Water Environ Res. 2026 May;98(5):e70395. doi: 10.1002/wer.70395.
ABSTRACT
This study presents a systematic and reproducible methodology for developing synthetic wastewater that mimics the bulk physicochemical characteristics of palm oil mill final effluent (SWM-POMEFE) at laboratory scale. The framework was established through four sequential phases: (1) physicochemical characterization of real POMEFE (R-POMEFE), (2) dose-response analysis of selected media, (3) iterative formulation of SWM-POMEFE, and (4) stability and statistical validation. R-POMEFE was characterized across 10 sampling events to establish baseline conditions for key parameters. Dose-response analyses of glucose, lignin, surfactant, unrefined red palm oil, and NH4Cl were conducted to reproduce COD, BOD5, color, O&G, and NH3-N contributions. Three progressively refined formulations were developed through iterative adjustments, demonstrating strong agreement between experimental results (Exp-R) and calibrated predictions (Cal-P), with deviations ranging from 0.3% to 6.3%. Statistical similarity analysis of the final SWM-POMEFE formulation showed that NH3-N, O&G, color, and turbidity closely matched the distribution of the R-POMEFE dataset, with mean values falling within the 95% confidence interval, interquartile range, and ±10% tolerance band. These parameters also exhibited very small standardized deviations (|z| ≤ 0.2), indicating negligible differences relative to the natural variability of the field measurements. TSS met all criteria except the interquartile range (z = 0.76). In contrast, COD and BOD5 fell outside the central distribution metrics but remained within the observed field range (z = 1.03 and 1.52, respectively). Although formal equivalence testing using the two one-sided tests procedure did not demonstrate strict equivalence, this was attributed to the large natural variability of the field measurements. Stability assessments further confirmed the robustness of the formulation, with < 5% variation during the 5-day short-term test and only minor reductions after 3-month storage, indicating that SWM-POMEFE provides a stable physicochemical surrogate for controlled laboratory studies.
PMID:42125849 | DOI:10.1002/wer.70395
