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Ma keia hana, rGO/nZVI composites i synthesized no ka manawa mua me ka hoʻohana 'ana i ke kaʻina hana maʻalahi a me ke kaiapuni e hoʻohana ana i ka Sophora yellowish lau extract ma ke 'ano he mea ho'ēmi a me ka stabilizer e hoʻokō i nā loina o ka "'ōmaʻomaʻo" kemika, e like me ka liʻiliʻi o ka pōʻino chemical synthesis. Ua hoʻohana ʻia kekahi mau mea hana no ka hōʻoia ʻana i ka synthesis kūleʻa o nā composites, e like me SEM, EDX, XPS, XRD, FTIR, a me zeta potential, e hōʻike ana i ka hana ʻana o ka composite kūleʻa. Ua hoʻohālikelike ʻia ka hiki ke hoʻoneʻe ʻia o ka moʻolelo composites a me ka nZVI maʻemaʻe i nā ʻano hoʻomaka o ka doxycycline antibiotic e noiʻi i ka hopena synergistic ma waena o rGO a me nZVI. Ma lalo o nā kūlana hoʻoneʻe o 25mg L-1, 25 ° C a me 0.05g, ʻo ka adsorptive removal rate o ka nZVI maʻemaʻe he 90%, aʻo ka adsorptive removal rate o doxycycline e ka rGO / nZVI composite i hiki i 94.6%, e hōʻoia ana i nZVI a me rGO . ʻO ke kaʻina hana adsorption e pili ana i kahi kauoha pseudo-second a ua ʻae maikaʻi ʻia me ka model Freundlich me ka nui adsorption hiki o 31.61 mg g-1 ma 25 ° C a me pH 7. Ua hoʻolālā ʻia kahi ʻano kūpono no ka wehe ʻana o DC. Eia kekahi, ʻo ka hoʻohana hou ʻana o ka rGO/nZVI composite ʻo 60% ma hope o ʻeono mau kaʻina hana hou.
He mea hoʻoweliweli koʻikoʻi ka nele o ka wai a me ka haumia i nā ʻāina āpau. I nā makahiki i hala iho nei, ua hoʻonui ʻia ka pollution wai, ʻoi aku ka pollution antibiotic, ma muli o ka hoʻonui ʻana i ka hana a me ka hoʻohana ʻana i ka wā maʻi COVID-191,2,3. No laila, ʻo ka hoʻomohala ʻana i kahi ʻenehana kūpono no ka hoʻopau ʻana i nā lāʻau antibiotic i ka wai ʻino he hana koʻikoʻi.
ʻO kekahi o nā lāʻau antibiotic semi-synthetic kūʻē mai ka hui tetracycline ʻo doxycycline (DC)4,5. Ua hōʻike ʻia ʻaʻole hiki ke hoʻololi ʻia nā koena DC i loko o ka wai o ka honua a me ka wai o ka ʻili, ʻo 20-50% wale nō i hoʻololi ʻia a hoʻokuʻu ʻia ke koena i loko o ke kaiapuni, e hoʻopilikia i nā pilikia koʻikoʻi a me ke olakino6.
Hiki i ka hoʻolaha ʻana iā DC ma nā haʻahaʻa haʻahaʻa ke pepehi i nā microorganism photosynthetic aquatic, hoʻoweliweli i ka laha ʻana o nā huakini antimicrobial, a hoʻonui i ka pale antimicrobial, no laila pono e wehe ʻia kēia mea haumia mai ka wai ʻino. ʻO ka hoʻohaʻahaʻa maoli o DC i ka wai he hana lohi loa. Hiki ke hoʻohaʻahaʻa wale nā kaʻina hana kino-kemika e like me photolysis, biodegradation a adsorption ma nā haʻahaʻa haʻahaʻa a me nā haʻahaʻa haʻahaʻa loa7,8. Eia nō naʻe, ʻo ke ala ʻoi aku ka maʻalahi, maʻalahi, pili i ke kaiapuni, maʻalahi e mālama a me ke ʻano kūpono ʻo adsorption9,10.
ʻO ka Nano zero valent iron (nZVI) he mea ikaika loa ia e hiki ke wehe i nā lāʻau antibiotic mai ka wai, me ka metronidazole, diazepam, ciprofloxacin, chloramphenicol, a me tetracycline. Ma muli o nā waiwai kupanaha i loaʻa iā nZVI, e like me ke kiʻekiʻe reactivity, ka ʻili nui, a me ka nui o nā wahi paʻa waho11. Eia naʻe, hiki i ka nZVI ke hoʻohui i loko o ka media wai ma muli o nā kaha van der Wells a me nā waiwai magnetic kiʻekiʻe, e hōʻemi ana i kona pono i ka wehe ʻana i nā mea haumia ma muli o ka hoʻokumu ʻana o nā papa oxide e kāohi i ka reactivity o nZVI10,12. Hiki ke ho'emi 'ia ka agglomeration o nZVI particles ma ka ho'ololi 'ana i ko lākou mau wahi me nā surfactants a me nā polymers a i 'ole ma ka hui 'ana me nā nanomaterials ma ke 'ano o nā composites, i hō'ike 'ia he ala kūpono e ho'omaika'i ai i ko lākou kūpa'a i ke kaiapuni13,14.
ʻO Graphene kahi mea kalapona kalapona ʻelua-dimensional i loaʻa i ka sp2-hybridized carbon atoms i hoʻonohonoho ʻia i loko o ka lattice honeycomb. He wahi ili nui kona, ikaika mechanical nui, hana electrocatalytic maikaʻi loa, conductivity thermal kiʻekiʻe, neʻe electron wikiwiki, a me kahi mea lawe kūpono e kākoʻo i nā nanoparticles inorganic ma kona ʻili. ʻO ka hui pū ʻana o nā nanoparticles metala a me ka graphene hiki ke ʻoi aku ma mua o nā pono pilikino o kēlā me kēia mea a, ma muli o kona ʻano kino a me nā waiwai kemika, hāʻawi i ka mahele maikaʻi loa o nā nanoparticles no ka mālama wai ʻoi aku ka maikaʻi15.
ʻO nā ʻāpana mea kanu ke koho maikaʻi loa i nā mea hoʻemi kemika ʻino i hoʻohana mau ʻia i ka synthesis o ka graphene oxide i hoʻemi ʻia (rGO) a me nZVI no ka mea hiki ke loaʻa, kūʻai ʻole, hoʻokahi ʻanuʻu, palekana kaiapuni, a hiki ke hoʻohana ʻia ma ke ʻano he mau mea hoʻemi. e like me nā flavonoids a me nā pūhui phenolic e hana pū me kahi stabilizer. No laila, ua hoʻohana ʻia ʻo Atriplex halimus L. leaf extract ma ke ʻano he mea hoʻoponopono a pani pani no ka hoʻohui ʻana o rGO/nZVI composites i kēia haʻawina. ʻO Atriplex halimus mai ka ʻohana Amaranthaceae kahi kumu lāʻau aloha nitrogen me kahi ākea ākea16.
Wahi a nā palapala i loaʻa, ua hoʻohana mua ʻia ʻo Atriplex halimus (A. halimus) e hana i nā composites rGO/nZVI ma ke ʻano he ʻano hana synthesis e pili ana i ka ʻoihana. No laila, ʻo ka pahuhopu o kēia hana he ʻehā ʻāpana: (1) phytosynthesis o rGO/nZVI a me nZVI makua composites me ka hoʻohana ʻana i ka A. halimus aquatic leaf extract, (2) characterization of phytosynthesized composites me ka hoʻohana ʻana i nā ʻano he nui e hōʻoia i kā lākou hana kūleʻa, (3 ) e aʻo i ka hopena synergistic o rGO a me nZVI i ka adsorption a me ka wehe ʻana i nā mea haumia kūlohelohe o nā lāʻau antibiotic doxycycline ma lalo o nā ʻāpana hopena like ʻole, e hoʻopaʻa i nā kūlana o ke kaʻina hana adsorption, (3) e noiʻi i nā mea hoʻohui i nā ʻano lapaʻau mau ma hope o ke kaʻina hana.
