1. 总(Zong)的(De)判(Pan)断(Duan)原(Yuan)则(Ze):(?)在(Zai)反(Fan)渗(Shen)透(Tou)膜(Mo)上(Shang)析(Xi)出(Chu)的(De)难(Nan)溶(Rong)盐(Yan)常(Chang)见(Jian)的(De)有(You):(?)CaCO3、(?)CaSO4、(?)SrSO4、(?)BaSO4、(?)CaF2、(?)Si(OH)4、(?)CaSiO3、(?)MgSiO3、(?)FeSiO3等(Deng)。(?)LSI值(Zhi)用(Yong)来(Lai)判(Pan)断(Duan)碳(Tan)酸(Suan)钙(Gai)的(De)结(Jie)垢(Gou)倾(Qing)向(Xiang),(?)而(?)其(Qi)它(Ta)难(Nan)溶(Rong)盐(Yan)如(Ru)CaSO4、(?)BaSO4、(?)CaF2等(Deng)是(Shi)否(Fou)在(Zai)RO膜(Mo)上(Shang)析(Xi)出(Chu),(?)则(Ze)需(Xu)用(Yong)溶(Rong)度(Du)积(Ji)Ksp来(Lai)判(Pan)断(Duan),(?)一(Yi)般(Ban)来(Lai)说(Shuo),(?)这(Zhe)些(Xie)难(Nan)溶(Rong)盐(Yan)的(De)析(Xi)出(Chu)没(Mei)有(You)碳(Tan)酸(Suan)钙(Gai)那(Na)么(Me)快(Kuai),(?)从(Cong)但(Dan)是(Shi),(?)一(Yi)旦(Dan)它(Ta)们(Men)在(Zai)膜(Mo)上(Shang)沉(Chen)淀(Dian),(?)清(Qing)洗(Xi)则(Ze)较(Jiao)困(Kun)难(Nan)。(?)
溶(Rong)度(Du)积(Ji)是(Shi)多(Duo)相(Xiang)离(Li)子(Zi)平(Ping)衡(Heng)的(De)平(Ping)衡(Heng)常(Chang)数(Shu),(?)可(Ke)根(Gen)据(Ju)下(Xia)式(Shi)表(Biao)达(Da):(?) AnBm(s)nA+mB Ksp=[A]n[B]m
溶(Rong)度(Du)积(Ji)常(Chang)数(Shu)与(Yu)水(Shui)中(Zhong)pH、(?)温(Wen)度(Du)和(He)溶(Rong)液(Ye)中(Zhong)其(Qi)它(Ta)盐(Yan)的(De)特(Te)性(Xing)有(You)关(Guan)。(?)然(Ran)而(?),(?)作(Zuo)为(Wei)估(Gu)算(Suan),(?)这(Zhe)些(Xie)变(Bian)量(Liang)对(Dui)Ksp的(De)影(Ying)响(Xiang)可(Ke)忽(Hu)略(Lue)不(Bu)计(Ji)。(?)常(Chang)见(Jian)难(Nan)溶(Rong)盐(Yan)溶(Rong)度(Du)积(Ji)见(Jian)下(Xia)表(Biao)
溶(Rong)度(Du)积(Ji)Ksp与(Yu)反(Fan)渗(Shen)透(Tou)浓(Nong)水(Shui)中(Zhong)离(Li)子(Zi)积(Ji)IPb有(You)如(Ru)下(Xia)关(Guan)系(Xi):(?) IPb>Ksp,(?)沉(Chen)淀(Dian)从(Cong)溶(Rong)液(Ye)中(Zhong)析(Xi)出(Chu) IPb=Ksp, 溶(Rong)液(Ye)为(Wei)饱(Bao)和(He)溶(Rong)液(Ye),(?)并(Bing)与(Yu)沉(Chen)淀(Dian)之(Zhi)间(Jian)建(Jian)立(Li)了(Liao)多(Duo)相(Xiang)离(Li)子(Zi)平(Ping)衡(Heng)。(?) IPb
这(Zhe)就(Jiu)是(Shi)溶(Rong)度(Du)积(Ji)规(Gui)则(Ze),(?)用(Yong)来(Lai)判(Pan)断(Duan)沉(Chen)淀(Dian)的(De)生(Sheng)成(Cheng)和(He)溶(Rong)解(Jie)。(?)为(Wei)慎(Shen)重(Zhong)起(Qi)见(Jian),(?)为(Wei)防(Fang)止(Zhi)难(Nan)溶(Rong)盐(Yan)在(Zai)RO膜(Mo)上(Shang)结(Jie)垢(Gou),(?)一(Yi)般(Ban)要(Yao)求(Qiu)IPb≤(?)0.8Ksp。(?)
