2 minute read
Soil Cement: Cement Modified Soils
from Living Systems
by TD Garden
Launch Stratify Fluid Grooming suPer-aBsorBent PolyMers (hydrogel) //
Advertisement
Digestive Translate Volatile
Super-absorbent polymers (SAP) are engineered to retain 200 – 400 times their own weight in water or other liquid. Once submerged in water the SAP absorb water at an extremely rapid rate and swell into a gel. It is through osmotic pressure that the SAP absorb and release the liquid, and thus, unlike a sponge, the gel will not leach when applied with pressure. Manufactured into multiple forms such as granules, fibers, nonwoven, knitted and woven textiles, SAP have a wide range of applications from personal hygiene products (i.e. pads, diapers) and medical surgery spill-control, to irrigation control for horticulture and agriculture, wire and cable water blocking, and toxic spill cleanup.
Within the landscape and horticultural field, SAP are generically known as Hydrogel and commercially known, among many other brand names, as Soil Moist, Stockabsorb®, Oasis Super Absorbent Fiber, PetroGuard, Watersorb®. Made of polyacrylate/polyacrylamide copolymers, the SAP were originally designed for use in conditions where there is high electrolyte or mineral content and a need for long term stability including numerous wet/dry cycles, such as in agriculture and horticulture. The driving force for the osmotic pressure is typically the higher concentration of sodium or potassium ions in the polymer than in its surrounding environment. Thus, water is drawn in and out of the polymer in an attempt to reach equilibrium. For landscape and agricultural uses, the exceptional absorption capacity is utilized to increase the soil’s water-holding capacity by 50 –100%, thus reducing irrigation requirements, fertilizer washout, stormwater runoff and soil erosion. Conversely, when the soil is dry and plants are in need of water, the SAP controlrelease the retained water and fertilizer to the growing plants through osmotic pressure. The SAP improve aeration in soil, reduce transplant shock, and prevent soil compaction, thus encouraging deep root penetration.
SAP granules can be integrated into soil mixes, or used as tackifiers in hydroseeding applications. Woven or nonwoven geotextiles are used for land water management and control, and can potentially be used for flood protection due to their extremely rapid rates of absorption. Engineered to have various filtering and absorption properties, SAP can be hydrophobic and demonstrate high capacity to absorb reactive chemicals, aliphatic and aromatic hydrocarbons and chlorocarbons, making them ideal for containing and removing chemical spills.
Manufacturers: JRM Chemical, Inc.; Stockhausen, Inc.; Polymers, Inc.; Advanced Polymeric Absorbents; Technical Absorbents Limited
162