ʻO ka Doxycycline hydrochloride (DC, MM = 480.90, ka hoʻohālikelike kemika C22H24N2O · HCl, 98%), ka hao chloride hexahydrate (FeCl3.6H2O, 97%), ka pauka graphite i kūʻaiʻia mai Sigma-Aldrich, USA. Ua kūʻai ʻia ka sodium hydroxide (NaOH, 97%), ethanol (C2H5OH, 99.9%) a me ka waikawa hydrochloric (HCl, 37%) mai Merck, USA. NaCl, KCl, CaCl2, MnCl2 a me MgCl2 ua kūʻai ʻia mai Tianjin Comio Chemical Reagent Co., Ltd. ʻO nā reagents a pau o ka maʻemaʻe analytical kiʻekiʻe. Ua hoʻohana ʻia ka wai hoʻoheheʻe pālua no ka hoʻomākaukau ʻana i nā wai wai āpau.
Ua hōʻiliʻili ʻia nā hiʻohiʻona o A. halimus mai ko lākou wahi kūlohelohe i ka Nile Delta a me nā ʻāina ma ke kahakai Mediterranean o ʻAigupita. Ua hōʻiliʻili ʻia nā mea kanu e like me nā alakaʻi pili aupuni a me ka honua17. Ua ʻike ʻo Prof. Manal Fawzi i nā ʻano mea kanu e like me ka Boulos18, a ua ʻae ke Keʻena ʻepekema ʻĀina o ke Kulanui ʻo Alexandria i ka hōʻiliʻili ʻana i nā ʻano mea kanu i aʻo ʻia no nā kumu ʻepekema. Loaʻa nā palapala laʻana ma ka Tanta University Herbarium (TANE), nā palapala palapala nos. 14 122–14 127, he lāʻau lāʻau lehulehu e hāʻawi ana i ke komo ʻana i nā mea i waiho ʻia. Eia kekahi, no ka wehe ʻana i ka lepo a i ʻole ka lepo, ʻoki i nā lau o ka mea kanu i mau ʻāpana liʻiliʻi, holoi ʻia i 3 mau manawa me ka paʻi a me ka wai i hoʻoheheʻe ʻia, a laila maloʻo ma 50 ° C. Hoʻopiliʻia ka mea kanu, 5 g o ka pauka maikaʻi i hoʻokomoʻia i loko o 100 ml o ka wai i hoʻopiliʻia a hoʻouluʻia ma 70 ° C no 20 min e loaʻa ai kahi extract. Ua kānana ʻia ka ʻāpana i loaʻa o Bacillus nicotianae ma o ka pepa kānana Whatman a mālama ʻia i loko o nā paipu maʻemaʻe a sterilized ma 4 ° C no ka hoʻohana hou ʻana.
E like me ka mea i hōʻike ʻia ma ka Figure 1, ua hana ʻia ka GO mai ka pauka graphite e ke ʻano Hummers i hoʻololi ʻia. 10 mg o GO pauka i hoopuehuia ma 50 ml o deionized wai no 30 min ma lalo o sonication, a laila 0.9 g o FeCl3 a me 2.9 g NaAc ua hui ia no 60 min. 20 ml o ka atriplex lau extract i hoʻohui ʻia i ka hopena i hoʻoulu ʻia me ka hoʻoulu ʻana a waiho ʻia ma 80 ° C no 8 mau hola. Ua kānana ʻia ka hopena ʻeleʻele. Ua holoi ʻia nā nanocomposites i hoʻomākaukau ʻia me ka ethanol a me ka wai bidistilled a laila hoʻomaloʻo ʻia i loko o ka umu ma 50 ° C no 12 mau hola.
Nā kiʻi kikoʻī a me nā kiʻi ʻōmaʻomaʻo o ka rGO/nZVI a me nZVI complexes a me ka wehe ʻana i nā lāʻau antibiotic DC mai ka wai haumia me ka hoʻohana ʻana iā Atriplex halimus extract.
ʻO ka pōkole, e like me ka mea i hōʻike ʻia ma ka Fig. 1, 10 ml o ka hao chloride solution i loaʻa i ka 0.05 M Fe3+ ions i hoʻohui ʻia i ka dropwise i 20 ml o kahi solution extract lau ʻawaʻawa no 60 mau minuke me ka hoʻomehana haʻahaʻa a me ka hoʻoulu ʻana, a laila ua centrifuged ka hopena ma kahi. 14,000 rpm (Hermle, 15,000 rpm) no 15 min e hāʻawi i nā ʻāpana ʻeleʻele, a laila holoi ʻia i 3 mau manawa me ka ethanol a me ka wai i hoʻomaloʻo ʻia a hoʻomaloʻo ʻia i ka umu ma 60 ° C. i ka pō.
Hōʻike ʻia nā mea hoʻohui rGO/nZVI a me nZVI i hoʻohui ʻia e nā mea kanu e ka spectroscopy ʻike maka ʻia (T70/T80 series UV/Vis spectrophotometers, PG Instruments Ltd, UK) i ka laulā o 200-800 nm. No ke kālailai ʻana i ka topography a me ka puʻunaue nui o ka rGO/nZVI a me nZVI composites, TEM spectroscopy (JOEL, JEM-2100F, Iapana, accelerating voltage 200 kV) ua hoʻohana ʻia. No ka loiloi i nā pūʻulu hana i hiki ke komo i loko o nā mea kanu i kuleana no ka hoʻihoʻi ʻana a me ke kaʻina hoʻokūpaʻa, ua lawe ʻia ka spectroscopy FT-IR (JASCO spectrometer ma ka laulā o 4000-600 cm-1). Eia kekahi, ua hoʻohana ʻia kahi mea anamanaʻo zeta (Zetasizer Nano ZS Malvern) e aʻo i ka uku o ka ʻili o nā nanomaterials synthesized. No nā ana ʻokoʻa X-ray o nā nanomaterials pauka, ua hoʻohana ʻia kahi diffractometer X-ray (X'PERT PRO, Netherlands), e hana ana ma kahi o kēia manawa (40 mA), ka uila (45 kV) ma ka pae 2θ mai 20° a 80. ° a me CuKa1 kukuna (\(\lambda =\ ) 1.54056 Ao). ʻO ka ikehu dispersive X-ray spectrometer (EDX) (model JEOL JSM-IT100) ke kuleana no ke aʻo ʻana i ka haku mele i ka wā e hōʻiliʻili ai i nā kukui X-a monochromatic Al K-α mai -10 a i 1350 eV ma XPS, ka nui wahi 400 μm K-ALPHA (Thermo Fisher Scientific, USA) ʻo 200 eV ka ikehu hoʻoili o ke kiko holoʻokoʻa a ʻo 50 eV ke kiko haiki. Hoʻokomo ʻia ka hāpana pauda ma luna o kahi mea hoʻopaʻa laʻana, kahi i waiho ʻia i loko o kahi keʻena ʻūhā. Ua hoʻohana ʻia ka spectrum C 1 ma ke ʻano he kuhikuhi ma 284.58 eV e hoʻoholo ai i ka ikehu hoʻopaʻa.
