Imfuno yeoksijini yeekhemikhali ikwabizwa ngokuba yimfuno yeoksijini yeekhemikhali (imfuno yeoksijini yeekhemikhali), ebizwa ngokuba yiCOD. Kukusetyenziswa kweekhemikhali oxidants (ezifana ne-potassium permanganate) uku-oxidize kunye nokubola izinto ezinokuthi zibole emanzini (ezifana ne-organic matter, i-nitrite, ityuwa ye-ferrous, i-sulfide, njl.), kwaye emva koko ubale ukusetyenziswa kwe-oksijini ngokusekelwe kwisixa sentsalela. i-oxidant. Njengemfuno yeoksijini ye-biochemical (BOD), luphawu olubalulekileyo lokungcoliseka kwamanzi. Iyunithi yeCOD yi ppm okanye mg/L. Ixabiso elincinci, kokukhona ungcoliseko lwamanzi lube khaphukhaphu.
Izinto ezinciphisa emanzini ziquka izinto ezahlukeneyo eziphilayo, i-nitrite, i-sulfide, ityuwa ye-ferrous, njl. Kodwa eyona nto iphambili yinto ephilayo. Ngoko ke, imfuno ye-oksijini yeekhemikhali (COD) isoloko isetyenziswa njengesalathisi sokulinganisa ubungakanani bezinto eziphilayo emanzini. Okukhona imfuno yemichiza yeoksijini, kokukhona iba mandundu ngakumbi ukungcoliseka kwamanzi ngezinto eziphilayo. Ukumiselwa kwemfuno ye-oksijini yeekhemikhali (COD) iyahluka ngokumiselwa kokunciphisa izinto kwiisampuli zamanzi kunye nendlela yokumisela. Ezona ndlela zixhaphakileyo zisetyenziswayo ngoku yi-acidic potassium permanganate oxidation method kunye ne-potassium dichromate oxidation method. Indlela ye-potassium permanganate (KMnO4) inezinga eliphantsi le-oxidation, kodwa ilula. Ingasetyenziselwa ukumisela ixabiso elithelekisayo lomxholo we-organic kwiisampulu zamanzi kunye namanzi acocekileyo angaphezulu kunye neesampuli zamanzi aphantsi komhlaba. Indlela ye-potassium dichromate (K2Cr2O7) inezinga eliphezulu le-oxidation kunye nokuphindaphinda okulungileyo. Kufanelekile ukumisela isixa esipheleleyo sezinto eziphilayo kwiisampuli zamanzi ekubekweni iliso kwamanzi amdaka.
Izinto eziphilayo ziyingozi kakhulu kwiinkqubo zamanzi zemizi-mveliso. Amanzi aqulethe inani elikhulu lezinto eziphilayo aya kungcolisa i-ion exchange resins xa edlula kwi-desalination system, ngakumbi i-anion exchange resins, eya kunciphisa amandla otshintshiselwano lwe-resin. Izinto eziphilayo zinokuncitshiswa malunga ne-50% emva kokunyangwa kwangaphambili (i-coagulation, ukucaciswa kunye nokuhluzwa), kodwa ayikwazi ukususwa kwinkqubo ye-desalination, ngoko ihlala ifakwe kwibhoyila ngamanzi okutya, okunciphisa ixabiso le-pH kwibhoyila. amanzi. Ngamanye amaxesha i-organic matter inokungeniswa kwisixokelelwano somphunga kwaye icondeze amanzi, nto leyo eya kunciphisa i-pH kwaye ibangele ukubola kwenkqubo. Umxholo ophezulu wezinto eziphilayo kwinkqubo yamanzi ejikelezayo iya kukhuthaza ukuveliswa kwe-microbial. Ngoko ke, nokuba i-desalination, amanzi ebhoyila okanye inkqubo yamanzi ajikelezayo, i-COD ephantsi, ingcono, kodwa akukho salathiso esihlangeneyo somda. Xa i-COD (indlela ye-KMnO4)> 5mg/L kwinkqubo yamanzi okupholisa okujikelezayo, umgangatho wamanzi uqalise ukuwohloka.
Imfuno yeoksijini yemichiza (COD) luphawu lomlinganiselo weqondo amanzi atyebe ngayo kwizinto eziphilayo, kwaye ikwayenye yezalathi ezibalulekileyo zokulinganisa iqondo lokungcoliseka kwamanzi. Ngophuhliso loshishino kunye nokunyuka kwabemi, imizimba yamanzi iya ingcoliseka ngakumbi, kwaye ukuphuhliswa kokufunyanwa kwe-COD kuye kwaphucula ngokuthe ngcembe.
