- Aerobic zone and anoxic zone can be formed in the ditch through controlling oxygen supply of the brush and TN removal is over 90%.
- Among all influencing factors,too high dissolved oxygen(DO) concentration must be avoided,which in aerobic zone should be less than 2 mg/L and which in anaerobic zone less 0.2 mg/L.
- An auxiliary medium was made by mixing shredded waste tyres,ethylene vinyl acetate(EVA) copolymer and zeolite in certain proportion and added into aerobic zone of A2/O process to investigate the influence on nitrogen removal efficiency.
- The Norwegians live in a comparatively cold zone.
- Supplies were parachuted into the earthquake zone.