Ngo-Agasti, osokhemisi bamemezele ukuthi bangenza lokho obekulokhu kubonakala kungenakwenzeka isikhathi eside: ukuphula ezinye zezinto ezingcolisa izinto eziphilayo ezihlala isikhathi eside ngaphansi kwezimo ezithambile. Izinto ze-Per- kanye ne-polyfluoroalkyl (PFAS), ezivame ukubizwa ngokuthi amakhemikhali angunaphakade, ziqoqana emvelweni nasemizimbeni yethu ngesivinini esesabekayo. Ukuqina kwazo, okugxile ekubopheni okunzima ukukuphula kwe-carbon-fluorine, kwenza i-PFAS ibe usizo kakhulu njengezingubo ezingangeni manzi nezinganamatheli kanye nama-foam okulwa nomlilo, kodwa kusho ukuthi amakhemikhali ahlala amakhulu eminyaka. Amanye amalungu aleli qembu elikhulu lamakhemikhali aziwa ngokuthi anobuthi.
Ithimba, eliholwa ngusokhemisi waseNorthwestern University uWilliam Dichtel kanye nomfundi waseBrittany Trang ngaleso sikhathi, lithole ubuthakathaka kuma-perfluoroalkyl carboxylic acid kanye nekhemikhali iGenX, eyingxenye yelinye ikilasi le-PFAS. Ukushisa ama-compounds ku-solvent kususa iqembu le-carboxylic acid yamakhemikhali; ukungezwa kwe-sodium hydroxide kwenza umsebenzi osele, kushiye ama-ion e-fluoride kanye nama-molecule e-organic angenabungozi. Lokhu kuphulwa kwesibopho se-C-F esinamandla kakhulu kungafezwa ku-120 °C kuphela (Science 2022, DOI: 10.1126/science.abm8868). Ososayensi banethemba lokuhlola le ndlela ngokumelene nezinye izinhlobo ze-PFAS.
Ngaphambi kwalomsebenzi, amasu amahle kakhulu okulungisa i-PFAS kwakuwukuchitha ama-compound noma ukuwaphula emazingeni okushisa aphezulu kakhulu kusetshenziswa amandla amaningi—okungase kungasebenzi kahle ngokuphelele, kusho uJennifer Faust, isazi samakhemikhali eKolishi laseWooster. “Yingakho le nqubo yokushisa okuphansi ithembisa ngempela,” kusho yena.
Le ndlela entsha yokuhlukaniswa yamukelwa ngokukhethekile ngokweminye imiphumela ka-2022 mayelana ne-PFAS. Ngo-Agasti, abacwaningi baseStockholm University abaholwa ngu-Ian Cousins babike ukuthi amanzi emvula emhlabeni wonke aqukethe amazinga e-perfluorooctanoic acid (PFOA) adlula izinga leseluleko se-US Environmental Protection Agency saleyo khemikhali emanzini okuphuza (Environ. Sci. Technol. 2022, DOI: 10.1021/acs.est.2c02765). Ucwaningo luthole amazinga aphezulu amanye ama-PFAS emanzini emvula.
“I-PFOA ne-PFOS [i-perfluorooctanesulfonic acid] sekuphele amashumi eminyaka zingakhiqizi, ngakho-ke kukhombisa ukuthi ziphikelela kangakanani,” kusho uFaust. “Bengingacabangi ukuthi zizoba khona kangaka.” Umsebenzi kaCousins, uthi, “empeleni uyisiphetho seqhwa.” UFaust uthole izinhlobo ezintsha ze-PFAS—lezo ezingaqashwa njalo yi-EPA—emanzini emvula ase-US ngamanani aphezulu kunalawa ma-compounds akudala (Environ. Sci.: Processes Impacts 2022, DOI: 10.1039/d2em00349j).
Isikhathi sokuthunyelwe: Disemba 19-2022