Study on Two-phase Anaerobic Technology for N-Phenylglycinonitrile Wastewater Treatment

N-phenylglycinonitrile is a kind of important chemical dye, its producing process make a large of wastewater. This kind of chemical wastewater has a high concentration and difficult to be decomposed. Study on bio-chemical treatment of this water was introduced in this paper.Before the treating of this water, the method for determines the concentration of phenylamine compound which contribute to the most proportion of CODcr of this wastewater should be found firstly, the concentration value of phenylamine and the value of CODcr are both have been used to evaluate the effect of treatment method. At first the concentration of phenylamine had been determined by means of national standard method, but it has some disadvantage during its distillated, because there has another compound called hydroxy-acetonitile in this wastewater, this compound would be decompounded into cyanogen and aldehyde under basic circumstances. The tow matters are all highly poisonous and evaporable. So change the way to a more secure and more feasible method, it is the ultraviolet spectrophotomety, at pH=6.6, the aniline is determined at 230nm. It has a good linear relationship when the concentration of aniline range from 0~34.00 mg/L , related coefficients is 0.9998. The relative standard deviation of aniline is less than 5.0%, the rates of recovery of aniline is 98.55%～100.61%, the results are satisfactory.During the inoculation and cultivation of sludge, the raw wastewater had been diluted, and then put it in the reactor which had been loaded the sludge form coke-oven plant. The concentration of inlet had been increased step by step during the cultivation process. Under the condition of two phase system in which the phase of producing methane had been apart into two stages, the inoculation sludge had begun to decompose the organic of this wastewater at last.When the CODcr=20000～30000mg/L, the two phase anaerobic system has the capability to remove some part of COD and aniline compound and at the same time there has no death of the sludge, this means that the cultivation had up to the scratch. After the success of the cultivation, the most proper value ranges of some important effect factors of this bio-chemical system had been determined. Fore phase of acid producing the proper condition is T=30～35℃,PH=6.0～6.5 HRT=24h and the capacity burden is 7.95CODcr/m~3d; fore phase of methane producing the condition is T=30～35℃,PH=8.0～8.5, HRT=48h, and the capacity burden of the two stages of methane producing are 4.65kgCOD/m~3d and 3.375kgCOD/m~3d respectively.Then the outlet of physic-chemical stage had been put into the bio-chemical stage fore several periodicities, the data shows that the removal rate of aniline compound is 50% and the CODcr is about 68%, and the removal of aniline is contributed only by the phase of acid producing but almost not by the phase of methane producing.At last, the sludge flocculation body and the image of the microbe of bio-chemical stage had been studied. Fore the fragment of the sludge flocculation body, the sludge flocculation body from phase of acid producing compare with the phase of methane producing is more incompact, the microbe are exposed on the surface of the sludge contrast with the phase of methane producing. Fore the image of microbe, the main microbe in phase of acid producing are bacillus、Clostriolium and vibrio, on the other hand the methanococcus is the most contribution of the microbe in the phase of methane producing, there still have some methanobacterium been found.