Use of hydrophilic polymers from disposable diapers to restore metal contaminated soils

RAMIRAN International ConferenceHydrophilic polymers swell to form gels that contain many times their dry weight in water. They are marketed as ‘superabsorbent polymers’, with different trade names, for incorporation into soils and substrates. YunKai et al. (2002) reviewed the effects of these polymers on agricultural soils and crops. Another use of hydrophilic polymers is in disposable diapers and similar products. A layer of polyacrylate polymer is located between cellulose fibres, and the whole contained by a plastic cover. Effects of metals on ecosystems and biological resources are increasingly recognised (Izquierdo et al., 2005; Pérez-de-Mora et al., 2006). It is too expensive to remove metals from severely contaminated soils, and the restoration of these sites does not imply a decrease in the total contents of toxic metals, but rather a change in their availability. Factors that influence the flow of metals from solid phases towards soil solution govern their bioavailability. In this manuscript, the emphasis is set on the effect of polyacrylate polymers on plant growth and quality of metal-contaminated soils, deriving from their effect on metal availability