Anaerobic ammonium-N removal from tannery wastewater was investigated using a lab-scale anaerobic baffled reactor( ABR). The results indicated that ABR could be used as a good anaerobic ammonium oxidation reactor,the stable and effective performance of ammonium-N and COD removal from tannery wastewater was demonstrated in the ANAMMOX ABR. When the NH+4-N concentration of the influents were in the range of 25. 0 mg·L- 1to 76. 2 mg·L- 1and COD ranged from 131 mg·L- 1to 237 mg·L- 1,under the volumetric loading...