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表(Biao)1 常(Chang)见(Jian)难(Nan)溶(Rong)盐(Yan)的(De)溶(Rong)度(Du)积(Ji)
盐(Yan) | Ksp(离(Li)子(Zi)以(Yi)mol/L表(Biao)示(Shi)) | Ksp((?)离(Li)子(Zi)以(Yi)mg/L表(Biao)示(Shi))(?) |
CaSO4 | 2.5*10-5 | 96300 |
SrSO4 | 6.3*10-7 | 5300 |
BaSO4 | 2.0*10-10 | 2.64 |
CaF2 | 5.0*10-11 | 723 |
Si(OH)4 | 2.0*10-3 | 96(mgl/L SiO2) |
注(Zhu):(?)硅(Gui)随(Sui)pH而(?)改(Gai)变(Bian)其(Qi)化(Hua)学(Xue)结(Jie)构(Gou)。(?)其(Qi)溶(Rong)度(Du)积(Ji)与(Yu)其(Qi)结(Jie)构(Gou)及(Ji)温(Wen)度(Du)有(You)关(Guan)。(?)如(Ru)果(Guo)硅(Gui)存(Cun)在(Zai)于(Yu)RO浓(Nong)水(Shui)中(Zhong)的(De)量(Liang)超(Chao)过(Guo)20mg/L,(?)其(Qi)结(Jie)垢(Gou)倾(Qing)向(Xiang)应(Ying)作(Zuo)估(Gu)算(Suan)。(?)
2. 硫(Liu)酸(Suan)钡(Bei)结(Jie)垢(Gou)倾(Qing)向(Xiang)计(Ji)算(Suan)步(Bu)骤(Zhou)如(Ru)下(Xia)
1)(?)计(Ji)算(Suan)浓(Nong)水(Shui)中(Zhong)Ba2+、(?)SO42-浓(Nong)度(Du)((?)mol/L)(?):(?)
[Ba2+]b=CF*[Ba2+]f
[SO42-]b=CF*[SO42-]f
式(Shi)中(Zhong)[Ba2+]b,(?)[SO42-]b------浓(Nong)水(Shui)中(Zhong)Ba2+,(?)SO42-浓(Nong)度(Du)
[Ba2+]f,(?)[SO42-]f------给(Gei)水(Shui)中(Zhong)Ba2+,(?)SO42-浓(Nong)度(Du)
CF-----反(Fan)渗(Shen)透(Tou)装(Zhuang)置(Zhi)的(De)浓(Nong)缩(Suo)系(Xi)数(Shu)
2)(?)计(Ji)算(Suan)离(Li)子(Zi)乘(Cheng)积(Ji)
IPb=[Ba2+]b*[SO42-]b
3) 浓(Nong)水(Shui)中(Zhong)离(Li)子(Zi)强(Qiang)度(Du)的(De)计(Ji)算(Suan)如(Ru)下(Xia)
μ(?)b=CF*μ(?)f
μ(?)f=1/2∑(?)cizi2
式(Shi)中(Zhong)μ(?)f为(Wei)给(Gei)水(Shui)离(Li)子(Zi)强(Qiang)度(Du),(?)也(Ye)可(Ke)列(Lie)为(Wei)ci为(Wei)i离(Li)子(Zi)浓(Nong)度(Du)((?)mol/L)(?);(?)zi为(Wei)i离(Li)子(Zi)的(De)价(Jia)数(Shu)
4)(?)由(You)μ(?)b值(Zhi),(?)查(Cha)离(Li)子(Zi)强(Qiang)度(Du)μ(?)与(Yu)Ksp曲(Qu)线(Xian)图(Tu)。(?)BaSO4的(De)溶(Rong)度(Du)积(Ji)与(Yu)离(Li)子(Zi)强(Qiang)度(Du)关(Guan)系(Xi)见(Jian)下(Xia)图(Tu)
5)(?)比(Bi)较(Jiao)IPb与(Yu)0.8Ksp值(Zhi)
如(Ru)果(Guo)IPb≤(?)0.8Ksp,(?)可(Ke)不(Bu)加(Jia)反(Fan)渗(Shen)透(Tou)阻(Zu)垢(Gou)剂(Ji)
如(Ru)果(Guo)IPb>0.8Ksp,(?)则(Ze)要(Yao)加(Jia)反(Fan)渗(Shen)透(Tou)阻(Zu)垢(Gou)剂(Ji)。(?)
上(Shang)一(Yi)篇(Pian):(?)除(Chu)磷(Lin)剂(Ji)的(De)分(Fen)类(Lei)及(Ji)使(Shi)用(Yong)
下(Xia)一(Yi)篇(Pian):(?)循(Xun)环(Huan)水(Shui)处(Chu)理(Li)简(Jian)介(Jie)
致(Zhi)力(Li)于(Yu)优(You)化(Hua)每(Mei)个(Ge)水(Shui)处(Chu)理(Li)项(Xiang)目(Mu),(?)打(Da)造(Zao)中(Zhong)国(Guo)环(Huan)保(Bao)行(Xing)业(Ye)品(Pin)牌(Pai)企(Qi)业(Ye)
保(Bao)护(Hu)环(Huan)境(Jing)是(Shi)我(Wo)们(Men)每(Mei)个(Ge)人(Ren)的(De)责(Ze)任(Ren)和(He)义(Yi)务(Wu)