Turbidimetric Determination of Anionic Polyacrylamide in Low Carbon Soil Extracts

Abstract

Concerns over runoff water quality from agricultural lands and construction sites have led to the development of improved erosion control practices, including application of polyacrylamide (PAM). We developed a quick and reliable method for quantifying PAM in soil extracts at low carbon content by using a turbidimetric reagent, Hyamine 1622. Three high-molecular weight anionic PAMs differing in charge density (7, 20, and 50 mol%) and five water matrices, deionized (DI) water and extracts from four different soils, were used to construct PAM calibration curves by reacting PAM solutions with hyamine and measuring turbidity development from the PAM-hyamine complex. The PAM calibration curve with DI water showed a strong linear relationship (r 2 = 0.99), and the sensitivity (slope) of calibration curves increased with increasing PAM charge density with a detection limit of 0.4 to 0.9 mg L -1 . Identical tests with soil extracts showed the sensitivity of the hyamine method was dependent on the properties of the soil extract, primarily organic carbon concentration. Although the method was effective in mineral soils, the highest charge density PAM yielded a more reliable linear relationship (r 2 > 0.97) and lowest detection limit (0.3 to 1.2 mg L ). Our results suggest that the hyamine test could be an efficient method for quantifying PAM in environmental soil water samples as long as the organic carbon in the sample is low, such as in subsurface soil material often exposed at construction sites.

Characterization of a Polyacrylamide Solution Used for Remediation of Petroleum Contaminated Soils

“…Organic agents, including polymers, biopolymers, and surfactants, have shown to improve the shear strength, stiffness, soil remediation, and erosion resistance behaviors of geomaterials [1,2,3,4,5,6,7,8]. Among them, biopolymers such as polyacrylamide (PAM) and Xanthan gum have shown great promise for enhanced oil recovery (EOR) because they lead to an increase in the viscosity of water, decrease in the mobility of water, and contact with a larger volume of the reservoir [9,10,11].…”

Small Strain Stiffness of Unsaturated Sands Containing a Polyacrylamide Solution

“…Soil improvements using organic agents such as polyacrylamide, xanthan gum, and surfactants have been developed which have shown promising results at improving the shear strength, stiffness, soil remediation, and erosion resistance of geomaterials [1,2,3,4,5,6,7,8,9]. Amongst them, polyacrylamide (PAM) influences irrigation through increased water infiltration and decreased erosion by its capacity to absorb and store water [10,11,12,13].…”

Measuring poly(acrylamide) flocculants in fresh water using inter-polymer complex formation

“…In the EU alone approximately 50,000 tonnes of poly(acrylamide) are used per annum for effluent treatment, and the polymer also finds commercial uses in paper, pulp, mineral and crude oil processing, coating applications and soil/sand treatment 2 . Due to its high usage, concerns regarding the release of the free monomer acrylamide (known to be highly toxic 3 ) and concerns over the toxicity of anionic/cationic polymers to aquatic lifeforms [4][5][6] , researchers have long been attempting to find new methods to determine the fate of the polymer after use [7][8][9][10][11][12][13][14][15][16] . In practice the intrinsic toxicity of the polymer released to the environment is reduced by many factors 17,18 so whilst these polyelectrolytes are not a priority for environmental control, our inability to trace these synthetic polymers and determine their spread through surface waters is a severe limiting factor to their future use.…”

“…They required several preparation steps that would not be suitable for large scale industrial testing. A key issue in many of these methods is ensuring that dissolved organic matter does not interfere in the measurement, an issue that only recent advances in the sensitivity of the detectors have begun to overcome 16,26 . Turbidometric analysis is possible if the polyacrylamide is hydrolysed with a quaternary ammonium cation achieve detection at low concentrations it is necessary to pass the solution through a cation exchange resin following alkaline hydrolysis, which is then evaporated and subsequently collected in order to reveal concentrations lower than 1 mg l -1 13 .…”

“…With all of these steps in place turbidometric measuring techniques were found to be accurate and reproducible to 1% at concentrations as low as 0.1 mg l -1 . Additionally these techniques have often been found to have varying effectiveness depending on the charge density of the polyacrylamide flocculant 16 .…”