Ko te pepa parahi, he pepa parahi tino angiangi, he tino ngāwari te āhua, he tino uaua te tukanga hanga. Ko te nuinga o tēnei tukanga ko te tango me te whakamahine i te parahi, te hanga i te pepa parahi, me ngā mahi tukatuka muri.
Ko te taahiraa tuatahi ko te tango me te whakamahine i te parahi. E ai ki ngā raraunga mai i te United States Geological Survey (USGS), i eke te hanga o te konganuku parahi o te ao ki te 20 miriona tana i te tau 2021 (USGS, 2021). Whai muri i te tangohanga o te konganuku parahi, mā roto i ngā taahiraa pēnei i te kuru, te huri, me te whakamānu, ka taea te whiwhi i te konupūmā parahi kei roto te 30% o te parahi. Kātahi ka uru ēnei konupūmā parahi ki tētahi tukanga whakamahine, tae atu ki te whakarewa, te whakamahine kaitahuri, me te electrolysis, ā, i te mutunga ka puta he parahi electrolytic me te parakore tae atu ki te 99.99%.
Ko te tukanga hanga o te pepa parahi e whai ake nei, ka taea te wehewehe kia rua ngā momo i runga i te tikanga hanga: te pepa parahi hiko me te pepa parahi hurihuri.
Ka hangaia te pepa parahi hiko mā te tukanga hikohiko. I roto i te pūtau hikohiko, ka memeha haere te anode parahi i raro i te mahi a te electrolyte, ā, ka neke ngā katote parahi, e peia ana e te ia, ki te katote ka hanga he putunga parahi ki runga i te mata o te katote. Ko te matotoru o te pepa parahi hikohiko i te nuinga o te wā kei waenga i te 5 ki te 200 maikiromita, ka taea te whakahaere tika i runga i ngā hiahia o te hangarau papa ara iahiko tā (PCB) (Yu, 1988).
Ko te pepa parahi kua hurihia, i tētahi atu taha, ka hangaia mā te mīhini. Ka tīmata mai i tētahi pepa parahi he maha mirimita te matotoru, ka āta whakaangawaritia mā te hurihuri, ā, ka puta he pepa parahi he matotoru kei te taumata maikoromita (Coombs Jr., 2007). He maeneene ake te mata o tēnei momo pepa parahi i te pepa parahi hikohiko, engari he nui ake te pūngao e pau ana i tana tukanga hanga.
I muri i te hanganga o te pepa parahi, me tukatuka anō i muri i te hanga, tae atu ki te whakamahana, te maimoatanga mata, me ētahi atu, hei whakapai ake i tana mahi. Hei tauira, ka taea e te whakamahana te whakarei ake i te ngāwari me te pakari o te pepa parahi, ko te maimoatanga mata (pēnei i te waikura, te paninga rānei) ka taea te whakarei ake i te ātete ki te waikura me te piri o te pepa parahi.
Hei whakarāpopototanga, ahakoa he uaua te tukanga whakaputa me te hanga o te pepa parahi, he nui te pānga o te hua ki tō tātou ao hou. He whakaaturanga tēnei o te ahunga whakamua hangarau, e huri ana i ngā rauemi taiao hei hua hangarau teitei mā roto i ngā tikanga hanga tino tika.
Heoi anō, he maha ngā wero kei roto i te tukanga hanga pepa parahi, tae atu ki te whakapaunga pūngao, te pānga ki te taiao, me ētahi atu. E ai ki tētahi pūrongo, ko te hanga o te 1 tana o te parahi e hiahiatia ana he 220GJ o te pūngao, ā, e 2.2 tana o ngā tukunga hauhā waro ka puta (Northey et al., 2014). Nō reira, me kimi e tātou he huarahi whai hua ake, he huarahi pai ake hoki mō te taiao hei hanga pepa parahi.
Ko tētahi otinga pea ko te whakamahi i te parahi hangarua hei hanga pepa parahi. E ai ki ngā pūrongo, ko te whakapaunga pūngao o te hanga parahi hangarua he 20% noa iho i te whakapaunga pūngao o te parahi tuatahi, ā, ka whakaitihia te whakamahinga o ngā rauemi parahi (UNEP, 2011). Hei tāpiri, me te whanaketanga o te hangarau, ka taea e tātou te whakawhanake i ngā tikanga hanga pepa parahi whai hua ake, penapena pūngao hoki, ka whakaitihia ake te pānga ki te taiao.
Hei whakamutunga, ko te tukanga whakaputa me te hanga o te pepa parahi he mara hangarau e kī ana i ngā wero me ngā whai wāhitanga. Ahakoa kua nui te ahunga whakamua, he nui tonu ngā mahi hei mahi kia taea ai e te pepa parahi te whakatutuki i ō tātou hiahia o ia rā, me te tiaki anō hoki i tō tātou taiao.
Wā tuku: Hōngongoi-08-2023