Degradation and Leaching of Acrylamide in Soil

Abstract

Since some uses of acrylamide could cause ground water contamination, potential hazards were assessed by evaluating the degradation and leaching of 14C‐acrylamide (labelled at the carboxyl position) in four soils: silt loam, clay loam, loamy fine sand, and loam. The soil degradation study utilized the biometer flask method. Acrylamide half‐life (t1/2) was estimated by the time required for release of one‐half the evolved 14CO2. Half‐life was influenced by incubation temperature, acrylamide concentration, and the season at which the soil was collected. At ambient temperature (22°C), half‐lives ranged from 18 to 45 hours for 25 ppm acrylamide (on a soil basis). Decreasing temperature or increasing acrylamide concentration increased half‐life. Half‐life was two and one‐half times greater in soil gathered in spring than the same soil gathered in summer. When acrylamide was incubated in anaerobically maintained soil, it apparently metabolized more slowly. Leaching was evaluated by soil TLC. Rf values, which ranged from 0.64 to 0.88, place acrylamide into the “mobile class.”

Polyacrylamide as an organic nitrogen source for soil microorganisms with potential effects on inorganic soil nitrogen in agricultural soil

“…Commercially-available PAM preparations may contain no more than 0.05% AMD monomer (Barvenik, 1994). Our data indicate that indigenous soil microbial communities are capable of rapidly degrading AMD to access both N and C. This conclusion supports the findings of Shanker et al (1990) who reported complete degradation of 500 mg AMD kg-1 applied to soil within 5 d and Lande et al (1979) who reported half-life Smith et al (1996) have claimed that a polyacrylamide solution of unspecified MW and charge type spontaneously depolymerized to form acrylamide monomer upon incubation, although the data presented do not appear to strongly support this claim. Acrylamide was present initially at low concentrations in the incubation mixtures, presumably as a contaminant.…”

Use of Synthetic Polymers and Biopolymers for Soil Stabilization in Agricultural, Construction, and Military Applications

“…One must note, though, that PAM has been used in wastewater treatment for decades, with little evidence that it is detrimental to organisms during release (Hamilton et al 1994;Lande et al 1979). Low levels of PAM are acceptable in potable water and in animal feeds.…”

Polyacrylamide preparations for protection of water quality threatened by agricultural runoff contaminants

“…PAM does not revert to AMD upon degradation (MacWilliams, 1978). Furthermore, AMD is easily metabolized by microorganisms in soil and biologically active waters, with a half life in tens of hours (Lande et al, 1979;Shanker et al, 1990). Bologna et al (1999) showed that AMD is not absorbed by plant tissues, and apparently breaks down rapidly even when injected directly into living plant tissue.…”

“…Degradation of the acryamide monomer (AMD) is fairly rapid (Kay-Shoemake et al, 1998a;Shanker et al, 1990;Lande et al, 1979). AMD was completely degraded within 5 days after applying 500 mg PAM kg" garden soil (Shanker et al, 1990).…”

“…AMD was completely degraded within 5 days after applying 500 mg PAM kg" garden soil (Shanker et al, 1990). Lande et al (1979) applied 25 mg PAM kg-1 soil and reported that half life of an AMD in agricultural soils was 18-45 h.…”