Ngo-Agasti, iingcali zekhemistri zabhengeza ukuba zinokwenza into ebibonakala ingenakwenzeka ixesha elide: ukuqhekeza ezinye zezona zinto zingcolisayo eziphilayo ezihlala ixesha elide phantsi kweemeko ezithambileyo. Izinto zePer- kunye ne-polyfluoroalkyl (PFAS), ezidla ngokubizwa ngokuba ziikhemikhali ezihlala ixesha elide, ziyaqokelelana kwindalo esingqongileyo nakwimizimba yethu ngesantya esoyikekayo. Ukuqina kwazo, okusekelwe kwikhonkco le-carbon-fluorine elinzima ukuliqhekeza, kwenza i-PFAS ibe luncedo ngakumbi njengezinto ezingangeni manzi nezinganamatheliyo kunye neefoam zokucima umlilo, kodwa oko kuthetha ukuba ezi khemikhali zihlala kangangeenkulungwane. Amanye amalungu olu didi lukhulu lweekhompawundi aziwa ngokuba netyhefu.
Eli qela, elikhokelwa yingcali yemichiza kwiYunivesithi yaseNorthwestern uWilliam Dichtel kunye nomfundi ophumeleleyo ngelo xesha uBrittany Trang, lifumene ubuthathaka kwi-perfluoroalkyl carboxylic acids kunye ne-GenX yekhemikhali, eyinxalenye yolunye udidi lwe-PFAS. Ukufudumeza iikhompawundi kwisinyibilikisi kususa iqela le-carboxylic acid yeekhemikhali; ukongezwa kwe-sodium hydroxide kwenza umsebenzi oseleyo, kushiya ngasemva ii-ion ze-fluoride kunye neemolekyuli ze-organic ezinobungozi. Oku kuqhekeka kwe-C-F bond enamandla kakhulu kunokwenziwa kwi-120 °C kuphela (Science 2022, DOI: 10.1126/science.abm8868). Izazinzulu zinethemba lokuvavanya le ndlela ngokuchasene nezinye iintlobo ze-PFAS.
Ngaphambi kwalo msebenzi, amaqhinga angcono okulungisa i-PFAS yayikukubamba iikhompawundi okanye ukuziqhekeza kubushushu obuphezulu kakhulu kusetyenziswa amandla amaninzi—asenokungasebenzi ngokupheleleyo, utshilo uJennifer Faust, ingcali yekhemistri kwiKholeji yaseWooster. “Yiyo loo nto le nkqubo yobushushu obuphantsi ithembisa ngokwenene,” utshilo.
Le ndlela intsha yokuhlalutya yamkelekile ngokukodwa kwimeko yezinye iziphumo zika-2022 malunga ne-PFAS. Ngo-Agasti, abaphandi beYunivesithi yaseStockholm abakhokelwa ngu-Ian Cousins baxele ukuba amanzi emvula kwihlabathi liphela aqulathe amanqanaba e-perfluorooctanoic acid (PFOA) adlula inqanaba lengcebiso le-US Environmental Protection Agency ngaloo khemikhali emanzini okusela (Environ. Sci. Technol. 2022, DOI: 10.1021/acs.est.2c02765). Olu phononongo lufumene amanqanaba aphezulu e-PFAS emanzini emvula.
“I-PFOA kunye ne-PFOS [i-perfluorooctanesulfonic acid] bezingasebenzi kangangeminyaka emininzi, ngoko ke oko kubonisa indlela ezihlala ngayo,” utshilo uFaust. “Andizange ndicinge ukuba ziya kubakho kangaka.” Umsebenzi kaCousins, utsho, “ngowona mthombo weqhwa.” UFaust ufumene iintlobo ezintsha ze-PFAS—ezo zingajongwa rhoqo yi-EPA—kumanzi emvula ase-US akwizinga eliphezulu kunezi zinto ziphilayo (Environ. Sci.: Processes Impacts 2022, DOI: 10.1039/d2em00349j).
Ixesha lokuthumela: Disemba-19-2022