Study of TSS Reduction in Digested POME Using Coagulation-Flocculation and Sand Filtration for Bioscrubber Pretreatment
Year: 2026
Type: article
Abstract: The bioscrubber circulation water at the Biogas Power Plant is sourced from overflow digested Palm Oil Mill Effluent (POME) containing very high Total Suspended Solids (TSS), exceeding 500 mg/L. High TSS causes fouling of sprayer nozzles, clogging of packing media, and reduces Thiobacillus bacterial activity in biological H 2 S oxidation. This study aims to evaluate the effectiveness of coagulation-flocculation using Aluminum Sulfate (Alum) and Polyaluminium Chloride (PAC), as well as sand filtration, in reducing TSS levels. Coagulation-flocculation tests were carried out as jar tests with dose variations of 0, 50, 100, 150, and 200 ppm for each coagulant, followed by 30-minute sedimentation. Filtration tests used 300 grams of silica sand (0.5-1.0 mm diameter) in a gravity-driven column (height 30 cm, diameter 5 cm) with three replicates. Furthermore, a novel mixing strategy was developed by combining digested POME with clarified POME from the final sedimentation pond (low TSS) at a 1: 3 ratio. Results show that PAC at optimal dose 150 ppm achieves TSS removal efficiency of 89.36% with final TSS of 150 ppm, outperforming Alum which achieved 82.47% at the same dose. Sand filtration consistently reduced TSS by an average of 80.20% while maintaining TDS at an average reduction of 26.18%, preserving dissolved organics as bacterial nutrients. The 1: 3 mixing strategy successfully reduced TSS to below 50 mg/L, eliminating nozzle and sprinkler clogging, preventing packing media fouling, and achieving H 2 S removal efficiency down to 10 ppm in the bioscrubber outlet. The combination of PAC 150 ppm and sand filtration, along with the 1: 3 mixing strategy, is recommended as a stage.
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7225412213