Abstract
Sewage treatment equipment plays a crucial role in environmental protection and sustainable water resource management. With the increasing pressure of urbanization and industrialization, the demand for efficient, durable, and intelligent wastewater treatment systems has never been greater. This paper explores the key components and advanced technologies in modern sewage treatment equipment, analyzes common treatment processes such as A/O, A²/O, and oxidation ditches, and discusses corrosion protection and maintenance strategies to extend equipment lifespan. Furthermore, the integration of smart monitoring and resource recovery is highlighted as a pathway toward energy-efficient and eco-friendly wastewater management. By combining technological innovation with sustainable practices, sewage treatment equipment can significantly contribute to water recycling and environmental preservation.1. Introduction
As global water scarcity intensifies, effective wastewater treatment has become a cornerstone of environmental sustainability. Sewage treatment equipment serves as the backbone of wastewater management systems, transforming polluted water into reusable or safely dischargeable effluent. In countries facing rapid urban development, the demand for reliable and scalable treatment solutions continues to grow. Modern equipment must not only meet stringent discharge standards but also withstand harsh operating conditions, including chemical corrosion, mechanical stress, and biological fouling. This article provides a comprehensive overview of the design, function, and advancement of sewage treatment equipment, emphasizing both technical performance and long-term durability.2. Key Treatment Processes and Equipment
Several proven biological processes form the foundation of contemporary wastewater treatment, each requiring specialized equipment tailored to its operational needs.Anoxic/Oxic (A/O) Process: This process enhances organic pollutant degradation and offers basic denitrification and phosphorus removal capabilities. It utilizes a two-stage reactor system—anaerobic hydrolysis followed by aerobic treatment—improving the performance of activated sludge. Key equipment includes submersible mixers, fine bubble diffusers, and return sludge pumps.Anaerobic-Anoxic-Oxic (A²/O) Process: A more advanced configuration, A²/O provides simultaneous nitrogen and phosphorus removal. With pollutant removal efficiency reaching 90–95% for BOD₅ and SS, and over 70% for total nitrogen, this system is ideal for large- and medium-sized municipal wastewater plants. The process requires precise control of dissolved oxygen and sludge recirculation, necessitating intelligent control systems and high-efficiency aeration devices.Oxidation Ditch: Also known as a continuous loop reactor, the oxidation ditch is a modified activated sludge process. It features a circular channel with horizontal aerators that maintain dissolved oxygen levels and promote biomass contact. Advantages include stable operation, simple maintenance, and flexibility in handling variable loads. However, challenges such as sludge bulking and foam formation require monitoring and mitigation through automated sensors and skimming systems.Sequencing Batch Reactor (SBR) and CAST Process: These time-sequenced batch processes offer excellent nutrient removal in compact systems. They are particularly suitable for small to medium-scale applications. Equipment includes programmable logic controllers (PLCs),滗水器 (decanters), and intermittent aeration systems.3. Durability and Corrosion Protection
Sewage treatment equipment often operates in highly corrosive environments due to exposure to moisture, industrial gases (e.g., SO₂), and fluctuating pH levels. The resulting electrochemical corrosion can severely reduce the service life of steel structures and mechanical components.Effective protection strategies include:Thermal Spraying with Zinc: Applying a zinc coating via thermal spraying creates a sacrificial anode that protects underlying steel. When combined with a sealed organic topcoat, this method can extend equipment life to 15–30 years—significantly longer than conventional organic coatings (2–4 years).Physical Barrier Protection: Sealing porous zinc layers with epoxy or polyurethane coatings prevents moisture and ions from reaching the metal substrate, inhibiting corrosion cell formation.Use of Corrosion-Resistant Materials: Stainless steel, fiberglass-reinforced plastic (FRP), and engineered polymers are increasingly used in pumps, tanks, and piping to enhance longevity.4. Equipment Maintenance and Smart Monitoring
To ensure continuous and efficient operation, regular maintenance supported by intelligent monitoring is essential. Modern sewage treatment plants are integrating IoT-based sensors and SCADA systems to track parameters such as dissolved oxygen, pH, flow rate, and sludge level in real time. Predictive maintenance algorithms analyze equipment performance data to detect anomalies early, reducing downtime and repair costs. Remote diagnostics and automated alerts enable operators to respond promptly to potential failures.5. Toward Resource Recovery and Water Reuse
Beyond purification, advanced treatment equipment is now designed to recover valuable resources. Anaerobic digesters produce biogas (mainly methane) from sludge, which can be used for heat or electricity generation. Nutrients like nitrogen and phosphorus can be extracted and converted into fertilizers. Treated effluent, after tertiary filtration and disinfection, can be reused for irrigation, industrial cooling, or even groundwater recharge—closing the water loop and promoting a circular economy.6. Conclusion
Sewage treatment equipment is at the heart of sustainable water management. By integrating robust materials, advanced biological processes, and smart technologies, modern systems can achieve high efficiency, long service life, and low environmental impact. As global water challenges intensify, continued innovation in equipment design, corrosion protection, and resource recovery will be essential. Investing in durable, intelligent, and multifunctional treatment solutions not only protects ecosystems but also supports a more resilient and water-secure future.Keywords: sewage treatment, equipment, corrosion protection, A²/O process, oxidation ditch, water reuse, smart monitoring
