| The nitrogen pollution of water body is becoming more and more serious, which has caused huge economic losses to industrial and agricultural production, and has seriously affected people’s normal life. Anaerobic ammonium oxidation(ANAMMOX) has the advantages of saving energy and unnecessary adding organic carbon source as well as less sludge production. The production of wastewater from Pharmaceutical factories and chemical fertilizer plants not only containing high concentrations of ammonia nitrogen, but also contains a certain amount of phosphate. phosphate may affect the performance of nitrogen removal, if using anaerobic ammonium oxidation process to treat this kind of wastewater. In order to accelerating the application of CANON and UASB-ANAMMOX, the effect of phosphate on the nitrogen removal characteristics of CANON and UASB-ANAMMOX was studied in this paper. The main conclusions are as follows:(1) After reducing the influent concentration of ammonia nitrogen, reducing the DO concentration and Adding little ANAMMOX bacterium, the CANON process was stable, the removal rate of ammonia nitrogen increased from 9.1% to 80.8%, NRR increased to 0.08 kg/(m3·d), and the TN removal rate reached 31.2%.In the subsequent load stage, using ratio of △(NO3-- N) /△(TN) and total nitrogen(TN) to measure the stability of partial nitrification and anammox to adjust the process operating parameters. The sludge concentration in the reactor was gradually increased, and the SEM diagram showed that the outer surface of the granular sludge was covered with some ellipsoid and rod of bacteria, and a small portion of the filamentous material.(2) When the phosphate concentration was 30 mg/L, the microbial concentration reached the maximum, the nitrogen removal efficiency of the reactor reached the highest, the average effluent concentration and efficiency was 14.2 mg/L and 98.3% the TN average removal rate was 85.3%, the average NRR was 1.06. In 113 d, phosphate concentration reached 100 mg/L, NRR and TN removal rate continued to decline, were 0.28 kg N/(m3·d) and 52.8%, microorganism concentration reached a lowest. The effect of shortcut nitrification was stable, and the effect of ANAMMOX was affected by phosphate, this also indicated that the phosphate had a inhibition effect on ANAMMOX. The sludge concentration gradually decreased, the particle size was smaller, the shape of the bacteria was less on the surface of sludge, and the porous structure of the surface was porous.(3) Under the conditions of high substrate concentration and continuous flow, concentration of phosphate in 15 ~ 700 mg / L, nitrogen removal performance was not significantly inhibited, nitrogen removal performance remains stable and efficient trend; when phosphate concentrations greater than 800 mg/L(25.8 mmol/L), the reactor nitrogen removal efficiency began to be inhibited, NH4+-N removal rate dropped from 96.5% to 74.1% NO2-- N from 97.8% fell to 75.6%, NRR from 5.7 kg N/(m3·d) fell to 4.4 kg N/(m3·d). Therefore, within the range of phosphate concentrations that the Anammox strain can endure, it may be possible to use ANAMMOX process to treat wastewater containing high nitrogen and phosphorus, the impact mechanism needs to be further researched.The indicator parameters of ANAMMOX performance have changed when the affected. The electrical conductivity of the effluent decreased gradually, the difference between the import and export of water and electricity has gradually become small,indicated the nitrogen removal effect of the reactor was affected. The monitoring of the electrical conductivity of the reactor was convenient and effective. The value of p H was used as the indicator of nitrogen removal performance of ANAMMOX. When the influent conditions were basically unchanged, detecting the influent and effluent of the p H value could determine whether the perfomance was affected, furthermore to taked remedial measures in time. |
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