Ua hoʻokō ʻia nā hoʻokolohua Adsorption e hoʻāʻo i ka pono o nā nanocomposites rGO/nZVI synthesized i ka wehe ʻana i ka doxycycline (DC) mai nā wai wai. Ua hana ʻia nā hoʻokolohua Adsorption i loko o 25 ml Erlenmeyer flasks ma ka wikiwiki haʻalulu o 200 rpm ma kahi orbital shaker (Stuart, Orbital Shaker/SSL1) ma 298 K. Ma ka hoʻoheheʻe ʻana i ka wai DC stock solution (1000 ppm) me ka wai bidistilled. No ka loiloi i ka hopena o ka rGO / nSVI dosage ma ka adsorption efficiency, nanocomposites o nā kaupaona like ʻole (0.01-0.07 g) i hoʻohui ʻia i ka 20 ml o ka hopena DC. No ke aʻo ʻana i nā kinetics a me adsorption isotherms, 0.05 g o ka adsorbent i hoʻokomo ʻia i loko o kahi wai wai o CD me ka neʻe mua (25-100 mg L-1). Ua aʻo ʻia ka hopena o ka pH ma ka wehe ʻana o DC ma ka pH (3-11) a me ka neʻe mua o 50 mg L-1 ma 25 ° C. Hoʻoponopono i ka pH o ka ʻōnaehana ma ka hoʻohui ʻana i kahi mea liʻiliʻi o ka HCl a i ʻole NaOH solution (Crison pH mika, pH mika, pH 25). Eia kekahi, ua noiʻi ʻia ka hopena o ka mahana hopena ma nā hoʻokolohua adsorption i ka laulā o 25-55 ° C. Ua aʻo ʻia ka hopena o ka ikaika ionic ma ke kaʻina adsorption ma o ka hoʻohui ʻana i nā ʻano ʻokoʻa like ʻole o NaCl (0.01-4 mol L-1) ma kahi kumu mua o DC o 50 mg L-1, pH 3 a me 7), 25 ° C, a he adsorbent dose o 0.05 g. Ua ana ʻia ka adsorption o ka non-adsorbed DC me ka ʻelua beam UV-Vis spectrophotometer (T70/T80 series, PG Instruments Ltd, UK) i hoʻolako ʻia me 1.0 cm ala lōʻihi quartz cuvettes ma nā lōʻihi hawewe (λmax) o 270 a me 350 nm. ʻO ka pākēneka o ka lawe ʻana i nā lāʻau antibiotic DC (R%; Eq. 1) a me ka nui adsorption o DC, qt, Eq. Ua ana ʻia ka 2 (mg/g) me ka hoʻohana ʻana i ka hoohalike aʻe.
kahi o %R ka mana wehe DC (%), Co ka manao mua DC ma ka manawa 0, a o C ka manao DC ma ka manawa t, pakahi (mg L-1).
kahi qe ka nui o ka DC i hoʻopili ʻia i kēlā me kēia ʻāpana nui o ka adsorbent (mg g-1), ʻo Co a me Ce nā manaʻo i ka manawa ʻole a ma ke kaulike, kēlā me kēia (mg l-1), ʻo V ka leo hoʻonā (l) , a ʻo ka m ka adsorption mass reagent (g).
Hōʻike nā kiʻi SEM (Fig. 2A-C) i ka morphology lamellar o ka rGO/nZVI composite me nā nanoparticles hao spherical i hoʻopuehu like ʻia ma kona ʻili, e hōʻike ana i ka hoʻopili kūleʻa ʻana o nā nZVI NPs i ka ʻili rGO. Eia kekahi, aia kekahi mau wrinkles i ka lau rGO, e hōʻoia ana i ka wehe ʻana o nā pūʻulu o ka oxygen i ka manawa like me ka hoʻihoʻi ʻana o A. halimus GO. Ke hana nei kēia mau wrinkles nui ma ke ʻano he kahua no ka hoʻouka ikaika ʻana i nā NP hao. Nā kiʻi nZVI (Fig. 2D-F) i hōʻike i nā NP hao spherical i hoʻopuehu loa a ʻaʻole i hōʻuluʻulu ʻia, ʻo ia ke kumu o ke ʻano o ka uhi ʻana o nā ʻāpana botanical o ka mea kanu. Ua ʻokoʻa ka nui o nā ʻāpana i loko o 15-26 nm. Eia nō naʻe, loaʻa i kekahi mau ʻāpana kahi morphology mesoporous me kahi ʻano o nā bulges a me nā lua, hiki ke hāʻawi i kahi mana adsorption kiʻekiʻe o nZVI, no ka mea hiki iā lākou ke hoʻonui i ka hiki ke hoʻopaʻa i nā molekala DC ma ka ʻili o nZVI. I ka hoʻohanaʻiaʻana o ka Rosa Damascus extract no ka synthesis o nZVI, ua likeʻole nā NP i loaʻa, me nā puka a me nāʻano likeʻole, i ho'ēmi i ko lākou pono i ka adsorption Cr (VI) a hoʻonui i ka manawa hoʻonā 23. Kūlike nā hopena me nZVI i hoʻohui ʻia mai nā lau ʻoka a me ka mulberry, ʻo ia ka nui o nā nanoparticles spherical me nā nui nanometer like ʻole me ka ʻike ʻole o ka agglomeration.
Nā kiʻi SEM o rGO/nZVI (AC), nZVI (D, E) composites a me EDX kumu o nZVI/rGO (G) a me nZVI (H) composites.
Ua aʻo ʻia ka haku mele o nā mea kanu-synthesized rGO/nZVI a me nZVI me ka hoʻohana ʻana iā EDX (Fig. 2G, H). Hōʻike nā haʻawina e haku ʻia ka nZVI me ke kalapona (38.29% ma ka nuipa), oxygen (47.41% ma ka nuipa) a me ka hao (11.84% ma ka nuipa), akā aia kekahi mau mea e like me ka phosphorus24, hiki ke loaʻa mai nā mea kanu. Eia kekahi, ʻo ke kiʻekiʻe o ka pākēneka o ke kalapona a me ka oxygen ma muli o ka loaʻa ʻana o nā phytochemicals mai nā mea kanu mea kanu i loko o nā ʻāpana nZVI subsurface. Hoʻokaʻawale like ʻia kēia mau mea ma rGO akā i nā lakio like ʻole: C (39.16 wt%), O (46.98 wt%) a me Fe (10.99 wt%), hōʻike pū ʻia ʻo EDX rGO/nZVI i ke alo o nā mea ʻē aʻe e like me S, ka mea. hiki ke pili me nā mea kanu extracts, hoʻohana ʻia. ʻOi aku ka maikaʻi o ka lākiō C:O a me ka hao i loko o ka rGO/nZVI composite me ka hoʻohana ʻana iā A. halimus ma mua o ka hoʻohana ʻana i ka eucalyptus lau extract, no ka mea e hōʻike ana i ka haku o C (23.44 wt.%), O (68.29 wt.%). a me Fe (8.27 wt.%). wt %) 25. Nataša et al., 2022 i hōʻike i kahi ʻano mea like o nZVI synthesized mai nā lau ʻoka a me ka mulberry a ua hōʻoia ʻo nā hui polyphenol a me nā molekole ʻē aʻe i loko o ka ʻāpana lau ke kuleana no ke kaʻina hoʻemi.
