Project Overview: The Qingshui Town Municipal Wastewater Treatment Plant is responsible for treating domestic sewage from approximately 50,000 residents in the town and surrounding areas, with a designed daily treatment capacity of 20,000 tons. The plant adopts the mainstream "A²/O (Anoxic-Aerobic-Anaerobic) + Secondary Settling Tank" process, and the resulting residual activated sludge is the key and challenging aspect of its treatment.

I. Challenges Faced: High Operating Costs and Complex Maintenance Dilemmas

Prior to this technical upgrade, the wastewater treatment plant used a traditional horizontal screw centrifuge for sludge dewatering. Although the centrifuge had a large processing capacity, after years of operation, its drawbacks became increasingly apparent, placing a heavy burden on the wastewater treatment plant's operation:

Stunning Energy Consumption and High Operating Costs: Horizontal screw centrifuges rely on ultra-high-speed rotation (typically above 3000 rpm) to generate centrifugal force, and their drive motors are extremely powerful, making them veritable "electricity guzzlers." Electricity costs for the sludge dewatering process account for a significant portion of the plant's total electricity bill, directly driving up the operating costs of public utilities.

Complex and expensive maintenance: Centrifuges are high-precision equipment. Wear and tear or damage to core components such as bearings and screw conveyors leads to complex repair processes that require specialized technicians. Spare parts and repair costs are extremely high, with a single major overhaul potentially costing tens or even hundreds of thousands of yuan.

Significant noise and vibration issues: High-speed rotation generates severe noise and vibration, not only deteriorating the working environment but also causing long-term damage to equipment foundations and plant structures. Separate soundproof rooms are typically required, increasing infrastructure costs.

High sensitivity to influent sludge concentration and poor stability: Centrifuge efficiency decreases when processing low-concentration sludge, and it is highly sensitive to fluctuations in influent sludge concentration. The sludge concentration in municipal wastewater treatment plants fluctuates, resulting in unstable moisture content in the centrifuge effluent, affecting the consistency of subsequent sludge treatment.

II. Solution: Introduction of Low-Energy, Easy-to-Maintain Screw Press Sludge Dewatering Machine

To fundamentally reduce operating costs (OPEX) and improve the stability of the treatment system, the Qingshui Town Wastewater Treatment Plant decided to upgrade its sludge dewatering system. After a comprehensive evaluation of various technologies, two screw press sludge dewatering machines were ultimately selected to replace the original horizontal screw centrifuge.

Key Reasons for Choosing the Screw Press:

Extreme Energy Saving: The screw press uses low-speed screw extrusion technology, with extremely low motor power (approximately 2.2kW per unit). Compared to centrifuges with tens of kilowatts, its energy consumption is only a fraction of the latter. This translates to significant electricity savings for municipal facilities operating year-round.

Extremely Simple Maintenance and Operation: The screw press has a simple structure with no high-speed rotating parts. Daily maintenance only requires routine checks and lubrication. Its unique self-cleaning structure virtually eliminates clogging, enabling 24-hour fully automatic continuous operation, greatly reducing the workload of operators and reliance on specialized skills.

Exceptional Environmental Compatibility: The equipment operates at low speeds with extremely low noise (<60 decibels) and minimal vibration, allowing for direct installation on upper floors without the need for special foundations or soundproof rooms, significantly improving the working environment. Furthermore, it consumes almost no flushing water, aligning with the green development concept of water and energy conservation.

Wide Concentration Adaptability: The screw press has a very wide range of requirements for influent sludge concentration (from 2000 mg/L to 50000 mg/L). Even with fluctuations in influent sludge concentration, it can operate stably and ensure sludge discharge efficiency, greatly enhancing the overall wastewater treatment system's resilience.

III. Results and Benefits: Significant Economic and Social Benefits

Since the screw press system was put into operation, the Qingshui Town Wastewater Treatment Plant has achieved breakthrough results in several aspects:

A Dramatic Reduction in Operating Costs:

Electricity Costs Reduced by Over 80%: According to meter readings, the electricity consumption of the sludge dewatering unit alone has decreased by more than 80%, saving the wastewater treatment plant over 200,000 yuan in electricity costs annually, demonstrating immediate economic benefits.

Significantly Reduced Maintenance Costs: The high costs of spare parts and professional repairs associated with centrifuges have been completely eliminated. The equipment operates stably with an extremely low failure rate, resulting in negligible annual maintenance costs.

Dual Improvement in Management Efficiency and Stability:

Achieving "Unmanned Operation": The fully automated operation mode frees operators from tedious equipment monitoring, allowing them to focus on more important process inspections and management, achieving both reduced manpower and increased efficiency.

Stable Sludge Output: Regardless of fluctuations in influent water quality, the moisture content of the final sludge cake remains consistently between 80% and 82%, facilitating subsequent sludge transportation and final disposal (such as delivery to landfills or incinerators).

Improved Working Environment and Corporate Image:

Noise pollution in the plant area has been completely eliminated, significantly improving the comfort of the working environment for employees. A quiet, clean, and automated wastewater treatment plant has also become a "window" for local environmental education and external presentation, enhancing the social image of public utilities.

IV. Conclusion

The successful renovation of the Qingshui Town Municipal Wastewater Treatment Plant demonstrates that the screw press sludge dewatering machine is an ideal technological path for modern municipal wastewater treatment, especially for small and medium-sized wastewater treatment plants, to improve efficiency and achieve refined operation. Through its revolutionary low energy consumption, low maintenance costs, high automation, and high stability, it precisely solves the long-standing operational pain points of traditional dewatering equipment (such as centrifuges) that have plagued the industry.

Against the backdrop of tightening fiscal budgets and increasingly stringent environmental requirements, choosing a screw press is not only a wise equipment investment but also a strategic move to be responsible for public resources and promote the development of municipal infrastructure towards a more economical, intelligent, and green direction.