13. Yiziphi izinyathelo zokuphepha zokulinganisa i-CODCr?
Isilinganiso se-CODCr sisebenzisa i-potassium dichromate njenge-oxidant, i-silver sulfate njengesisusa ngaphansi kwezimo ezine-acidic, ebilisa futhi iphinde ishintshe amahora angu-2, bese siyiguqulela ekusetshenzisweni komoyampilo (GB11914–89) ngokulinganisa ukusetshenziswa kwe-potassium dichromate. Amakhemikhali afana ne-potassium dichromate, i-mercury sulfate kanye ne-concentrated sulfuric acid asetshenziswa esilinganisweni se-CODCr, okungenzeka ukuthi sibe nobuthi obukhulu noma obudlekayo, futhi adinga ukushisisa kanye ne-reflux, ngakho-ke ukusebenza kufanele kwenziwe ku-fume hood futhi kufanele kwenziwe ngokucophelela okukhulu. Uketshezi oluwudoti Kumele lugaywe kabusha futhi lulahlwe ngokuhlukana.
Ukuze kuthuthukiswe i-oxidation ephelele yezinto ezinciphisa emanzini, i-silver sulfate idinga ukungezwa njenge-catalyst. Ukuze wenze i-sulfate yesiliva isakazwe ngokulinganayo, i-sulfate yesiliva kufanele ichithwe ku-concentrated sulfuric acid. Ngemva kokuqedwa ngokuphelele (cishe izinsuku ezi-2), i-acidification izoqala. ye-sulfuric acid ku-Erlenmeyer flask. Indlela kazwelonke yokuhlola ejwayelekile ibeka ukuthi i-0.4gAg2SO4/30mLH2SO4 kufanele yengezwe esilinganisweni ngasinye se-CODCr (isampula lamanzi angu-20mL), kodwa idatha efanele ibonisa ukuthi kumasampula amanzi avamile, ukungeza u-0.3gAg2SO4/30mLH2SO4 kwanele ngokuphelele, futhi asikho isidingo sokwenza kanjalo. sebenzisa i-Silver sulfate eyengeziwe. Kumasampula amanzi okukhuculula okukalwa njalo, uma kukhona ukulawulwa kwedatha okwanele, inani le-sulfate yesiliva lingancishiswa ngokufanelekile.
I-CODCr iyinkomba yento ephilayo equkethwe endle, ngakho ukusetshenziswa komoya-mpilo kwama-ion e-chloride nezinto ezinciphisayo ezingaphili kufanele kususwe ngesikhathi sokulinganisa. Ukuze kuphazamiseke izinto ezincishiswayo ezingaphili njenge-Fe2+ ne-S2-, inani elilinganiselwe le-CODCr lingalungiswa ngokusekelwe esidingweni se-oxygen esicatshangelwayo ngokusekelwe ekugxilweni kwayo okulinganiselwe. Ukuphazanyiswa kwama-ion e-chloride Cl-1 ngokuvamile kususwa nge-mercury sulfate. Uma inani elingeziwe lingu-0.4gHgSO4 ngesampula yamanzi angu-20mL, ukuphazamiseka kwama-ion chloride angu-2000mg/L kungasuswa. Kumasampula amanzi endle avame ukukalwa anezingxenye ezingashintshiwe, uma okuqukethwe kwe-ion ye-chloride kukuncane noma isampula yamanzi ene-dilution factor ephakeme isetshenziselwa ukukala, inani le-mercury sulfate lingancishiswa ngokufanelekile.
14. Iyini indlela yokwenza isiliva sulfate?
Indlela eyi-catalytic ye-silver sulfate iwukuthi izinhlanganisela eziqukethe amaqembu e-hydroxyl odabeni oluphilayo kuqala zifakwe i-potassium dichromate zibe i-carboxylic acid endaweni ene-asidi eqinile. Ama-acids anamafutha akhiqizwe ku-hydroxyl organic matter asabela ngesiliva sulfate ukuze akhiqize isiliva le-acid enamafutha. Ngenxa yesenzo sama-athomu esiliva, Iqembu le-carboxyl lingakwazi ukukhiqiza kalula i-carbon dioxide namanzi, futhi ngesikhathi esifanayo likhiqize isiliva elisha le-fatty acid, kodwa i-athomu ye-carbon yayo ingaphansi kweyokuqala. Lo mjikelezo uyaphinda, kancane kancane ukhiphe zonke izinto eziphilayo zibe isikhutha namanzi.
