Study On The Enhanced Coagulation And Micro-flocculation To Remove The Micro-particles Of Synthetic Gas Scrubbing Wastewater From Synthetic Ammonia

Synthetic gas scrubbing wastewater from synthetic ammonia is produced from synthetic gas section. It is hard to treat because in the process of circulation, a lot of micro-paticles which are from water gas come into the wastewater. The most important objective of this paper is to solve the technology problem, search for the effective treatment process and reuse method. Through to determine SS, COD and particle surface potential of scrubbing wastewater, author analyzed the characteristics of wastewater and the cause of the handle hard. Take the scrubbing wastewater as an object, study the influencing factors of enhanced coagulation and micro-flocculation fiber filtration.Study of enhanced coagulation demonstrated:1) the scope of pH application:PAFC>PAC> FeCl3, pH<6, the flocculation effect of PAFC and PAC is not good,but when pH>7, the effect is good both of them. pH=6-8, the turbidity removal ability of PAC is excellent. The turbidity removal effect of FeCl3 is better in alkaline condition than in acidic condition, and by increasing the dosage of FeCl3, the effective pH is contractible and tend to alkaline condition.2) pH=4, the order of positive charge density is:FeCl3> PAFC> PAC, so the order of the Zata potential is: FeCl3>PAFC>PAC; pH=6～8, the order of the Zata potential is:PAFC>PAC>FeCl3; pH=10, the order of the Zata potential is:PAC>PAFC>FeCl3, but in general, the difference of them is not obvious.3) pH=4, the order of effluent turbidity is:PAFC<PAC<FeC 13; pH=4, the effluent turbidity of PAFC and PAC is closer and is lower than FeCl3; the treatment effect of the three kinds coagulants is very close when the pH between 8～10.4) All of the three kinds coagulants reduce the effluent pH, but PAFC make the most influence, secondly the PAC, and the last is FeCl3, the average effluent pH of the three kinds coagulants arrive at the minimum with the dosage of 120mg/l.Study of the micro-flocculation demonstrated:1) effluent turbidity increased with the increasing filtration rate, the turbidity decreased rapidly within the 120 minutes under the condition of every filter rate, but with the filtration continuing the declining of the turbidity tend to stable.2) The higher initial turbidity, then the effluent turbidity is also higher; under different initial turbidity the removal efficiency was close to.3) Whatever in low initial turbidity or in high initial turbidity, the removal effect of PAC matched with CPAM is better than that of FeCl3, the optimum dosage of PAC and CPAM is, PAC:5mg/1, CPAM: 0.2mg/l; the optimum dosage of FeCl3 is 5mg/1.4) Effluent turbidity was decreasing with the increasing of the degree of filter compression.5) In the long-period operating condition, effluent turbidity can be stable within 10 minutes, the turbidity of the mature period showed a single downward trend. Effective operation period of high turbidity water conditions is up to 20h.6) Whatever in which operate conditions, the effect of the filler S is the best, secondly is the filler P, then is the filler R, according with the density of the three kinds filler(S>P>R).