Industrial wastewater is often characterized by complex composition, high pollutant concentrations, high toxicity, and resistance to biodegradation, making it "difficult wastewater." The petroleum, chemical, pharmaceutical, pesticide, and textile printing and dyeing industries are major sources of this type of wastewater. Common characteristics include high chemical oxygen demand (COD), bioinhibitory or toxic substances, high salinity, and poor biodegradability.
During biological treatment, the presence of refractory organic matter and toxic substances in wastewater can severely inhibit microbial activity, resulting in poor biochemical treatment results. Effective pretreatment can improve wastewater quality by increasing biodegradability (BOD5/COD ratio), reducing toxicity, and degrading large organic molecules, thereby creating favorable conditions for subsequent biological treatment or other advanced treatment processes.
The core of UV-AOPs technology lies in the activation of oxidants or catalysts through ultraviolet radiation, efficiently generating highly oxidizing hydroxyl radicals (OH), which in turn oxidize and degrade organic pollutants in water. It is a preferred pretreatment process for difficult industrial wastewater.
UV-AOPs primarily include the following:
·UV/H2O2 Process: H2O2 undergoes photolysis under UV light to produce ·OH.
This process is relatively simple to operate, suitable for a wide pH range and a wide range of influent concentrations. The H2O2 decomposition products are H2O and O2, resulting in no secondary pollution.
·UV/O3/H2O2 Process: Ozone itself has strong oxidizing properties, and its combination with UV light can significantly increase the yield of ·OH and the efficiency of pollutant degradation. This process combines photolysis, direct ozone oxidation, and hydroxyl radical oxidation, making it particularly suitable for treating complex and complex water bodies.
UV/Fenton (Photo-Fenton) Process: UV light is introduced to the traditional Fenton reagent (Fe2+/H2O2). UV light promotes the reduction of Fe3+ to Fe2+, accelerates the Fenton reaction cycle, increases ·OH yield, and broadens the optimal pH range.
Key metrics for measuring the effectiveness of industrial wastewater pretreatment:
·BOD5/COD improvement
·Specific pollutant removal
·COD removal rate
To improve treatment efficiency, UV advanced oxidation processes can incorporate pretreatment at the front end of the process.
Physical and chemical pretreatment techniques such as coagulation and sedimentation, flotation, activated carbon adsorption, and filtration can be combined individually to increase UV light transmittance and the effective utilization of ·OH, thereby reducing overall treatment costs.
WSH紫外明渠
WTV紫外垂直模块
ZL大型管道式紫外
CLEAR中压紫外
MOL板式臭氧发生器
UV-AOP高级氧化
D.FITE滤布滤池
