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CYANIDE in WATER and SOIL: Chemistry, Risk, and Management - Chapter 8

Cyanide có thể được liên kết với các chất rắn trong nước bị ô nhiễm và các hệ thống đất. Vì vậy, phương pháp phân tích tổng xyanua hoặc các loài xyanua cụ thể trong đất, bùn cặn, nhà máy và mô động vật, rắn và dễ dàng các hình thức phức hợp giải pháp và pha rắn kết tủa với các kim loại trong môi trường. Nó có thể dạng rắn kết tủa với một số kim loại, bao gồm đồng, kẽm, nickel, và sắt trong những người khác [1]. Sắt sắt xyanua chất rắn như Phổ xanh, Fe4 (Fe (CN) 6) 3. | 8 Analysis of Cyanide in Solids and Semi-Solids David A. Dzombak Joseph T. Bushey Sharon M. Drop and Rajat S. Ghosh CONTENTS 8.1 Direct Acid Distillation. 156 8.2 Acid Solution Extraction . 157 8.3 Neutral Solution Extraction. 158 8.4 Alkaline Solution Extraction . 158 8.5 Effect of Extraction Solution pH. 159 8.6 Effect of Liquid-Solid Ratio . 161 8.7 Effect of Extraction Time. 162 8.8 Extraction of Plant and Animal Tissue and other Semi-Solid Materials. 163 8.8.1 Plant Tissue Analysis. 163 8.8.2 Animal Tissue Samples . 164 8.8.3 Alternative Extraction Procedures for Plant Tissue . 164 8.8.4 Analytical Methods for Use with Plant Tissue . 164 8.9 Quality Control and Method Performance Evaluation. 165 8.10 Summary and Conclusions . 165 References . 166 Cyanide can be associated with solids in contaminated water and soil systems. Therefore methods for analyzing total cyanide or specific cyanide species in soils sludges plant and animal tissue solid wastes and other solids are of interest. As discussed in Chapters 2 and 5 free cyanide is very reactive and readily forms solution complexes and solid phase precipitates with metals in the environment. It can form solid precipitates with a number of metals including copper zinc nickel and iron among others 1 . Iron-iron cyanide solids such as Prussian Blue Fe4 Fe CN 6 3 s and Turnbull s Blue Fe3 Fe CN 6 2 s are the most common cyanide solid phases in the environment as iron is very reactive with free cyanide and is ubiquitous 2 . Iron-iron cyanide solids have limited to moderate solubility in water with the solubility dependent on pH and oxidation-reduction potential 2 3 . Solid phases consisting of simple salts of free cyanide or metal-cyanide complexes such as KCN NaCN and K2Ni CN 4 are not encountered in the environment to any appreciable extent as these solids dissolve readily in water. Aqueous cyanide species can also adsorb onto various inorganic and organic phases with the extent of adsorption being dependent on pH