Anaerobic Technologies in Focus: The IC Process and the Policies Reshaping Industrial Wastewater

Global industrial wastewater policy is escalating from "compliance discharge" toward mandatory "resource recovery" and "zero liquid discharge." The EU, through its Circular Economy Action Plan, requires member states to increase industrial wastewater reuse rates and extends carbon footprint accounting to the full life cycle of wastewater treatment. China continuously updates and tightens industrial water pollutant discharge standards, with increasingly stringent limits on total nitrogen, total phosphorus, and characteristic pollutants for industries such as chemicals, pharmaceuticals, and printing and dyeing.

Some water-scarce regions and highly polluting industries are mandated to adopt zero or near-zero liquid discharge technologies. Germany has established a differentiated pretreatment technical standard system by industry, requiring industrial wastewater to meet specific quality requirements before discharge into municipal wastewater treatment plants, implementing strict source control. Against this tightening backdrop, advanced Anaerobic Technologies have moved from optional efficiency measures to core compliance strategy-and among them, the IC Process stands out.

Defining the IC Process Within Modern Anaerobic Technologies

IC, or Internal Circulation Anaerobic Reactor, is the third-generation high-efficiency anaerobic treatment technology built upon UASB. Its core innovation is the built-in gas-lift internal circulation system, enabling autonomous wastewater recirculation without external return pumps. The reactor features a dual-zone configuration-a lower main reaction zone and an upper polishing zone. Biogas gas-lift creates hydraulic internal circulation, significantly increasing upflow velocity and enhancing sludge-wastewater contact. With extremely high compactness, it is specifically designed for high-concentration, high-flow industrial organic wastewater, combining high efficiency, energy savings, and minimal footprint-the core process for modern industrial high-strength wastewater treatment. As regulatory pressure grows, the IC Process has become the reference point against which other Anaerobic Technologies are measured.

Flexible GFS Tank Construction for Anaerobic Systems

Delivering these anaerobic processes requires containment built for speed and adaptability. GFS tanks are assembled on-site from prefabricated panels, with short construction periods and support for expansion, relocation, and reuse-advantages distinctly different from immovable concrete tanks. Concrete tank pouring requires formwork, rebar tying, pouring, and long curing periods, with a single tank construction taking months. Rain, snow, and low temperatures force work stoppages and delays. Once poured, they are permanent fixed structures that cannot be dismantled, expanded, or relocated-project relocation means complete abandonment.

GFS Tanks vs. Concrete Tanks

GFS tank panels are all factory-prefabricated, transported to site, and directly assembled with simple procedures. Construction can proceed even in low-temperature, light-rain conditions, with installation time only one-third that of concrete tanks-construction schedules are controllable. For expansion, additional steel panels can be installed to increase volume; for plant relocation, tanks can be fully disassembled with panels transported to new sites for reassembly and reuse, significantly reducing material and construction costs for new construction and reconstruction. This is ideally suited for short-term environmental projects, phased expansion projects, and relocated construction projects-and it pairs naturally with the compact footprint of the IC Process.

Papermaking Wastewater: Sources and Scale

Papermaking wastewater originates from the entire production chain of pulp and papermaking, covering chemical pulping (alkaline and sulfate processes), mechanical pulping, recycled fiber pulping, and papermaking-the largest volume and highest suspended solids industrial wastewater in the light industry sector. Key pollution stages include raw material preparation (chipping and washing of wood or grass), cooking (the core chemical pulping stage producing high-concentration black liquor), washing and screening, bleaching (multistage bleaching discharges), papermaking (sheet forming, pressing, and drying discharges), and white water recirculation (wire section and press section water). Cooking black liquor is the core pollution source with extremely high COD and strong alkalinity. White water has large volume but low pollutant concentration and can be recycled. Recycled fiber pulping wastewater contains inks, adhesives, and fillers requiring deinking treatment. Large paper mills discharge tens of thousands of tons daily-one of the largest volume industrial wastewater sectors, and a prime candidate for Anaerobic Technologies such as the IC Process.

