Effect Of K~+ On Denitrification Efficiency Of ANAMMOX Process For Treatment Of High Salinity Wastewater At Medium And Low Temperature

Anaerobic ammonium oxidation process(ANAMMOX)as a new type of nitrogen removal process has developed rapidly in recent years.The application of anaerobic ammonium oxidation to treat salty wastewater is a new idea.Because the concentration of salty wastewater in actual engineering fluctuates greatly,the actual temperature is It is unstable,so it is very meaningful to domesticate anaerobic ammonium oxidizing sludge which can resist low temperature and high salinity.Under the double stress of salinity and low temperature,the anaerobic ammonium oxidation treatment of high salt wastewater is strengthened by exogenous addition of K~+.In this paper,the following contents were investigated through experiments:rapid initiation of anaerobic ammonium oxidation reactor by strain flow;change of low-temperature salinity domestication and denitrification efficiency and granular sludge change;and addition of K~+to anaerobic ammonia under medium and low temperature conditions Intensification study on denitrification performance of oxidized high salt wastewater.(1)Quickly start the anaerobic ammonia oxidation reactor by means of strain addition under medium temperature conditions(30?);the sludge in the startup process is taken from the mature anaerobic ammonia oxidation sludge,and partly from the secondary sedimentation tank sludge,through the mature The addition of oxy-ammonia oxidized sludge gradually shortens HRT and increases the concentration of influent matrix.The anaerobic ammonium oxidation reactor is successfully started through 90d,and the total nitrogen load of the reactor is stable at 1.37kg/(m~3·d).During the start-up of the reactor,the color of the sludge undergoes a yellow-black-red process,and the sludge granulation gradually becomes obvious.After the reactor is successfully started,the MLSS and MLVSS can reach 8388.5 mg/L and 7511.5mg/L,respectively,and the MLSS/MLVSS is as high as 0.90.The anaerobic ammonium oxidation reactor can be quickly started by means of bacterial addition.(2)Exploring the characteristics of sludge particles and the effect of nitrogen removal efficiency in the process of intermediate temperature stepwise salinity gradient;the salinity acclimation by gradually increasing the salinity gradient;the salinity with the medium temperature salinity acclimation process The improvement of nitrogen removal efficiency was gradually weakened,and the inhibition of 20g/L was obvious.The 30g/L produced severe inhibition of nitrogen removal efficiency was only 79.04%when no salt was added;the granular sludge gradually became tight under 0?20g/L salinity stress,30g/Lgranular sludge gradually disintegrated into fine-grained sludge;with the increase of salinity,the content of soluble EPS(S-EPS)gradually increased,and the abrupt increase occurred under the salinity of 20g/L,accompanied by a large amount of sludge floating,and the strain screening appeared.The process,the biomass is greatly reduced;the salinity acclimation process under medium temperature conditions is a screening process of a strain,the nitrogen removal efficiency gradually decreases with the increase of salinity,and the 0?20g/L salinity stress promotes cell release.EPS resists the bad environment and makes the cells more closely integrated.(3)Exploring the anaerobic ammonium oxidation sludge after acclimation of medium temperature salinity suddenly with the salinity cooling,the low-temperature reduction of the load,the gradual salinity of the reactor after the domestication and the change of sludge particles;the middle temperature with the salinity after domestication After the ammonia oxidizing sludge suddenly drops its salinity,the sludge is too much at room temperature,the reactor biomass is insufficient,the nitrite concentration is too high,the denitrification effect continues to be poor,the particles gradually disintegrate,and the denitrification efficiency With the increase of salinity,the nitrogen removal efficiency decreased gradually.The total nitrogen removal load was 0.64kg/(m~3·d)at low temperature(15°C)salinity 20g/L,and the total nitrogen removal rate was 88.81%.The biomass and nitrous acid under low temperature conditions The salt has obvious inhibition on the denitrification efficiency.As the salinity increases,the EPS increases with the salinity,and the PS/PN ratio increases by 0.39,and the sludge granularity deteriorates.(4)The effects of K~+on the denitrification efficiency under anaerobic ammonium oxidation resistance salinity in short-term and long-term experiments were investigated by static batch and continuous flow tests.The short-term 5mmol/LK~+on unaccompanied anaerobic ammonia oxidation Under the salt stress of 6g/L,X(than anammox activity)can be increased by 35.76%.With the increase of K~+concentration under medium and low temperature and high salinity,the denitrification efficiency first increased and then decreased.5mmol/LK~+is the best promotion point at medium temperature(30°C)high salinity(30g/L),the total nitrogen removal rate is increased by 10.87%,and 10mmol/LK~+is low temperature(15°C)high salinity(20g/L).Under the optimal promotion point,the total nitrogen removal rate increased by 3.94%,and the inhibition of 20mmol/LK~+under medium and low temperature conditions.