39.Yintoni iasidi yamanzi kunye nealkalinity?
Ubumuncu bamanzi bubhekisa kwisixa sezinto eziqulethwe emanzini ezinokuthoba iziseko ezomeleleyo. Kukho iintlobo ezintathu zezinto ezenza i-asidi: i-acids eqinile enokuthi idibanise ngokupheleleyo i-H + (efana ne-HCl, i-H2SO4), i-acids ebuthathaka ehlukanisa ngokuyinxenye i-H+ (H2CO3, i-organic acids), kunye neetyuwa ezenziwe ngee-asidi ezomeleleyo kunye neziseko ezibuthathaka (ezifana ne NH4Cl, FeSO4). I-Acidity ilinganiswa nge-titration kunye nesisombululo esisisiseko esomeleleyo. I-acidity elinganiswe nge-methyl orange njengesalathisi ngexesha le-titration ibizwa ngokuba yi-methyl orange acidity, kubandakanywa ne-acidity eyenziwe luhlobo lokuqala lwe-asidi eqinile kunye nohlobo lwesithathu lwetyuwa eqinile; i-acidity elinganiswe ngephenolphthalein njengoko isalathisi sibizwa ngokuba yi-phenolphthalein acidity, Sisimbuku sezi ntlobo zintathu ze-asidi zingentla, ngoko ke ikwabizwa ngokuba yi-acidity epheleleyo. Amanzi endalo ngokubanzi akanayo iasidi eyomeleleyo, kodwa aqulethe i-carbonates kunye neebhicarbonates ezenza amanzi abe alkaline. Xa kukho iasidi emanzini, kudla ngokuthetha ukuba amanzi angcoliswe yiasidi.
Ngokwahlukileyo kwi-acidity, i-alkalinity yamanzi ibhekiselele kwisixa sezinto ezisemanzini ezinokunciphisa iiasidi ezinamandla. Izinto ezenza i-alkalinity ziquka iziseko ezomeleleyo (ezifana ne-NaOH, KOH) ezinokuthi zidibanise ngokupheleleyo i-OH-, iziseko ezibuthathaka ezihlukanisa i-OH- (ezifana ne-NH3, i-C6H5NH2), kunye neetyuwa ezenziwe ngeziseko ezinamandla kunye ne-acids ezibuthathaka (ezifana ne-Na2CO3; K3PO4, Na2S) kunye nezinye iindidi ezintathu. I-alkalinity ilinganiswa nge-titration kunye nesisombululo esinamandla se-asidi. I-alkalinity elinganiswa kusetyenziswa i-methyl orange njengesalathisi ngexesha le-titration sisimbuku sezi ntlobo zintathu zingentla ze-alkalinity, ebizwa ngokuba yi-alkalinity epheleleyo okanye i-methyl orange alkalinity; umlinganiselo we-alkalinity usebenzisa i-phenolphthalein njengoko isalathisi sibizwa ngokuba yi-phenolphthalein base. Idigri, kubandakanywa ialkalinity eyenziwe luhlobo lokuqala lwesiseko esomeleleyo kunye nenxalenye yealkalinity eyenziwe luhlobo lwesithathu lwetyuwa elomeleleyo yealkali.
Iindlela zokulinganisa ubumuncu kunye ne-alkalinity ziquka i-acid-base indicator titration kunye ne-potentiometric titration, eziguqulwa ngokubanzi zibe yi-CaCO3 kwaye zilinganiswe nge-mg/L.
40.Lithini ixabiso le-pH yamanzi?
Ixabiso le-pH yi-logarithm engalunganga yomsebenzi we-ion ye-hydrogen kwisisombululo samanzi esilinganisiweyo, oko kukuthi, pH=-lgαH+. Ngenye yezibonakaliso ezisetyenziswa ngokuqhelekileyo kwinkqubo yokucocwa kwamanzi amdaka. Ngaphantsi kweemeko ze-25oC, xa ixabiso le-pH liyi-7, imisebenzi ye-hydrogen ions kunye ne-hydroxide ions emanzini iyalingana, kwaye i-concentration ehambelanayo yi-10-7mol / L. Ngeli xesha, amanzi angathathi hlangothi, kwaye ixabiso le-pH> 7 lithetha ukuba amanzi ane-alkaline. , kunye nexabiso le-pH<7 means the water is acidic.
Ixabiso le-pH libonisa i-asidi kunye ne-alkalinity yamanzi, kodwa ayikwazi ukubonisa ngokuthe ngqo i-acidity kunye ne-alkalinity yamanzi. Ngokomzekelo, i-acidity ye-0.1mol / L yesisombululo se-hydrochloric acid kunye ne-0.1mol / L isisombululo se-acetic acid nayo yi-100mmol / L, kodwa ixabiso labo le-pH lihluke kakhulu. Ixabiso le-pH ye-0.1mol / L isisombululo se-hydrochloric acid yi-1, ngelixa ixabiso le-pH le-0.1 mol / L isisombululo se-acetic acid yi-2.9.