ʻO ka morphology o nZVI synthesized i loko o nā mea kanu (Fig. S2A,B) he spherical a he hapa ʻole, me ka nui o ka nui o 23.09 ± 3.54 nm, akā naʻe ua ʻike ʻia nā kaulahao ma muli o nā kaha van der Waals a me ka ferromagnetism. He ʻaelike maikaʻi kēia ʻano ʻāpana nui a me ka spherical me nā hopena SEM. Ua ʻike ʻia kahi ʻike like e Abdelfatah et al. i ka makahiki 2021 i ka wā i hoʻohana ʻia ai ka lāʻau castor bean i ka synthesis o nZVI11. ʻO ka Ruelas tuberosa lau extract NP i hoʻohana ʻia ma ke ʻano he mea hoʻohaʻahaʻa i nZVI he ʻano spherical hoʻi me ke anawaena o 20 a 40 nm26.
Hybrid rGO/nZVI composite TEM kiʻi (Fig. S2C-D) i hōʻike i ka rGO he basal plane me ka marginal folds a wrinkles e hāʻawi ana i nā wahi hoʻouka he nui no nZVI NPs; ʻO kēia lamellar morphology e hōʻoiaʻiʻo ana i ka hana kūleʻa o rGO. Eia hou, nZVI NPs he spherical shape me ka nui o ka nui mai ka 5.32 a hiki i ka 27 nm a hoʻokomo ʻia i loko o ka papa rGO me ka hoʻopuehu ʻaneʻane like. Ua hoʻohana ʻia ka eucalyptus lau extract e synthesize Fe NPs/rGO; Ua hōʻoia pū nā hualoaʻa TEM ua hoʻomaikaʻi nā wrinkles i ka papa rGO i ka hoʻopuehu ʻana o Fe NP ma mua o Fe NP maʻemaʻe a hoʻonui i ka reactivity o nā composites. Ua loaʻa nā hopena like e Bagheri et al. 28 i ka wā i hana ʻia ai ka composite me ka hoʻohana ʻana i nā ʻenehana kani ultrasonic me ka nui o ka nanoparticle hao ma kahi o 17.70 nm.
Hōʻike ʻia ka FTIR spectra o A. halimus, nZVI, GO, rGO, a me rGO/nZVI ma Fig. 3A. ʻIke ʻia ka hele ʻana o nā pūʻulu hana ili i nā lau o A. halimus ma 3336 cm-1, e pili ana i nā polyphenols, a me 1244 cm-1, e pili ana i nā hui carbonyl i hana ʻia e ka protein. ʻO nā hui ʻē aʻe e like me nā alkanes ma 2918 cm-1, nā alkenes ma 1647 cm-1 a me nā hoʻonui CO-O-CO ma 1030 cm-1 ua ʻike pū ʻia, e hōʻike ana i ka hele ʻana o nā mea kanu e hana i nā mea hoʻopaʻa sila a kuleana no ka hoʻihoʻi. mai Fe2+ a Fe0 a hele i rGO29. Ma keʻano laulā, hōʻike ka nZVI spectra i nā kiʻekiʻe o ka absorption e like me ke kō ʻawaʻawa, akā me kahi kūlana hoʻololi iki. Hōʻike ʻia kahi pūnaʻi ikaika ma 3244 cm-1 e pili ana me OH stretching vibrations (phenols), kahi kiʻekiʻe ma 1615 e like me C=C, a ʻo nā kaula ma 1546 a me 1011 cm-1 e ala mai ana ma muli o ke kau ʻana o C=O (polyphenols and flavonoids) , CN -pūʻulu o aromatic amines a me aliphatic amines ua nānā pūʻia ma 1310 cm-1 a me 1190 cm-1, respectively13. Hōʻike ka FTIR spectrum o GO i ka hiki ʻana mai o nā pūʻulu o ka oxygen kiʻekiʻe, e komo pū ana me ke kāʻei hoʻolōʻihi alkoxy (CO) ma 1041 cm-1, ka pūʻulu epoxy (CO) ma 1291 cm-1, C=O kikoo. ua puka mai kekahi pūʻulu o C=C i 1619 cm-1, he pūʻali ma 1708 cm-1 a me kahi pūʻulu ākea o ka OH pūʻolo haʻalulu ma 3384 cm-1, i hōʻoia ʻia e ke ʻano Hummers i hoʻomaikaʻi ʻia, e hoʻoheheʻe maikaʻi ana i ka. kaʻina hana graphite. I ka hoʻohālikelike ʻana i ka rGO a me ka rGO/nZVI composites me GO spectra, ua hoʻemi nui ʻia ka ikaika o kekahi mau pūʻulu o ka oxygen, e like me OH ma 3270 cm-1, a ʻo nā mea ʻē aʻe, e like me C=O ma 1729 cm-1, pau loa. hoemiia. ua nalowale, e hōʻike ana i ka wehe ʻana i nā pūʻulu hana i loko o ka oxygen i GO e ka A. halimus extract. ʻIke ʻia nā kiʻekiʻe kiʻekiʻe hou o rGO ma C=C ʻāʻī ma kahi o 1560 a me 1405 cm-1, e hōʻoia ana i ka hōʻemi ʻana o GO i rGO. Ua ʻike ʻia nā ʻano like ʻole mai 1043 a 1015 cm-1 a mai 982 a 918 cm-1, ma muli paha o ke komo ʻana o nā mea kanu31,32. Ua ʻike pū ʻo Weng et al., 2018 i kahi attenuation koʻikoʻi o nā hui hana oxygenated i GO, e hōʻoia ana i ka hoʻokumu ʻana o ka rGO ma o ka bioreduction, ʻoiai nā ʻāpana lau eucalyptus, i hoʻohana ʻia e synthesize i hoʻemi ʻia i ka hao graphene oxide composites, hōʻike kokoke loa i ka FTIR spectra o nā mea kanu. hui hana. 33 .
A. FTIR spectrum of galium, nZVI, rGO, GO, composite rGO/nZVI (A). Roentgenogrammy composites rGO, GO, nZVI a me rGO/nZVI (B).
Ua hōʻoia nui ʻia ka hoʻokumu ʻana o rGO/nZVI a me nZVI composites e nā hiʻohiʻona diffraction X-ray (Fig. 3B). Ua ʻike ʻia kahi peak Fe0 kiʻekiʻe ma 2Ɵ 44.5°, e pili ana i ka index (110) (JCPDS no. 06–0696)11. ʻO kekahi kiʻekiʻe ma 35.1° o ka mokulele (311) pili i ka magnetite Fe3O4, 63.2° hiki ke pili me ka Miller index o ka (440) mokulele ma muli o ke alo o ϒ-FeOOH (JCPDS no. 17-0536)34. Hōʻike ka hiʻohiʻona X-ray o GO i kahi kiʻekiʻe ma 2Ɵ 10.3° a me kahi kiʻekiʻe ʻē aʻe ma 21.1°, e hōʻike ana i ka exfoliation piha o ka graphite a e hōʻike ana i ka hele ʻana o nā pūʻulu o ka oxygen ma ka ʻili o GO35. Ua hoʻopaʻa ʻia nā hiʻohiʻona hui o rGO a me rGO/nZVI i ka nalo ʻana o nā piko GO hiʻona a me ka hoʻokumu ʻana o nā peaks rGO ākea ma 2Ɵ 22.17 a me 24.7° no ka rGO a me rGO/nZVI composites, i hōʻoia i ka hoʻihoʻi maikaʻi ʻana o GO e nā mea kanu. Eia nō naʻe, ma ke kumu hoʻohālikelike rGO/nZVI, ua ʻike ʻia nā piko hou e pili ana i ka mokulele lattice o Fe0 (110) a me bcc Fe0 (200) ma 44.9\(^\circ\) a me 65.22\(^\circ\). .