Imvelaphi yokubhaqwa kwe-COD inokulandwa emva phaya kwiminyaka yoo-1850, xa iingxaki zongcoliseko lwamanzi zaye zatsala umdla wabantu. Ekuqaleni, i-COD yayisetyenziswa njengesalathiso seziselo ze-acidic ukulinganisa ukuxinwa kwezinto eziphilayo kwiziselo. Nangona kunjalo, ekubeni indlela yokulinganisa epheleleyo yayingekasungulwa ngelo xesha, kwakukho impazamo enkulu kwiziphumo zokumisela zeCOD.
Ekuqaleni kwenkulungwane ye-20, kunye nokuqhubela phambili kweendlela zokuhlalutya iikhemikhali zanamhlanje, indlela yokufumanisa i-COD yaphuculwa ngokuthe ngcembe. Kwi-1918, i-chemist yaseJamani u-Hasse wachaza i-COD njengexabiso elipheleleyo lezinto eziphilayo ezidliwe yi-oxidation kwisisombululo se-acidic. Emva koko, ucebise indlela entsha yokumisela i-COD, eyokusebenzisa isisombululo esiphezulu se-chromium dioxide njenge-oxidant. Le ndlela inokwenza ngokufanelekileyo i-oxidize into ephilayo kwi-carbon dioxide kunye namanzi, kwaye ilinganise ukusetyenziswa kwee-oxidants kwisisombululo ngaphambi nangemva kwe-oxidation ukumisela ixabiso le-COD.
Nangona kunjalo, iintsilelo zale ndlela ziye zavela ngokuthe ngcembe. Okokuqala, ukulungiswa kunye nokusebenza kwee-reagents kunzima kakhulu, oko kwandisa ubunzima kunye nexesha lokuchitha uvavanyo. Okwesibini, izisombululo eziphezulu zechromium dioxide ziyingozi kwimo engqongileyo kwaye azihambelani nosetyenziso olusebenzayo. Ke ngoko, izifundo ezilandelayo ziye zafuna kancinci kancinci kwaye ichaneke ngakumbi indlela yokumisela i-COD.
Ngeminyaka yoo-1950, usokhemisti waseDatshi uFriis wenza indlela entsha yokumisela i-COD, esebenzisa i-persulfuric acid egxininise kakhulu njenge-oxidant. Le ndlela ilula ukusebenza kwaye inokuchaneka okuphezulu, okuphucula kakhulu ukusebenza kakuhle kwe-COD yokufumanisa. Nangona kunjalo, ukusetyenziswa kwe-asidi ye-persulfuric nayo ineengozi ezithile zokhuseleko, ngoko ke kusafuneka ukuba ubeke ingqalelo kukhuseleko lokusebenza.
Emva koko, ngophuhliso olukhawulezayo lwetekhnoloji yesixhobo, indlela yokumisela i-COD ngokuthe ngcembe ifezekise i-automation kunye nobukrelekrele. Ngeminyaka yee-1970, i-COD yokuqala yokuhlalutya ngokuzenzekelayo yavela, enokuqonda ukuqhutyelwa ngokupheleleyo kunye nokufunyanwa kweesampuli zamanzi. Esi sixhobo asiphuculi nje kuphela ukuchaneka nokuzinza kwe-COD, kodwa siphucula kakhulu ukusebenza kakuhle.
Ngokwandiswa kolwazi lokusingqongileyo kunye nophuculo lweemfuneko zolawulo, indlela yokubona i-COD nayo iyenziwa ngokuqhubekayo. Kwiminyaka yakutshanje, ukuphuhliswa kweteknoloji ye-photoelectric, iindlela ze-electrochemical kunye ne-biosensor iteknoloji iye yakhuthaza ukutsha kwe-COD yokufumanisa iteknoloji. Ngokomzekelo, iteknoloji ye-photoelectric inokumisela umxholo we-COD kwiisampuli zamanzi ngokutshintshwa kwezibonakaliso ze-photoelectric, kunye nexesha elifutshane lokufumanisa kunye nokusebenza okulula. Indlela ye-electrochemical isebenzisa i-electrochemical sensors ukulinganisa amaxabiso e-COD, aneenzuzo ze-sensitivity ephezulu, ukuphendula ngokukhawuleza kwaye akukho mfuneko ye-reagents. Itekhnoloji ye-Biosensor isebenzisa izixhobo zebhayoloji ukubona ngokuthe ngqo izinto eziphilayo, eziphucula ukuchaneka kunye nokucaciswa kokumiselwa kweCOD.
