الفهرس | Only 14 pages are availabe for public view |
Abstract The entitled thesis “Removal of some important anions from aqueous solutions by marine nanomaterials” includes five chapters and the data are collected in 8Tables and 25Figures. Chapter One: is an indicatory part deals with the occurrence, resources and toxicity of heavy metals. One of the foremost important environmental issues for all countries is heavy metals in water resources. The industrial use of metals, particulary heavy metals, has increased alarmingly as a result of modernization, thus becoming a priority concern because of their environment toxicity. Plus, chronic exposure of these metals to toxicity in humans results innumerousdisordersofthe nervous system, respiratory system, renal system, hepatic system and reproductive system. Also, they reduce growth and development, whenever, the accumulation of metal ions in human bodies will occur through either direct intake or food chains. Plus, metals also cause allergies and prolonged long-term contact with certain metals or their compounds may even be carcinogenic and in extreme cases death. Main anthropogenic sources of metals are: power plants, mining industry and refining of metal ores, metallurgical industry, electronic, chemicals, nuclear industry, agriculture and waste disposal. Accordingly, most of the heavy metals represent serious threats to the humans and the fauna and flora of the receiving bodies of water because they are persistent and nonbiodegradable. Due to world population growth, developing industries, and long-time droughts, usable water resources have recently declined. In addition to over-exploitation, natural water resources are contaminated with polluted discharges from industries, outletsand drains that make water shortages even worse in rich water areas. Rainfall streams or storm water can be stored to control water shortages for a short time, but treating and reusing wastewatersis the best way. |