Masana kimiyyar Brazil suna duba yiwuwar canza sludge daga samar da masaku zuwa albarkatun kasa don masana'antar yumbu na gargajiya, suna fatan duka biyu za su rage tasirin masana'antar masaku da ƙirƙirar sabbin albarkatun ƙasa mai dorewa don yin bulo da tayal.