Iindlela zokufumanisa i-COD ziye zaqhuba inkqubo yophuhliso ukusuka kuhlalutyo lweekhemikhali zemveli ukuya kwisixhobo sanamhlanje, iteknoloji ye-photoelectric, iindlela ze-electrochemical kunye ne-biosensor iteknoloji kwiminyaka embalwa edlulileyo. Ngokuhambela phambili kwenzululwazi kunye nobuchwepheshe kunye nokwanda kwemfuno, iteknoloji yokufumanisa i-COD isaphuculwa kwaye ihlaziywa. Kwixesha elizayo, kunokubonwa kwangaphambili ukuba njengoko abantu benikela ingqalelo ngakumbi kwimiba yokungcoliseka kwendalo, itekhnoloji yokufumanisa iCOD iya kukhula ngakumbi kwaye ibe yindlela ekhawulezayo, echanekileyo nethembekileyo yokufumanisa umgangatho wamanzi.
Okwangoku, iilabhoratri zisebenzisa ezi ndlela zimbini zilandelayo zokubona iCOD.
1. Indlela yokumisela i-COD
Indlela esemgangathweni yePotassium dichromate, ekwaziwa ngokuba yindlela ye-reflux (uMgangatho weSizwe weRiphabhlikhi yaBantu baseTshayina)
(I) Umgaqo
Yongeza inani elithile le-potassium dichromate kunye ne-catalyst yesilivere yesulfate kwisampuli yamanzi, ubushushu kunye ne-reflux kwixesha elithile kwindawo eqinile ye-acidic, inxalenye ye-potassium dichromate iyancitshiswa ngezinto ezixutywe ne-oxidizable kwisampuli yamanzi, kwaye intsalela I-potassium dichromate ifakwe i-ammonium ferrous sulfate. Ixabiso le-COD libalwa ngokusekelwe kwisixa se-potassium dichromate esetyenzisiweyo.
Kuba lo mgangatho wawuyilwe ngo-1989, zininzi izinto ezingeloncedo ekuwulinganiseni nomgangatho wangoku:
1. Kuthatha ixesha elininzi, kwaye isampuli nganye kufuneka ihlaziywe ngeeyure ze-2;
2. Isixhobo se-reflux sithatha indawo enkulu, okwenza ukuzimisela kwebhetshi kube nzima;
3. Iindleko zokuhlalutya ziphezulu, ngakumbi kwi-sulfate yesilivere;
4. Ngethuba lenkqubo yokumisela, inkunkuma yamanzi e-reflux iyamangalisa;
5. Iityuwa zemercury ezinetyhefu ziqhelene nongcoliseko lwesibini;
6. Isixa se-reagents esisetyenzisiweyo sikhulu, kwaye iindleko zokusetyenziswa ziphezulu;
7. Inkqubo yovavanyo inzima kwaye ayifanelekanga ukunyuselwa.
(II) Izixhobo
1. Isixhobo se-reflux se-250mL yonke iglasi
2. Isixhobo sokufudumeza (iziko lombane)
3. I-25mL okanye i-50mL i-burette ye-asidi, i-conical flask, i-pipette, i-volumetric flask, njl.
(III) iiReagents
1. Isisombululo esisemgangathweni sePotassium dichromate (c1/6K2Cr2O7=0.2500mol/L)
2. Isisombululo sesalathisi seFerrocyanate
3. Isisombululo esisemgangathweni se-ammonium ferrous sulfate [c(NH4)2Fe(SO4)2·6H2O≈0.1mol/L] (linganisa ngaphambi kokusetyenziswa)
4. Isisombululo sesulfuric acid-silver sulfate
Indlela esemgangathweni ye-potassium dichromate
(IV) Amanyathelo okuzimisela
I-Ammonium ferrous sulfate Calibration: I-pipette echanekileyo eyi-10.00mL yesisombululo esisemgangathweni se-potassium dichromate kwi-500mL yeflaski e-conical, xuba malunga ne-110mL ngamanzi, kancinane yongeza i-30mL ye-asidi ye-sulfuric egxininisiweyo, kwaye ungcangcazele kakuhle. Emva kokupholisa, yongeza ama-3 amaconsi esisombululo se-ferrocyanate (malunga ne-0.15mL) kunye ne-titrate ngesisombululo se-ammonium ferrous sulfate. Isiphelo seso sihlandlo xa umbala wesisombululo uguquka ukusuka kumthubi ukuya eluhlaza okwesibhakabhaka ukuya kumbala obomvu obomvu.
