敞开式循环冷却水的pH值碱度及加酸量估算齐冬子

·10·IndustrialwaterWastewaterVol.30NO.21999pH、齐冬子(100031):从分析水中pH与碳酸盐碱度的关系入手,在总结大量实践经验的基础上,提出了三种类型补充水的循环冷却水的总碱度与pH值之间的关系式。在分析了循环冷却水的自然pH变化规律后,归纳出了四种不同类型补充水的循环冷却水的自然pH值的计算公式,提出了循环冷却水中加酸量的估算公式。:循环冷却水;碱度;加酸量计算:TU991.27:A:1006_4826(1999)02_0010_05EstimationofpHValue,AlkalinityandAcidAddingQuantityinOpenSytemofRecirculatingCoolingWaterQIDong_ziABSTRACT:TherelationalexpressionsbetweenthetotalalkalinityandpHvalueofthreekindsofmake_uprecirculatingcoolingwaterareraisedbyanalyzingtherelationshipbetweenpHandcarbonatealkalinityofthewaterandsummarizingplentyofpracticalexperiences.ThenaturalpHvaluecalculationformulaeoffourdifferentkindsofmake_uprecirculatingcoolingwaterareestablishedandanestimationformulaofaddingacidinrecirculatedcoolingwaterisproposedafteranalyzingthelawofthenaturalpHchangeofrecirculatingcoolingwater.KEYWORDS:recirculatingcoolingwater;alkalinity;acidaddingcalculation:1999-03-08pH。,pH。pH。,。,。,,,《》1994,No.3。。1pHpH。,H+。:①:NaOH、Ca(OH)2,OH-;②:NH3、C6H5NH2,OH-;③:、、、、、,OH-,H+。,、、、。M:·11·IndustrialwaterWastewaterVol.30NO.219991pH(%)H2CO3100α010099.9999.9699.8699.5698.6295.7587.7069.2041.6218.646.74100α10.010.040.140.441.384.2512.3030.8058.3781.3293.12100α20.010.040.14pH2.02.53.03.54.04.55.05.56.06.57.07.5100α197.0897.8395.3687.0368.0240.2217.546.302.080.670.21pH8.08.59.09.510.010.511.011.512.012.513.0M=[HCO3-]+2[CO32-]+[HO-]-[H+](1)pH7.0,[H+];[OH-]pH10;pH6～9,(1)[HO-]-[H+],:M=[HCO3-]+2[CO32-](2),。HCO3-CO32-(),,()。CO2,CO2H2CO3。:CO2+H2OH2CO3,CO2,H2CO31%,25℃,[H2CO3]/[CO2]=0.0037()。,CO2。,[CO2][H2CO3],[H2CO3]=[CO2]=[CO2+H2CO3],:H2CO3H++HCO3-HCO3-H++CO32-K1=[H+][HCO3-][H2CO3]=4.45×10-7(25°C)(3)K2=[H+][CO32-][HCO3-]=4.69×10-11(25°C)(4),K1、K2。Ct,:Ct=[H2CO3]+[HCO3-]+[CO32-]α0、α1α2H2CO3、HCO3-CO32-,:Ct=Ct·α0+Ct·α1+Ct·α2α0+α1+α2=1、pH,K1、K2。25℃,(%)1。pH:pH=-lg[H+](5)(3)[H+](5),:pH=lg[HCO3-]-lgK1-lg[H2CO3]pK1=-lgK1,:pH=lg[HCO3-]+pK1-lg[H2CO3](6)(6)pH。pK1,。pH6～9,1,HCO3-,CO32-。