This article provides a paragraph on rivers. Rivers have always played an important role in shaping civilisation. Besides supplying water, rivers also provide means of transportation, recreation, hydropower generation and waste disposal. However, rivers have also generally caused problems of flooding, change of course resulting in migration of people, loss of properties, etc. Rivers can be classified in the following [...]
Many toxic compounds produced by human activities cannot be degraded by microorganisms available in natural water bodies and soil sediments. But genetic engineering is being applied to generate microorganisms that may be capable of degrading them. Some examples of such toxic compounds are: polychlorinated biphenyls (PCBs), chlorinated benzenes, and chlorinated phenols. Recently two strategies have been applied to the development [...]
Environmental biotechnology has made rapid strides during the past three or four decades. Many problems pertaining to accumulation of hazardous wastes and toxic metals in water, wastewater and soil have been solved. We now use biological methods not only for wastewater treatment but also for air pollution control. Bioremediation, whether it be by natural attenuation, bio-augmentation or use of genetically [...]