'O ka hikiwawe zeta ka 'ike ma waena o kahi papa ionic i ho'opili 'ia i ka ili o kahi mea iki a me ka wai e ho'oholo ai i ka waiwai electrostatic o kekahi mea a e ana i kona kūpa'a37. Ua hōʻike ʻo Zeta i ka nānā ʻana o nā mea kanu-synthesized nZVI, GO, a me rGO/nZVI composites i ko lākou kūpaʻa ma muli o ka loaʻa ʻana o nā uku maikaʻi ʻole o -20.8, -22, a me -27.4 mV, kēlā me kēia, ma ko lākou ʻili, e like me ka hōʻike ʻana ma ke Kiʻi S1A- C. . Kūlike ia mau hopena me kekahi mau hōʻike e hōʻike ana i nā hopena i loaʻa i nā ʻāpana me nā koina zeta hiki ke emi ma lalo o -25 mV e hōʻike ana i kahi kiʻekiʻe o ka paʻa ma muli o ka repulsion electrostatic ma waena o kēia mau ʻāpana. ʻO ka hui pū ʻana o rGO a me nZVI e hiki ai i ka composite ke loaʻa i nā koina maikaʻi ʻole a no laila ʻoi aku ka paʻa o ka paʻa ma mua o GO a i ʻole nZVI wale nō. No laila, ʻo ke ʻano o ka electrostatic repulsion e alakaʻi i ka hoʻokumu ʻana i nā composites paʻa rGO/nZVI39. ʻO ka ʻili maikaʻi ʻole o GO e hiki ke hoʻopuehu ʻia i loko o kahi ʻano wai me ka ʻole o ka agglomeration, kahi e hana ai i nā kūlana kūpono no ka launa pū ʻana me nZVI. ʻO ka hoʻopiʻi maikaʻi ʻole paha e pili ana me ka hele ʻana o nā hui hana like ʻole i ka ʻawaʻawa melon extract, e hōʻoiaʻiʻo ana i ka pilina ma waena o GO a me ka hao precursors a me ka mea kanu extract e hana rGO a me nZVI, kēlā me kēia, a me ka rGO / nZVI paʻakikī. Hiki i kēia mau mea kanu ke hana ma ke ʻano he capping agents, ʻoiai lākou e pale i ka hōʻuluʻulu ʻana o nā nanoparticles hopena a pēlā e hoʻonui ai i ko lākou kūpaʻa40.
Ua hoʻoholo ʻia ka haku mele a me ka valence states o ka nZVI a me rGO/nZVI composites e XPS (Fig. 4). Ua hōʻike ʻia ka haʻawina XPS holoʻokoʻa ʻo ka rGO/nZVI composite ka nui o nā mea C, O, a me Fe, e kūlike me ka palapala palapala EDS (Fig. 4F–H). Aia ka spectrum C1 i ʻekolu piko ma 284.59 eV, 286.21 eV a me 288.21 eV e hōʻike ana iā CC, CO a me C=O. Ua māhele ʻia ka spectrum O1 i ʻekolu mau piko, me 531.17 eV, 532.97 eV, a me 535.45 eV, i hāʻawi ʻia i nā pūʻulu O=CO, CO, a me NO. Eia naʻe, ʻo nā piko ma 710.43, 714.57 a me 724.79 eV e pili ana iā Fe 2p3/2, Fe+3 a me Fe p1/2. Ua hōʻike ka XPS spectra o nZVI (Fig. 4C-E) i nā piko no nā mea C, O, a me Fe. ʻO nā kiʻekiʻe ma 284.77, 286.25, a me 287.62 eV e hōʻoiaʻiʻo i ka hiki ʻana mai o nā huila hao-carbon, ʻoiai lākou e pili ana iā CC, C-OH, a me CO. Ua pili ka spectrum O1 me ekolu peaks C–O/iron carbonate (531.19 eV), hydroxyl radical (532.4 eV) a me O–C=O (533.47 eV). ʻO ka piko ma 719.6 e pili ana iā Fe0, aʻo FeOOH e hōʻike ana i nā piko ma 717.3 a me 723.7 eV, eia kekahi,ʻo ka piko ma 725.8 eV e hōʻike ana i ka heleʻana o Fe2O342.43.
Nā haʻawina XPS o nZVI a me rGO/nZVI composites, kēlā me kēia (A, B). Huipuia piha o nZVI C1s (C), Fe2p (D), a me O1s (E) a me rGO/nZVI C1s (F), Fe2p (G), O1s (H).
Hōʻike ka N2 adsorption/desorption isotherm (Fig. 5A, B) i ka nZVI a me rGO/nZVI composites no ke ʻano II. Eia kekahi, ua hoʻonui ʻia ka ʻāpana kiko kiko (SBET) o nZVI mai 47.4549 a i 152.52 m2/g ma hope o ka makapō me rGO. Hiki ke wehewehe ʻia kēia hopena e ka emi ʻana o nā waiwai magnetic o nZVI ma hope o ka makapō rGO, a laila e hōʻemi ana i ka hōʻuluʻulu particle a hoʻonui i ka ʻili o nā composites. Eia kekahi, e like me ka mea i hōʻike ʻia ma ka Fig. 5C, ʻoi aku ka kiʻekiʻe o ka pore volume (8.94 nm) o ka rGO / nZVI composite ma mua o ka nZVI kumu (2.873 nm). Ua like kēia hopena me El-Monaem et al. 45 .
No ka loiloi ʻana i ka mana adsorption e wehe i ka DC ma waena o ka rGO/nZVI composites a me ka nZVI kumu ma muli o ka hoʻonui ʻana i ka ʻike mua, ua hana ʻia kahi hoʻohālikelike ma o ka hoʻohui ʻana i kahi pānaʻi mau o kēlā me kēia adsorbent (0.05 g) i DC ma nā ʻano kumu mua. Haʻina i ʻimi ʻia [25]. –100 mg l–1] ma 25°C. Ua hōʻike ʻia nā hopena i ʻoi aku ka maikaʻi o ka wehe ʻana (94,6%) o ka rGO/nZVI composite ma mua o ka nZVI kumu (90%) ma kahi haʻahaʻa haʻahaʻa (25 mg L-1). Eia nō naʻe, i ka wā i hoʻonui ʻia ai ka hoʻomaka ʻana i ka 100 mg L-1, ua hāʻule ka pono o ka wehe ʻana o rGO/nZVI a me nZVI makua i 70% a me 65%, i kēlā me kēia (Figure 6A), ma muli paha o ka liʻiliʻi o nā wahi hana a me ka hoʻohaʻahaʻa ʻana. nZVI nā ʻāpana. ʻO ka mea ʻē aʻe, ua hōʻike ʻo rGO/nZVI i kahi kiʻekiʻe kiʻekiʻe o ka wehe ʻana o DC, ʻo ia paha ma muli o kahi hopena synergistic ma waena o rGO a me nZVI, kahi i ʻoi aku ka kiʻekiʻe o nā kahua paʻa paʻa no ka adsorption, a i ka hihia o rGO/nZVI, ʻoi aku. Hiki ke hoʻopili ʻia ka DC ma mua o ka nZVI paʻa. Eia kekahi, ma ka fig. Hōʻike ka 6B i ka hoʻonui ʻana i ka mana adsorption o ka rGO / nZVI a me nZVI composites mai 9.4 mg / g a hiki i 30 mg / g a me 9 mg / g, me ka hoʻonui ʻana i ka neʻe mua mai 25-100 mg / L. -1.1 i ka 28.73 mg g-1. No laila, ua hoʻopili maikaʻi ʻia ka helu hoʻoneʻe DC me ka manaʻo DC mua, ʻo ia ma muli o ka helu palena o nā kikowaena hopena i kākoʻo ʻia e kēlā me kēia adsorbent no ka adsorption a me ka wehe ʻana o DC i ka hopena. No laila, hiki ke hoʻoholoʻia mai kēia mau hopena i loaʻa i ka rGO / nZVI composites iʻoi aku ka maikaʻi o ka adsorption a me ka ho'ēmiʻana, a hiki ke hoʻohanaʻia ka rGO i loko o ka rGO / nZVI ma keʻano he adsorbent a me ka mea lawe.
