Umhlaba unenkinga enkulu yamabhodlela epulasitiki.Ukuba khona kwayo olwandle sekuyinkinga yomhlaba wonke.Ukudalwa kwayo kwaqala ngawo-1800 lapho ibhodlela lepulasitiki likhulelwa njengendlela yokugcina ama-sodas epholile futhi ibhodlela ngokwalo laliyisinqumo esithandwayo.Inqubo ehilelekile ekwenzeni ibhodlela lepulasitiki yaqala ngokuhlanganiswa kwamakhemikhali kwezinhlobo ezimbili ezihlukene zama-molecule egesi namafutha aziwa ngokuthi ama-monomers.Lezi zinhlanganisela zibe sezincibilika bese zibunjwa kabusha zibe isikhunta.Amabhodlela abe esegcwaliswa ngemishini.
Namuhla, uhlobo oluvame kakhulu lwebhodlela lepulasitiki yi-PET.I-PET ayisindi futhi ivame ukusetshenziselwa amabhodlela eziphuzo.Uma igaywa kabusha, iyehla ngekhwalithi futhi ingase igcine isithatha indawo yokhuni noma yefiber.Abakhiqizi kungase kudingeke bengeze ipulasitiki emsulwa ukuze balondoloze ikhwalithi efanayo.Ngenkathi i-PET ingaphinda igaywe kabusha, okubi kwayo okuyinhloko ukuthi impahla kunzima ukuyihlanza.Nakuba ukugaywa kabusha kwe-PET kubalulekile emvelweni, le pulasitiki isiphenduke enye esetshenziswa kakhulu amabhodlela.
Ukukhiqizwa kwe-PET kuyinqubo enkulu yamandla namanzi.Le nqubo idinga amanani amakhulu ezinto ezimbiwa phansi ezimbiwa phansi, okuyenza ibe into engcolisa kakhulu.Ngawo-1970, i-US yayiyi-export kawoyela enkulu kunazo zonke emhlabeni.Namuhla, singenisa uwoyela omkhulu kakhulu emhlabeni.Futhi u-25% wamabhodlela epulasitiki esiwasebenzisayo enziwe ngamafutha.Futhi lokhu akubala ngisho amandla asetshenziswa ukuthutha la mabhodlela.
Olunye uhlobo lwebhodlela lepulasitiki yi-HDPE.I-HDPE iwuhlobo lwepulasitiki olungabizi kakhulu futhi oluvame kakhulu.Inikeza umgoqo omuhle womswakama.Nakuba i-HDPE ingenayo i-BPA, ithathwa njengephephile futhi igaywa kabusha.Ibhodlela le-HDPE nalo lisobala futhi libolekisa ekuhlobiseni isikrini sikasilika.Ifanele imikhiqizo enamazinga okushisa angaphansi kuka-190 degrees Fahrenheit kodwa ayiwafanele amafutha abalulekile.Lamabhodlela epulasitiki kufanele asetshenziselwe imikhiqizo yokudla kanye nezinto ezingaboli, njengamajusi.
Amanye amabhodlela amanzi adume kakhulu aqukethe i-BPA, okuyinhlanganisela yokwenziwa eyaziwa ngokuphazamisa uhlelo lwe-endocrine.Kuphazamisa ukukhiqizwa kwamahomoni omzimba futhi kuye kwaxhunyaniswa nokwanda kwengozi yomdlavuza ohlukahlukene ezinganeni.Ngakho-ke, ukuphuza amanzi emabhodleleni epulasitiki akuyona nje ingozi yezempilo, kodwa futhi kunomthelela emvelweni webhodlela lepulasitiki.Uma ungathanda ukugwema lawa makhemikhali anobuthi, qiniseka ukuthi ukhetha ibhodlela lamanzi elingenayo i-BPA nezinye izithasiselo zepulasitiki.
Esinye isisombululo esihle kakhulu sokungcola kwepulasitiki ukuthenga amabhodlela amanzi angasetshenziswa kabusha.Ucwaningo lukhombisa ukuthi ukwanda kokuthengiswa kwamabhodlela agcwalisekayo kungagcina amabhodlela epulasitiki afinyelela ku-7.6 billion ukuthi angangeni olwandle unyaka ngamunye.Uhulumeni anganciphisa noma avimbele amabhodlela epulasitiki asetshenziswa kanye ukuze kwehliswe inani lokungcola akukhiphela olwandle.Ungaphinda uthinte abenzi benqubomgomo bangakini futhi ubazise ukuthi usekela isenzo sokunciphisa ipulasitiki esetshenziswa kanye kuphela.Ungacabanga nokuba yilungu lenhlangano yangakini yendawo ukuze ubambe iqhaza kulo mzamo.
Inqubo yokukhiqiza ibhodlela lepulasitiki ihilela izinyathelo eziningana.Okokuqala, ama-pellets epulasitiki ashiswa ngesikhunta somjovo.Umoya onomfutho ophezulu ube usuvuthela ama-pellets epulasitiki.Ngemva kwalokho, amabhodlela kufanele apholiswe khona manjalo ukuze alondoloze isimo sawo.Enye inketho ukuzungeza i-nitrogen eyi-liquid noma ukuphefumula umoya ekamelweni lokushisa.Lezi zinqubo ziqinisekisa ukuthi ibhodlela lepulasitiki lizinzile futhi alilahlekelwa ukuma kwalo.Uma selipholile, ibhodlela lepulasitiki lingagcwaliswa.
Ukugaywa kabusha kubalulekile, kodwa amabhodlela epulasitiki amaningi awagaywa kabusha.Yize ezinye izikhungo zokugaywa kabusha zamukela amabhodlela agaywe kabusha, iningi ligcina lisendaweni yokulahla imfucumfucu noma olwandle.Ulwandle luqukethe amathani epulasitiki aphakathi kwezigidi ezi-5 neziyi-13 unyaka ngamunye.Izilwane zasolwandle zidla ipulasitiki kanti enye ingena ngisho nasemgqeni wokudla.Amabhodlela epulasitiki aklanyelwe ukuthi abe izinto ezisetshenziswa kanye.Kodwa-ke, ungakhuthaza abanye ukuthi baphinde basebenzise futhi bakhethe izinketho ezisebenzisekayo nezigaywa kabusha esikhundleni salokho.
Amabhodlela epulasitiki enziwe ngezinto ezihlukahlukene.Izinto ezisetshenziswa kakhulu zifaka i-PE, PP, ne-PC.Ngokuvamile, amabhodlela enziwe nge-polyethylene asobala noma a-opaque.Amanye ama-polymers ane-opaque kakhulu kunamanye.Kodwa-ke, ezinye izinto aziboni futhi zingancibilika.Lokhu kusho ukuthi ibhodlela lepulasitiki elenziwe ngepulasitiki elingaphinde lisetshenziswe livamise ukubiza kakhulu kunelo elenziwe ngezinto ezigaywe kabusha.Nokho, izinzuzo zokugaywa kabusha kwepulasitiki zifanele izindleko ezengeziwe.
Isikhathi sokuthumela: Jun-07-2022