Study On Supercritical Water Oxidation Of2,4-Diaminotoluene Wastewater

TDI (toluene di-isocynate), which was produced by TDA (tolylene di-amine),found a variety of application as an intermediate in the manufacture of polyurethane.Because of waste water pollution emission contained TDA, it would bring severeharm to environment and human health. The general method used in degradation highconcentration of TDA wastewater pollution is inefficient. Suitable processing methodand optimize process was essential to improve efficiency of wastewater process.As a new type of organic waste water oxidation technology, the technology ofsupercritical water oxidation (SCWO) have developed since1980s, In thesupercritical reaction system, solvent of water had a advantage of cleaning, cheap andeasy to obtain. In addition, the final product of N2、CO2、H2O could be directlydischarged and quickly oxidation, It reached the national emission standard.Firstly, the TDA wastewater of a chemical company in Gansu province wasanalyzed. The wastewater was investigated from technology, and gas chromatographyand spectrophotometric were employed to study the main compositions wastewater.The results is as follows: PNT30.909mg/L, DNT19.38mg/L, TDA12.996mg/L,4A2NT14.827mg/L，2A4NT0.797mg/L, which provide basic theory of TDAproduction wastewater degradation study.Secondly, during phosgene produced production, the high concentrations TDAwastewater was generated and investigated, and TDA organic wastewater was studiedin terms the oxidation degradation efficiency and influencing factors by the advancedsupercritical water oxidation reaction intermittent experiment. The catalyst screeningexperimental results showed that FeSO47H2O has best catalytic effect. In addition,the temperature, pressure and retention time of waste water was studied andconcluding that the optimum conditions as follows: pH is3.5, the antioxidantconcentration is9%, the temperature is450℃,the pressure is26.5MPa, the responsetime is300s, the catalyst dosage flow is10mg/L. Under the optimal conditions, theremoval rate of CODCris96.79%.Based on the Research and investigation of supercritical water oxidationprocedure wastewater of TDA industrialization applications, wastewater disposalprocedure was design, several basic supercritical reactors and basic data weredescribed, the cost of wastewater treatment is218.3yuan per ton.