The Fenton oxidation method in photovoltaic wastewater treatment is an efficient and important technology, mainly used to treat the auxiliary waste liquid and cleaning wastewater generated in the photovoltaic industry during the cutting, grinding, slicing of silicon rods, and grinding, corrosion, and polishing of silicon wafers. These wastewaters contain high concentrations of organic matter (such as polyethylene glycol), suspended matter (such as silicon powder, silicon carbide), and pollutants such as fluoride ions, acids and alkalis, which are difficult to treat. The following is a detailed analysis of the Fenton oxidation method in photovoltaic wastewater treatment:
1. Principle of Fenton oxidation method
Fenton oxidation method is an advanced oxidation technology based on the chemical reaction of Fenton reagent (composed of hydrogen peroxide and ferrous ions) under acidic conditions. In this process, ferrous ions (Fe^2+) react with hydrogen peroxide (H2O2) as a catalyst to generate hydroxyl radicals (·OH) with high oxidation ability. These hydroxyl radicals have extremely strong oxidation potentials and can non-selectively oxidize and degrade most organic matter in water, and eventually mineralize them into small molecules such as carbon dioxide, water, and inorganic salts.
2. Application of Fenton oxidation method in photovoltaic wastewater treatment
1. Treatment effect:
The Fenton oxidation method can effectively decompose organic pollutants in wastewater, and can even completely oxidize and decompose them into harmless substances without causing new pollution.
For high concentrations of organic matter and suspended solids in photovoltaic wastewater, Fenton oxidation method shows strong treatment capabilities, significantly improves the biodegradability of wastewater, and provides favorable conditions for subsequent biological treatment.
2. Influencing factors:
pH: The optimal pH for the Fenton reaction is usually between 2 and 4. Within this range, Fe^2+ mainly exists in free form, which is conducive to the generation of hydroxyl radicals. A pH value that is too high or too low will inhibit the generation of hydroxyl radicals and reduce the treatment effect.
Reaction time: Reaction time has a significant impact on treatment effectiveness. In the early stage of the reaction, the COD removal rate increases rapidly; as the reaction time prolongs, the growth of the removal rate gradually slows down. Therefore, experiments are needed to determine the optimal reaction time to balance treatment effectiveness and cost.
The dosage of H2O2 and Fe^2+: The dosage of H2O2 and Fe^2+ is the key factor affecting the treatment effect. Appropriately increasing the dosage can improve the treatment effect, but excessive use will cause the decomposition of hydrogen peroxide to produce oxygen instead of hydroxyl radicals, reducing treatment efficiency and increasing costs.
3. Considerations in practical applications:
In practical applications, experiments need to be conducted based on the specific composition and properties of photovoltaic wastewater to determine the optimal Fenton oxidation conditions.
Wastewater treated by the Fenton oxidation method may contain a certain amount of iron ions and suspended solids, which need to be removed through subsequent treatment processes (such as coagulation, sedimentation, filtration, etc.).
Considering the cost issues of the Fenton oxidation method (such as the cost of hydrogen peroxide and ferrous sulfate, sludge treatment costs, etc.), in practical applications it may be necessary to combine it with other treatment methods to improve the overall treatment efficiency and economy.
3. Conclusion
Fenton oxidation method, as an efficient and environmentally friendly wastewater treatment technology, has broad application prospects in photovoltaic wastewater treatment. By optimizing reaction conditions and treatment process combinations, the treatment effect and economy can be further improved, providing strong support for the sustainable development of the photovoltaic industry.
