Research On Disposing Wastewater From Methyltin Mercaptide Production Using UV/Fenton And UV/O₃

Wastewater from Methyltin mercaptide production in 081 base has a so complex composition and a so bad biodegradability that there hasn't an effective techniques that can deal with it. Our team has decided that this wastewater can be pretreated via separating oik rime, blasting ammonia. The effect of degradation of organic compound and the improvement of biodegradability of pretreated wastewater after disposed by UV/Fenton and UV/O3 is studied.First, the effect deposed by UV/Fenton is studied. The influential factors, which are the composition of the Fenton reagent, the dosage of H₂O₂, the initial pH are analyzed. And then the optimal reaction factor which is more effective and economical is obtained, which are the initial pH is 4, H2O2:Fe2+=5:1, H₂O₂ is put in by three times, 0.5 times of theoretical H₂O₂ dosage. Biodegradability and total dosage of stannous in the outlet after UV/Fenton reaction are analyzed. The results show that in the UV/Fenton reaction, the disposal of the non-biodegradable organic matter in the wastewater not only needs a certain long of time but also a certain dosage of oxidant. The results also show that the flocculation after UV/Fenton reaction is important that the COD removal ratio is 54.3% before flocculation and 75% after flocculation.Then the effect deposed by UV/ O₃ is studied. The effect is better around the neutral pH, which shows that H₂O₂ is the prime middle production of the UV/O₃ reaction; the he improvement of biodegradability is enhanced with the incensement of dosage of O₃. There is a critical dosage of 70.7 mg/L, the biodegradability can increase substantially at the dosage. Similarly, this also shows that in the UV/ O₃ reaction, the disposal of the non-biodegradable organic matter in the wastewater not only needs a certain long of time but also a certain dosage of oxidant. Because of the low ratio of transmission of O₃ and other reasons, the critical dosage is increased and so is the application cost of UV/ O₃.Change of concentration of O₃ with time of the UV/ O₃ reaction shows distribution of the concentration of O₃ in the reaction proposed by BaTian who applied the the membrane theory and the principle of the transmission of O₃ in the chemical reaction. That is in the UV/ O₃ reaction, concentration of O₃ monishes because of the reaction and grow when O₃ is absorbed by wastewater, so it will fluctuate near a certain concentration which can be considered as a balance concentration. Stair dynamics models established for UV/ O₃ systems were well supported by the experiment results.BOD is measured by calefacient techniques to compare the improvement of biodegradability of the wastewater after UV/ O₃ reaction. The results show that the measurement of BOD by calefacient techniques is exact, so calefacient techniques can measure the biodegradability of same wastewater perfectly.