Sorption of heavy metals on non−conventional adsorbents

Abstract

The Thesis is divided into 6 chapters. Chapterand#8722;1 includes general introduction of pollution and particularly emphasized on water pollution. The indiscriminate disposal of water after use in the form of wastewater causes water pollution. Water pollution could be in the form of any change in the physical, chemical and biological properties of water which has harmful effect on living things. It could take place in various water sources, like ponds, lakes, rivers, seas and oceans. One of the causes of water pollution is the release of waste into the water bodies, for example domestic waste, industrial effluents, agricultural wastes. In addition infection agents, plant nutrients, exotic organic chemicals, inorganic materials and compounds sediments and heat totally spoil the quality of water. Other causes of pollution in the sea include events such as oil spills and atmospheric deposition (where pollutants enter water bodies through falling particles, dissolving in rain, snow, or direct dissolving in water. Ground water pollution falls into two broad categories: Point source and Non-Point source pollution. Since non-point source pollution affects a larger area, it is generally considered to be more hazardous than point source pollution. Chemical pollutants are subdivided into organic and inorganic pollutants. Organic pollution is the most common form of water pollution. These pollutants can be classified into two groups named biodegradable in which naturally occurring compounds are placed and non-biodegradable which includes synthetic compounds.Those aquatic organisms which either multiplied excessively or are otherwise undesirable, harmful or injurious are classified as biological pollutants. These pollutants generally arise as secondary result of pollution by sewage or trade wastes.For the treatment of industrial wastewater, there are various methods which include primary treatment, secondary treatment and tertiary treatment.