I-Persulfate Oxidation yeCyanide Wastewater Treatment: Ucwaningo Oluphelele

Isingeniso

I-Cyanide, inhlanganisela enobuthi obukhulu, isetshenziswa kakhulu ezinqubweni ezahlukahlukene zezimboni njengokufaka i-electroplating, ukumbiwa kwezimayini, kanye nokuqedwa kwensimbi. Ngenxa yalokho, kukhiqizwa amanzi amaningi angcolile aqukethe i-cyanide , okubeka usongo olukhulu emvelweni nasempilweni yabantu. Izindlela zokwelapha amanzi angcolile zendabuko ze-Cyanide , njenge-alkaline chlorination, zinezinkinga eziningana. Lokhu kufaka phakathi ukwakheka kwemikhiqizo enobuthi, ukusetshenziswa kwamakhemikhali amaningi, kanye nokusebenza kahle kokususa ama-complex e-metal-cyanide. Ngenxa yalokho, kunesidingo esikhulayo sobuchwepheshe bokwelapha obusebenza kahle nobunobungani nemvelo.

Eminyakeni yamuva nje, izinqubo ze-oxidation ezithuthukisiwe (ama-AOP) ziye zavela njengezindlela ezithembisayo zokwelapha amanzi angcolile e-cyanide. Phakathi kwalezi, inqubo ye -Persulfate oxidation idonsele ukunaka okukhulu ngenxa yamandla ayo aqinile e-oxidation, ukusebenza kwebanga elibanzi le-pH, kanye nokusebenza okulula. Lokhu okuthunyelwe kwebhulogi kuhlose ukunikeza umbono ophelele wendlela ye-persulfate oxidation yokwelashwa kwamanzi angcolile e-cyanide, ehlanganisa indlela esebenza ngayo, izici ezithonyayo, kanye nezicelo ezisebenzayo.

I-Mechanism ye-Persulfate Oxidation

I-Persulfate, ekhona njenge-peroxydisulfate (PDS) noma i-peroxymonosulfate (PMS), ingenziwa isebenze ngezindlela ezihlukahlukene, njengokushisa, ukukhanya kwe-UV, izinsimbi eziguqukayo, noma i-alkalinity, ukuze kukhiqizwe ama-radicals e-sulfate asebenza kakhulu. Lawa ma-radicals e-sulfate anamandla aphezulu e-oxidation, okuwenza akwazi ukwenza i-oxidize ukungcola okuhlukahlukene kwe-organic kanye ne-inorganic, okuhlanganisa i-cyanide.

Indlela yokusabela ye-persulfate oxidation ye-cyanide iyinkimbinkimbi futhi ihilela izinyathelo eziningi. Ngokuvamile, ama-sulfate radicals ahlangana nama-cyanide ions akhe i-cyanate njengomkhiqizo ophakathi nendawo. I-cyanate ingabuye ifakwe i-oxidized noma i-hydrolyzed ukuze ikhiqize imikhiqizo yokugcina enobuthi obuncane, njenge-nitrate, i-ammonium, negesi ye-nitrogen. Izindlela zokusabela ezithile ziyahlukahluka kuye ngezimo zokusabela njenge-pH, izinga lokushisa, nokuba khona kwezinye izinto. Endaweni ene-acidic, ukusabela kulandela ukulandelana okuthile, kuyilapho endaweni eyisisekelo, indlela yokusabela iyashintsha, futhi ama-hydroxyl radicals nawo angabamba iqhaza enqubweni ye-oxidation. I-Hydroxyl radicals ingakhiqizwa kusukela ekuphenduleni kwama-sulfate radicals ngamanzi noma ekusebenzeni kwe-persulfate nge-alkalinity, futhi ukusabela kwawo nge-cyanide kuyindlela ebalulekile yokukhishwa kwe-cyanide.

