Catalytic oxidation is an advanced oxidation process that involves the use of photocatalysts to initiate oxidation reactions under light. The method uses the power of light-activated catalysts to generate highly reactive oxygen species, such as hydroxyl radicals (*OH), which then oxidize and decompose organic and inorganic pollutants in water and air. Photocatalytic processes typically rely on semiconductors because the catalysts generate electron-hole pairs when exposed to ultraviolet (UV) or visible light. These pairs participate in redox reactions, leading to the production of reactive oxygen species that ultimately cause the pollutants to gradually fragment. Photocatalytic oxidation is used in environmental applications, including water and wastewater treatment, air purification, and remediation of various pollutants, and the technology is valued for its ability to address persistent and recalcitrant pollutants and its potential for sustainable and energy-efficient treatment processes.
1. The first step is to prepare the photocatalyst in nanoparticle or film form.
2. The next step involves fixing the photocatalyst and then preparing the reactor system that includes the wastewater and photocatalyst.
3. Once the reactor system is set up, the photocatalyst is exposed to a specific light source.
Once exposed to light, the photocatalyst absorbs photons, resulting in the excitation of electrons from the valence band to the conduction band.
Absorbed photons generate electron-hole pairs. Electrons move to the conduction band, while holes remain in the valence band.
Electrons in the conduction band and holes in the valence band then undergo redox reactions with water and oxygen in the surrounding environment.
Oxygen molecules are reduced to form superoxide radicals (O2) and hydroxyl radicals (OH) by reacting with photogenerated electrons and holes.
These photoactivated chemical reactions are characterized by free radical mechanisms, initiated by the reaction of photons of appropriate energy levels with molecules of chemical species present in solution, independent of the catalyst. In this case, electrons of the semiconductor crystal structure form electron-vacancy pairs under excitation. The charged carriers interact with different compounds (electron donors and acceptors) adsorbed on the catalyst surface to generate free radicals, which react with the pollutants in the adsorbed state. The surface area and number of active sites provided by the catalyst for the adsorption of pollutants (and therefore the properties of the catalyst) play an important role in determining the overall degradation rate. Titanium dioxide has the best photocatalytic performance and the greatest quantum yield.
Highly reactive oxygen species, especially hydroxyl radicals, attack and oxidize organic and inorganic pollutants in wastewater.
TiO2 +h TiOe-+h+
OH- +h+OH H2O + h+ OH+ H+
OH+ Organic compounds CO2+ H2O
Shandong Longantai Environmental Protection Sci-tech Co., Ltd., established in 2005, focuses on energy-saving and compliant treatment of industrial wastewater, wastewater recycling and reuse, and wastewater resource and energy recovery. The company provides high-value comprehensive solutions and key equipment. It integrates research and development, manufacturing, process design, project construction, and water services operation. Longantai has strong capabilities and a complete quality system in the R&D and manufacturing of water treatment catalysts, critical water treatment equipment, wastewater resource recovery equipment, and industrial energy recovery equipment.
Longantai company provides high-value-added comprehensive energy-saving and emission reduction solutions in major technological and engineering applications such as industrial wastewater, refractory wastewater, high-salinity wastewater, high-concentration wastewater treatment, energy-saving upgrades for wastewater treatment standards, wastewater recycling and reuse, and water quality improvement for rivers and lakes. These solutions effectively improve resource utilization, reduce enterprise costs, and contribute positively to green, low-carbon, and high-quality development.
Longantai places great emphasis on the role of research and development in its growth. The company currently holds over 50 invention patents, more than 10 utility model patents, 1 design patent, 1 first prize for provincial-level scientific and technological progress, and 1 first prize for scientific and technological progress from the China Environmental Protection Industry Association. Longantai has established industry-academia-research collaborations with several top domestic and international universities and research institutions. Over the years, the company has been recognized with numerous honors, including National High-Tech Enterprise, National "Little Giant" Enterprise for Specialized and New Technology, Provincial Gazelle Enterprise, Provincial Specialized and New Technology Enterprise, Provincial Manufacturing Champion, Provincial Innovative Small and Medium-Sized Enterprise, Hidden Champion Enterprise, Provincial "One Enterprise, One Technology" R&D Center, and Provincial Industrial Design Center.
Longantai is a leading domestic provider of water treatment solutions, a manufacturer of critical water treatment equipment, and a water services operator. The projects it has served have received extensive coverage from numerous mainstream media outlets, including China Environment News, Xinhua News, Phoenix News, Sina, and various provincial TV stations.
Longantai is a collaborative and open platform with a comprehensive innovation system, mature practical technologies, and advanced manufacturing expertise. It brings together a team of passionate, responsible, grateful, and ambitious professionals. As Longantai continues to grow, it is eager to collaborate sincerely with partners worldwide, working together to contribute to the protection of the environment and the pursuit of sustainable development for humanity. With the mission of "developing energy-efficient and resource-sustainable environmental technologies and equipment for our customers," Longantai strives to fulfill its dreams and responsibilities with gratitude. With humility and dedication, the company aims to work alongside friends from all sectors to safeguard our clear waters, blue skies, and peaceful, harmonious homeland.
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