The researchers studied how a chemical called BDE-28 sticks to different types of natural soils. They found that there are two types of sorption happening - one fast and one slow. The fast sorption happens quickly, while the slow sorption takes longer to reach its maximum. The fast sorption contributes more to the total amount of BDE-28 sorbed at the beginning, while the slow sorption becomes more important later on. The way BDE-28 sticks to the soils can be described as either linear or nonlinear, depending on the soil's organic matter content.