15.Iziphi izinyathelo zokuphepha zokulinganisa i-BOD5?
Ukulinganisa kwe-BOD5 kuvame ukusebenzisa indlela evamile yokuhlanjululwa kanye ne-inoculation (GB 7488–87). Umsebenzi uwukubeka isampula lamanzi eliye lahlukaniswa, lasusa izinto ezinobuthi, futhi lahlanjululwa (ngenani elifanele le-inoculum equkethe ama-microorganisms e-aerobic engeziwe uma kudingeka). Ebhodleleni lesiko, fukamela ebumnyameni ku-20 ° C izinsuku ezingu-5. Ngokulinganisa okuqukethwe kwe-oxygen encibilikisiwe kumasampula amanzi ngaphambi nangemva kwesiko, ukusetshenziswa kwe-oksijeni phakathi kwezinsuku ezingu-5 kungabalwa, bese i-BOD5 ingatholakala ngokusekelwe ku-dilution factor.
Ukunqunywa kwe-BOD5 kuwumphumela ohlangene wemiphumela yezinto eziphilayo kanye namakhemikhali futhi kufanele kwenziwe ngokuhambisana ngokuqinile nemininingwane yokusebenza. Ukushintsha noma yisiphi isimo kuzothinta ukunemba nokuqhathaniswa kwemiphumela yokulinganisa. Izimo ezithinta ukunqunywa kwe-BOD5 zifaka inani le-pH, izinga lokushisa, uhlobo lwe-microbial kanye nenani, okuqukethwe kukasawoti we-inorganic, i-oxygen encibilikile kanye ne-dilution factor, njll.
Amasampula amanzi okuhlolwa kwe-BOD5 kufanele agcwaliswe futhi avalelwe emabhodleleni esampula, futhi agcinwe esiqandisini ngo-2 kuya ku-5°C kuze kube yilapho esehlaziywa. Ngokuvamile, ukuhlolwa kufanele kwenziwe phakathi namahora angu-6 ngemva kokuthatha isampula. Kunoma yikuphi, isikhathi sokugcina samasampula amanzi akufanele sidlule amahora angu-24.
Lapho kulinganiswa i-BOD5 yamanzi angcolile ezimbonini, njengoba amanzi angcolile ezimbonini ngokuvamile aqukethe umoya-mpilo omncane ongancibilikisiwe futhi aqukethe izinto eziphilayo ezingaboli kakhulu, ukuze kugcinwe isimo se-aerobic ebhodleleni lempucuko, isampula lamanzi kufanele lihlanjululwe (noma lihlanjululwe futhi lihlanjululwe). Lokhu kusebenza Lesi isici esikhulu kunazo zonke sendlela evamile yokuhlanjululwa. Ukuze kuqinisekiswe ukwethembeka kwemiphumela elinganisiwe, ukusetshenziswa komoya-mpilo kwesampula lamanzi ahlanjululiwe ngemva kwesiko izinsuku ezi-5 kufanele kube kukhulu kuno-2 mg/L, futhi umoya-mpilo osalayo oncibilikisiwe kufanele ube mkhulu kuno-1 mg/L.
Inhloso yokwengeza isisombululo se-inoculum ukuqinisekisa ukuthi inani elithile lama-microorganisms lilulaza izinto eziphilayo emanzini. Inani lesixazululo se-inoculum lingcono kakhulu ukuthi ukusetshenziswa komoyampilo phakathi kwezinsuku ezi-5 kube ngaphansi kuka-0.1mg/L. Uma usebenzisa amanzi acwengekile alungiselelwe i-distiller yensimbi njengamanzi e-dilution, kufanele kuthathwe ukunakekelwa ukuze kuhlolwe okuqukethwe kwe-ion yensimbi kuwo ukuze kugwenywe ukuvimbela ukukhiqizwa kwe-microbial kanye ne-metabolism. Ukuze kuqinisekiswe ukuthi i-oxygen encibilikisiwe emanzini ahlanjululwe iseduze nokugcwala, umoya ohlanzekile noma umoya-mpilo ohlanzekile ungethulwa uma kunesidingo, bese ufakwa ku-incubator engu-20oC isikhathi esithile ukuze ulinganise nokucindezela ingxenye ye-oxygen. umoya.
