Tackiness of a novel biodegradable binder for erosion control mulch

Kraft lignin, acidic (LA) and alkaline (LB) types, byproducts of pulp manufacturing were mixed with crude glycerol, a by-product of biodiesel production, and humic acid to produce a mulch tackifier for soil erosion control. Lignin was dried at 70°C for 24 h before use. The study was a full factorial with lignin levels of 20, 50, and 80% and humic acid levels of 1, 2, and 5% (w/w). The remaining portion consisted of crude glycerol. The samples were homogenized using water to facilitate the homogenization process. After homogenization, the samples were left to settle for 36 h and then separated into solid and liquid portions. Both portions were dried at 70°C for 24 h and tested for tack after wetting with water. Dried lignin, as a standalone ingredient, was also tested for tack. The values for the strength of tack were compared to those obtained from a commercial tackifier. Acidic lignin could be used with lignin content ≥50%. Acidic lignin was comparable to the commercial tackifier, whereas alkaline lignin was found to have significantly more tack but was found to be unsuitable for soil erosion use. © 2020 Canadian Biosystems Engineering. All rights reserved.