ʻO ka maikaʻi o ka hoʻoneʻe ʻana a me ka mana adsorption DC no ka rGO / nZVI a me nZVI composite he (A, B) [Co = 25 mg l-1-100 mg l-1, T = 25 °C, dose = 0.05 g], pH. ma ka mana adsorption a me ka hoʻoneʻe DC pono ma rGO / nZVI composites (C) [Co = 50 mg L–1, pH = 3-11, T = 25°C, pāʻina = 0.05 g].
He mea koʻikoʻi ka Solution pH i ke aʻo ʻana i nā kaʻina hana adsorption, no ka mea e pili ana i ka degere o ka ionization, speciation, a me ka ionization o ka adsorbent. Ua hoʻokō ʻia ka hoʻokolohua ma 25 ° C me kahi ʻano adsorbent mau (0.05 g) a me ka hoʻomaka mua o 50 mg L-1 i ka pae pH (3-11). Wahi a ka loiloi palapala46, he mole amphiphilic ka DC me nā pūʻulu hana ionizable (phenols, hui amino, alcohols) ma nā pae pH like ʻole. ʻO ka hopena, hiki i nā hana like ʻole o DC a me nā hale pili i ka ʻili o ka rGO/nZVI composite hiki ke hoʻopili electrostatically a hiki ke noho ma ke ʻano he cation, zwitterions, a me nā anion, aia ka mole DC ma ke ʻano he cationic (DCH3+) ma ka pH <3.3, zwitterionic (DCH20) 3.3 < pH < 7.7 a me ka anionic (DCH− a i ʻole DC2−) ma PH 7.7. ʻO ka hopena, hiki i nā hana like ʻole o DC a me nā hale pili i ka ʻili o ka rGO/nZVI composite hiki ke hoʻopili electrostatically a hiki ke noho ma ke ʻano he cation, zwitterions, a me nā anion, aia ka mole DC ma ke ʻano he cationic (DCH3+) ma ka pH <3.3, zwitterionic (DCH20) 3.3 < pH < 7.7 a me ka anionic (DCH- a i ʻole DC2-) ma PH 7.7. В результате различные функции ДК и связанных с ними структур на поверхности композита rGO/nZVI могут могут структур ут существовать в виде катионов, цвиттер-ионов и анионов, молекула ДК существует в виде катиона (DCH3+) при3 т ионный (DCH20) 3,3 < pH < 7,7 и анионный (DCH- a i ole DC2-) pри pH 7,7. ʻO ka hopena, hiki i nā hana like ʻole o DC a me nā hale pili i ka ʻili o ka rGO / nZVI composite hiki ke hoʻopili electrostatically a hiki ke noho ma ke ʻano o nā cations, zwitterions, a me nā anion; aia ka mole DC ma ke ʻano he cation (DCH3+) ma ka pH <3.3; ionic (DCH20) 3.3 < pH < 7.7 a me ka anionic (DCH- a i ʻole DC2-) ma ka pH 7.7.因此，DC 的各种功能和rGO/nZVI 复合材料表面的相关结构可能会发生静电相互作电相互作用面、两性离子和阴离子的形式存在，DC 分子在pH < 3.3 时以阳离子(DCH3+) 的形式存在，两性离子(DCH20) 3.3 < pH < 7.7 和阴离子(DCH- 或DC2-) 在PH 7.7.因此: hohonu / Dec 和 和 和 复合表面表面 相互相互, 相关 在两 形式形式,3 形式阳离子 阳离子 (dch3 +) 形式存在，两性离子(DCH20) 3.3 < pH < 7.7 和阴离子(DCH- 或DC2-) 在PH 7.7. Следовательно, различные функции ДК и родственных им структур на поверхности композита rGO/nZVI могут могут вструктить ствия и существовать в виде катионов, цвиттер-ионов и анионов, а молекулы ДК являются катионными (+ДЦ3 рими (+ДЦ3 ри3, Др. No laila, hiki i nā hana like ʻole o DC a me nā hale pili i ka ʻili o ka rGO/nZVI composite ke komo i loko o nā pilina electrostatic a noho ma ke ʻano o nā cations, zwitterions, a me nā anion, ʻoiai nā molekala DC he cationic (DCH3+) ma ka pH <3.3. Loaʻa ka helu o ka wai (DCH20) i ka 3,3 < pH < 7,7 a me ka ʻāpana (DCH- a i ʻole DC2-) i ka pH 7,7. Aia ma ke ʻano he zwitterion (DCH20) ma 3.3 < pH < 7.7 a me kahi anion (DCH- a i ʻole DC2-) ma pH 7.7.Me ka piʻiʻana o ka pH mai ka 3 a hiki i ka 7, ua hoʻonuiʻia ka mana adsorption a me ka pono o ka weheʻana o DC mai 11.2 mg / g (56%) i 17 mg / g (85%) (Fig. 6C). Eia naʻe, i ka piʻi ʻana o ka pH i 9 a me 11, ua emi iki ka mana adsorption a me ka hoʻoneʻe ʻana, mai 10.6 mg / g (53%) a i 6 mg / g (30%). Me ka piʻi ʻana o ka pH mai 3 a i 7, ua noho nui nā DC ma ke ʻano o nā zwitterions, kahi i hoʻohuli ʻole ʻia ai lākou me ka rGO/nZVI composites, ka nui o ka pilina electrostatic. I ka piʻi ʻana o ka pH ma luna o 8.2, ua hoʻopiʻi maikaʻi ʻia ka ʻili o ka adsorbent, no laila ua emi a emi iho ka mana adsorption ma muli o ka repulsion electrostatic ma waena o ka doxycycline a me ka ʻili o ka adsorbent. Hōʻike kēia ʻano i ka hoʻopili ʻana o DC ma rGO/nZVI composites i hilinaʻi nui i ka pH, a hōʻike pū ʻia nā hopena i kūpono nā mea hoʻohui rGO/nZVI ma ke ʻano he adsorbents ma lalo o nā kūlana acidic a kū ʻole.
ʻO ka hopena o ka mahana ma ka adsorption o kahi wai wai o DC i lawe ʻia ma (25-55 ° C). Hōʻike ka Figure 7A i ka hopena o ka piʻi ʻana o ka mahana ma ka hoʻoneʻe ʻana o nā lāʻau antibiotic DC ma rGO / nZVI, ua maopopo ka hoʻonui ʻana i ka hiki ke hoʻoneʻe a me ka hiki ke hoʻonui ʻia mai ka 83,44% a me 13,9 mg / g i 47% a me 7,83 mg / g. , pakahi. ʻO kēia emi nui ma muli paha o ka piʻi ʻana o ka ikehu wela o nā ion DC, e alakaʻi ana i ka desorption47.
Ka hopena o ka wela ma ka wehe ʻana a me ka Adsorption Capacity o CD ma rGO/nZVI Composite (A) [Co = 50 mg L–1, pH = 7, Dose = 0.05 g], Adsorbent Dose ma ka wehe ʻana a me ka wehe ʻana o ka CD Ka hopena o ka CD. ʻO ka hoʻomaka mua ʻana i ka hiki adsorption a me ka pono o ka wehe ʻana o DC ma ka rGO/nSVI composite (B) [Co = 50 mg L–1, pH = 7, T = 25°C] (C, D) [Co = 25-100 mg L–1, pH = 7, T = 25 °C, hoʻopaʻa ʻia = 0.05 g].
