Recovery of hydrogel from baby diaper wastes and its application for enhancing soil irrigation management

Improving irrigation management by using hydrogels is an advanced approach for maximizing agricultural land productivity. This experimental study demonstrated the technical feasibility of utilizing superabsorbent polymer recovered from waste baby diapers for increasing water retention in soil and improving irrigation management. After separation, recovery and cleaning of the recycled hydrogel, experimental parametric study was performed. It investigated the swelling capacity and kinetics, de-swelling behavior, and the effects of temperature, salt concentration, and pH on the performance of recycled hydrogel. Red clay soil modified with the recovered hydrogel was used to investigate water retention ability in soil. The swelling capacity increases with time, until it approaches an equilibrium state within about 100 min. At normal conditions, the equilibrium swelling capacity achieves an equilibrium value of 235 g water/g hydrogel. The swelling capacity increases with temperature, while it decreases with increasing pH or salt concentration. The addition of the recycled hydrogel to soil decreases water loss by infiltration and enhances irrigation management and plant growth.