I-dilution factor inqunywa ngokusekelwe kumgomo wokuthi ukusetshenziswa kwe-oxygen kukhulu kuno-2 mg/L futhi umoya-mpilo osele oncibilikisiwe mkhulu kuno-1 mg/L ngemva kwezinsuku ezingu-5 zesiko. Uma i-dilution factor inkulu kakhulu noma incane kakhulu, ukuhlolwa kuzohluleka. Futhi ngenxa yokuthi umjikelezo wokuhlaziya we-BOD5 mude, uma kwenzeka isimo esifanayo, awukwazi ukuphinda uhlolwe njengoba unjalo. Lapho ulinganisa ekuqaleni i-BOD5 yamanzi angcolile embonini ethile, ungakwazi kuqala ukukala i-CODCr yawo, bese ubhekisela kudatha ekhona yokuqapha yamanzi angcolile anekhwalithi yamanzi afanayo ukuze uqale unqume inani le-BOD5/CODCr lesampula lamanzi okufanele likalwe, futhi ubale. isilinganiso sebanga le-BOD5 ngokusekelwe kulokhu. futhi unqume isici sokuhlanjululwa.
Kumasampula amanzi aqukethe izinto ezivimbela noma ezibulala imisebenzi ye-metabolic yamagciwane e-aerobic, imiphumela yokulinganisa ngokuqondile i-BOD5 kusetshenziswa izindlela ezivamile izosuka enanini langempela. Ukwelashwa kwangaphambili okuhambisanayo kufanele kwenziwe ngaphambi kokulinganisa. Lezi zinto nezici zinomthelela ekunqumeni kwe-BOD5. Kubandakanya izinsimbi ezisindayo nezinye izinto ezinobuthi ezingaphili noma ezingaphili, i-chlorine esele nezinye izinto ezikhipha i-oxidizing, inani le-pH eliphezulu kakhulu noma eliphansi kakhulu, njll.
16. Kungani kudingekile ukujova lapho kukalwa i-BOD5 yamanzi angcolile ezimbonini? Ungagonywa kanjani?
Ukunqunywa kwe-BOD5 kuyinqubo yokusebenzisa i-oxygen ye-biochemical. Ama-microorganisms kumasampula amanzi asebenzisa izinto eziphilayo emanzini njengezakhamzimba ukuze zikhule futhi zizalane. Ngesikhathi esifanayo, zibola izinto eziphilayo futhi zidle umoya-mpilo oncibilikisiwe emanzini. Ngakho-ke, isampula yamanzi kufanele ibe nenani elithile lama-microorganisms angakwazi ukwehlisa izinto eziphilayo kuwo. amakhono microorganisms.
Amanzi angcolile ezimbonini ngokuvamile aqukethe amanani ahlukahlukene ezinto ezinobuthi, ezingavimbela ukusebenza kwezilwanyana ezincane. Ngakho-ke, inani lama-microorganisms emanzini angcolile ezimbonini lincane kakhulu noma alikho nhlobo. Uma kusetshenziswa izindlela ezijwayelekile zokulinganisa indle yasemadolobheni ecebile nge-microbial, okuqukethwe kweqiniso kwe-organic emanzini angcolile kungase kungabonwa, noma okungenani kube phansi. Isibonelo, kumasampula amanzi alashwe ngezinga lokushisa eliphezulu nokuvalwa inzalo futhi i-pH yawo iphezulu kakhulu noma iphansi kakhulu, ngaphezu kokuthatha izinyathelo zokwelapha zangaphambili ezifana nokupholisa, ukwehlisa izibulala-magciwane, noma ukulungisa inani le-pH, ukuze uqinisekise. ukunemba kwesilinganiso se-BOD5, izinyathelo ezisebenzayo kufanele futhi zithathwe. Ukugoma.
