The Emergency Capacity Of Aniline Using PAC In Water Treatment Plant And The Selection Of The Disposal Technology Of Emergency Waste

With the rapid developmeng of economy,that the increasing emergent water resource pollutions events has received wide attention.As the last line of a gate,the water treatment plant bear the burden of supplying secure drinking water. The activated carbon adsorption has been regarded as the most effective method adopted by most water treatment plants.Aniline being the subject of the study,this paper aims to find out the extent to what the powdered activated carbon(PAC) can deal with.The result of the study can give some suggestions when another emergency pollution happens.Besides,after the adsorption,the PAC came into sludge with aniline in high concentration.The best disposal technology was screened out by establishing a set of index system.The result can give some advice to the disposal of h azardous waste and environment management.By adsorption capacity experiment and adsorption kinetics experiment,1#PAC is screened as the best activated carbon for its adsorption capacity.When the amont of PAC equals to 80mg/L,the largest concentration of aniline allowed is 0.7mg/L,on the condition that the concentration of aniline is reduced to 0.1mg/L.When it comes to raw water from Songhua River,however,the concentration of aniline allowed is reduced to 0.3mg/L,with the amont of PAC the same,because of the competitive adsorption of NOM.To figure out the adsorption mechanism,the characterization of 3 kinds of PAC is carried out by nitrogen adsorption-desorption test,idoine sorption value,phenol sorption value,p H of point of zero charge and Boehm titration. It turns out that 2#PAC and 3#PAC exceed 1#PAC far and away in specific surface area and pore volume.But 1#PAC has a basic surface while 2#PAC and 3#PAC has a acid surface.Considering the different adsorption effect of the 3 kinds of PAC,it was concluded that the surface chemical property of the PAC plays a significant role in the adsorption behavior of aniline.Thus it is suggested that p H of point of zero charge be considered in PAC selection.In addition,the adsorption capacity of phenol depends on not only the pore structure,but the functional group on the PAC,thus the phenol sorption value is not proper for the pore diameter.To see how different modification methods of PAC affect the adsorption of aniline and intensify the adsorption effect and reduce the amount of PAC used,three different modification methods were adopted.It turns out that KOH modification increased the adsorption capacity by 2.5 times,with a more basic surface.The 2#PAC behaved the best when the ratio of KOH to PAC was 3,which can deal with raw water when the concentration of aniline was 0.5mg/L.The adsorption capacity of PAC after HNO3 treated,however, is reduced with a lower p Hpzc and more acid oxygen-containing functional group which augmented the competitive adsorption of water.Ammonium hydroxide modification doesn’t influence the adsorption behavior.The PAC additioned at the water-intake came into the feed water sludge after coagulation and precipitate,with aniline in high concentration,whict must be carefully disposed as hazardous waste.To screen out the most porper disposal technology,a set of index system with 4 criterion layer,12 indexes is established.Analytic hierarchy process helped to calculate the weitht of each index.To multiply the weight by the corresponding score,the fin al scores of each disposal method was known.The first two methods suggested were cement kiln and hazardous wastes co-process technology and incineration.