Nitrogen removal from synthetic wastewater through combined partial nitrification (PN) and anammox processes in a new integrated multi-environment wastewater treatment technology called BioCAST was investigated.  Based on the design and operation strategy of BioCAST technology, it was assumed that this technology was suitable for nitrogen removal by the combined nitrification and anammox processes. This is due to the fact that the BioCAST technology contains several zones with different environmental conditions that are required for the growth and activity of both ammonium oxidizing bacteria (AOB) and anammox bacteria. Moreover, the three zones are in physical contact with each other, implying that the byproduct of nitrification; i.e. nitrite will be readily converted by the anammox bacteria to nitrogen gas via the anammox process. The system operated with ammonium concentration in the range of 10 to 350 mg/l for 120 days at hydraulic retention times of 2 and 4 days. The nitrogen loading rates (NLR) during the reported operation period changed in the range of 0.0021 to 0.17 kg/m3.d. The most favorable dissolved oxygen (DO) concentration inside the aerobic, microaerophilic and anoxic zones of the first BioCAST bioreactor was found to be in the range of 0.9-1.2 mg/l, 0.1-0.4 mg/l and 0.0 mg/l, respectively. The most favorable pH during partial nitrification and anammox processes was found to be in the range of 7.5-8.1 in aerobic and microaerophilic zones and 7.8-8.1 in the anoxic zone of the bioreactor.  The BioCAST technology demonstrated ammonia-nitrogen as well as total nitrogen (TN) removal efficiencies up to 85.6% and 81.2%, respectively, through PN and the anammox processes. Furthermore, scanning electron microscopy (SEM) revealed the presence of irregular cauliflower structure of anammox bacteria inside the BioCAST bioreactor. In conclusion, the BioCAST technology with unique characteristics for combined partial nitrification (PN) and anammox processes is suitable for the removal of nitrogen from a synthetic wastewater without the need for organic carbon.