Effects Of NME And NPE On Sewage Treatment And Sludge Reduction

According to relevant statistics,the disposal cost of the waste water in the sewage treatment plant accounts for about half of the operating cost of the sewage treatment plant.Therefore,the study on sludge reduction is very necessary.At present,the most commonly used in the sludge reduction process is the addition of.uncouplers Uncouplers are generally difficult to degrade and have a certain degree of biological toxicity.And there is the problem of secondary pollution According to relevant literature research,nipagin methyl ester and nipagin propyl ester are commonly used antiseptic and antimicrobial agents and are widely used in cosmetics.These two kinds of antibacterial agents basically do no harm to the human body.The experiments study the water treatment and sludge reduction with NME alone,NPE alone and the two combined.Through the study of this experiment,it is expected to develop a new type of sludge reduction technology that is environmentally friendly and has no harm to the human body.The effect of different concentrations of nipagin methyl ester on the system sludge reduction effect and the system sewage treatment effect was observed firstly.The reactor was operated for more than 40 days.The results showed that when the concentration of nipagin methyl ester was 1 mg/L,the effect of sludge reduction was the best at 38%.The results showed that the concentration 1 mg/L of nipagin methyl ester had little effect on the removal rates of COD,NH₄⁺-N and TN in the system.However,the removal rate of phosphate is quite different.In the actual engineering application,we can use chemical phosphorus removal to increase the removal rate of PO₄^3--P in the system.Compared with the effluent which has no antibacterial agent,the average removal rate of COD was increased by 2.3%;The average removal rate of NH₄⁺-N was decreased by 0.47%;the average removal rate of PO₄^3--P was decreased by 12.36%;the average removal rate of TN was decreased by 2.08%.Then the concentration gradient setting is unchanged.The NPE is studied.Considering the effect of concentration and sludge reduction,the optimal concentration of nipagin propyl ester is 5 mg/L.The results showed that when the concentration of nipagin proply ester was 5 mg/L,the effect of sludge reduction was the best at 41%.The results showed that the concentration 5 mg/L of nipagin propyl ester will improve the removal rates of COD,NH₄⁺-N and TN in the system,although the influence is very slightly.However,the removal rate of phosphate is decreased.Compared with the effluent which has no antibacterial agent,the average removal rate of COD was increased by 2.76%;The average removal rate of NH₄⁺-N was increased by 13.12%;the average removal rate of PO₄^3--P was decreased by 6%;the average removal rate of TN was increased by 10.05%.Through the above study,the concentration of 1mg/L nipagin methyl paraben was determined to be the best effect of sludge reduction.and nipagin propyl ester was considered in consideration of the concentration and sludge reduction,and the relatively better concentration of 5 mg/L was selected.When NME and NPE are combined.The percent of NME and NPE showed above of each reactor is R0:0%,0%;R1:0%,100%;R2:25%,75%;R3:50%,50%;R4:75%,25%;R5:100%,0%;R2 has the best sludge reduction effect at 31%.T he effect increased by9%and 13% compared to nipagin propyl ester alone and nipagin methyl parabealone.And the effect of sewage treatment has sligtly difference to the blank group.At the same time,the EPS,sludge elemental analysis,and sludge dewaterin g performance of the system sludge were analyzed after 42 days of reactor operation.It was found that the nipagin methyl ester and nipagin propyl ester had no harm to the system under the conditions with the best sludge reduction effect,but the sludge element analysis showed that the calorific value of the sludge would be reduced to some extent,and the dewatering performance was basically the same as that of the blank group.SOUR was used to characterize the activity of microorganisms in different SBR systems,and the Monod equation was used.Fit the system's microbial utilization rate of dissolved oxygen.When the substrate is sufficient,the microorganisms degrade the organic matter at the maximum metabolic rate,which is in accordance with the zero-order reaction kinetics.When the substrate is relatively small,the metabolic rate conforms to the first-order kinetics.The experimental results are also basically consistent with the Monon equation.