In the heart of China’s Xinjiang region, a groundbreaking solution to a longstanding problem in power plant operations is emerging from the labs of Zheneng Aksu Thermal-Power Co., Ltd. The challenge? Managing the complex and fluctuating water quality of wet desulfurization wastewater, a byproduct of coal-fired power generation. The solution? A cutting-edge zero-discharge advanced treatment control system, developed by lead author Bo Zhang and his team.
Wet desulfurization is a critical process in power plants, removing sulfur dioxide from exhaust gases to reduce air pollution. However, the wastewater generated is notoriously difficult to treat due to its fluctuating water quality. This variability has historically made it challenging to achieve zero liquid discharge (ZLD), a goal that minimizes environmental impact and conserves water resources.
Zhang’s system, detailed in a recent study published in ‘Desalination and Water Treatment’ (translated from Chinese as ‘Desalination and Water Purification’), tackles this issue head-on. The process begins with a pretreatment and softening subsystem, where sodium hypochlorite, lime, and sodium carbonate work together to soften the hardness of calcium and magnesium in the wastewater. “This step is crucial,” Zhang explains, “as it prepares the wastewater for the subsequent membrane concentration process.”
The softened wastewater then enters a membrane concentration subsystem, utilizing forward osmosis to reduce the volume of wastewater. The concentrated wastewater is directed into a flue evaporation crystallization treatment subsystem, where residual heat from flue gas separates salt from the water. The salt precipitate is recycled, and the water is evaporated, achieving zero liquid discharge.
But what sets this system apart is its adaptive intelligence. A fuzzy neural network water quality controller continuously monitors and adjusts operating parameters in real-time, ensuring the system can handle the ever-changing water quality. “This intelligent adjustment is key to maintaining the system’s efficiency and effectiveness,” Zhang notes.
The commercial implications for the energy sector are significant. Power plants can now achieve zero liquid discharge more efficiently and cost-effectively, reducing their environmental footprint and potentially lowering operational costs. Moreover, the system’s adaptability to water quality fluctuations means it can be applied across various power plants, regardless of their specific wastewater challenges.
This research opens up exciting possibilities for the future. As power plants worldwide strive to meet increasingly stringent environmental regulations, systems like Zhang’s could become standard practice. Furthermore, the adaptive control system could inspire similar innovations in other industries grappling with complex wastewater treatment challenges. The journey towards sustainable power generation just got a significant boost, thanks to the pioneering work of Bo Zhang and his team at Zheneng Aksu Thermal-Power Co., Ltd.