,MHCO3-,(6):pH=lgM+pK1-lg[H2CO3](7),pH。pH,。(6)、(7),pH(pH)。pH,;pH,;pHlgM。pH。pH。,pH,。pH,,。pH,HCO3-CO32-,CaCO3;pH,HCO3-CO32-,CaCO3。(6)、(7)pH,。[H2CO3],、、,。:HCO3-CO32-CO32-HCO3-H2CO3100α02.460.720.170.040.01100α20.461.454.4712.9331.9759.7882.4693.7097.9299.3399.79·12·IndustrialwaterWastewaterVol.30NO.219992MpH。(6)、(7)、。,,。①pHlgM,。②MpH,MN。pHpH、MN,pH,MM、N,。pH,MM、N。,NMM。③pH_M。。,pH_M,。,2。TH。pH、TH、M,。:pHpH。M、M、THmg/L,CaCO3。ⅠlgM=0.629pH-3.0276.8～8.550～30050～300pHTHMⅢlgM=0.679pH-3.6706.5～7.59.0～11.05015050150Ⅱ()lgM=0.608pH-2.5427.5～8.550～150200～300■。2pHpH,pH,。pH,,pH。pH,。。:,pH。pH,。:,,。,,,CO2CO2。CO2,CO2,CO2。,,CO2,。Ca(HCO3)2—※CaCO3↑+H2O+CO2←,CO2。α0、α1α2,,N·M。pHpH。pH。。,3。,pH。,。,M。pH、THN,。,。pH。pH。pH。。ABpH。,,,pH。。ApH9.0,B9.3。D,pH,pH。,CO2、。·13·IndustrialwaterWastewaterVol.30NO.219993pH(N=1.3～5.0)pHTHMAApH=6.78+0.204pH+0.094N+0.0022M6.8～8.350～30050～200BB()pH=6.75+0.204pH+0.0819N+0.0022M7.5～8.550～300200～300,:AM=50～200mg/L,CaCO3;BM200mg/L,CaCO3。CpH=pH+0.1N+0.86.5～7.55050DpH=7.90+0.1N+0.0055M9.0～11.0150150,HCO3-,CO32-,OH-。CO32-OH-CO2HCO3-,pH。HCO3-pH。pH9.0～11.0,8.5。,CpH,。pH,8.0。3pH、3.1自然pH值的估算pH、A、B、CD,N、pHMpH。,pH。,pH。,FeCl3Al2(SO4)3pH0.4～0.5,。。,,pH=pH,M=M。3.2总碱度的估算pH、Ⅰ、ⅡⅢ,pH。pH,pH。。,,HCl,pH。,pH。,pH0.1～1.1。,。,,NO3-NO2-,pH,。A、B、CDpH,pH,0.2。,pH。pH,pH。pH。3.3加酸量的估算pH,,ΔM。ΔM=M-M(mg/L,CaCO3):M—pH,mg/L(CaCO3);M—pH,mg/L(CaCO3)。,。ΔMA。98%pH,A=49ΔM/(50×0.98×1000)=ΔM/1000,(g/L)(kg/m3)49[H+]molH2SO4,g/[H+]molH2SO4()。V·A。V,(m3)。B·A。B·14·IndustrialwaterWastewaterVol.30NO.219994pH-M(),m3/h。3.4加酸量计算方法中应注意的问题ΔM,ΔM。。①ΔM=M-M,=×A。pHpH。pHpH,。,pHpH,pH。,pHpH。ΔMM-M。pHpH,pH。,pH。,,B×A。:。:,,B×A。②M。Ct=M/(α1+2α2),pHα1α2。Ct=Ct=M/(α1+2α2)=M/(α1+2α2)。M。ΔM,。。Ct,。3.5碱度计算的图解法Ⅰ、ⅡⅢM,。,pH-MpH-M,1。,。,M,,pH。,pH-M。pH、M,,。,,,。pH6.0、7.59.0M(4),,,。图1循环水的pH-M关系pH6.0pH7.5pH9.0lgM0.7471.1060.404M430.53851.14276.06M5.5812.762.54lgM1.69052.0181.4225lgM2.6342.932.441ⅠⅡⅢM49.03104.2326.45pH-M。pHM。,MpH。pH、M。pH-M,pH-M,。3.6电脑计算法,、,。,,,、pH,pH、、、pH、、。,,。,。:,,。