POLYMER TYPE AND WATER-QUALITY EFFECTS ON SOIL DISPERSION

Ten polyacrylamide (PAM) and derivatized guar compounds, with different charges were tested at 0, 10, and 50 mg L** minus **1 concentration with low electrolyte solution (1 mol//c m** minus **3) at 0, 5, and 20 sodium absorption ratio values for their ability to reduce dispersion of three soils. Dispersion was determined by measuring the soil settling rate in solution. All compounds were effective in promoting clay fluocculation at a concentration of 10 mg L** minus **1. When compared at comparable charge, the PAM compounds were more effective than the guar compounds. This result is consistent with their higher molecular weight. The order of effectiveness of the compounds was cationic greater than nonionic greater than anionic.