Malunga neminyaka engama-6,000 eyadlulayo, amaSumer afumanisa isiselo esimnandi esaye saduma ehlabathini lonke: ibhiya.Ukuze kugcinwe ukuhambelana kwencasa, ukutsha kunye nomgangatho webhiya, inkqubo yokuhluza inwebu ngexesha lotywala kufuneka ilawule ngokuqinileyo i-microorganisms, i-organic matter, ingcaciso, kunye nencasa engcono.I-Dongguan Qinda ineminyaka eyi-18 yophuhliso kunye namava okuvelisa, idibene nebhubhoratri inokubonelela ngeenkonzo ze-microbial kunye nokuqinisekisa, ukuqinisekisa ukuzinza kunye nokusebenza kakuhle kweemveliso ezinikeziweyo.
