Preparation And Characteristics Of Foam Inhibitor For Inhibiting Volatilization Of Ammonia Accident Wastewater

During the emergency treatment of ammonia accidents,a large amount of ammonia-containing wastewater will be produced under the dilution of water spray.Although the concentration is low,the volatility is still very strong.The ammonia dissolved in water（NH₃）will escape into the air again,which will cause serious harm to the life safety of emergency rescue personnel and the surrounding environment.At present,this kind of wastewater is often ignored in the treatment process.Generally,water spray and other methods are used to dilute or absorb ammonia.This method has a certain effect,but its limitations are also obvious.Based on this,this paper explores a new environment-friendly wastewater treatment method-foam covering,which can improve the water spray technology for the disposal of volatile substances.Through the physical barrier and adsorption of the foam layer,the volatilization of ammonia wastewater can be suppressed to achieve the effect of harmless treatment of ammonia accident wastewater.In this paper,Waring Blender method is used to screen and mix the selected surfactants and foam stabilizers,and a combination scheme with strong foaming and foam stabilizing ability is determined.Then the prepared foam is covered on the surface of ammonia wastewater to explore the effect of inhibiting volatilization and the influencing factors.Finally,the scheme of foam inhibiting ammonia volatilization is optimized according to the analysis results,and the research conclusions are as follows:（1）The mechanism of foam covering to inhibit the volatilization of ammonia accident wastewater（or ammonia water）is reflected in two aspects:one is physical barrier,which blocks the ammonia water surface from the outside air;The second is the adsorption of foam membrane,which makes the escaped NH₃trapped in the foam liquid membrane.（2）After the foam blowing agent is compounded,the optimal proportion of the foaming solution is about 0.23%sodium dodecyl sulfate,0.30%lauramide propyl betaine and 0.23%lauryl glucoside.（3）In the inhibition experiment,the volume of foam layer has a significant inhibitory effect on ammonia concentration,ammonia volatilization and maximum NH₃escape.Among the foaming agent types,the anionic type has the worst inhibition effect,and the amphoteric type and compound type have the best effect.However,the concentration of foaming solution has no significant effect on the inhibition effect.After further optimizing the ratio of foam solution,the stability and the inhibition rate of mass loss are also enhanced,but the improvement effect is not obvious in the inhibition of the extreme escape amount.（4）After optimizing the foam suppression scheme,it can be seen that the secondary coverage is obviously better than the single coverage effect.The secondary coverage time is at the beginning of the foam burst,and the coverage amount is the same as the first amount.To sum up,foam coating can effectively inhibit the volatilization of ammonia wastewater,which is reflected in reducing the extreme value of escape amount and delaying the escape rate,so that it can be stabilized at a low level for a long time.Among them,the volume of foam layer is the key factor affecting the inhibition effect.Improving the stability of foam can enhance the physical barrier and adsorption of foam layer.If the stability cannot be further improved,the method of secondary covering can be considered.