(V) Ukuzimisela
Thatha i-20mL yesampuli yamanzi (ukuba kuyimfuneko, thatha ngaphantsi kwaye ungeze amanzi kwi-20 okanye uhlambulule ngaphambi kokuthatha), yongeza i-10mL ye-potassium dichromate, iplagi kwisixhobo se-reflux, uze ungeze i-30mL ye-sulfuric acid kunye ne-sulfate yesilivere, ubushushu kunye ne-reflux ye-2h. . Emva kokupholisa, hlambulula udonga lwetyhubhu ye-condenser nge-90.00mL yamanzi kwaye ususe i-conical flask. Emva kokuba isisombululo sipholile kwakhona, yongeza amaconsi ama-3 esisombululo sesalathisi se-asidi kunye ne-titrate kunye nesisombululo esiqhelekileyo se-ammonium ferrous sulfate. Umbala wesisombululo uguquka ukusuka kumthubi ukuya kuluhlaza okwesibhakabhaka ukuya kumdaka obomvu, oyindawo yokugqibela. Rekhoda ubungakanani besisombululo esisemgangathweni se-ammonium ferrous sulfate. Ngelixa ulinganisa isampuli yamanzi, thatha i-20.00mL yamanzi adilizwe ngokutsha kwaye wenze uvavanyo olungenanto ngokwamanyathelo okusebenza afanayo. Rekhoda ubungakanani besisombululo esisemgangathweni se-ammonium ferrous sulfate esisetyenziswe kwititration engenanto.
Indlela esemgangathweni ye-potassium dichromate
(VI) Ukubala
CODCr(O2, mg/L)=[8×1000(V0-V1)·C]/V
(VII) Izilumkiso
1. Ubuninzi be-ion ye-chloride edibeneyo kunye ne-0.4g ye-mercuric sulfate inokufikelela kwi-40mg. Ukuba i-20.00mL isampuli yamanzi ithathwa, ubuninzi be-chloride ion concentration ye-2000mg / L inokudityaniswa. Ukuba i-concentration ye-chloride ion iphantsi, inani elincinci le-mercuric sulfate linokongezwa ukugcina i-mercuric sulfate: i-chloride ion = 10: 1 (W / W). Ukuba inani elincinci le-mercuric chloride liyancipha, alichaphazeli ukuzimisela.
2. Uluhlu lweCOD olugqitywe yile ndlela yi-50-500mg/L. Kwiisampulu zamanzi ezinemfuno yemichiza yeoksijini engaphantsi kwe-50mg/L, 0.0250mol/L isisombululo esiqhelekileyo se-potassium dichromate kufuneka sisetyenziswe endaweni yoko. I-0.01mol/L isisombululo esisemgangathweni se-ammonium ferrous sulfate kufuneka sisetyenziswe ukubuyisela umva. Iisampulu zamanzi ezineCOD ezingaphezu kwe-500mg/L, zixutywe phambi kokumiselwa.
3. Emva kokuba isampuli yamanzi ishushu kwaye ihlaziywe, inani eliseleyo le-potassium dichromate kwisisombululo kufuneka libe yi-1 / 5-4 / 5 yexabiso elongezelelweyo.
4. Xa usebenzisa isisombululo esisemgangathweni se-potassium hydrogen phthalate ukujonga umgangatho kunye nokusebenza kweteknoloji ye-reagent, ekubeni i-CODCr yethiyori yegram nganye ye-potassium hydrogen phthalate yi-1.176g, i-0.4251g ye-potassium hydrogen phthalate (HOOCC6H4COOK) ichithwe emanzini adityanisiweyo kwakhona, idluliselwe kwi-flask ye-volumetric ye-1000mL, kwaye ihlanjululwe kwi-mark kunye namanzi adilizwe ngokutsha ukwenza isisombululo esiqhelekileyo se-CODcr ye-500mg / L. Yilungiselele entsha xa isetyenziswa.
