Absorption and adsorption Heavy metals 40 Analysis 21 Carbon, Activated 19 Carbon dioxide 17 Purification 16 Adsorption 13 Atomic absorption spectroscopy 11 Sewage 10 Copper 8 Trace elements 8 Dissertations 7 Dissertations, Academic 7 Environmental aspects 7 Gases 7 Water 7 Metal ions 6 Physiology 6 Research 6 Chemistry, Analytic 5 Effect of heavy metals on 5 Brown algae 4 Cadmium 4 Heavy metals removal 4 Metals 4 Supercritical fluid extraction 4 Agricultural wastes 3 Ammonia 3 Chromium 3 Contamination 3