Lapho kulinganiswa i-BOD5 yamanzi angcolile ezimbonini, uma okuqukethwe kwezinto ezinobuthi kukhulu kakhulu, amakhemikhali ngezinye izikhathi asetshenziselwa ukuwakhipha; uma amanzi angcolile ene-acidic noma ane-alkali, kufanele asuswe kuqala; futhi ngokuvamile isampula lamanzi kufanele lihlanjululwe ngaphambi kokuba izinga lisetshenziswe. Ukunqunywa ngendlela ye-dilution. Ukwengeza inani elifanele lesixazululo se-inoculum esiqukethe ama-microorganisms afuywayo e-aerobic kwisampula yamanzi (njengengxube yethangi lokungenisa umoya elisetshenziselwa ukwelapha lolu hlobo lwamanzi angcolile ezimbonini) ukwenza isampula lamanzi liqukathe inani elithile lezilwanyana ezincane ezinamandla okwehlisa izinga lezinto eziphilayo. udaba. Ngaphansi kwesimo sokuthi kuhlangatshezwane nezinye izimo zokulinganisa i-BOD5, lawa ma-microorganisms asetshenziselwa ukubola izinto eziphilayo emanzini angcolile ezimbonini, futhi ukusetshenziswa komoya-mpilo kwesampula lamanzi kukalwa izinsuku ezingu-5 zokutshala, futhi inani le-BOD5 lamanzi angcolile ezimboni lingatholakala. .
Uketshezi oluxubile lwethangi lokungenisa umoya noma ukungcola kwethangi lesibili lokuthungatha lesikhungo sokukhuculula indle kuwumthombo ofanele wama-microorganisms wokunquma i-BOD5 yamanzi angcolile engena endaweni yokuhlanza indle. Ukujova okuqondile ngendle yasekhaya, ngenxa yokuthi i-oksijini encane noma ayikho encibilikile, ijwayele ukuvela kwezinambuzane ze-anaerobic, futhi idinga isikhathi eside sokutshala nokuvumelana. Ngakho-ke, lesi sixazululo se-acclimated inoculum sifanelekile kuphela emanzini athile angcolile ezimbonini anezidingo ezithile.
17. Yiziphi izinyathelo zokuphepha zokulungiselela amanzi ahlanjululwayo lapho ukala i-BOD5?
Izinga lamanzi e-dilution libaluleke kakhulu ekunembeni kwemiphumela yesilinganiso se-BOD5. Ngakho-ke, kuyadingeka ukuthi ukusetshenziswa komoya-mpilo wamanzi ahlanjululwayo angenalutho izinsuku ezi-5 kumele kube ngaphansi kuka-0.2mg/L, futhi kungcono kakhulu ukuwalawula ngaphansi kuka-0.1mg/L. Ukusetshenziswa komoyampilo wamanzi ahlanjululwe anomuthi afakwe isitofu izinsuku ezi-5 kufanele kube Phakathi kuka-0.3~1.0mg/L.
Isihluthulelo sokuqinisekisa ikhwalithi yamanzi e-dilution ukulawula okuqukethwe okuphansi kwezinto eziphilayo kanye nokuqukethwe okuphansi kwezinto ezivimbela ukukhiqizwa kwamagciwane. Ngakho-ke, kungcono ukusebenzisa amanzi a-distilled njengamanzi ahlanjululwayo. Akufanelekile ukusebenzisa amanzi ahlanzekile enziwe nge-ion exchange resin njengamanzi e-dilution, ngoba amanzi akhishwe kaningi Aqukethe izinto eziphilayo ezihlukene ne-resin. Uma amanzi kampompi asetshenziselwa ukulungisa amanzi acwengekile aqukethe izinhlanganisela ezithile eziphilayo eziguquguqukayo, ukuze zivimbele ukuthi zingahlali emanzini acwecwe, ukwelapha ngaphambi kokukhipha ama-organic compounds kufanele kwenziwe ngaphambi kokukhishwa kwe-distillation. Emanzini acwengekile akhiqizwe kuma-distillers ensimbi, kufanele kuqashelwe ukuhlola okuqukethwe kwe-ion yensimbi kuwo ukuze kugwenywe ukuvimbela ukukhiqizwa kanye nokusetshenziswa kwe-metabolism yama-microorganisms futhi kuthinte ukunemba kwemiphumela yokulinganisa i-BOD5.
