(1) Biological nano-film dust suppression technology has been included in the *Compendium of Advanced Technologies for Air Pollution Prevention and Control* issued by the Ministry of Science and Technology and the Ministry of Environmental Protection.
Biological nano-film is a double-layer ionized film with an interlayer spacing at the nanometer scale; it maximizes the spreadability of water molecules and possesses strong charge-adsorption properties. When sprayed onto the surface of materials, the film attracts and aggregates fine dust particles into larger clumps, causing them to settle due to increased weight.
(2) Cloud-mist dust suppression technology has been included in the *Compendium of Advanced Technologies for Air Pollution Prevention and Control* issued by the Ministry of Science and Technology and the Ministry of Environmental Protection.
This technology utilizes high-pressure ionic atomization and ultrasonic atomization to generate ultra-fine "dry fog" with droplet sizes ranging from 1 μm to 100 μm. These ultra-fine, dense droplets maximize the contact area with dust particles; collisions and subsequent coagulation form larger, heavier agglomerates that eventually settle naturally, thereby eliminating the dust.
(3) Wet dust collection technology has been included in the *Compendium of Advanced Technologies for Air Pollution Prevention and Control* issued by the Ministry of Science and Technology and the Ministry of Environmental Protection.
Wet dust collection technology draws in dust-laden air via a pressure drop and removes dust through the combined effects of centrifugal force and the mixing of water with the dust-laden gas stream. Key design features, such as a unique impeller, enable higher dust removal efficiency.
(4) Electrostatic dust removal technology has reached a stage of mature application, yet emission concentrations struggle to meet new control standards.
Electrostatic dust removal technology in my country has matured, with its primary technical capabilities ranking among the best internationally.
This technology is widely and maturely applied in areas such as high-temperature flue gas treatment at thermal power plants. However, due to inherent limitations in the dust removal mechanism, it is difficult to significantly improve efficiency further; newly installed systems generally limit emission concentrations to around 100 mg/m³. Furthermore, efficiency is highly sensitive to fluctuations in dust resistivity. In actual operation, uncertainties regarding the fuel used often cause flue gas parameters to deviate from design specifications, frequently resulting in emission concentrations that far exceed the designed control limits. As national requirements for flue gas pollution control become increasingly stringent-particularly regarding the emission of fine particulate matter-electrostatic precipitation technology faces significant challenges.
(5) Bag-type dust removal technology is undergoing rapid development.
Compared to electrostatic precipitation, bag-type dust removal technology had a later start in China. However, through the introduction, assimilation, and adaptation of foreign technologies, my country has made substantial progress in this field. Bag-type dust collector technologies have become increasingly advanced, refined, and diverse; the supply chains for filter media, dust-cleaning mechanisms, and accessories have achieved industrial scale; and the performance of certain bag-type dust removal equipment now rivals the best in the world. Dust-laden exhaust gas treated by bag-type filtration systems can achieve emission concentrations as low as 5 mg/m³, while investment and operating/maintenance costs have steadily decreased and filter bag lifespans have extended. Driven by increasingly strict national standards for flue gas pollution control, bag-type dust removal technology is seeing widespread adoption and is currently in a phase of rapid growth.
(6) "Electrostatic-to-Bag" conversion and hybrid electrostatic-bag technologies are gaining traction.
As national requirements for industrial flue gas pollution control tighten, electrostatic precipitation technology faces severe challenges. Some enterprises previously using electrostatic precipitators have been forced to retrofit their systems to bag-type dust collectors because they could not meet emission standards-a process referred to as "electrostatic-to-bag" conversion. Meanwhile, given the significant prior investment in existing electrostatic precipitators for high-temperature industrial flue gas, some domestic manufacturers are employing "hybrid electrostatic-bag dust removal" technology. This approach involves retrofitting the downstream section of existing electrostatic precipitators with bag-type dust collectors, effectively transforming the system from a pure electrostatic precipitator into a hybrid electrostatic-bag unit.
