Based on the above equations, the fittings were calculated and
listed in Table 2. As can be seen, the correlation coefficients of R2
with the fitted Langmuir equation are all greater than those with
Freundlich equation. Apparently, the adsorption of lignosulfonate
on coal and kaolinite surfaces preferably adapted to monolayer
adsorption in deionised water and saline water. Although lignosulfonate molecules and aggregates coexist in both solutions, single
molecules are in the majority [8] and would probably take the priority of adsorbing on both coal and kaolinite particles