Uma amanzi okuhlanjululwa asetshenzisiwe engahlangabezani nezidingo zokusetshenziswa ngenxa yokuthi aqukethe izinto eziphilayo, umphumela ungaqedwa ngokwengeza inani elifanele le-inoculum yethangi lokungenisa umoya bese uyigcina endaweni yokushisa yegumbi noma u-20oC isikhathi esithile. Inani lokujova lisekelwe esimisweni sokuthi ukusetshenziswa komoyampilo ezinsukwini ezi-5 cishe ku-0.1mg/L. Ukuvimbela ukuzala kwe-algae, ukugcinwa kufanele kwenziwe ekamelweni elimnyama. Uma kune-sediment emanzini ahlanjululwe ngemva kokugcinwa, i-supernatant kuphela engasetshenziswa futhi i-sediment ingasuswa ngokuhlunga.
Ukuze kuqinisekiswe ukuthi i-oksijini encibilikisiwe emanzini e-dilution iseduze nokugcwala, uma kunesidingo, ipompo ye-vacuum noma i-ejector yamanzi ingasetshenziswa ukuhogela umoya ohlanzekile, i-micro air compressor ingasetshenziswa futhi ukujova umoya ohlanzekile, kanye ne-oxygen. ibhodlela lingasetshenziswa ukwethula umoya-mpilo ohlanzekile, bese amanzi ane-oksijini Amanzi ahlanjululwe afakwa ku-incubator engu-20oC isikhathi esithile ukuvumela umoya-mpilo oncibilikisiwe ukuthi ufinyelele ukulingana. Amanzi ahlanjululwayo abekwe ekamelweni eliphansi lokushisa ebusika angase aqukathe umoya-mpilo omningi kakhulu oncibilike, futhi okuphambene kuyiqiniso ezinkathini zokushisa okuphezulu ehlobo. Ngakho-ke, uma kunomehluko omkhulu phakathi kwezinga lokushisa legumbi kanye no-20oC, kufanele lifakwe ku-incubator isikhathi esithile ukuze lizinze kanye nemvelo yesiko. ibhalansi ye-oxygen partial pressure.
18. Indlela yokunquma i-dilution factor lapho ukala i-BOD5?
Uma i-dilution factor inkulu kakhulu noma incane kakhulu, ukusetshenziswa komoyampilo ezinsukwini ezi-5 kungase kube kuncane kakhulu noma kube kuningi, kudlule ububanzi bokusetshenziswa komoyampilo okuvamile futhi kubangele ukuhlola kuhluleke. Njengoba umjikelezo wokulinganisa we-BOD5 umude kakhulu, uma isimo esinjalo senzeke, asikwazi ukuphinda sihlolwe njengoba sinjalo. Ngakho-ke, ukunakwa okukhulu kufanele kukhokhwe ekunqumeni kwe-dilution factor.
Nakuba ukwakheka kwamanzi angcolile ezimbonini kuyinkimbinkimbi, isilinganiso senani layo le-BOD5 nenani le-CODCr ngokuvamile liphakathi kuka-0.2 no-0.8. Isilinganiso samanzi angcolile asuka ekwenzeni iphepha, ukunyathelisa nokudaya, nezimboni zamakhemikhali siphansi, kuyilapho isilinganiso samanzi angcolile aphuma embonini yokudla siphezulu. Lapho kulinganiswa i-BOD5 yamanzi angcolile aqukethe izinto eziphilayo eziyimbudumbudu, njengamanzi angcolile okusanhlamvu e-distiller, isilinganiso sizoba ngaphansi kakhulu ngoba i-particle ye-particle iguguleka ngaphansi kwebhodlela lamasiko futhi ayikwazi ukubamba iqhaza ekuphenduleni kwamakhemikhali ezinto eziphilayo.
Ukunqunywa kwe-dilution factor kusekelwe ezimweni ezimbili lapho kulinganisa i-BOD5, ukusetshenziswa kwe-oksijeni ezinsukwini ezingu-5 kufanele kube kukhulu kune-2mg / L futhi i-oxygen encibilikisiwe esele kufanele ibe mkhulu kune-1mg / L. I-DO ebhodleleni lesiko ngosuku olulandelayo ngemuva kokuhlanjululwa ngu-7 kuya ku-8.5 mg/L. Uma sicabanga ukuthi ukusetshenziswa komoyampilo ezinsukwini ezi-5 kungu-4 mg/L, isici se-dilution siwumkhiqizo wevelu ye-CODCr nama-coefficients amathathu we-0.05, 0.1125, kanye no-0.175 ngokulandelanayo. Isibonelo, uma usebenzisa ibhodlela lesiko elingu-250mL ukukala i-BOD5 yesampula lamanzi nge-CODCr engu-200mg/L, izici ezintathu zokuhlanjululwa yilezi: ①200×0.005=10 izikhathi, ②200×0.1125=22.5 izikhathi, kanye ③200=0 1 . 35 izikhathi. Uma kusetshenziswa indlela yokuhlanza eqondile, amavolumu amasampula amanzi athathiwe yile: ①250÷10=25mL, ②250÷22.5≈11mL, ③250÷35≈7mL.
