Effects of Soil and Water Properties on Anionic Polyacrylamide Sorption

Knowing the sorptive behavior of anionic polyacrylamide by soils is useful in predicting the appropriate application rate, depth of effective treatment, and its mobility in soils. The effectiveness of cation PAM enhancement on PAM sorption varied with soil texture and was greater in fine soils than in sandy soils.
Soil and water properties such as texture, clay mineralogy, OM, and concentration of dissolved salts will affect PAM sorption.
Water-soluble PAMs have been used as soil amendments for various agricultural purposes, such as minimization of surface water run-off, soil erosion and crusting, stabilization of soil structure, and enhancing infiltration . High molecular weight and moderately anionic charged Polyacrylamide are the most effective types in soil application Addition of Polyacrylamide PAM to soil will affect soil dispersion, flocculation, and aggregation .
Knowledge of the sorptive behavior of Polyacrylamide is useful in predicting appropriate dose of application, depth of effective treatment, its mobility in soil, and changes in soil physical conditions. With good knowledge of polymer–soil interactions, the optimal amount of polymer application can be potentially prescribed.
Polyacrylamide is one of the most widely used polymers. Its sorption by sand, silica, alumina, clay minerals, latex, cellulose, and other materials has been the topic of previous publications. Greenland and Theng presented comprehensive reviews on the sorption of polymers in clay suspensions. Pefferkorn discussed interfacial processes involving PAM sorption. Nevertheless, little information was found in the literature regarding the sorption reaction between soil and PAM. In addition, the molecular weight of PAM used in irrigation is much higher but the concentration is much lower compared with those earlier studies. Information on PAM sorption at concentrations as low as 10 mg L−1 is sparse, possibly because of the difficulty in determining PAM concentrations in soil solutions .