SINOKLE Homogeneous and Heterogeneous Multi-Stage Catalytic Oxidation Technology: Application and Evaluation in Wastewater Treatment
Against the backdrop of rapid industrial development, industrial wastewater is becoming ever more complex, with refractory organics, high salinity and high organic loading standing out as major challenges. Conventional treatment processes face low catalytic efficiency, incomplete pollutant degradation, rapid catalyst deactivation and high operating costs. By integrating a homogeneous catalyst with a highly efficient, fast hydroxyl radical (-OH) generation technique and a heterogeneous catalyst built on the synthesis of multiple active metal oxides, high-porosity microporous forming, and hydrophilic modification for anti-fouling and anti-clogging, SINOKLE has developed a homogeneous-heterogeneous multi-stage catalytic oxidation technology. With the distinctive advantage of synergistic catalysis, it demonstrates remarkable competitiveness in wastewater treatment and offers an efficient solution for advanced industrial wastewater treatment. Through the synergy of homogeneous and heterogeneous catalysis, the technology achieves breakthroughs in the efficiency of reactive species generation, the depth of pollutant degradation and process stability, effectively overcoming the technical bottlenecks of conventional catalytic oxidation processes.
The series of ozone catalysts developed by SINOKLE
I. Core technical advantages: the distinctive features of synergistic homogeneous and heterogeneous catalysis
The homogeneous-heterogeneous multi-stage catalytic oxidation technology integrates the core strengths of both catalyst types into a synergistically enhanced catalytic system, laying the foundation for upgrading wastewater treatment processes:
1. Efficient generation of reactive species: The homogeneous catalyst, relying on a highly efficient and fast hydroxyl radical (-OH) generation technique, rapidly produces large quantities of highly active hydroxyl radicals in the reaction system, achieving fast initial oxidation of pollutants. The heterogeneous catalyst, by synthesizing multiple active metal oxides, further catalyses the generation of hydroxyl radicals, superoxide radicals and other reactive species through valence-state transitions of metal ions, creating a synergistic effect with the species produced by homogeneous catalysis and greatly enhancing the oxidizing capacity of the reaction system.
2. Sufficient reaction interface: The heterogeneous catalyst adopts high-porosity microporous forming technology, building a rich microporous structure that markedly increases the specific surface area per unit volume. This not only provides stable interfacial support for the reaction between the homogeneous catalyst and pollutants, but also extends the contact time between pollutants and reactive species, solving the core problems of insufficient reaction interface and low mass-transfer efficiency in conventional catalytic processes.
3. Strong anti-fouling performance and stability: Through hydrophilic modification for anti-fouling and anti-clogging, the heterogeneous catalyst greatly improves the hydrophilicity of its surface, reducing the adsorption, attachment and scaling of pollutants on the catalyst surface and effectively preventing catalyst deactivation. At the same time, the synergy between homogeneous and heterogeneous catalysis lowers the load on either catalyst alone; the two protect each other, extending the stable operating cycle of the overall catalytic system and ensuring the continuity and completeness of the reaction.
4. Flexible regulation of catalytic performance: The technology can flexibly adjust the dosage of the homogeneous catalyst and the active metal oxide ratio and pore-structure parameters of the heterogeneous catalyst according to the characteristics of the wastewater, enabling customized optimisation of the catalytic system to suit the degradation requirements of different pollutants. Compared with a single catalytic technology, it offers far greater process adaptability.
II. Multi-dimensional positive effects on wastewater treatment processes
1. Enhanced removal of refractory organics and greater treatment depth
For refractory organic wastewater from the pharmaceutical, petrochemical and printing and dyeing industries, the homogeneous-heterogeneous multi-stage catalytic oxidation technology strengthens treatment through synergistic catalysis: on the one hand, the hydroxyl radicals rapidly generated by the homogeneous catalyst quickly attack the molecular structure of pollutants, breaking their stable chemical bonds and decomposing large-molecule refractory organics into small-molecule, readily biodegradable substances; on the other hand, the active metal oxides and high-porosity structure of the heterogeneous catalyst work together to deeply oxidise and decompose the small-molecule intermediates, ultimately converting them into harmless substances such as carbon dioxide and water, thereby avoiding the increased toxicity caused by the accumulation of intermediates.
2. Adaptation to high-salinity, high-load water quality and expanded process applicability
The high-salinity environment in industrial wastewater often suppresses the performance of conventional catalytic processes, whereas the homogeneous-heterogeneous multi-stage catalytic oxidation technology has exceptionally strong water-quality adaptability:
For high-salinity wastewater, the active metal oxides of the heterogeneous catalyst work in synergy with the homogeneous catalyst to effectively overcome the inhibition of the catalytic reaction by salt ions. The reactive species can still maintain stable oxidation activity in a high-salinity environment, rapidly decomposing chlorinated organics and other refractory pollutants, and can sustain stable treatment performance after several days of continuous operation, with catalytic activity decay far lower than that of conventional single-catalyst processes.
For wastewater with a high organic load, the homogeneous catalyst's rapid generation of reactive species quickly reduces the pollutant load, while the high-porosity structure of the heterogeneous catalyst ensures efficient subsequent deep oxidation. Compared with conventional processes, the introduction of this technology raises the COD removal rate from 42% to 88% and the benzene-series removal rate from 51% to 98%, greatly reducing the pollutant load and easing the burden on downstream treatment units.
3. Lower operating energy consumption and cost, and improved process economics
Conventional catalytic oxidation processes rely on single homogeneous catalysis, which entails high catalyst consumption and difficult recovery, or on heterogeneous catalysis, which suffers from low efficiency and high energy consumption. The homogeneous-heterogeneous multi-stage catalytic oxidation technology, through synergistic action, achieves a dual optimisation of energy consumption and catalyst consumption.
The efficient hydroxyl generation capacity of the homogeneous catalyst reduces the dosage of oxidant, while the high catalytic activity and stability of the heterogeneous catalyst lower the proportion of homogeneous catalyst required, cutting overall oxidant consumption by more than 50%. At the same time, the anti-fouling and anti-clogging properties of the heterogeneous catalyst extend its service life and reduce catalyst replacement frequency. Together with the efficient utilisation of the homogeneous catalyst, this substantially lowers the operating cost of wastewater treatment and improves the economic feasibility of the process.
4. Ensured process stability and a longer operating cycle
The synergistic catalytic system of the homogeneous-heterogeneous multi-stage catalytic oxidation technology is little affected by fluctuations in water quality. The hydrophilic modification of the heterogeneous catalyst effectively prevents clogging and scaling of equipment and catalyst, reducing maintenance frequency. In addition, the technology does not produce secondary pollution such as metal leaching, meeting the heavy metal discharge standard GB 8978-1996. Compared with conventional catalytic processes, its operational stability is markedly improved, and the service life of the heterogeneous catalyst can be extended to more than 6 years (against an industry average of 2-3 years), greatly reducing the extra costs arising from process start-stop and equipment maintenance.
The homogeneous-heterogeneous multi-stage catalytic oxidation technology independently developed by SINOKLE, with its core advantages of efficient reactive species generation, sufficient reaction interface, strong anti-fouling stability and flexible regulation of catalytic performance, comprehensively optimises wastewater treatment processes across the dimensions of pollutant removal depth, process applicability, operating economics and stability. The technology not only effectively overcomes the treatment difficulties of industrial wastewater with refractory organics, high salinity and high load, but also greatly reduces treatment energy consumption and cost through synergistic catalysis. It is in line with the trend of green and environmentally friendly development and has broad prospects for industrial application.
