Palm Oil Wastewater Treatment in Indonesia: GFS Tanks and Anaerobic Technologies

Indonesia, the world's largest palm oil producer, generates millions of tons of Palm Oil Mill Effluent (POME) annually. This high-strength organic wastewater poses serious environmental risks if left untreated, yet presents significant opportunities for renewable energy recovery through modern anaerobic digestion technologies. This article explores how Glass-Fused-to-Steel (GFS) Tanks combined with advanced Anaerobic Technologies provide effective POME treatment solutions for Indonesian palm oil mills, converting waste into valuable biogas resources while ensuring environmental compliance.

Indonesia's extensive palm oil industry, concentrated across Sumatra, Kalimantan, and Sulawesi, generates substantial POME during the milling process. The extraction of crude palm oil from fresh fruit bunches involves three key production stages that produce this wastewater: rinsing of fresh fruit bunches, clarification of extracted crude palm oil at the pressing station, and pressing of empty fruit bunches. For every ton of fresh fruit bunches processed, mills discharge approximately 0.7 to 1 m³ of POME. Fresh POME is characterized as a hot (60–80°C), acidic (pH 3.3–4.6), thick brownish liquid containing high solids, oil and grease, with COD levels ranging from 44,000 to 83,000 ppm and BOD from 14,000 to 34,000 ppm. This nutrient-rich effluent contains nitrogen, phosphate, potassium, magnesium, and calcium, making it potentially valuable as fertilizer after proper treatment.

Effective POME treatment follows a systematic process designed to protect Indonesia's water resources while recovering renewable energy. The treatment begins with mechanical bar screens that remove large suspended solids and floating debris, preventing subsequent equipment blockage and damage. Horizontal flow oil separators are then utilized to remove oil and grease, reducing the organic load on biological treatment units. A regulating tank balances flow fluctuations, temperature variations, and pH levels, creating consistent conditions for anaerobic digestion. The conditioned wastewater then enters the anaerobic digester where microorganisms break down organic matter in an oxygen-free environment. The Upflow Solids Reactor (USR) Process is specifically suited for this application due to its ability to handle high-solids organic wastewater with total solids content of 3–6%. Following digestion, treated effluent undergoes further stabilization and can be applied to farmland as fertilizer.

The Upflow Solids Reactor (USR) Process is an advanced anaerobic digestion technology particularly effective for Indonesian POME treatment. Operating in vertical, cylindrical reactor tanks with air-tight roofs, the USR handles organic wastewater with high solid content (TS: 3%–6%) without requiring mechanical stirring. Wastewater flows upward through the reactor, passing through a dense sludge bed where microorganisms efficiently degrade complex organic pollutants. The sludge remains in the reactor bottom with a solids retention time exceeding hydraulic retention time, ensuring stable biological activity even with fluctuating influent characteristics. Under mesophilic digestion conditions, POME treatment typically maintains a volumetric load of 3–5 kg COD/(m³·d), achieving 90–95% COD/BOD removal rates with hydraulic retention times of 7–9 days. With a biogas production rate of 27–30 m³ per m³ of POME at 60–65% methane content, the USR Process effectively converts waste to energy.

Glass-Fused-to-Steel (GFS) Tanks serve as the foundation of modern POME treatment infrastructure in Indonesia. Manufactured by firing molten glass onto steel plates at temperatures of 820°C to 930°C, these tanks create an inert, inorganic bond that combines the strength and flexibility of steel with outstanding corrosion resistance of glass. The double coating layer structure (2C2F) protects both interior and exterior faces with ground and surface coatings on each side. This construction provides exceptional resistance to the acidic, high-strength conditions typical of POME, ensuring long-term durability with minimal maintenance requirements. GFS tanks are prefabricated in factory conditions and assembled on-site using a bolted system—a team of just 7 workers can complete installation in 40 days, significantly reducing construction time and costs compared to traditional welded structures.

Indonesia's palm oil mills benefit from diverse storage and cover solutions tailored to specific treatment requirements. GFS Tanks provide superior corrosion resistance for aggressive wastewater environments. Galvanized Steel Tanks deliver tough, wear-resistant protection through a galvanizing process. Fusion Bonded Epoxy (FBE) Tanks, developed in collaboration with AkzoNobel, incorporate innovative coating technology. High-quality AISI 304/316 Stainless Steel Tanks meet stringent requirements for high-purity applications. Cover solutions include Aluminum Geodesic Dome Roofs for corrosion resistance and broad span capabilities; Glass-Fused-to-Steel Roofs for air-tight pressurized structures suitable for odor control; Single and Double Membrane Roofs optimized for anaerobic digestion processes; Aluminum Alloy Trough Deck Roofs for economical water storage; Stainless Steel Roofs for superior anti-corrosion performance; and FRP Roofs for non-air-tight applications.

Comprehensive POME treatment requires integrated supporting equipment for reliable operation. Gas Holders provide safe, dependable biogas storage for energy utilization. Lagoons/Black Membrane systems offer economical large-capacity storage for treated effluent. Hot Water Boilers maintain optimal digestion temperatures for mills without sufficient waste heat. Emergency Torch Systems ensure safe biogas pressure management during process upsets. Lifting Pumps are specifically designed for handling high-solids wastewater. Dehydration and Desulfurization Tanks purify biogas by removing moisture and corrosive hydrogen sulfide. Screw Sludge Dewatering Machines provide efficient solid-liquid separation, minimizing sludge volume and disposal costs. Each equipment component contributes to a complete, efficient treatment system.

As a professional EPC Contractor, Center Enamel delivers comprehensive POME treatment solutions to Indonesian palm oil mills. The company provides full engineering, procurement, and construction services, managing projects from concept through commissioning. With certifications including CE/EN1090, ISO 9001, NSF61, WRAS, and EN28765, quality assurance is maintained throughout project execution. Design standards incorporate AWWA D103, OSHA, EN28765, and EuroCode requirements. Center Enamel's comprehensive approach includes:

• Customized system design based on site-specific wastewater characteristics and treatment goals
• Professional engineering for USR reactors, acidification tanks, and auxiliary systems
• High-quality GFS tanks with corrosion resistance and 30+ year service life
• Complete biogas collection, purification, and utilization systems
• On-site installation supervision with ISO and OSHA safety compliance
• Biological startup, performance testing, and operator training
• Seamless coordination with local contractors and international suppliers

Palm oil mill effluent treatment in Indonesia has evolved from simple disposal to a sophisticated process generating renewable energy. GFS Tanks provide robust containment for anaerobic digestion, with corrosion resistance and modular construction enabling fast installation. The USR Process achieves high removal efficiency while converting organic pollutants into valuable biogas. Through comprehensive EPC services, Center Enamel delivers complete one-stop solutions for palm oil mills across Sumatra, Kalimantan, and Sulawesi, ensuring environmental compliance and sustainable energy recovery.