1.2 Chemical treatment
Application of chemical methods, the excessive use of certain reagents easily lead to secondary pollution of water, so the design should be done before the relevant experimental research work. Chemical methods include iron charcoal, chemical redox method (fenton reagent, H2O2, O3), deep oxidation technology.
1.2.1 iron charcoal method
The industrial operation shows that the biodegradability of effluent can be greatly improved by using Fe-C as the pretreatment step of pharmaceutical wastewater. Lou Maoxing and other iron-carbon - microelectrolysis - anaerobic - aerobic - air flotation combined treatment of erythromycin, ciprofloxacin hydrochloride and other pharmaceutical intermediates production of waste water, iron carbon treatment of COD removal rate of 20 %, The final water to the national "Integrated Wastewater Discharge Standard" (GB8978-1996) a standard.
1.2.2 Fenton Reagent Treatment
The combination of ferrous salt and H2O2 is called Fenton reagent, which can effectively remove the refractory organic matter that can not be removed by traditional wastewater treatment technology. With the deepening of research, UV (UV), oxalate (C2O42-), etc. into the Fenton reagent, so that the oxidation capacity greatly enhanced. TiO2 was used as catalyst and 9W low pressure mercury lamp as light source. Fenton reagent was used to treat the pharmaceutical wastewater. The decolorization rate was 100% and the COD removal rate was 92.3%. The nitrobenzene compound decreased from 8.05mg / L to 0.41 mg / L.
1.2.3 Oxidation method
The use of this method can improve the biodegradability of wastewater, while COD has a better removal rate. Such as Balcioglu and other three kinds of antibiotic wastewater for ozone oxidation treatment, the results show that the ozone oxidation of wastewater not only BOD5 / COD ratio has increased, and COD removal rate of 75% or more.
1.2.4 Oxidation technology
Also known as advanced oxidation technology, which brings together the modern light, electricity, sound, magnetic, materials and other similar disciplines of the latest research results, including electrochemical oxidation, wet oxidation, supercritical water oxidation, photocatalytic oxidation and Ultrasonic degradation method and so on. The ultraviolet photocatalytic oxidation technology has the advantages of novelity, high efficiency, no selectivity to waste water, especially suitable for the degradation of unsaturated hydrocarbons, and the reaction conditions are also mild, no secondary pollution, has a good application prospects. Compared with UV, heat, pressure and other treatment methods, ultrasonic treatment of organic matter more direct, lower requirements on the equipment, as a new approach, is being more and more attention. Xiao Guangquan et al. Treated the pharmaceutical wastewater with ultrasonic-aerobic biological contact method. The total COD removal rate of wastewater was 96% when the ultrasonic treatment was 60s and the power was 200w.