scholarly journals Humic substances in natural waters and their complexation with trace metals and radionuclides: a review. [129 references]

1985 ◽  
Author(s):  
S. Jr. Boggs ◽  
D. Livermore ◽  
M.G. Seitz
Keyword(s):  
Trace Metals ◽  
Humic Substances ◽  
Natural Waters

Complexation of Lead in Model Solutions of Humic Acid: Heterogeneity and Effects of Competition with Copper, Nickel, and Zinc

2006 ◽  
Vol 3 (4) ◽  
pp. 276 ◽  
Author(s):  
Ismail I. Fasfous ◽  
C. L. Chakrabarti ◽  
John Murimboh ◽  
Tahir Yapici
Keyword(s):  
Humic Acid ◽  
Trace Metals ◽  
Trace Metal ◽  
Humic Substances ◽  
Metal Concentration ◽  
Natural Waters ◽  
Metal Bioavailability ◽  
Copper Nickel ◽  
Model Solutions ◽  
Equilibrium Function

Environmental Context. Metal bioavailability and toxicity are often related to free metal concentration rather than total metal concentration. Humic substances are chemically and physically heterogeneous complexants for metals in natural waters, and play an important role in trace metal transport, fate, and bioavailability. Metal bioavailability, which depends on chemical speciation of metals, is greatly influenced by the presence of other trace metals and major cations in natural waters. In this work, the effects of heterogeneity of humic substances, and of competition of trace metals on lead speciation in model solutions have been studied to gain a better understanding of these effects on complexation of trace metal lead and its bioavailability. Abstract. Physicochemical heterogeneity of a well characterized humic acid (HA) in its complexation with a trace metal lead in model solutions was investigated using pseudo-polarography at a stationary mercury drop electrode, and the differential equilibrium function (DEF) of Pb(ii)–HA complexes was determined. The complexation of Pb(ii) by HA was determined by taking into account the dependence of the strength of the binding on the metal (Pb) loading. Also investigated were the effects of competition of the trace metals copper, nickel, and zinc on the DEF of Pb(ii)–HA complexes in model solutions. The results showed that these trace metals competed with trace metal lead for binding by HA even when present at the same concentrations as that of lead.

scholarly journals Adsorptive and Coagulative Removal of Trace Metals from Water Using Surface Modified Sawdust-Based Cellulose Nanocrystals

J ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 193-205
Author(s):  
Opeyemi A. Oyewo ◽  
Sam Ramaila ◽  
Lydia Mavuru ◽  
Taile Leswifi ◽  
Maurice S. Onyango
Keyword(s):  
Trace Metals ◽  
Adsorption Capacity ◽  
Cellulose Nanocrystals ◽  
Inductively Coupled Plasma ◽  
Electrostatic Interactions ◽  
Natural Waters ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Major Drawback ◽  
Surface Modified

The presence of toxic metals in surface and natural waters, even at trace levels, poses a great danger to humans and the ecosystem. Although the combination of adsorption and coagulation techniques has the potential to eradicate this problem, the use of inappropriate media remains a major drawback. This study reports on the application of NaNO2/NaHCO3 modified sawdust-based cellulose nanocrystals (MCNC) as both coagulant and adsorbent for the removal of Cu, Fe and Pb from aqueous solution. The surface modified coagulants, prepared by electrostatic interactions, were characterized using Fourier transform infrared, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive spectrometry (SEM/EDS). The amount of coagulated/adsorbed trace metals was then analysed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). SEM analysis revealed the patchy and distributed floccules on Fe-flocs, which was an indication of multiple mechanisms responsible for Fe removal onto MCNC. A shift in the peak position attributed to C2H192N64O16 from 2θ = 30 to 24.5° occurred in the XRD pattern of both Pb- and Cu-flocs. Different process variables, including initial metal ions concentration (10–200 mg/L), solution pH (2–10), and temperature (25–45 °C) were studied in order to investigate how they affect the reaction process. Both Cu and Pb adsorption followed the Langmuir isotherm with a maximum adsorption capacity of 111.1 and 2.82 mg/g, respectively, whereas the adsorption of Fe was suggestive of a multilayer adsorption process; however, Fe Langmuir maximum adsorption capacity was found to be 81.96 mg/g. The sequence of trace metals removal followed the order: Cu > Fe > Pb. The utilization of this product in different water matrices is an effective way to establish their robustness.

OXIDATION OF HUMIC SUBSTANCES PRIOR TO THE DETECTION OF PCBs AND PAHs IN NATURAL WATERS BY FLUOROMETRY ON SOLID SORBENT

2005 ◽  
Vol 25 (5) ◽  
pp. 407-419 ◽  
Author(s):  
L. Belfatmi ◽  
S. Ait Lyazidi ◽  
M. Lamotte ◽  
Ph. Fornier de Violet
Keyword(s):  
Humic Substances ◽  
Natural Waters ◽  
Solid Sorbent

Separation and Concentration of Trace Metals from Natural Waters

1953 ◽  
Vol 25 (12) ◽  
pp. 1927-1928 ◽  
Author(s):  
D. E. Carritt
Keyword(s):  
Trace Metals ◽  
Natural Waters

Miniaturized and direct spectrophotometric multi-sample analysis of trace metals in natural waters

2016 ◽  
Vol 497 ◽  
pp. 18-23 ◽  
Author(s):  
Gemma Albendín ◽  
José A. López-López ◽  
Juan J. Pinto
Keyword(s):  
Trace Metals ◽  
Natural Waters ◽  
Sample Analysis
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