Limitations in the use of commercial humic acids in water and soil research

Malcolm, Ronald L.; MacCarthy, Patrick

doi:10.1021/es00151a009

Cited by 368 publications

(196 citation statements)

References 22 publications

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“…These findings are supported by a multiple linear regression for CMC versus alkyl-C and N + S contents [CMC ) 24.6 -0.189 alkyl C -2.64 (N + S); R 2 ) 0.77, P < 0.10, n ) 6] that was determined from data from this and previous works (17) and from commercial-HAs (Aldrich) (32) (Tables S3 and S5).…”

Section: Resultssupporting

confidence: 81%

Biobased Surfactant-Like Molecules from Organic Wastes: The Effect of Waste Composition and Composting Process on Surfactant Properties and on the Ability to Solubilize Tetrachloroethene (PCE)

Quadri

Chen

Jawitz

et al. 2008

Environ. Sci. Technol.

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In this work, four surfactant-like humic acids (HAs) obtained from garden lignocellulose wastes and kitchen food wastes mixed with garden-lignocellulose wastes, both before and after composting, were tested for surfactant properties and the ability to solubilize tetrachloroethene (PCE). The waste-derived HAs showed good surfactant properties, lowering the water surface tension from 74 mN m -1 to 45.4 ( 4.4 mN m -1 , with a critical micelle concentration (CMC) of 1.54 ( 1.68 g L -1 , which is lower than many synthetic ionic surfactants. CMC was affected by both waste origin and composting processes. The addition of food waste and composting reduced CMC by adding alkyl-C (measured by CP MAS 13 C NMR) and N-and S-HA contents (amide molecules), so that a multistep regression was found [CMC ) 24.6 -0.189 alkyl C -2.64 (N + S); R 2 ) 0.77, P < 0.10, n ) 6]. The four HAs solubilized PCE at the rate of 0.18-0.47 g PCE/g aqueous biosurfactant. These results were much higher than those reported in the literature for a commercial HA (0.026 g/g), but they were in line with those measured in this work for nonionic surfactants such as Tween-80 (0.69 g/g) and Triton X-100 (1.08 g/g).

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Section: Resultssupporting

confidence: 81%

Biobased Surfactant-Like Molecules from Organic Wastes: The Effect of Waste Composition and Composting Process on Surfactant Properties and on the Ability to Solubilize Tetrachloroethene (PCE)

Quadri

Chen

Jawitz

et al. 2008

Environ. Sci. Technol.

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“…The chemical shift assignments are depicted elsewhere: 0-50 ppm (ppm=10 −6 ), mainly aliphatic or paraffinic carbons; 50-60 ppm, methoxy groups; 60-96 ppm, -CH 2 O-groups; 96-108 ppm, anomeric groups; 108-145 ppm, aromatic groups; 145-162 ppm, phenolic groups; 162-190 ppm, carboxylic groups; and 190-230 ppm, non carboxylic carbonyl groups (Malcolm and MacCarthy, 1986;Kang and Xing, 2008). The integration results of the HA carbon distributions are listed in Table 2, which is similar to the reported peat and leonardite HA results (Malcolm and MacCarthy, 1986). The HA tested contains a high content of aromatic groups and carboxylic groups, and its aromaticity is 47.92%.…”

Section: Structural Characterization Of the Commercial Hamentioning

confidence: 99%

Effects of humic acid and bovine serum albumin on the agglomeration and sedimentation of oxide nanoparticles

Lin

Chen

et al. 2014

J. Zhejiang Univ. Sci. A

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Abstract:To better understand the nanoparticle (NP) transport in the environment, the agglomeration and sedimentation of Al 2 O 3 , SiO 2 , and TiO 2 NPs were evaluated after being treated with bovine serum albumin (BSA) and a commercial humic acid (HA). The morphology of NP agglomerates was examined through a transmission electron microscope (TEM), and the agglomeration kinetics was evaluated using established time-resolved dynamic light scattering techniques. BSA treatments decreased the hydrodynamic diameters (d H ) of the three NPs in both NaCl and CaCl 2 electrolytes due to their steric repulsive forces caused by the BSA globular architecture. The treatments using HA induced the smallest d H of NPs in NaCl electrolyte, but the largest d H of NPs was found in CaCl 2 electrolyte, because the HA bound to each other via calcium complexation and thereby enhanced the NP agglomeration. The zeta potentials of NPs were not the dominant factor to affect agglomeration. The NP sedimentation kinetics were studied through measuring the suspension optical absorbance. It was shown that the BSA treatments retarded the sedimentation in most situations; however, HA treatments accelerated the sedimentation greatly in CaCl 2 electrolyte, which was consistent with the measured changes in the d H values. The smallest d H of HA-treated NPs in NaCl electrolyte did not result in the lowest sedimentation rate, which indicated that the agglomeration size was not the only factor to affect the NP sedimentation.

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“…#53680) for a final concentration of 200 mg/l HA (Fisher et al 2006). Several workers, including Malcolm and Mccarthy (1986) have pointed out differences between commercial humic acids, like the ones used in the present study, and HA derived from natural sources. Specifically, commercial HA have considerably higher carbon-to-nitrogen ratios and high ash contents (Malcolm and Mccarthy 1986).…”

Section: Methodsmentioning

confidence: 76%

“…Several workers, including Malcolm and Mccarthy (1986) have pointed out differences between commercial humic acids, like the ones used in the present study, and HA derived from natural sources. Specifically, commercial HA have considerably higher carbon-to-nitrogen ratios and high ash contents (Malcolm and Mccarthy 1986). These factors are unlikely to fundamentally affect the behavior of HA with respect to chelating chemical signals or acting as antagonists to chemoreceptors.…”

Section: Methodsmentioning

confidence: 85%

Humic Acid Interferes with Species Recognition in Zebrafish (Danio rerio)

et al. 2007

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Few studies have addressed how chemosensation may be impaired by chemical alterations of the environment and anthropogenic disturbance. Humic acid (HA) is a pervasive, naturally occurring organic derivative found in aquatic and terrestrial environments; human activity, however, can lead to elevated levels of HA. Recent studies suggest that environments that contain high levels of HA may hinder chemical communication. We tested the ability of adult zebrafish (Danio rerio) to discriminate between conspecific and heterospecific urinary chemical cues found in the presence and absence of HA. We show that high humic acid levels (200 mg/l) can impair the ability to differentiate conspecifics from heterospecifics. We also found that zebrafish prefer untreated water over HA-treated water. These findings suggest that, in addition to human-produced synthetic compounds, changes in the abundance of naturally occurring substances may also negatively impact natural behaviors in aquatic species by disturbing the sensory environment.

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Limitations in the use of commercial humic acids in water and soil research

Cited by 368 publications

References 22 publications

Biobased Surfactant-Like Molecules from Organic Wastes: The Effect of Waste Composition and Composting Process on Surfactant Properties and on the Ability to Solubilize Tetrachloroethene (PCE)

Biobased Surfactant-Like Molecules from Organic Wastes: The Effect of Waste Composition and Composting Process on Surfactant Properties and on the Ability to Solubilize Tetrachloroethene (PCE)

Effects of humic acid and bovine serum albumin on the agglomeration and sedimentation of oxide nanoparticles

Humic Acid Interferes with Species Recognition in Zebrafish (Danio rerio)

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