Integrated Biogas Plant Design with USR Process for POME Treatment and High-Solids Industrial Wastewater

The core challenges of industrial wastewater treatment center on the "three highs"-high difficulty, high cost, and high energy consumption. Wastewater from new energy, chemical, and pharmaceutical industries is complex in composition with numerous characteristic pollutants, and traditional treatment processes are difficult to remove effectively. Chinese companies have significant price advantages in the mid-to-low-end equipment segment. The industry also faces continuous technological upgrade pressure from increasingly stringent emission standards, as well as new requirements for digitalization and low-carbon transformation on operational refinement management capabilities.

Meeting these challenges requires process designs that are robust, low-maintenance, and tolerant of difficult wastewater conditions. The USR Process was developed specifically for this purpose-offering a simplified, clog-resistant anaerobic pathway for high-solids organic streams.

USR Reaction Process

High-solids organic wastewater, after simple pretreatment to remove large debris, is uniformly fed into the reactor through the bottom distribution system. The upward flow drives solid substrates and anaerobic sludge to slowly rise and thoroughly mix. In the sealed anaerobic environment, microorganisms sequentially hydrolyze/acidity and then methanogenically ferment, degrading macromolecular organic pollutants and generating biogas and treated water. Without complex separation structures, gentle hydraulic disturbance prevents clogging. The mixed liquor rises to the upper portion of the reactor where natural gas-liquid-solid separation occurs. Biogas is collected, effluent overflows, and solid sludge and unreacted substrate settle back to the lower reaction zone for continued reaction, with a small amount of aged sludge periodically discharged-continuous stable operation.

This process simplicity translates directly into reliability in the field, especially where influent quality fluctuates sharply. Palm oil mill effluent is the most demanding test case-and its extreme water quality profile explains why purpose-built POME Treatment is essential.

Palm Oil Mill Effluent Key Water Quality Characteristics

Prominent "five highs and one low"-high COD, high BOD, high oil and grease, high suspended solids, high temperature, low pH-pollution load far exceeding conventional industrial wastewater, one of the highest concentration wastewater categories in agricultural processing. Very high COD-combined wastewater 45,000-100,000 mg/L, oil separation wastewater peaking above 150,000 mg/L-dozens to hundreds of times higher than municipal wastewater. High BOD-25,000-65,000 mg/L, BOD/COD 0.5-0.6-excellent biodegradability with very high anaerobic digestion efficiency. High oil and grease-combined 2,000-8,000 mg/L, oil separation above 10,000 mg/L-oil readily adheres and scales on pipe/equipment surfaces, affecting heat transfer and causing blockages.

High suspended solids-10,000-20,000 mg/L-primarily fruit pulp residues, fruit shell fibers, colloidal proteins-readily settling and clogging equipment. Moderate total nitrogen-ammonia 500-1,500 mg/L with abundant organic nitrogen but low inorganic nitrogen. High total phosphorus-200-800 mg/L. Very low pH-raw water pH 4.0-5.0-requires alkali neutralization before biological treatment. High temperature-discharge 60−80∘C60−80∘C — requires cooling to 35−38∘C35−38∘C before anaerobic digestion. Water quality varies significantly with palm oil mill processing seasons-peak production during fresh fruit bunch harvest season (March-September annually) with full-load operation, wastewater volume and organic concentration at maximum; off-season (October-February) with reduced or halted production-water quality fluctuations require high shock load resistance.

This extreme and seasonally variable profile is exactly what a properly engineered Biogas Plant Design must accommodate-combining robust anaerobic reactors, corrosion-resistant tanks, and shock-tolerant process control.

Ghana Municipal Domestic Wastewater Treatment Project

Completed installation in 2021, treating 1,800m3/day1,800m3/day of municipal wastewater using UBF anaerobic +A2/O+A2/O nitrogen/phosphorus removal mature processes. Equipped with multiple Center Enamel GFS tanks including 1 UBF anaerobic reactor, 1 secondary clarifier, and 2 internal/external double-layer A2/OA2/O biological tanks. Influent has high COD, BOD, suspended solids, and nitrogen/phosphorus concentrations-after full treatment, effluent parameters are significantly reduced with pH stable at 6.5-9.0, fully meeting local environmental discharge standards. Corrosion-resistant, conveniently assembled GFS tanks efficiently solve urban domestic wastewater pollution while balancing treatment effectiveness and O&M economics-a mature municipal wastewater case in Africa.