Hōʻike ʻia ka hopena o ka hoʻonui ʻana i ka nui o ka rGO / nZVI composite adsorbent mai 0.01 g a i 0.07 g ma ka hoʻoneʻe ʻana a me ka mana adsorption. 7B. ʻO ka hoʻonui ʻana i ka nui o ka adsorbent i alakaʻi i ka emi ʻana o ka hiki ke hoʻololi mai 33.43 mg / g i 6.74 mg / g. Eia nō naʻe, me ka hoʻonui ʻana i ka nui o ka adsorbent mai 0.01 g a i 0.07 g, hoʻonui ka hoʻoneʻe ʻana mai 66.8% a i 96%, ʻo ia hoʻi, e pili pū me ka hoʻonui ʻana i ka helu o nā kikowaena hana ma ka ʻili nanocomposite.
Ua aʻo ʻia ka hopena o ka neʻe mua ʻana i ka mana adsorption a me ka wehe ʻana [25-100 mg L-1, 25 ° C, pH 7, dose 0.05 g]. I ka hoʻonuiʻiaʻana o ka hoʻonui muaʻana mai ka 25 mg L-1 a hiki i ka 100 mg L-1, ua emi iho ka nui o ka weheʻana o ka rGO / nZVI composite mai 94.6% a hiki i 65% (Fig. 7C), ma muli paha o ka nele o ka mea hana i makemakeʻia. paena. . Hoʻopili i nā manaʻo nui o DC49. Ma kekahiʻaoʻao, i ka piʻiʻana o ka manaʻo mua, ua hoʻonuiʻia ka mana adsorption mai 9.4 mg / g a hiki i ka 30 mg / g a hiki i ka loaʻaʻana o ke kaulike (Fig. 7D). Ma muli o ka hoʻonui ʻia ʻana o ka ikaika hoʻokele me ka manaʻo DC mua i ʻoi aku ka nui ma mua o ka DC ion mass transfer resistance a hiki i ka ʻili 50 o ka rGO/nZVI composite.
ʻO ka manawa pili a me nā haʻawina kinetic e hoʻomaopopo i ka manawa kaulike o ka adsorption. ʻO ka mea mua, ʻo ka nui o ka DC i hoʻopili ʻia i loko o nā minuke 40 mua o ka manawa hoʻopili ma kahi o ka hapalua o ka huina kālā i hoʻopili ʻia i ka manawa holoʻokoʻa (100 mau minuke). ʻOiai ka hui ʻana o nā molekala DC i loko o ka hoʻonā e neʻe wikiwiki ai lākou i ka ʻili o ka rGO/nZVI composite e hopena i ka adsorption nui. Ma hope o 40 min, hoʻonui mālie a me ka mālie o ka hoʻolaha DC a hiki i ke kaulike ma hope o 60 min (Fig. 7D). Ma muli o ka hoʻopili ʻia ʻana o ka nui kūpono i loko o nā minuke 40 mua, e liʻiliʻi ka hui ʻana me nā molekala DC a ʻoi aku ka liʻiliʻi o nā wahi hana i loaʻa no nā molekala non-adsorbed. No laila, hiki ke hoemiia ka helu adsorption51.
No ka hoʻomaopopo maikaʻi ʻana i nā kinetics adsorption, ua hoʻohana ʻia nā ʻāpana laina o pseudo first order (Fig. 8A), pseudo second order (Fig. 8B), a me Elovich (Fig. 8C) kinetic models. Mai nā palena i loaʻa mai nā haʻawina kinetic (Table S1), ua maopopo ke kumu hoʻohālike pseudosecond ke kumu hoʻohālike maikaʻi loa no ka wehewehe ʻana i nā kinetics adsorption, kahi i hoʻonohonoho ʻia ai ka waiwai R2 ma mua o nā kumu hoʻohālike ʻelua. Aia kekahi ʻano like ma waena o nā mana adsorption i helu ʻia (qe, cal). ʻO ke kauoha pseudo-kekona a me nā waiwai hoʻokolohua (qe, exp.) he mea hōʻike hou aʻe e ʻoi aku ka maikaʻi o ke kauoha pseudo-second ma mua o nā hiʻohiʻona ʻē aʻe. E like me ka mea i hōʻike ʻia ma ka Papa 1, ʻo nā waiwai o ka α (ka helu mua adsorption) a me ka β (desorption mau) e hōʻoia i ke kiʻekiʻe o ka helu adsorption ma mua o ka helu desorption, e hōʻike ana i ka manaʻo o DC e hoʻopili pono i ka rGO/nZVI52 composite. .
Linear adsorption kinetic plots of pseudo-second order (A), pseudo-first order (B) and Elovich (C) [Co = 25–100 mg l–1, pH = 7, T = 25 °C, dose = 0.05 g ].
ʻO nā haʻawina o nā isotherms adsorption e kōkua i ka hoʻoholo ʻana i ka mana adsorption o ka adsorbent (RGO/nRVI composite) ma nā ʻano ʻokoʻa adsorbate (DC) a me nā mahana ʻōnaehana. Ua helu ʻia ka nui o ka adsorption me ka hoʻohana ʻana i ka isotherm Langmuir, i hōʻike ʻia he homogeneous ka adsorption a ua hoʻokomo ʻia ka hoʻokumu ʻana o kahi monolayer adsorbate ma ka ʻili o ka adsorbent me ka ʻole o ka launa pū ʻana ma waena o lākou53. ʻElua mau hiʻohiʻona isotherm i hoʻohana nui ʻia, ʻo ia nā hiʻohiʻona Freundlich a me Temkin. ʻOiai ʻaʻole hoʻohana ʻia ka ʻano Freundlich no ka helu ʻana i ka mana adsorption, kōkua ia i ka hoʻomaopopo ʻana i ke kaʻina adsorption heterogeneous a ʻo nā hakahaka ma ka adsorbent he ʻokoʻa ka ikaika, aʻo ke kumu hoʻohālike Temkin e kōkua i ka hoʻomaopopo ʻana i nā waiwai kino a me nā waiwai o ka adsorption54.
Hōʻike nā kiʻi 9A-C i nā ʻāpana laina o nā hiʻohiʻona Langmuir, Freindlich, a me Temkin. ʻO nā koina R2 i helu ʻia mai ka Freundlich (Fig. 9A) a me Langmuir (Fig. 9B) laina laina a hōʻike ʻia ma ka Papa 2 e hōʻike ana i ka adsorption DC ma ka rGO/nZVI composite e hahai ana i ka Freundlich (0.996) a me Langmuir (0.988) isotherm nā hiʻohiʻona a me Temkin (0.985). ʻO ka nui o ka mana adsorption (qmax), i helu ʻia me ka Langmuir isotherm model, he 31.61 mg g-1. Eia kekahi, ʻo ka waiwai i helu ʻia o ka mea hoʻokaʻawale dimensionless (RL) ma waena o 0 a me 1 (0.097), e hōʻike ana i kahi kaʻina adsorption maikaʻi. A i ʻole, ʻo ka helu Freundlich mau (n = 2.756) e hōʻike i kahi makemake no kēia kaʻina hana absorption. Wahi a ke kumu hoʻohālike laina o ka isotherm Temkin (Fig. 9C), ʻo ka adsorption o DC ma ka rGO/nZVI composite he hana adsorption kino, no ka mea, ʻo ka b ˂ 82 kJ mol-1 (0.408)55. ʻOiai e hoʻopili pinepine ʻia ka adsorption kino e nā ikaika van der Waals nāwaliwali, pono ka adsorption o kēia manawa ma nā rGO/nZVI composites e koi i nā ikehu adsorption haʻahaʻa [56, 57].