Izinto Ezithonya

1. I-Persulfate Concentration

Ukugcwala kwe-persulfate kuyisici esibalulekile esithinta ukusebenza kahle kokwelashwa kwamanzi angcolile e-cyanide. Ngokuvamile, ukwandisa umthamo we-persulfate kungathuthukisa ukukhiqizwa kwama-radicals e-sulfate, ngaleyo ndlela kukhuthaze ukugeleza kwe-cyanide. Kodwa-ke, i-persulfate eyeqile ingase iholele ekuzicimeni kokusabela kwe-sulfate radicals, kunciphise ukusebenza kahle kwe-oxidation jikelele. Ngaphezu kwalokho, ukugxila okuphezulu kwe-persulfate kungakhuphula izindleko zokwelashwa futhi kubangele izinkinga zemvelo ezingaba khona ngenxa ye-persulfate esele emanzini ahlanzekile. Ngakho-ke, ukugxila okufanele kwe-persulfate kufanele kunqunywe ngokuhlolwa okusekelwe ezicini zamanzi angcolile.

2. Inani le-pH

I-pH yamanzi angcolile ithinta kakhulu inqubo ye-persulfate oxidation. Izimo ezihlukile ze-pH zingathinta ukwenziwa kusebenze kwe-persulfate, izinhlobo nokusebenza kabusha kwama-radicals akhiqiziwe, kanye nohlobo lwe-cyanide. Ezimweni ezine-acidic, ama-sulfate radicals ayizinhlobo eziyinhloko ezisabelayo futhi abonisa ukusabela okuphezulu ku-cyanide. Njengoba i-pH ikhula, ingxenye yama-hydroxyl radicals ekhiqizwa ekuphenduleni kwama-sulfate radicals ngamanzi noma ekucushweni kwe-persulfate nge-alkalinity iyakhuphuka. Ezimweni ze-alkaline, ama-hydroxyl radicals angase adlale indima ebaluleke kakhulu ku-cyanide oxidation. Noma kunjalo, amanani e-pH aphezulu kakhulu noma aphansi angaba nemiphumela engemihle ekuphenduleni. Isibonelo, nge-pH ephansi kakhulu, ukuzinza kwe-persulfate kungase kuthinteke, kuyilapho i-pH ephezulu kakhulu, ukuncibilika kwamanye ama-ion ensimbi emanzini angcolile kungase kushintshe, okungase kube nomthelela ekusebenzeni kwe-persulfate kanye nenqubo ye-oxidation.

3. Ukushisa

Izinga lokushisa lingasheshisa ukwenziwa kusebenze kwe-persulfate kanye nezinga lokusabela phakathi kwama-radicals ne-cyanide. Amazinga okushisa aphezulu ngokuvamile aholela ekukhiqizeni okusheshayo kwama-sulfate radicals kanye ne-cyanide oxidation esebenza kahle kakhudlwana. Kodwa-ke, ukukhulisa izinga lokushisa kudinga ukufaka amandla okwengeziwe, okuphakamisa izindleko zokwelashwa. Ukwengeza, uma izinga lokushisa liphezulu kakhulu, lingabangela ukubola kwe-persulfate nokunye ukusabela okungafuneki ohlangothini. Ngakho-ke, lapho kukhethwa izinga lokushisa elifanele lokusabela, kufanele kube nebhalansi phakathi kokusebenza kahle kokwelashwa nokusetshenziswa kwamandla.

4. Ukuba khona kwe-Metal Ions

Ama-ion ensimbi avame ukutholakala emanzini angcolile ezimboni, afana ne-Cu²⁺, Zn²⁺, Fe²⁺, ne-Ni²⁺, angaba nemiphumela ehlukile kunqubo ye-persulfate oxidation. Amanye ama-ion ensimbi, afana ne-Cu²⁺, angasebenza njengama-catalysts ukwenza kusebenze i-persulfate, akhiqize ama-radicals e-sulfate engeziwe futhi athuthukise ukukhishwa kwe-cyanide. Ngakolunye uhlangothi, ama-ion ensimbi athile angase akhe ama-complexes ane-cyanide, ayenze izinze futhi kube nzima uku-oxidize. Ngaphezu kwalokho, ama-ion ensimbi angase futhi abambe iqhaza ekuphenduleni okuseceleni kwe-persulfate noma ama-radicals, okuthinta yonke indlela yokusabela nokusebenza kahle. Ukuqonda indima ye-ion yensimbi ohlelweni lwe-oxidation ye-persulfate kubalulekile ekwenzeni inqubo yokwelashwa kwe-cyanide - equkethe amanzi angcolile.

