MX-80 bentonite is considered as one of the best backfill materials for high-level radioactive nuclear waste. Herein, the
bentonite is characterized by using XRD and FTIR techniques. Sorption of radionickel to MX-80 bentonite in the presence/absence
of humic acid (HA) or fulvic acid (FA) as a function of pH is investigated. The results indicate that the presence of HA or
FA decreases the sorption of Ni2+ obviously. The different experimental processes do not affect the sorption of nickel to FA/HA bound bentonite. The sorption
of Ni2+ on FA/HA-bound bentonite decreases with the increasing FA/HA content in the systems. The mechanism of nickel sorption is
also discussed in detail.