Freundlich (A), Langmuir (B), a me Temkin (C) linear adsorption isotherms [Co = 25–100 mg L–1, pH = 7, T = 25 °C, dose = 0.05 g]. Plot of the van't Hoff equation for DC adsorption by rGO/nZVI composites (D) [Co = 25–100 mg l-1, pH = 7, T = 25–55 °C and dose = 0.05 g].
No ka loiloi ʻana i ka hopena o ka hoʻololi ʻana i ka wela ma ka wehe ʻana o DC mai rGO/nZVI composites, ua helu ʻia nā ʻāpana thermodynamic e like me ka hoʻololi entropy (ΔS), hoʻololi entalpy (ΔH), a me ka hoʻololi ʻana o ka ikehu manuahi (ΔG) mai nā hoohalike. 3 a me 458.
kahi \({K}_{e}\)=\(\frac{{C}_{Ae}}{{C}_{e}}\) – thermodynamic equilibrium mau, Ce a me CAe – rGO i ka hoʻonā, pakahi / nZVI DC kaʻina ma ka ʻili kaulike. ʻO R a me RT ke kinoea mau a me ka mahana adsorption, kēlā me kēia. ʻO ka hoʻolālā ʻana iā ln Ke kūʻē i ka 1/T e hāʻawi i kahi laina pololei (Fig. 9D) kahi e hiki ai ke hoʻoholo i ka ∆S a me ∆H.
Hōʻike ka waiwai ΔH maikaʻi ʻole he exothermic ke kaʻina hana. Ma kekahi ʻaoʻao, aia ka waiwai ΔH i loko o ke kaʻina hana adsorption kino. ʻO nā waiwai ΔG maikaʻi ʻole i ka Papa 3 e hōʻike ana hiki ke adsorption a hiki i ka manawa. Hōʻike nā waiwai maikaʻi ʻole o ΔS i kahi kauoha kiʻekiʻe o nā molekala adsorbent ma ke kikowaena wai (Papa 3).
Hoʻohālikelike ka Papa 4 i ka rGO/nZVI composite me nā adsorbents ʻē aʻe i hōʻike ʻia ma nā haʻawina mua. He mea akaka ka loaʻa ʻana o ka mea hoʻohui VGO/nCVI i ka mana adsorption kiʻekiʻe a hiki ke lilo i mea hoʻohiki no ka wehe ʻana i nā lāʻau antibiotic DC mai ka wai. Eia kekahi, ʻo ka adsorption o rGO / nZVI composites he kaʻina wikiwiki me ka manawa equilibration o 60 min. Hiki ke wehewehe ʻia nā waiwai adsorption maikaʻi o ka rGO/nZVI composites e ka hopena synergistic o rGO a me nZVI.
Hōʻike nā kiʻi 10A, B i ka hana kūpono no ka wehe ʻana i nā lāʻau antibiotic DC e ka rGO/nZVI a me nZVI complexes. Wahi a nā hopena o nā hoʻokolohua i ka hopena o ka pH ma ka pono o DC adsorption, me ka piʻi ʻana o ka pH mai 3 a hiki i 7, ʻaʻole i hoʻomalu ʻia ka adsorption DC ma ka rGO/nZVI composite e nā pilina electrostatic, ʻoiai ua hana ʻo ia ma ke ʻano he zwitterion; no laila, ʻaʻole i pili ka hoʻololi ʻana i ka waiwai pH i ka hana adsorption. Ma hope mai, hiki ke hoʻomalu ʻia ka mīkini adsorption e nā pilina non-electrostatic e like me ka hoʻopaʻa ʻana o ka hydrogen, nā hopena hydrophobic, a me ka π-π stacking mau pilina ma waena o ka rGO/nZVI composite a me DC66. Ua ʻike maopopo ʻia ua wehewehe ʻia ke ʻano o nā adsorbates aromatic ma nā ʻili o ka graphene layered e π–π stacking interactions ma ke ʻano he mea hoʻokele nui. ʻO ka composite he mea papa e like me ka graphene me ka nui absorption ma 233 nm ma muli o ka hoʻololi π-π*. Ma muli o ka loaʻa ʻana o nā apo ʻala ʻehā i loko o ka molecular structure o ka DC adsorbate, ua kuhi mākou aia kahi ʻano o ka π-π-stacking pilina ma waena o ka DC aromatic (π-electron acceptor) a me ka ʻāina waiwai i ka π-electrons ma luna. ka ʻili RGO. /nZVI nā hui. Eia kekahi, e like me ka mea i hōʻike ʻia ma ka fig. 10B, ua hana ʻia nā haʻawina FTIR no ke aʻo ʻana i ka launa pū ʻana o ka rGO/nZVI composites me DC, a me ka FTIR spectra o rGO/nZVI composites ma hope o DC adsorption i hōʻike ʻia ma ke Kiʻi 10B. 10b. ʻIke ʻia kahi kiʻekiʻe hou ma 2111 cm-1, e pili ana i ka vibration framework o ka paʻa C=C, e hōʻike ana i ka hele ʻana o nā pūʻulu hana kūlohelohe kūpono ma ka ʻili o 67 rGO/nZVI. Hoʻololi nā piko ʻē aʻe mai 1561 a i 1548 cm-1 a mai 1399 a i 1360 cm-1, e hōʻoiaʻiʻo ana hoʻi i ka hana nui o nā pilina π-π i ka adsorption o ka graphene a me nā mea pollutants organik68,69. Ma hope o DC adsorption, ua emi ka ikaika o kekahi mau pūʻulu o ka oxygen, e like me OH, i 3270 cm-1, e hōʻike ana i ka hoʻopaʻa ʻana i ka hydrogen kekahi o nā hana adsorption. No laila, ma muli o nā hopena, loaʻa ka DC adsorption ma ka rGO/nZVI composite ma muli o ka π-π stacking interactions a me ka H-bonds.
ʻO ka hana kūpono o ka adsorption o nā lāʻau antibiotic DC e rGO / nZVI a me nZVI complexes (A). FTIR adsorption spectra o DC ma rGO/nZVI a me nZVI (B).
Ua hoʻonui ʻia ka ikaika o nā puʻupuʻu absorption o nZVI ma 3244, 1615, 1546, a me 1011 cm-1 ma hope o ka adsorption DC ma nZVI (Fig. 10B) i hoʻohālikelike ʻia me nZVI, pono e pili i ka pilina me nā pūʻulu hana o ka carboxylic acid. O na hui ma DC. Eia naʻe, ʻo kēia haʻahaʻa haʻahaʻa o ka hoʻouna ʻana i nā pūʻulu i ʻike ʻia ʻaʻole ia he loli nui i ka pono adsorption o ka phytosynthetic adsorbent (nZVI) i hoʻohālikelike ʻia me nZVI ma mua o ke kaʻina hana adsorption. Wahi a kekahi noiʻi hoʻoneʻe DC me nZVI71, ke hana ʻo nZVI me H2O, hoʻokuʻu ʻia nā electrons a laila hoʻohana ʻia ʻo H+ e hana i ka hydrogen ikaika loa. ʻO ka mea hope loa, ʻae kekahi mau pūhui cationic i nā electrons mai ka hydrogen hana, e loaʻa ana -C=N a me -C=C-, ka mea i pili i ka māhele ʻana o ke apo benzene.
Ka manawa hoʻouna: Nov-14-2022