5. Isikhathi Sokusabela

Isikhathi esanele sokuphendula siyadingeka ukuze kuqinisekiswe i-oxidation ephelele ye-cyanide. Njengoba ukusabela kuqhubeka, ukuhlushwa kwe-cyanide kuncipha kancane kancane. Nokho, ngemva kwesikhathi esithile, izinga lokusabela lingase lehlise ijubane ngenxa yokuncipha kwama-reactants noma ukunqwabelana kwemikhiqizo yokusabela. Isikhathi esilungile sokuphendula sincike ezicini ezihlukahlukene, okuhlanganisa ukugxila kokuqala kwe-cyanide, izimo zokusabela (ezifana nokugxila kwe-persulfate, i-pH, nezinga lokushisa), kanye nohlobo lwe-matrix yamanzi angcolile. Izikhathi zokusabela ezinwetshiwe azihlali ziholela ekwenyukeni okulinganayo kokusebenza kahle kokukhipha i-cyanide futhi zingase futhi ziholele ekusetshenzisweni kwamandla kanye nezindleko zokwelashwa.

Izicelo Ezimbonini Ezihlukene

1. Imboni ye-Electroplating

Enqubweni ye-electroplating, i-cyanide ivame ukusetshenziswa ukuze kuqinisekiswe ikhwalithi yensimbi. Amanzi angcolile akhiqizwa nge-electroplating aqukethe ukugxila okuphezulu kwe-cyanide ne-metal - cyanide complexes. I-Persulfate oxidation ibonise amandla amakhulu ekwelapheni amanzi angcolile e-cyanide e-electroplating. Isibonelo, ucwaningo lubonise ukuthi lapho kukhona amanani afanelekile e-Cu²⁺ (njenge-activator) ne-peroxydisulfate, kufika ku-99% we-cyanide angakhishwa phakathi nemizuzu engu-20. Le ndlela ingabhidliza kahle insimbi - i-cyanide complexes futhi iguqule i-cyanide ibe izinto ezinobuthi obuncane, ihlangabezane nezindinganiso eziqinile zokukhipha amanzi angcolile e-electroplating.

2. Imboni Yezimayini

Imboni yezimayini, ikakhulukazi izimayini zegolide, ikhiqiza inani elikhulu le-cyanide - equkethe amanzi angcolile kanye nezinsalela. I-Cyanide isetshenziswa ekukhishweni kwegolide ukwenza igolide elincibilikayo - i-cyanide complexes. I-Persulfate - izinqubo ze-oxidation ezithuthukisiwe zingasetshenziswa ukwelapha kokubili amanzi angcolile kanye nezinsalela. Isibonelo, ekwelapheni izinsalela zegolide ze-cyanide, i-ultrasonic - activated persulfate oxidation isihloliwe. Ngokusebenzisa u-2.0 wt.% we-potassium persulfate ku-pH 10.0 imizuzu engama-60, ukusebenza kahle kokukhipha i-cyanide kungafinyelela ku-53.47%. Ngokusebenza kokushisa ku-60 ° C, ukusebenza kahle kukhuphukela ku-62.18%, futhi ngaphansi kokusebenza kwe-ultrasonic ngamandla angu-100%, ukusebenza kahle kokususa kungafinyelela ku-74.76%. Ngemuva kwe-ultrasonic - i-activated persulfate - ukwelashwa kwe-oxidation okuthuthukisiwe, okuqukethwe kwe-cyanide kusisombululo esinobuthi se-leaching sensalela kungahlangabezana nezinga likazwelonke, okubonisa ukuthi kungenzeka le ndlela embonini yezimayini.