Delivering projects of this scale consistently depends on manufacturing capacity and quality control. Center Enamel's smart manufacturing base provides that foundation.

Center Enamel's Smart Manufacturing Base Scale

Center Enamel's core intelligent manufacturing base is located in Hebei Province, China, covering a total area of over 150,000m2150,000m2, with Phase I mature manufacturing facility and Phase II high-end environmental equipment industrial park-dual-base synergy ensures stable production capacity. The base includes dedicated R&D office buildings, proprietary material laboratories, and finished product testing centers, with full-process quality control systems meeting ISO, NSF, CE, and other international standards. The facility operates to green manufacturing standards, certified as a Provincial Green Factory-balancing efficient production with energy conservation and emission reduction. The company has 6 marketing service centers across China, establishing a nationwide production-sales network ensuring stable global order delivery. The base is adjacent to expressway networks and major logistics hubs, with complete container shipping capabilities-supporting simultaneous large-scale tank projects globally. The base employs over 500 staff, with multiple parallel automated production lines-facility scale and production capacity firmly placing it among the global top tier of GFS tank equipment manufacturers.

Manufacturing strength is complemented by full project integration. As a complete Biogas Plant Design and EPC provider, Center Enamel controls every stage from design through commissioning.

Full-Industry-Chain Integrated Delivery Capability

Center Enamel is the only company globally integrating proprietary enamel frit R&D, self-manufactured tanks, and EPC general contracting-full-process self-control from solution design, equipment production, cross-border logistics, overseas construction, to post-construction O&M-significantly reducing client coordination and time costs.

Not every tank application requires gas-tight sealing, however. For atmospheric water storage duties, Center Enamel offers a cost-effective alternative roof solution that complements its biogas-grade covers.

FRP Roof Cover Solution

FRP Roof is a general-purpose economical roof for atmospheric pressure storage tanks without air-tightness requirements, suitable for drinking water storage, agricultural irrigation water, firewater reserve, and general production wastewater temporary storage. It is available in two styles: flat and dome, allowing flexible selection based on tank specifications and site aesthetic requirements. The roof is integrally molded from resin and fiberglass, lightweight, with natural water resistance and mild acid/alkali corrosion resistance. It will not rust or rot in long-term humid environments, eliminating the frequent anti-corrosion maintenance required for metal roofs.

The dome style features excellent drainage performance due to its curved structure, resisting water accumulation, dust buildup, snow load, and strong winds. The flat style facilitates the installation of maintenance walkways, level gauges, and vents on top, making inspection and operation convenient. The product is fully insulated with no risk of galvanic corrosion, will not contaminate drinking water quality, and meets environmental standards for domestic water storage.

The modular design with low individual component weight allows for simple on-site hoisting and assembly, offering high construction efficiency and affordable procurement and installation costs. It is only suitable for atmospheric pressure water storage tanks without biogas collection or pressurization requirements, and is not recommended for anaerobic fermentation gas-producing conditions. It is widely used in rural agricultural water storage tanks, industrial park firewater tanks, waterworks buffer tanks, and small to medium-sized domestic wastewater temporary storage facilities, making it a cost-effective general-purpose roof choice for conventional water storage applications.

Frequently Asked Questions

What should a Biogas Plant Design include for high-solids wastewater?

A robust design includes pretreatment for debris and oil removal, temperature and pH adjustment, a clog-resistant anaerobic reactor such as the USR Process, gas collection with desulfurization, and corrosion-resistant tanks. Center Enamel integrates all these into a single EPC delivery.

Why is the USR Process preferred for POME Treatment?

POME contains high suspended solids, oil, and fiber that clog conventional reactors. The USR Process removes complex separators, relies on upflow hydraulics, tolerates high solids, and requires no granular sludge cultivation-ensuring stable operation and fast start-up.

How does Center Enamel support biogas projects after delivery?

Center Enamel provides 24/7 O&M support, remote fault diagnosis, process parameter tuning, on-site inspection and refurbishment, plus expert support for anaerobic commissioning and biogas upgrading. This full-lifecycle service protects long-term biogas yield and equipment reliability.