41. Zeziphi iindlela eziqhelekileyo zokulinganisa ixabiso le-pH?
Kwimveliso eyiyo, ukuze ukhawuleze kwaye ubambe ngokukhawuleza utshintsho kwixabiso le-pH lamanzi amdaka angena kwindawo yokucocwa kwamanzi amdaka, eyona ndlela ilula kukulinganisa ngephepha lovavanyo lwe-pH. Kumanzi amdaka angenambala ngaphandle kokungcola okunqunyanyisiweyo, iindlela ze-colorimetric nazo zingasetyenziswa. Okwangoku, indlela esemgangathweni yelizwe lam yokulinganisa ixabiso le-pH lomgangatho wamanzi yindlela ye-potentiometric (i-GB 6920-86 yeglasi ye-electrode method). Ngokuqhelekileyo ayichaphazeli umbala, i-turbidity, izinto ze-colloidal, i-oxidants, kunye nee-agent zokunciphisa. Inokulinganisa i-pH yamanzi acocekileyo. Isenokulinganisa kwakhona ixabiso le-pH lamanzi amdaka emizi-mveliso angcoliseke ngokweqondo elahlukileyo. Le ikwayindlela esetyenziswa ngokubanzi yokulinganisa ixabiso le-pH kuninzi lwezityalo zokucocwa kwamanzi amdaka.
Umgaqo wokulinganisa i-potentiometric yexabiso le-pH kukufumana amandla e-electrode ebonisayo, oko kukuthi, ixabiso le-pH, ngokulinganisa umahluko okhoyo phakathi kwe-electrode yeglasi kunye ne-electrode yereferensi enamandla eyaziwayo. I-electrode yereferensi ngokuqhelekileyo isebenzisa i-calomel electrode okanye i-electrode ye-Ag-AgCl, kunye ne-calomel electrode isetyenziswa kakhulu. Undoqo we-pH potentiometer yi-DC amplifier, eyandisa amandla okwenziwa yi-electrode kwaye ibonise kwintloko yemitha ngendlela yamanani okanye izikhombisi. I-Potentiometers idla ngokuxhotyiswa ngesixhobo sembuyekezo yeqondo lokushisa ukulungisa umphumo weqondo lokushisa kwi-electrode.
Umgaqo wokusebenza wemitha ye-pH ye-intanethi osetyenziswa kwizityalo zokucocwa kwamanzi amdaka yindlela enokuthenjwa, kwaye izilumkiso zokusetyenziswa ziyafana nezo zeemitha ze-pH zaselabhoratri. Nangona kunjalo, ngenxa yokuba i-electrodes esetyenzisiweyo isoloko ifakwe emanzini amdaka okanye iitanki zomoya kunye nezinye iindawo eziqulethe inani elikhulu leoli okanye i-microorganisms ixesha elide, ngaphezu kokufuna imitha ye-pH ukuba ixhotyiswe ngesixhobo sokucoca ngokuzenzekelayo kwi-electrodes, i-manual. ukucoca kwakhona kuyafuneka ngokusekelwe kwiimeko zomgangatho wamanzi kunye namava okusebenza. Ngokubanzi, imitha ye-pH esetyenziswa kumanzi angenayo okanye itanki yokungenisa umoya icocwa ngesandla kanye ngeveki, ngelixa imitha ye-pH esetyenziswa kumanzi amdaka inokucocwa ngesandla kanye ngenyanga. Kwiimitha ze-pH ezinokulinganisa ubushushu kunye ne-ORP kunye nezinye izinto, kufuneka zigcinwe kwaye zigcinwe ngokwemiqathango yokusetyenziswa efunekayo kumsebenzi wokulinganisa.
42.Ngawaphi amanyathelo okuthintela ukulinganisa ixabiso le-pH?
⑴I-potentiometer kufuneka igcinwe yomile kwaye ingangenwa luthuli, inikwe amandla rhoqo ukuze igcinwe, kunye nenxalenye yoqhagamshelo olukhokelela kwi-electrode kufuneka igcinwe icocekile ukunqanda amathontsi amanzi, uthuli, i-oyile, njalo njalo. Qinisekisa umgangatho olungileyo xa usebenzisa amandla e-AC. Ii-potentiometers eziphathekayo ezisebenzisa iibhetri ezomileyo kufuneka zibuyisele iibhetri rhoqo. Ngexesha elifanayo, i-potentiometer kufuneka ihlaziywe rhoqo kwaye i-zeroed ukulinganisa kunye nokugcinwa. Emva kokuba ihlanjululwe ngokufanelekileyo, indawo ye-zero ye-potentiometer kunye ne-calibration kunye ne-positioning regulators ayikwazi ukujikelezwa ngokuthanda ngexesha lovavanyo.
