate Advanced Oxidation Process (P-AOP) is studied in this article. Catechin tannins were extracted from domestically sourced Omani date pits (Fardh and Khalas) using Soxhlet extraction with 50% ethanol and were subsequently characterized via Fourier Transform Infrared (FTIR) and ferric tests. Leachate samples collected from the Barka Engineered Landfill underwent treatment under varying operational parameters. Coagulation-flocculation was optimized at 70 mg/L tannin dosage, pH = 5.8, and 60 minute reaction time, while P-AOP was performed at a 1:6 sodium persulfate-to-zinc sulfate heptahydrate ratio, pH = 11, 200 RPM, for 140 min. Spectrophotometric analysis confirmed removals of 74% COD, 60% ammonia, and 96% color, with a 12,433% increase in TSS. Design Expert software was utilized to develop a statistical model and optimize treatment conditions. The efficacy of this hybrid method was highlighted by the obtained results, exhibiting the potential of agricultural waste-derived tannins in sustainable leachate management, aligned with Oman Vision 2040 and the UN Sustainable Development Goals.

Keywords:

hybrid treatment, Persulfate Advanced Oxidation (P-AOP), date pit tannins, landfill leachate, sustainable waste management

Author Biographies

Shabib Al Rashdi, Center of Excellence in Environmental Science & Technology (CEEST), National University of Science and Technology, Oman

Hala Ali Al Zaabi, Department of Mechanical and Industrial Engineering, National University of Science and Technology, Oman

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