Ozone Catalytic Oxidation for Potassium Dihydrogen Phosphate Wastewater
Potassium dihydrogen phosphate (monopotassium phosphate) is an important chemical raw material widely used in agriculture, food processing and pharmaceutical manufacturing. The wastewater generated during its production, however, contains high concentrations of organic matter (COD 300-1000 mg/L) and inorganic salts (salt content can reach hundreds of grams per litre), far exceeding national discharge standards. Discharged without effective treatment it causes serious environmental pollution, leading to eutrophication, excessive algal growth and disruption of the aquatic ecosystem. In one 2019 survey, a river next to a potassium dihydrogen phosphate plant suffered a severe blue-green algae bloom, causing major losses to local fisheries.
Figure 1. Eutrophication caused by potassium dihydrogen phosphate leakage
Conventional physicochemical treatment produces about 0.5 tonnes of chemical sludge for every tonne of potassium dihydrogen phosphate wastewater treated, which increases downstream treatment difficulty and poses a potential risk to soil and water. Biological treatment, for its part, struggles with the high salt content, which is toxic to microorganisms, and suffers from slow reaction rates and poor tolerance of water-quality fluctuations. With global industrialisation accelerating, wastewater from potassium dihydrogen phosphate production now amounts to tens of millions of tonnes a year, making its treatment an increasingly prominent challenge for environmental protection and sustainable development.
Figure 2. Salt toxicity in potassium dihydrogen phosphate wastewater causing sludge bulking
Why Ozone Catalytic Oxidation
The development of SINOKLE's ozone catalytic oxidation technology mirrors the innovation trajectory of the water treatment field. Since ozone was first used in water treatment at the beginning of the twentieth century, the technology has evolved from basic application to advanced catalytic oxidation. Ozone is a strong oxidant with a redox potential of 2.07 V: it rapidly attacks organic pollutants and converts them into harmless small molecules. The hydroxyl radicals (·OH) produced when ozone decomposes are even more powerful, with an oxidation potential of 2.8 V, and can oxidise almost any organic compound in water.
Figure 3. SINOKLE ozone micro-nano bubble generator
SINOKLE's technology builds on this by introducing a dedicated catalyst that markedly raises ozone utilisation efficiency. The strong oxidising power of ozone destroys organic pollutants, while the catalytic oxidation step converts phosphorus, nitrogen and similar species into more stable forms, reducing environmental impact and by-product formation. In potassium dihydrogen phosphate wastewater, for example, the process degrades organophosphorus compounds effectively and lowers their environmental load.
Performance
In phosphorus-bearing wastewater, SINOKLE's ozone catalytic oxidation process achieves COD removal above 85%, well above the 50-60% of conventional physicochemical treatment. It also removes ammonia nitrogen effectively, further improving water quality. The innovation lies in the high activity and stability of the catalyst, which delivers efficient pollutant removal at a low ozone dosage. That lowers treatment cost and reduces ozone-related by-products such as bromate, improving process safety - and giving the process greater application value in potassium dihydrogen phosphate wastewater treatment.