5. Iziphumo zokumiselwa kweCODCr kufuneka zigcine amanani amane abalulekileyo.
6. Ngethuba lovavanyo ngalunye, isisombululo se-ammonium ferrous sulfate standard titration kufuneka silinganiswe, kwaye utshintsho logxininiso kufuneka lunikwe ingqalelo ekhethekileyo xa ubushushu begumbi buphezulu. (Ungongeza kwakhona i-10.0ml yesisombululo esiqhelekileyo se-potassium dichromate kwindawo engenanto emva kwe-titration kunye ne-titrate nge-ammonium ferrous sulfate ukuya ekupheleni.)
7. Isampuli yamanzi kufuneka igcinwe isitsha kwaye ilinganiswe ngokukhawuleza.
Izinto eziluncedo:
Ukuchaneka okuphezulu: I-reflux titration yindlela yokumisela ye-COD yakudala. Emva kwexesha elide lophuhliso kunye nokuqinisekiswa, ukuchaneka kwayo kuye kwaqatshelwa ngokubanzi. Inokubonakalisa ngokuchanekileyo umxholo wangempela wezinto eziphilayo emanzini.
Usetyenziso olubanzi: Le ndlela ifanelekile kwiindidi ezahlukeneyo zeesampulu zamanzi, kubandakanywa ukugxilwa okuphezulu kunye nokuncinci okuphantsi kwamanzi amdaka endalo.
Inkcazo yokusebenza: Kukho imigangatho yokusebenza eneenkcukacha kunye neenkqubo, ezilungele ukuba abaqhubi bazi kakuhle kwaye baphumeze.
Izinto ezingeloncedo:
Ukuchitha ixesha: I-reflux titration ihlala ithatha iiyure ezininzi ukugqiba ukumiselwa kwesampulu, ekucacayo ukuba ayihambisani nemeko apho iziphumo kufuneka zifumaneke ngokukhawuleza.
Ukusetyenziswa kwe-reagent ephezulu: Le ndlela idinga ukusetyenziswa kwee-reagents ezininzi zeekhemikhali, ezingabizi nje kuphela, kodwa zingcolisa indalo ukuya kumlinganiselo othile.
Umsebenzi onzima: Umsebenzisi kufuneka abe nolwazi oluthile lwemichiza kunye nezakhono zokulinga, kungenjalo kunokuchaphazela ukuchaneka kweziphumo zokumisela.
2. I-spectrophotometry yokwetyisa ngokukhawuleza
(I) Umgaqo
Isampuli yongezwa ngexabiso elaziwayo lesisombululo se-potassium dichromate, kwindawo eqinile ye-sulfuric acid medium, kunye ne-sulfate yesilivere njenge-catalyst, kwaye emva kokushisa okuphezulu kokushisa, ixabiso le-COD lichongwa ngezixhobo ze-photometric. Ekubeni le ndlela inexesha elifutshane lokuzimisela, ungcoliseko oluncinci lwesibini, umthamo omncinci we-reagent kunye neendleko eziphantsi, iilebhu ezininzi zisebenzisa le ndlela ngoku. Nangona kunjalo, le ndlela ineendleko eziphezulu zesixhobo kunye neendleko eziphantsi zokusetyenziswa, ezifanelekileyo ukusetyenziswa kwexesha elide kwiiyunithi ze-COD.
(II) Izixhobo
Izixhobo zangaphandle zaphuhliswa ngaphambili, kodwa ixabiso liphezulu kakhulu, kwaye ixesha lokuzimisela lide. Ixabiso reagent jikelele ayifikeleleki kubasebenzisi, kwaye ukuchaneka akukho phezulu kakhulu, kuba imigangatho esweni izixhobo zangaphandle yahlukile kwezo zelizwe lam, ikakhulu ngenxa yokuba umgangatho unyango lwamanzi kunye nenkqubo yolawulo lwamazwe angaphandle yahlukile kwezo zam ilizwe; indlela ye-spectrophotometry yokugaya ngokukhawuleza isekelwe ikakhulu kwiindlela eziqhelekileyo zezixhobo zasekhaya. Ukumiselwa okukhawulezileyo kwe-COD ngumgangatho wokuqulunqwa kwale ndlela. Yaqanjwa kwasekuqaleni kweyee-1980. Emva kweminyaka engaphezulu kwe-30 yokusetyenziswa, iye yaba ngumgangatho weshishini lokhuseleko lokusingqongileyo. Isixhobo sasekhaya se-5B sisetyenziswe ngokubanzi kuphando lwezenzululwazi kunye nokubeka iliso ngokusemthethweni. Izixhobo zasekhaya zisetyenziswe ngokubanzi ngenxa yeenzuzo zabo zexabiso kunye nenkonzo yexesha emva kokuthengisa.
