Metals Speciation In Soils

Metal Speciation and Contamination of Soil provides a thorough overview of the biogeochemical processes governing the behavior, transport, and bioavailability of heavy metals in contaminated soils and suggests alternative approaches for effective remediation. This important new book contains contributions from experts in various disciplines who explore the issues from theoretical, experimental, and pragmatic perspectives. Topics include redox chemistry, kinetics of metal reactions, spectroscopic characterization of metal ion reactions at surface, modeling hydrologic transport phenomena and colloid-associated transport of metals through the soil profile to ground water, and remediation alternatives.

Report, the editors replaced the term "speciation" wherever it occurred by "identification and quantification," or "description of abundance," or "reactivity," or "transformation" of a chemical species, according to whichever one of the four meanings the author had evidently meant to convey. In line with the Dahlem Workshop Model, this Report comprises the background papers written in advance of the meeting on the current status of problems in environmental research and on advanced analytical tech niques for the identification and quantification of chemical species, as well as the group reports summarizing the results of the discussions held during the meeting. Each group report was prepared during the meeting by one "rapporteur" with the help of members of that group and finalized by the rapporteur (listed as the first author of the group report) after the meeting, taking into account both verbal comments made during the presentation of the reports in the plenary session at the end of the workshop and written comments received afterwards.

"Heavy Metals: Problems and Solutions" is divided into three sections dealing with basic geochemical processes, remediation and case studies. The basic geochemical processes are discussed with respect to mobility in the environment and impact as well as methods to derive guidelines for heavy metals. Remediation focuses on currently available methods to treat contaminated sediments and soils. In addition, it considers the concept of geochemical engineering for remediation of large areas contaminated by metals. A number of case studies of polluted sediments and soils and their environmental impact highlight the principles discussed in the first two sections.

The particular behavior of trace metals in the environment is determined by their specific physico-chemical form rather than by their total concentration. The introduction of atomic absorption spectrometry has lead to a plethora of scientific papers and reports in which metal concentrations in the environment are only reported as total concentrations. Only recently has the need for improved knowledge on the various forms and bioavailability of metals been realised. Considerable research effort is now devoted to measuring the concentrations of trace metals in surface waters. Efforts are made to couple chemical analytical techniques to process-related biological problems. The proceedings of the workshop on The Speciation of Metals in Water, Sediment and Soil Systems held in Sunne, Sweden, comprise these efforts and show aspects for further cooperation between analytical chemists and biologists.

Understanding the mechanisms associated with metal complexes and the sequestering metal contaminants in the environment is essential for effective remediation. Heavy Metal Release in Soils describes and quantifies desorption/release kinetics and dissolution reactions in the release of heavy metals from soil. The book focuses on: New techniques - microscopic surface techniques, NMR and electrophoresis, XAFS, SFM, and time-resolved ATR-FTIR Theoretical analysis and kinetic approaches - adsorption/desorption hysteresis, competitive sorption and transport, multi-component models, speciation kinetics, isotherms and soil and metal parameters, and the role of soil properties on transport Applications - arsenic speciation and mobility in contaminated soils, modeling activity of CD, Zn, and Cu in contaminated soils, and in situ chemical immobilization A timely addition to the literature, this book highlights the desorption/release mechanisms for the purpose of resolving remediation dilemmas in contaminated environments. It gives you the added advantage of case studies at both the microscopic and macroscopic scales, and provides both experimental and numerical investigations. With contributions from an international panel of authors, Heavy Metals Release in Soils fills a gap in the current literature concerned with subsurface contaminant fate and transport processes.

Proceedings of the NATO Advanced Study Institute on Metal Speciation in the Environmental held in Cesme, Turkey, October 9-20, 1989

The elevated heavy metal contamination in soils has given rise to the accurate assessment of the availability and mobility of heavy metals and the development of remediation strategies. In this study, soi! column-Donnan membrane technique (SC-DMT) and diffusive gradients in thin¬films gels (DGT) were used to measure the concentration and speciation of Cd, Cu, Ni, Pb, and Zn in eighteen soil solutions, covering a wide range of metal sources (natural and anthropogenic) and concentrations. The availability of Cd, Cu, Pb, and Zn in nine contaminated soils was evaluated by combining chemical extractions with multi-elementary stable isotopic dilution (ID) method. The isotopically exchangeable pool and the operationally defined pool determined by chemical extractions were then compared to probe the relationships between metal availabilities and their bearing phases. The mufti-surface model was used to assess the rote of the major soil components (organic matter, clay, iron hydroxides, and manganese hydroxides) in controlling metal availability. The combination of analytical approaches and speciation modeling can provide mutual validation and a more comprehensive picture of the availability of metals. In our work, model calculation generally provided an adequate prediction of metal speciation in soi! solution and solid phase, and it can be a promising tool to decipher the underlying mechanisms of the differences in metal availabilities in soils.