| With the continuous development of seafood processing industry, the Marine environment and other problems such as environmental deterioration in the catchment area, deep processing of a large amount of waste water into the sea, the difficulty of wastewater treatment and processingcosts have increased How to control the sources of pollution, to ensure the healthy development of the seafood processing industry has become a major problem to be solved urgently. In this study,sol-gel methodwas employed to prepare pure- Ti O2 photocatalyst, then changing the properties of photocatalysts by barriering the recombination of electron-hole pairs or decresing the band gap. Floating photocatalyst Li+-Ti O2, Sn4+-Ti O2 were synthesized through a coupling agent method and its photocatalytic abilityof photocatalytic oxidation of ammonia nitrogen and COD in seafood processing waste water is discussed at last,andits application has achieved good effect. Many influential factors of heterogeneous photocatalytic degradation of ammonia nitrogen and COD in seafood processing waste water are considered, as well as the kinetics. The results are as follows:(1) The nano-Ti O2 photocatalyst was prepared via sol-gel method. And the crystal structure and surface morphology were characterized by XRD and SEM. The photo- catalytic degradation of seafood processing waste water by nano-titanium dioxide prepared during the experiment was studied in a photo-catalytic system of Ti O2 with the UV excitation.The effects of differ-ent degradation variables on the degradation efficiency were investigated,including amount of catalyst,p H value,in-itial concentration of ammonia- N and chemical oxygen demand( COD) in seawater,and catalytic reaction time.The results showed that nano-Ti O2 photocatalyst led to effective degradation of seafood processing wastewater and the pollutants under the optimal conditions for photocatalytic degradation of ammonia-N and COD.It was foundthat 69.76% of ammonia-N and 73.33% of COD were eliminated under the conditions of 0.9 mg /L of Ti O2,cat-alytic reaction for 3 h,initial ammonia-N of 80 mg /L,initial COD of 300 mg /L,and p H of 9.(2) The nano-Ti O2 photocatalyst was prepared via sol-gel method. The crystal structure and surface morphology were characterized by XRD and SEM. These results indicated that: For Sn-doped Ti O2, the crystalline size were 19.18nm、20.05nm、21.80nm、29.70nm; the effect of nano-Ti O2/ Sn4 + dosage, the ratio of dopant Sn4 +,initial ammonia-N concentration, p H value, H2O2 concentration, and reaction time, respectively, on the oxidation removal of diesel was investigated. It reveals that when the experiment is undertaken under the very condition: lithium doping amount 3% of seafood processing waste water, ammonia nitrogen concentration of 50 mg/L, the initial concentration of COD 600 mg/L, Li+-Ti O2dosage1.5 g/L H2O2 volume fraction is 3%; reaction time is 2 hours; p H value is 8, ammonia nitrogen and COD photocatalytic oxidation degradation rate can reach 86.45% and 74.67% respectively.(3) The Li+-doped nanometer titanium dioxide photocatalyst was prepared via sol-gel method, and the crystal structure and surface morphology were characterized by XRD and TEM techniques. the Li+-Ti O2 obtanined is anatase crystal form, and particle size was 15.6-52.4nm. the photocatalytic degradation of seafood processing wastewater was investigated by utilization of Li+-doped titanium dioxide in simulated seawater exposed to UV irradiation. In the experiment, the influences of doping content of Li+, Li+-doped titanium dioxide dosage, p H value, initial concentration of COD and ammonia-N and the presence of assistance oxidant peroxide, respectively, on the COD and ammonia-N removal from sea food processing wastewater were investigated. A systematic optimization study was carried out through a orthogonal test on the basis of the results of the single-factor experiments. It reveals that when the experiment is undertaken under the very condition: lithium doping amount 5% of seafood processing waste water, ammonia nitrogen concentration of 80 mg/L, the initial concentration of COD 300 mg/L, Li+-Ti O2 dosage0.9 g/L H2O2 volume fraction is 5%; reaction time is 2 hours; p H value is 8, ammonia nitrogen and COD photocatalytic oxidation degradation rate can reach 81.50% and 78.67% respectively.(4) The reaction kinetics had been studied by using the Sn4+-Ti O2 powder as photocatalyst. The result showed that the kinetic could be described by Langmuir-Hinshelwood equation, and the photocatalytic oxidation comformed to one order dynamics equation.(5) Activated carbon and Polypropylene polyhedral ball bonding photocatalyst is prepared through coupling agent method. Effect of photocatalytic degradation factors load times, the times of using simulated wastewater of seafood processing pollution. two kinds of load type catalyst efficient sea products deep have apply processing in the pollution of wastewater treatment. Study load number and the number of repeated use of catalytic degradation in seafood processing wastewater ammonia-N and COD degradation effects. Polypropylene polyhedron in the supported catalyst, load times are the main factors that influence the photocatalytic properties of nanometer catalyst, through the degradation experiment of ammonia nitrogen and COD in seafood processing waste, conditions for preparation of catalyst system can be identified as: 3 times, the removal efficiency of 72.13% and 65.67% respectively. Li+-Ti O2/AC catalyst photocatalytic performance of the key factors are the load times and calcination temperature. calcination temperature is 500℃, the removal efficiency of 52.43% and 36.61% respectively.load 4 times, the removal efficiency is 75.48% and 62.14% respectively. Comparison of 2 kinds of photocatalyst, Comparing the influence of supported catalysts on the photocatalytic oxidation of ammonia-N and COD, we found that the polypropylene polyhedral sphere was the best choice.(6) The photocatalytic oxidation of ammonia-N and COD in seafood processing wastewater was investigated by using the three kinds of catalyst under UV and sunlight irradiation.The experimental results show Li+-Ti O2 and Sn4+-Ti O2 catalysts had higher activity for photocatalytic oxidation of ammonia-N and COD than pure Ti O2 powder. Furthermore, while reaction time was 6h, the photooxidation rate of ammonia-N were 89.14% and 60.72% respectively.Li+-Ti O2 catalyst had higher activity than Sn4+-Ti O2. while ammonia-N initial concentration were 100mg/L and COD1200mg/L the oxidation removal rate of ammonia-N and COD in seafood processing wastewater were 87.94% and 73.72% respectively, after 4h treatment for UV irriadiation. |
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