| The water quality of nightsoil wastewater on passenger trains has "three high" characteristic: high concentration of organic substance, NH3-N and suspended solid, so it is difficult to treat. This thesis is developed with the treatment of nightsoil wastewater on passenger trains, and putting emphasis on the study of anaerobic ammonia oxidation (ANAMMOX) process which is used for biological nitrogen removal from the nightsoil wastewater on passenger trains. The main contents and conclusions are as follows:It was shown from the experimental study on pretreatment that adopting sieves to filter the residue and acidification can get a good effect on removing COD and SS from nightsoil wastewater. The average COD and SS removal rate was 48.8% and 89.4% respectively.It took about four months to start up the anaerobic baffled reactor (ABR). When the OLR reached to 8kgCOD/(m3·d), the COD removal rate maintained 80%, and the highest removal rate reached to 81.7%.The experimental results indicated that when the HRT was more than 24h, the COD removal rate increased slightly. Considering the economic perspective, the best HRT to treat this wastewater was about 24h.pH in each compartment of ABR reactor took on the law of decreasing first and then rising. It was shown that there was phase separating in ABR.The study on ANAMMOX process in this thesis was based on Anaerobic sequencing batch reactor (ASBR). It took more than four months to start up the ANAMMOX reactor successfully. When the volumetric loading of NH3-N, NO2--N and total nitrogen were about 0.3, 0.35 and 0.65 kg/(m3·d) respectively, the removal rate reached the highest 73.5%, 91.3% and 74.1% respectively. In the last days of this experiment, the ratio among the decrement of the NH3-N and NO2--N and the increment of NO3--N was 1: 1.35: 0.18; The NO2--N which was removed by the effect of ANAMMOX averagely occupied 96.8% of the total NO2--N amount. It was indicated that the ANAMMOX bacterium had become the preponderant microorganism.It was shown from the experimental study on the effect factors of ANAMMOX reaction that the optimal pH value was 8.0, the optimal temperature was 30°C, and the reasonable HRT was between 18h and 24h. The ANAMMOX reactor operated normally, when the organic COD in influent was less than 200mg/L. The removal rate of NH3-N descended to 11.4%, when the organic COD reached to 700mg/L in influent. It was indicated that overfull organism accelerated the growth of heterotrophic bacteria, which restrained the ANAMMOX reaction seriously. The removal of NO2--N was comparative stable in this process, because of the enhancement of the denitrification. When the influent concentration of NO2--N was more than 600mg/L, the restraint phenomenon began to appear, when the concentration reached to 800mg/L, the restraint phenomenon became obvious, when the concentration reached to about 1000mg/L, the ANAMMOX reaction was restrained completely.
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