3. Metal Finishing Industry

Embonini yokuqeda insimbi, i-cyanide isetshenziswa ezinqubweni ezihlukahlukene zokwelashwa kwendawo. I-cyanide ewumphumela - equkethe amanzi angcolile idinga ukuphathwa kahle ukuze kugwenywe ukungcoliswa kwemvelo. I-Persulfate oxidation ingahlanganiswa ezinhlelweni zokwelashwa kwamanzi angcolile zezitshalo zokuqeda insimbi. Ngokulungiselela izimo zokusabela, ezifana nokulungisa ukugxila kwe-persulfate, i-pH, nesikhathi sokusabela, ukususwa kwe-cyanide okuseqophelweni eliphezulu kungafinyelelwa. Lokhu akusizi nje kuphela imboni yokuqedela insimbi ukuthi ihambisane nemithetho yemvelo kodwa futhi kunciphisa izingozi ezingaba khona ezihlobene nokukhishwa kwe-cyanide.

Case Studies

Icala 1: Ukwelashwa Kwangempela Kwamanzi Angcolile E-Electroplating

Ucwaningo lwenziwa emanzini angcolile e-electroplating aqukethe i-cyanide, aphathwa ngenqubo ye-persulfate oxidation. Lapho inani elithile le-persulfate lengezwa, inani elikhulu le-cyanide emanzini angcolile lingakhishwa ngokuphelele phakathi nemizuzu engu-20. Imiphumela yokuhlolwa okuningi ibonise ukuthi kokubili ama-hydroxyl radicals nama-sulfate radicals ayenomthwalo wemfanelo wokukhipha i-cyanide, futhi iminikelo yawo yayiqhathaniswa. I-Cyanate ne-nitrite zitholwe njengemikhiqizo eyinhloko. Lolu cwaningo lwecala lubonise ukusebenza kwe-persulfate oxidation ekwelapheni amanzi angcolile e-electroplating cyanide emhlabeni wangempela.

Icala lesi-2: Ukwelashwa Kwezinsalela Zegolide Ze-Cyanide

Emsebenzini wokumba igolide, izinsalela ze-cyanide zegolide zaphathwa nge-persulfate - inqubo ye-oxidation ethuthukisiwe. Izinsalela zazinamazinga aphezulu e-cyanide okwakudingeka ehliswe ukuze ahlangabezane nezindinganiso zokulahla. Ngokuhlola, kwatholakala ukuthi ngokusebenzisa i-potassium persulfate kanye nokuthuthukisa izimo zokusabela, okuhlanganisa i-pH, izinga lokushisa, nezindlela zokuvula (njengokuvula i-ultrasonic), okuqukethwe kwe-cyanide kusixazululo esinobuthi se-leaching yezinsalela kungase kwehle kakhulu. Ngemuva kwe-ultrasonic - i-activated persulfate - ukwelashwa kwe-oxidation okuthuthukisiwe, okuqukethwe kwe-cyanide kusixazululo se-leaching enobuthi kuhlangabezane nezinga lezwe laseChina. Leli cala libonisa ukusetshenziswa ngempumelelo kwe-persulfate oxidation ekwelapheni izinsalela zegolide ze-cyanide, okuhlinzeka ngesixazululo esisebenzayo sokulahlwa okuphephile kwemfucuza yasezimayini.

Izinselele kanye Nemibono Yekusasa

1. Izinselelo

• Ukusebenza kahle kwezindleko : Nakuba i-persulfate oxidation ikhombisa amandla amakhulu ekwelapheni amanzi angcolile e-cyanide, izindleko ze-persulfate kanye namandla adingekayo ukuze kusebenze (njengokushisa noma ukusebenza kwe-ultrasonic) zingaba phezulu kakhulu. Ukuthuthukisa izindlela ezingabizi kakhulu zokukhiqiza nokusebenzisa i-persulfate kuyadingeka ukuze lobu buchwepheshe busebenze kabanzi.