(III) Amanyathelo okuzimisela
Thatha isampula ye-2.5ml--yongeza i-reagent--digest imizuzu eyi-10--ipholile imizuzu emi-2--ugalele kwisitya se-colorimetric--umboniso wezixhobo ubonisa ngokuthe ngqo i-COD yoxinaniso lwesampuli.
(IV) Izilumkiso
1. Iisampuli zamanzi eziphezulu zeklorini kufuneka zisebenzise i-reagent ephezulu ye-chlorine.
2. Ulwelo olulahlwayo lumalunga ne-10ml, kodwa luneasidi kakhulu kwaye kufuneka luqokelelwe kwaye lulungiswe.
3. Qinisekisa ukuba indawo ehambisa ukukhanya kwi-cuvette icocekile.
Izinto eziluncedo:
Isantya esikhawulezayo: Indlela ekhawulezayo idla ngokuthatha imizuzu embalwa ukuya kwimizuzu elishumi ukuya kuthi ga kwimizuzu elishumi ukugqiba ukumiselwa kwesampulu, efanelekileyo kakhulu kwiimeko apho iziphumo kufuneka zifumaneke ngokukhawuleza.
Ukusetyenziswa okuncinci kwe-reagent: Xa kuthelekiswa nendlela ye-reflux ye-titration, indlela ekhawulezayo isebenzisa ii-reagents zeekhemikhali ezimbalwa, ineendleko eziphantsi, kwaye inempembelelo encinci kwindalo.
Ukusebenza okulula: Amanyathelo okusebenza kwendlela ekhawulezayo alula, kwaye umqhubi akufuneki abe nolwazi oluphezulu kakhulu lwekhemikhali kunye nezakhono zovavanyo.
Izinto ezingeloncedo:
Ukuchaneka okusezantsi kancinci: Kuba indlela ekhawulezayo iqhele ukusebenzisa ezinye iindlela ezilula zokuphendula imichiza kunye neendlela zokulinganisa, ukuchaneka kwayo kunokuba sezantsi kancinci kunendlela ye-reflux titration.
Umda olinganiselweyo wokusetyenziswa: Indlela ekhawulezayo ifaneleka ikakhulu ekumiselweni kwamanzi amdaka endalo adityanisiweyo aphantsi. Kumanzi amdaka agxininiswe kakhulu, iziphumo zawo zokuzimisela zinokuchaphazeleka kakhulu.
Ukuchatshazelwa yimiba yokuphazamiseka: Indlela ekhawulezayo inokuvelisa iimpazamo ezinkulu kwezinye iimeko ezikhethekileyo, njengaxa kukho izinto ezithile eziphazamisayo kwisampulu yamanzi.
Isishwankathelo, indlela ye-reflux titration kunye nendlela ekhawulezayo nganye ineenzuzo zayo kunye nokungalunganga. Yiyiphi indlela yokukhetha ixhomekeke kwimeko yesicelo esithile kunye neemfuno. Xa ukuchaneka okuphezulu kunye nokusebenza okubanzi kuyadingeka, i-reflux titration inokukhethwa; xa iziphumo ezikhawulezayo zifunwa okanye inani elikhulu leesampuli zamanzi zicutshungulwa, indlela ekhawulezayo iyindlela efanelekileyo yokukhetha.
U-Lianhua, njengomvelisi wezixhobo zokuvavanya umgangatho wamanzi iminyaka engama-42, uye waphuhlisa imizuzu engama-20.I-COD yokugaya ngokukhawuleza i-spectrophotometryindlela. Emva kwenani elikhulu lokuthelekiswa kovavanyo, liye lakwazi ukufezekisa impazamo engaphantsi kwe-5%, kwaye ineenzuzo zokusebenza okulula, iziphumo ezikhawulezayo, iindleko eziphantsi kunye nexesha elifutshane.
Ixesha lokuposa: Jun-07-2024
