Experimental Study On The ANAMMOX Process Under The Low Concentration Of Ammonia

According to the existing circumstance of low concentration of the influent water quality in many municipal sewage plants, low rate of C/N value and traditional biological denitrification, the process, treating wastewater with low concentration of ammonia, was studied by SBR reactor, based on the returns about the ANAMMOX process treating wastewater with high concentration of Ammonia. Through the experimental investigation of ANAMMOX process, the ANAMMOX reactor was started up under the low concentration of Ammonia; Based on the successful startup of reactor, the effect of environmental factors on ANAMMOX process was studied. Several conclusions were summarized as follows:(1) By mixing aerobic nitrifying sludge and ordinary anaerobic sludge, the ANAMMOX reactor was started up successfully and cultivate chocolatebrown particle sludge with ANAMMOX activity under the low concentration of ammonia nitrogen, which created conditions for the further study of ANAMMOX technology under low concentration of ammonia. It took more than five months for the ANAMMOX reactor startup, which was departed into initial phase of startup, transition period and steadily operative period.(2) The systemic stable operation was realized after experiencing the initial phase of startup and transition period. At the end of the reactor startup, the removal rate of ammonia and nitrite achieved 94.5%, 97.4% respectively; The volume loads of ammonia and nitrite were respectively 11.4 g/(m³Â·d), 11.1 g/(m³Â·d).(3) Through the influence study of single factor like pH, temperature, organic matter on the ANAMMOX reaction, the results indicated: under the low concentration of ammonia the appropriate value of pH was between 7.5 and 8.0 and the optimal pH value was 7.51; the appropriate value of temperature was between 30℃and 35℃ and the optimal value was about 30℃; the appropriate value of organic matter was between 0 mg/L and 50 mg/L, within which the reaction rate of ANAMMOX maintained about 3.38×10^-4mg/mg MLSS.h, and ANAMMOX reaction was inhibited when the concentration of COD was more than 50mg/L.(4) Based on the single factor experiment, the orthogonal test about influence factors as pH, temperature and temperature were done. The results of orthogonal test indicated that the primary and secondary sequence of the factors effecting the ANAMMOX reaction rate were organic matte, temperature, pH and the optimal value of COD, temperature and pH were respectively 50mg/L, 30℃, 7.5.