• Ubunzima be-Wastewater Matrix : I-Industrial cyanide - amanzi angcolile aqukethe imvamisa aqukethe ingxube eyinkimbinkimbi yezinto ezahlukahlukene, kufaka phakathi ama-ion ensimbi ahlukene, amakhemikhali e-organic, kanye nosawoti. Lezi zingxenye zingasebenzisana ne-persulfate kanye nama-radical, okuthinta indlela yokusabela kanye nokusebenza kahle. Ukuqonda nokulawula lokhu kuxhumana okuyinkimbinkimbi kuyinselele ekusetshenzisweni okusebenzayo.

• I-Persulfate Esele kanye Nemikhiqizo Engaphelele : I-persulfate esele emanzini ahlanziwe ingabangela izinkinga zemvelo ezingaba khona, kanti eminye imikhiqizo engaphelele, njenge-nitrite, ingadinga nokwelashwa okwengeziwe ukuze ihlangabezane nezindinganiso zemvelo eziqinile. Ukuthuthukisa izindlela zokususa ngempumelelo i-persulfate esele kanye nokulawula ukwakheka kwemikhiqizo engaphelele kuyindawo ebalulekile yocwaningo olwengeziwe.

I-2. Imibono Yesikhathi Esizayo

• Izindlela Ezintsha Zokusebenzisa I- Persulfate: Ucwaningo luyaqhubeka ukuthuthukisa izindlela ezintsha nezisebenza kahle kakhulu zokusebenzisa i-persulfate. Isibonelo, ukusebenzisa ama-catalyst amasha njenge-nanomaterials noma izinhlaka zensimbi - eziphilayo (ama-MOF) ukuze kusebenze i-persulfate kunganikeza amazinga aphezulu okusabela kanye nokukhetha. Ngaphezu kwalokho, ukuhlola inhlanganisela yezindlela ezahlukene zokusebenzisa i-Persulfate, njengokusebenzisa ukushisa kanye ne-Catalyst ngesikhathi esisodwa, kungathuthukisa kakhulu ukusebenza kwenqubo yokuxiliswa kwe-Persulfate.

• Ukuhlanganiswa Nezinye Izindlela Zokwelapha : Ukuhlanganisa i-persulfate oxidation nezinye izindlela zokwelapha, njengokwelashwa kwezinto eziphilayo, ukuhlunga i-membrane, noma ukumuncwa, kungafeza imiphumela yokwelapha engcono kakhulu. Isibonelo, ukwelapha ngaphambi kokusebenzisa i-persulfate oxidation ukuze kuqedwe amakhemikhali e-cyanide ayinkimbinkimbi kungenza amanzi angcolile afaneleke kakhulu ekwelashweni kwezinto eziphilayo okulandelayo.

• Ukuqapha Nokwenza Inqubo Isebenze Kahle : Ukuthuthukiswa kwamasu okuqapha ngaphakathi kwenqubo yokuxiliswa kwe-persulfate, njengokuthola ngesikhathi sangempela amazinga aqinile kanye nemikhiqizo yokubola kwe-cyanide, kungasiza ekuqondeni kangcono inqubekela phambili yokusabela kanye nokwenza ngcono inqubo yokwelapha. Lokhu kungaholela ezinhlelweni zokwelashwa kwamanzi amdaka e-cyanide ezisebenza kahle futhi ezinokwethenjelwa.

Sengiphetha, indlela ye-persulfate oxidation ibonisa isithembiso esikhulu ekwelapheni i-cyanide - equkethe amanzi angcolile. Ngocwaningo oluqhubekayo kanye nentuthuko yokubhekana nezinselele ezikhona, lobu buchwepheshe bunamandla okuba indlela evamile yokuhlanza amanzi angcolile e-cyanide ezimbonini ezihlukahlukene, okubambe iqhaza ekuvikelweni kwemvelo kanye nentuthuko esimeme.