⑵Amanzi asetyenzisiweyo ukulungisa isisombululo se-buffer esisemgangathweni kunye nokuhlamba i-electrode akufuneki iqulathe i-CO2, ibe nexabiso le-pH phakathi kwe-6.7 kunye ne-7.3, kunye ne-conductivity engaphantsi kwe-2 μs/cm. Amanzi aphathwe ngeanion kunye ne-cation exchange resin angahlangabezana nale mfuneko emva kokubilisa kwaye ayiyeke ipholile. Isisombululo esilungisiweyo se-buffer standard kufuneka sitywinwe kwaye sigcinwe kwibhotile yeglasi enzima okanye ibhotile ye-polyethylene, kwaye emva koko igcinwe kwifriji kwi-4oC ukwandisa ubomi benkonzo. Ukuba igcinwe kumoya ovulekileyo okanye kwiqondo lobushushu begumbi, ubomi benkonzo ngokubanzi abunakudlula kwiinyanga ezi-1, isithinteli esisetyenzisiweyo asinakubuyiselwa kwibhotile yokugcina ukuze iphinde isetyenziswe.
⑶ Phambi komlinganiselo osesikweni, qala ujonge ukuba isixhobo, i-electrode, kunye nesithinteli esiqhelekileyo ziqhelekile na. Kwaye imitha ye-pH kufuneka ilinganiswe rhoqo. Ngokuqhelekileyo umjikelo wokulinganisa yikota enye okanye isiqingatha sonyaka, kwaye indlela yokulinganisa amanqaku amabini isetyenziselwa ukulinganisa. Oko kukuthi, ngokoluhlu lwexabiso le-pH lwesampulu eza kuvavanywa, izisombululo ezibini zesithinteli eziqhelekileyo ezikufutshane kuyo zikhethiwe. Ngokubanzi, umahluko wexabiso le-pH phakathi kwezisombululo ezibini zesithinteli kufuneka ubuncinane ube mkhulu kune-2. Emva kokubeka kwindawo ngesisombululo sokuqala, vavanya isisombululo sesibini kwakhona. Umahluko phakathi kwesiphumo sokubonisa se-potentiometer kunye nexabiso le-pH eliqhelekileyo lesisombululo se-buffer sesibini esisemgangathweni akufanele sibe sikhulu kune-0.1 yeyunithi ye-pH. Ukuba impazamo inkulu kune-0.1 yeyunithi ye-pH, isisombululo sesithathu somgangatho wesithinteli kufuneka sisetyenziswe kuvavanyo. Ukuba impazamo ingaphantsi kwe-0.1 yeeyunithi ze-pH ngeli xesha, kunokwenzeka ukuba kukho ingxaki kwisisombululo se-buffer sesibini. Ukuba impazamo isenkulu kuneyunithi ye-pH ye-0.1, kukho into engalunganga nge-electrode kwaye i-electrode kufuneka iqhutywe okanye ifakwe entsha.
⑷Xa utshintsha i-buffer eqhelekileyo okanye isampuli, i-electrode kufuneka ihlanjululwe ngokupheleleyo ngamanzi adibeneyo, kwaye amanzi afakwe kwi-electrode kufuneka afakwe ngephepha lokucoca, aze ahlanjululwe ngesisombululo sokulinganiswa ukuphelisa impembelelo efanayo. Oku kubalulekile kusetyenziso lwezithinteli ezibuthathaka. Oku kubaluleke ngakumbi xa usebenzisa izisombululo. Xa ulinganisa ixabiso le-pH, isisombululo esinamanzi kufuneka sixutywe ngokufanelekileyo ukwenza isisombululo sifane kwaye sifezekise ukulingana kwe-electrochemical. Xa ufunda, ukushukumisa kufanele kuyekwe kuze kumiswe ixeshana ukuze ufundo luzinze.
⑸ Xa ulinganisa, qala uhlambe i-electrode ezimbini ngononophelo ngamanzi, emva koko uhlambulule ngesampulu yamanzi, emva koko untywilisele i-electrodes kwibhekile encinci enesampulu yamanzi, hlunguza ibhekile ngononophelo ngezandla zakho ukwenza iyunifomu yamanzi, kwaye urekhode Ixabiso le-pH emva kokuba ufundo luzinzile.
Ixesha lokuposa: Oct-26-2023
