From Waste to Resource: Center Enamel's USR Process in Aquaculture Wastewater Projects

In today’s era of global food demand and sustainability, aquaculture—often referred to as the “blue revolution”—has taken center stage as one of the fastest-growing sectors in the food industry. However, behind its rapid expansion lies a critical environmental challenge: managing and treating aquaculture wastewater. This wastewater, often laden with high concentrations of organic matter, nitrogen, phosphorus, and suspended solids, can cause environmental degradation if left untreated.

To address this pressing issue, Shijiazhuang Zhengzhong Technology Co., Ltd (Center Enamel), a renowned leader in industrial and municipal wastewater solutions, has introduced an innovative approach to aquaculture effluent treatment—the Upflow Sludge Reactor (USR) process. With decades of technical experience and a solid track record in wastewater treatment system manufacturing, Center Enamel provides a powerful and efficient method for treating aquaculture wastewater, transforming waste into valuable resources.

The Growing Need for Advanced Aquaculture Wastewater Solutions

Aquaculture wastewater poses a unique treatment challenge due to its complex composition. Effluents from fish farms, shrimp ponds, and hatcheries typically contain:

High levels of ammonia nitrogen (NH₃-N) and total nitrogen (TN) from fish excretion and unconsumed feed.

Elevated biological oxygen demand (BOD) and chemical oxygen demand (COD) due to organic waste from feces and feed residues.

Suspended solids (TSS) resulting from uneaten feed and biological growth.

Pathogens and antibiotics from disease prevention practices.

If discharged untreated, these pollutants can lead to severe environmental problems such as eutrophication, algal blooms, and the destruction of aquatic habitats. Thus, it becomes essential for aquaculture operations to adopt sustainable, efficient wastewater treatment solutions to comply with environmental regulations and ensure long-term operational viability.

What is the USR Process?

The USR (Upflow Sludge Reactor) process is a high-rate anaerobic treatment technology designed to handle wastewater with high organic content. It relies on a dense bed of anaerobic sludge microorganisms that digest organic matter in an oxygen-free environment. Wastewater flows upward through this sludge blanket, and during the process, organic pollutants are broken down, producing biogas (primarily methane and carbon dioxide) as a by-product.

Key Features of the USR Process:

Compact reactor design with high sludge retention efficiency.
Low energy consumption, thanks to the anaerobic nature of the process.
High volumetric loading capacity, making it ideal for high-strength aquaculture wastewater.
Biogas recovery, providing potential energy reuse.
Reduced sludge production, minimizing downstream handling and disposal costs.

Advantages of Using the USR Process in Aquaculture Wastewater Treatment

1. Effective Removal of Organic Pollutants

The USR process efficiently reduces COD and BOD concentrations. By creating an optimal environment for anaerobic microbes, the reactor achieves high treatment performance, even with fluctuating influent concentrations.

2. Efficient Ammonia and Nitrogen Reduction

While traditional anaerobic systems struggle with nitrogen removal, Center Enamel’s integrated USR system includes post-aeration or anoxic/oxic (A/O) processes to target ammonia and total nitrogen effectively. This makes it suitable for stricter discharge standards.

3. Energy Recovery Through Biogas Production

One of the biggest benefits of the USR process is the generation of biogas during the digestion of organic matter. This methane-rich biogas can be captured and used for onsite heating, electricity generation, or even fuel substitution, lowering overall energy costs.

4. Compact Footprint and Scalable Design

The USR reactor's vertical and modular design means it takes up less space than conventional aerobic systems. This compact footprint is particularly advantageous for coastal or land-constrained aquaculture sites.

5. Low Sludge Yield

Compared to aerobic processes, the USR reactor generates significantly less excess sludge, reducing sludge management costs and simplifying post-treatment.

6. Corrosion-Resistant, Durable Construction

Center Enamel manufactures its USR reactors with glass-fused-to-steel tanks or epoxy-coated tanks, both offering excellent corrosion resistance, long service life, and easy cleaning—ideal for the challenging conditions of aquaculture wastewater.

How Center Enamel Customizes USR Systems for Aquaculture Projects

Center Enamel understands that no two aquaculture operations are the same. Whether it's a small inland tilapia farm or a large coastal shrimp production complex, wastewater characteristics vary based on species, feed practices, and water exchange rates. Hence, the company offers custom-engineered solutions based on site-specific needs.

Project Design Considerations:

Influent characteristics (COD, BOD, NH₃-N, TSS)
Daily flow volume
Discharge requirements
Availability of land and energy
Integration with reuse systems or recirculating aquaculture systems (RAS)

Using advanced process simulation tools and pilot testing data, Center Enamel engineers optimize the reactor configuration, hydraulic retention time (HRT), sludge retention time (SRT), and biogas handling system.

Components of the USR System:

Anaerobic reactor (USR tank)
Primary settling tank
Gas-liquid-solid separator (three-phase separator)
Biogas collection dome
Optional secondary treatment (e.g., SBR, A/O systems)
Sludge dewatering and drying units
SCADA-based control system for automation and remote monitoring

Why Center Enamel Leads in USR Reactor Solutions

With more than 30 years of experience, Center Enamel has become a globally recognized manufacturer of USR reactors and wastewater treatment tanks. The company serves over 100 countries, offering:

In-house R&D for advanced anaerobic reactor technologies.
Factory-produced tanks using international quality standards (ISO, NSF, AWWA).
On-site commissioning, training, and after-sales support.
Certifications and compliance with environmental regulations in multiple regions.
Custom coatings for challenging wastewater conditions.

Whether it's for aquaculture, food processing, municipal sewage, or industrial wastewater, Center Enamel continues to be a preferred supplier for advanced anaerobic treatment systems globally.

Center Enamel’s Vision for the Future of Aquaculture Wastewater Treatment

Center Enamel is committed to pushing the boundaries of what's possible in wastewater treatment. In the coming years, the company aims to further enhance its USR technology by integrating:

AI-powered monitoring and predictive maintenance tools.
Membrane bioreactor (MBR) polishing steps for near-zero liquid discharge.
Modular containerized USR systems for remote and decentralized aquaculture farms.
Enhanced nutrient recovery techniques to extract phosphorus and nitrogen for use as agricultural fertilizers.

Additionally, Center Enamel is exploring carbon credits and green finance programs that allow aquaculture businesses to gain financial benefits for installing sustainable wastewater treatment systems.

By combining innovation, reliability, and environmental responsibility, Center Enamel’s USR process offers a transformative solution for a sustainable aquaculture future.

As the aquaculture industry continues to expand, so does the urgency of implementing effective wastewater treatment solutions. Center Enamel's USR process addresses this need with cutting-edge technology, delivering superior performance, sustainability, and economic viability.

By turning aquaculture wastewater from a challenge into an opportunity—producing energy, reducing pollution, and creating value—Center Enamel exemplifies how engineering excellence and environmental stewardship can go hand in hand.

For aquaculture operations seeking reliable, scalable, and eco-friendly wastewater treatment, Center Enamel’s USR systems stand as a proven and future-ready choice.