干旱区生态环境知识资源中心(Arid): Humic substances in natural waters and their complexation with trace metals and radionuclides: a review. [129 references]

Arid

DOI	10.2172/5569909
报告编号	ANL-84-78
来源ID	OSTI_ID: 5569909
	Humic substances in natural waters and their complexation with trace metals and radionuclides: a review. [129 references]
	Boggs, S. Jr.; Livermore, D.; Seitz, M.G.
英文摘要	Dissolved humic substances (humic and fulvic acids) occur in surface waters and groundwaters in concentrations ranging from less than 1 mg(C)/L to more than 100 mg(C)/L. Humic substances are strong complexing agents for many trace metals in the environment and are also capable of forming stable soluble complexes or chelates with radionuclides. Concentrations of humic materials as low as 1 mg(C)/L can produce a detectable increase in the mobility of some actinide elements by forming soluble complexes that inhibit sorption of the radionuclides onto rock materials. The stability of trace metal- or radionuclide-organic complexes is commonly measured by an empirically determined conditional stability constant (K'), which is based on the ratio of complexed metal (radionuclide) in solution to the product concentration of uncomplexed metal and humic complexant. Larger values of stability constants indicate greater complex stability. The stability of radionuclide-organic complexes is affected both by concentration variables and envionmental factors. In general, complexing is favored by increased of radionuclide, increased pH, and decreased ionic strength. Actinide elements are generally most soluble in their higher oxidation states. Radionuclides can also form stable, insoluble complexes with humic materials that tend to reduce radionuclide mobility. These insoluble complexes may be radionuclide-humate colloids that subsequently precipitate from solution, or complexes of radionuclides and humic substances that sorb to clay minerals or other soil particulates strongly enough to immobilize the radionuclides. Colloid formation appears to be favored by increased radionuclide concentration and lowered pH; however, the conditions that favor formation of insoluble complexes that sorb to particulates are still poorly understood. 129 refs., 25 figs., 19 tabs.
出版年	1985
报告类型	Technical Report
语种	英语
国家	美国
来源学科分类	54 ENVIRONMENTAL SCIENCES ; ACTINIDE COMPLEXES ; STABILITY ; ACTINIDES ; CHEMICAL REACTIONS ; FULVIC ACIDS ; HUMIC ACIDS ; METALS ; CHELATES ; CHELATING AGENTS ; COLLOIDS ; GROUND WATER ; LIGANDS ; PH VALUE ; REVIEWS ; SURFACE WATERS ; TRACE AMOUNTS ; COMPLEXES ; DISPERSIONS ; DOCUMENT TYPES ; ELEMENTS ; HYDROGEN COMPOUNDS ; ORGANIC ACIDS ; ORGANIC COMPOUNDS ; OXYGEN COMPOUNDS ; WATER 520300* -- Environment, Aquatic-- Radioactive Materials Monitoring & Transport-- (1989) ; 520200 -- Environment, Aquatic-- Chemicals Monitoring & Transport-- (-1989)
URL	http://www.osti.gov/scitech/servlets/purl/5569909
资源类型	科技报告
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/263730
推荐引用方式 GB/T 7714	Boggs, S. Jr.,Livermore, D.,Seitz, M.G.. Humic substances in natural waters and their complexation with trace metals and radionuclides: a review. [129 references],1985.