| o-Cresol is an important chemical material. o-Cresol was synthesized from o-toluidine via diazo-reaction and hydrolization reaction, and the treatment process of its production waste water and waste acid were investigated in this paper.In the diazonium experiment, using o-toluidine and sulfuric aicd solution reaction then cooling, after that, the sodium nitrite solution was slowly added by drops after the temperature is below 0℃. In the hydrolization experiment, o-cresol was separated by vapor distillation. The best reaction condition is that:the concentration of sulfuric acid solution which been used in diazo-reaction is 30%; 35% sodium nitrite solution should be feed under liquid surface as the rate 0.8 mL·min-1, the feeding speed of diazonium salt is 20mL·min-1; the concentration of sulfuric acid which be used in hydrolization is 50%. Under this condition the yield of o-cresol is 86.2%, its purity is 99.65% by HPLC.The better way of dealing with the waste water is N3520 resins adsorption. And the better condition is that: adsorpt condition: the pH value is 2;the temperature is room temperature, the flow speed is 4BV·h-1.Under this condition its max adsorptive capacity is 26BV, desorption condition:the temperature is 40℃; the flow speed is 1.0 BV·h-1; desorption agent is 5%NaOH-60% alcohol;the dosage is 2BV.After disposal,the out water is clarity, the removal rate of o-cresol is more than 99%, the consistence is less than 0.5 mg·L-1,COD value is less than 300mg·L-1.The quality of the out water is steady, accord with the phenol waster water blow down standard under 0.5mg·L-1.The o-cresol in the waste acid is disposed by adsorption of activated carbon. The results show that the better condition is that: the flow speed is 3BV·h-1; the tempera- ture in the 15℃～25℃; the max adsorptive capacity is 60 BV. After pretreatment, COD value is less than 250 mg·L-1.And the removal rate is more than 95%.Bipolar membrane electrodialysis is used to separate Na2SO4 from the waster acid which has been pretreatment. By the change of deal time, SO42-can recovery effectively,SO42- concentration in salt chamber reduce from 4.04mol·L-1 to 0.26mol·L-1, and SO42- concentration in acid room increase to 4.59mol·L-1 . After pretreatment process and bipolar membrane electrodialysis, COD value of the recovery sulfuric acid is less than 10mg·L-1, removal rate is more than 99.6%, the content of o-cresol is less than 0.5mg·L-1, removal rate of o-cresol is more than 99.98%.Contrast with traditional technics, the produce rate of this way has been increased obviously. And the waster water has been disposed by a easier technique, arrived at the emission standard. At the same time , the waster acid has been disposed too.
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