The Clogging of Nonwoven Geotextiles With Cattle Manure Slurries

Three different types of heat-bonded, needle-punched, nonwoven polyester geotextile specimens with similar hydraulic conductivities, but with different O₉₀ values and average pore opening sizes, were exposed to a 3.6 m head of cattle manure slurry containing 7.5% total solids (TS) in laboratory columns to test the effect of pore opening size on geotextile specimen clogging. Geotextile specimens, with the smallest pore openings, were also exposed to 1, 2, and 4% TS cattle manure slurries to test the sealing effect of the TS. After 100 days of exposure to the slurries, geotextile specimen clogging was verified by measuring the geotextile specimen hydraulic conductivity using 0.9 and 3.65 m falling water head tests after removing all of the manure liquids and solids. The lowest volumetric infiltration rate, 1.1 L/m²/day, was obtained for geotextile specimens with the smallest pore opening size after 80 days of exposure to the 7.5% TS cattle manure slurry. Geotextile specimen infiltration rates were exponentially related to the amount of TS in the manure slurries. The geotextile specimen hydraulic conductivity values (for water), after the removal of the cattle manure slurries and all surface solids, was 10⁵ times smaller that that measured before testing. This indicates that geotextile specimen clogging did occur while in contact with the cattle manure slurries.