Stability, solubility and maximum metal binding capacity in metal–humic complexes involving humic substances extracted from peat and organic compost

The Cananéia-Iguape estuarine–lagoon complex (São Paulo state, Brazil) is a natural laboratory to study metal binding by humic substances (HS) in subtropical settings. This transitional environment is evolving into a freshwater environment due to water input from the Ribeira River, funneled through the Valo Grande Canal (Iguape). Past mining activities in the Ribeira River basin and maritime traffic are suspected to be potential sources of trace metals in the system. In this study, the trace metal contents of Free Humic Acids (FHA), Bound Humic Acids (BHA), and Fulvic Acids (FA) extracted from sedimentary organic matter were investigated. Moreover, the sources of HS were traced using their stable carbon isotope compositions and C/N ratios. The results suggested a mixed marine–terrestrial source of FHA, BHA, and FA. Copper and Cr were the most abundant trace metals bound to HS. On average, Cu showed concentrations of 176, 115, and 37.9 μg g−1 in FHA, BHA, and FA, respectively, whereas Cr showed average concentrations of 47.4, 86.3, and 43.9 μg g−1 in FHA, BHA, and FA, respectively. Marine FHA showed the highest binding capacity for trace metals, whereas terrestrial FA derived from the decay of mangrove organic matter showed the lowest binding capacity.

Download Full-text

Determination of the Heavy Metal Binding Capacity (HMBC) of Environmental Samples

Small-scale Freshwater Toxicity Investigations ◽

10.1007/1-4020-3553-5_7 ◽

2006 ◽

pp. 215-231 ◽

Cited By ~ 1

Author(s):

Gabriel Bitton ◽

Marnie Ward ◽

Roi Dagan

Keyword(s):

Heavy Metal ◽

Metal Binding ◽

Environmental Samples ◽

Binding Capacity ◽

Heavy Metal Binding ◽

Metal Binding Capacity

Download Full-text

Lead Absorption and Excretion in Rats Given Insoluble Salts of Pectin and Alginate

International Journal of Toxicology ◽

10.1080/10915810600683291 ◽

2006 ◽

Vol 25 (3) ◽

pp. 195-203 ◽

Cited By ~ 18

Author(s):

Maxim Khotimchenko ◽

Irina Serguschenko ◽

Yuri Khotimchenko

Keyword(s):

Metal Binding ◽

Calcium Alginate ◽

Binding Capacity ◽

Laboratory Animals ◽

Lead Removal ◽

Lead Absorption ◽

Calcium Pectate ◽

Inner Organs ◽

Metal Binding Capacity

Exposure to environmental lead remains a widespread problem in most industrialized countries. Usage of modern agents purposed for elimination of heavy metals as well as for therapy and prevention of chronic poisoning does frequently result in toxic signs. Dietary nonstarch polysaccharides were suggested to be effective when used for this purpose. The present study was conducted to estimate metal binding capacity and effects of calcium salts of pectate and alginate on lead absorption, distribution, and removal with feces. Under in vitro conditions calcium alginate showed the highest lead-binding capacity in comparison with other agents studied. Metal binding capacity of calcium pectate was slightly lower. In rats simultaneous administration of lead acetate and suspensions containing calcium alginate or calcium pectate prevented metal absorption and significantly reduced lead accumulation in inner organs and femur. In experiments estimating lead removal from inner organs and femur in rats preliminary exposed to the heavy metal, calcium alginate and calcium pectate were the most effective agents studied in comparison with others, as indicated by reduced lead concentration in organs and femur as well as increased metal content in feces of laboratory animals. The results suggest that calcium pectate and calcium alginate may be considered perspective dietary compounds purposed for prevention and treatment of chronic lead poisoning.

Download Full-text

Sorption and Desorption of Cu(II) by Ganoderma Lucidum

Water Quality Research Journal ◽

10.2166/wqrj.1991.012 ◽

1991 ◽

Vol 26 (2) ◽

pp. 187-200 ◽

Cited By ~ 20

Author(s):

Jose T. Matheickal ◽

Leela Iyengar ◽

C. Venkobachar

Keyword(s):

Metal Binding ◽

Ganoderma Lucidum ◽

Binding Capacity ◽

Simple Mathematical Model ◽

Fast Reaction ◽

Adsorption Equilibria ◽

Equilibrium Data ◽

Almost All ◽

Sorption Media ◽

Metal Binding Capacity

Abstract Experimental results on the uptake of Cu(II) by Ganoderma lucidum (M) and its alkali treated residue (Mc) indicated that the metal binding is a fast reaction. The pH of the sorption media affect the metal binding capacity. The equilibrium data for both M and Mc appear to fit well, the Langmuir isotherm. A simple mathematical model is developed based on adsorption equilibria and mass balance to predict the concentration of metal that can be desorbed. Disagreement between the model predicted and experimental desorption equilibria indicated that biosorption of Cu(II) by M and Mc is irreversible. EDTA and HCl are efficient eluants capable of recovering almost all the bound metal.

Download Full-text