氨吹脱过程的传质模型万文玉

万文玉,肖宝清(北京科技大学土木与环境工程学院,北京100083):,,,。,,,,ηpH、、,,,85%。:;;;:TQ113;TB657.7　:A　:0253-4320(2007)S1-0331-04MasstransfermodelofammoniaremovalWANWen-yu,XIAOBao-qing(SchoolofConstructionandEnvironmentalEngineering,BeijingUniversityofScienceandTechnology,Beijing100083,China)Abstract:Anewammoniaevaporationcolumnwithsprayerreplacingstuffingisdesigned,inwhichammonianitrogenwastewatercontactsupliftedairflowafteratomized,andthepurgingefficiencyofammonianitrogenisincreasedbyincreasingitsinterface.Reasonablehypothesesoftheprocessaremade,andamasstransfermodelofammoniaremovalprocessisobtainedusingdifferentialcalculus.thefactorsincludingpH,temperature,runtimeandairfeedwhichaffectthepurgingefficiencyofammonia-nitrogenarediscussed.Theresultsshowedtheremovalratioofammoniacouldbeabove85%underproperconditionsbyusingthenewammoniaevaporationcolumn.Keywords:ammoniaevaporationcolumn;blow-denitrogenation;ammonianitrogenwastewater;masstransfermodel　:2006-11-09　:(1981-),,,,[e-mail];(1966-),,,,。　　,,、,,,[1-2]。(NH+4)(NH3),,:NH3+H2ONH+4+OH-。,pH;,,pH,,,,,[3-4]。,,,,。[5],,、[6]。1　(1),,。:,NaOHpH,,,,,。1—;2—;3—;4—;5—;6—;7—图1　试验装置图·331·27(1)现代化工June200720076ModernChemicalIndustryDOI:10.16606/j.cnki.issn0253-4320.2007.s1.0852　2.1　(1),,,,,2,,1,,2。图2　液滴内部浓度分布示意图　　:ci,cL,rm,rf。(2),,;(3),,;(4);(5),,;(6),。2.2　(1)[7],ce=PG·H(1),ce(mol/L),PG(kPa),H。Fick[8],J=-Dcir(2),JNH3[kmol/(s·m2)],ci(mol/L),r(m),DNH3(m2/s)。rr+Δr,(6):4πr2Jr-4π(r+Δr)2Jr+Δr=0(3)　　:r=rf,ci=cL;r=rm,ci=ce=PG·H,cL(mol/L);(2)(3):J=Drmrf(cL-ce)r2(rm-rf)　(rfrrm)(4)(2)Jr=rfdt=-cLdrf(5)　　(4)(5),drfdt=-Drm(cL-ce)cLrf(rm-rf)(6)　　(上接第330页)2　/μm0～2020～4040～6060～8080～105105～1491492.765.1922.8931.6723.5311.822.1471.741#4.047.0224.330.5520.3512.021.7269.882#2.526.3621.6733.3523.911.40.872.023#2.175.8923.5232.8321.6310.943.0271.014#2.767.9522.1728.8724.3212.911.0268.315#3.967.1322.5529.5625.429.372.0167.826#1.284.7626.830.7721.0911.780.5270.877#1.758.9226.0229.0223.119.072.1170.018#2.08.5622.0132.0322.8810.591.9369.899#3.817.8819.634.8121.9811.030.8970.972,,,,。3　,、、、,。,,、、、,,。[1],.[M].:,1989:163-172.[2],.[M].:,1998.[3],.[J].,1998,19(3):37-39.□·332·现代化工27(1)　　:t=0,rf=rm,t(s);(6):2r3f+r3m-3rmr2f=6Drm(cL-ce)cLt(7)　　(3)NH3:-VLdcdt=4nπr2mJr=rm(8)　　　VL=nB,VL(m3),c(mol/L),n,B。(8)dcdt=-4πr2mBDrf(cL-ce)rm(rm-rf)(9)　　:t=0,c=cL,rf=rm,(9)(6),dcdrf=4πr2fBcL(10)　　:c=cL,rf=rm,(10),c=cL-43πBcL(r3m-r3f)(11)　　NH3ηη=cL-ccL=1-ccL(12)　　(11)(12),rf=3r3m-3η4πB(13)　　(13)(7),r3m-η2πB-rm(r3m-3η4πB)23=2Drm(cL-ce)cLt(14)　　(14)。2.3　η(14),ηcL、ce、rm、D、B、t,(3)、(4),D,Brm,,cL、ce、t。(1)G=2r3f+r3m-3rmr2f(15)rf,:G′=6rf(rf-rm)0(16)　　(16),(15)0,,Grf。(2)G=6Drm(cL-ce)cLt(17)G=6Drm(1-cecL)t(18)(18),GcL、t,ce。(3)(13),ηrf。2.3(1)～(3),ηcL、t,ce。2.4　2.4.1　pH对吹脱效率的影响80℃,30min,0,pH3。/g·L-1:1—3.0;2—1.0;3—0.6;4—0.1图3　pH对吹脱效率的影响3,pH,。pH。pH,,,cL,,,η。2.4.2　温度对吹脱效率的影响pH11,30min,0,4。/g·L-1:1—3.0;2—1.0;3—0.6;4—0.1图4　温度对吹脱效率的影响4,,。,,,,ce;,,,,cL,,,η。·333·20076:2.4.3　吹脱时间对吹脱效率的影响pH11,1.63m3/min,80℃,5。/g·L-1:1—3.0;2—1.0;3—0.6;4—0.1图5　吹脱时间对吹脱效率的影响5,,。η,tη。,cLce0,,ηt。2.4.4　鼓风量对吹脱效率的影响pH11,80℃,30min,,6。/g·L-1:1—3.0;2—1.0;3—0.6;4—0.1图6　鼓风量对吹脱效率的影响6,pH1180℃,,,PG,,0,,PG,,ce,η。3　(1),,,,。(2),,,,r3m-η2πB-rm(r3m-3η4πB)23=2Drm(cL-ce)cLt　　(3)ηpH,,。(4),,85%,,,。[1]CheungKC,ChuLM,WongMH.Ammoniastrippingasapretreatmentforlandfillleachate[J].Water,AirandSoilPollution,1997,94:209-221.[2],.[M].:,1989.[3].[M].:,1985.[4],,.[J].,2005,20(1):9-12.[5]SmithPG,ArabFK.Theroleofairthebubblesinthedesorptionofam-moniafromlandfillleachateinhighphaeratedlagoon[J].Water,AirandSoilPult,1998,38(3/4):333-343.[6],.[J].,1999,12(2):67-71.[7],.[M].:,2001.[8]CusslerEL.[M].:,2002.□　　:CN200580011392.0:CN1942527,:(1)、(Tm),2、;(2)(Tg)Tm。、,:60℃36600.5mm20%;25℃、50Hz(E′)1×108～2×109Pa;60℃、50Hz(E′)1×107～1×109Pa。:·334·现代化工27(1)