Uma uthatha amasampula kanye nokwenza isiko kanjena, kuzoba nemiphumela ye-oxygen encibilikisiwe engu-1 kuya ku-2 ehambisana nalezi zimiso ezimbili ezingenhla. Uma kukhona izilinganiso ezimbili zokuhlanjululwa ezihambisana nezimiso ezingenhla, inani lazo elimaphakathi kufanele lithathwe lapho kubalwa imiphumela. Uma i-oxygen esele encibilikisiwe ingaphansi kuka-1 mg/L noma ngisho uziro, isilinganiso se-dilution kufanele senyuswe. Uma ukusetshenziswa kwe-oxygen encibilikisiwe ngesikhathi sesiko kungaphansi kwe-2mg/L, okunye okungenzeka ukuthi isici sokuhlanjululwa sikhulu kakhulu; okunye okungenzeka ukuthi izinhlobo ze-microbial azifaneleki, azisebenzi kahle, noma ukugcwala kwezinto ezinobuthi kuphezulu kakhulu. Ngalesi sikhathi, kungase kube nezinkinga ngezici ezinkulu ze-dilution. Ibhodlela lesiko lidla umoya-mpilo oncibilike kakhulu.
Uma amanzi e-dilution engamanzi e-inoculation dilution, njengoba ukusetshenziswa komoyampilo kwesampula lamanzi angenalutho kungu-0.3~1.0mg/L, ama-coefficients e-dilution angu-0.05, 0.125 kanye no-0.2 ngokulandelanayo.
Uma inani elithile le-CODCr noma ububanzi obulinganiselwe besampula yamanzi baziwa, kungaba lula ukuhlaziya inani layo le-BOD5 ngokuya ngesici sokuhlanjululwa esingenhla. Uma uhla lwe-CODCr lwesampula yamanzi lungaziwa, ukuze kufinyezwe isikhathi sokuhlaziya, lungalinganiselwa phakathi nenqubo yokukala ye-CODCr. Indlela ethize yilena: qala ngokulungisa isisombululo esijwayelekile esiqukethe i-0.4251g potassium hydrogen phthalate ilitha (inani le-CODCr lalesi sixazululo ngu-500mg/L), bese uyihlanza ngokulingana namanani e-CODCr angu-400mg/L, 300mg/L, futhi 200mg. /L, isixazululo se-dilute esingu-100mg/L. I-Pipette 20.0 mL yesisombululo esijwayelekile enenani le-CODCr lika-100 mg/L kuya ku-500 mg/L, engeza izinto ezivuselelayo ngokwendlela evamile, futhi ulinganise inani le-CODCr. Ngemva kokushisisa, ukubilisa nokushintshashintsha imizuzu engu-30, zipholisa ngokwemvelo ngezinga lokushisa elilingana negumbi bese umboza futhi ugcine ukuze ulungiselele uchungechunge olujwayelekile lwe-colorimetric. Enqubweni yokukala inani le-CODCr lesampula lamanzi ngokwendlela evamile, lapho i-reflux ebilisayo iqhubeka imizuzu engu-30, iqhathanise nokulandelana kombala kwenani elishisiwe le-CODCr elijwayelekile ukuze ulinganise inani le-CODCr lesampula lamanzi, futhi unqume i-dilution factor lapho kuhlolwa i-BOD5 ngokusekelwe kulokhu. . Ukuphrinta nokudaya, ukwenza iphepha, amakhemikhali kanye namanye amanzi alahlwayo embonini aqukethe izinto eziphilayo okunzima ukuzigaya, uma kunesidingo, yenza ukuhlolwa kwe-colorimetric ngemva kokubilisa nokushintshashintsha imizuzu engu-60.
Isikhathi sokuthumela: Sep-21-2023