Three Decades of Anaerobic Technologies and EPC Delivery

Center Enamel has been deeply engaged in the environmental bolted storage equipment field for over 30 years. Starting with proprietary enamel anti-corrosion material technology, the company has gradually completed the full-industry-chain upgrade from a single tank manufacturer to a comprehensive environmental EPC service provider. Throughout its 30+ year history, the company has been recognized as a National High-Tech Enterprise, National Specialized and Sophisticated "Little Giant," Manufacturing Single Champion, and Provincial Green Factory. It has successfully delivered over 30,000 environmental projects globally, establishing itself as a leading enterprise in the global GFS tank storage industry. The company has fully integrated the entire chain from enamel frit R&D and intelligent environmental equipment manufacturing to EPC project contracting-every business breakthrough achieved through proprietary core anti-corrosion technology, and every anaerobic installation backed by that same engineering depth.

The R&D Team Behind Every Anaerobic Installation

Center Enamel has built a full-chain professional team covering R&D, design, marketing, installation, and after-sales. The R&D team is led by national-level materials technology experts, specializing in enamel frit and tank anti-corrosion core technologies. External senior environmental engineering and mechanical structure engineers are retained to strengthen R&D capabilities, focusing on anti-corrosion coating formulations, specialty corrosion-resistant tanks, and anaerobic supporting integrated equipment-continuously breaking through industry technological barriers. The team operates through proprietary laboratories with external university research collaboration, conducting year-round new material and new process durability pilot testing and long-term corrosion simulation testing. Specialized enamel formulations are iteratively developed for extreme conditions such as high-salinity wastewater, strong acid or alkali POME, and high-organic livestock manure-providing core technical support for the company's annual new invention and utility patents and building a proprietary material technology barrier that protects long-life anaerobic assets.

Center Enamel at a Glance

Economical Roofing for Water Storage Tanks

Rounding out the containment system, the Aluminum Alloy Trough Deck Roof is a cost-effective tank cover solution for clean water and wastewater storage, primarily designed for drinking water, production wastewater, and firewater reserve tanks, balancing practicality and cost advantages. The main body is integrally formed from anti-corrosion aluminum alloy plates, paired with aluminum support trusses. Its lightweight design imposes less load on the tank foundation, reducing civil construction investment.

A naturally formed dense oxide protective layer on the surface resists rain and mild wastewater corrosion, withstands outdoor exposure, and effectively blocks wind, rain, insects, fallen leaves, and odor volatilization, protecting water quality by preventing dust and debris from falling in and causing secondary contamination. The flat roof structure is neat and orderly, allowing installation of maintenance walkways, guardrails, vents, and level monitoring ports on top, facilitating daily inspection and equipment maintenance. The simple sealing structure enables straightforward installation with short construction timelines and virtually eliminates the need for anti-corrosion painting maintenance, resulting in extremely low operational costs. It is suitable for various small, medium, and large atmospheric pressure water storage tanks, and has been widely implemented in waterworks clear water tanks, industrial circulating water tanks, park firewater tanks, and domestic wastewater temporary storage facilities-highly compatible with water storage applications that do not require biogas collection or high-pressure sealing.

Frequently Asked Questions

What makes the IC Process different from UASB?
The IC Process adds a built-in gas-lift internal circulation system, creating a dual-zone reactor with higher upflow velocity, better sludge contact, and a much smaller footprint.

Which industries benefit most from Anaerobic Technologies?
High-strength streams from papermaking, brewing, starch, pharmaceutical, and chemical production see the strongest returns in COD removal and biogas recovery.

How long has Center Enamel delivered these systems?
Over 30 years, with 30,000+ projects completed and proprietary enamel technology protecting tank corrosion resistance.

Tell us your flow rate, COD load, and discharge targets, and our engineers will match the right Anaerobic Technologies to your site. Connect with Center Enamel today to scope an IC Process solution built around your exact wastewater profile.