Thursday, 4 October 2018

E-content



                      E-CONTENT
                  WATER POLLUTION

   CLASSIFICATION OF WATER POLLUTANTS

ANALYSING
         Water pollution is defined as the addition of an excess material or heat that is harmful to the living organism or which impairs the beneficial uses of water. Pollution makes water physically impure, foul or filthy.
·        Pollution changes the natural qualities of water, so that it becomes unsuitable for the uses to which it is normally put to.
·        Pollutants may be present in water either as suspended particles or as dissolved compounds or both.
·        The dissolved compounds are more difficult to remove and hence these taint the water resources more seriously than the suspended impurities.
DESIGNING
 Related to the topic, four images and a video are shown. The video gives information about water pollution and the images are shown to get an idea about different types of water pollutants.
DEVELOPMENT
INTRODUCTION
               Water pollutants are classified in to four broad categories chemical, physical, physiological and biological. The introduction of these contaminants in to the aquatic system is likely to cause health hazards, harm to ecology, damage to structures or amenities and interference with legitimate uses of water.

CHEMICAL POLLUTANTS

                Chemical contaminants are subdivided into organic and inorganic pollutants.
ORGANIC POLLUTANTS
                Organic pollution is the most common form of water pollution. It is caused by the naturally  occurring compounds like proteins, fats, carbohydrates etc as well as by synthetic compounds like dyes, pesticides, herbicides etc. The synthetic organic pollutants cause more harm to the environment than naturally occurring ones.
INORGANIC POLLUTANTS
                  These pollutants largely originate from industrial wastes. Inorganic acids and alkalis can do extensive damage to a water body by breaking down its natural buffer system and altering its normal pH values.
PHYSICAL POLLUTANTS
                  The onslaught on the natural qualities of water occurs not only when chemical constituents are introduced in the aquatic systems, but also when the physical parameters of water are drastically altered. Physical pollution is less damaging than chemical pollution.

COLOUR
          Many trade wastes discharging in to watercourses have a distinct colour which these may impart to the water. The colour in most cases is due to organic dyes.
TURBIDITY
                A distinct physical characteristics of sewage and industrial waste is their degree of turbidity which is caused by the presence of colloidal matter.
SUSPENDED MATTER
                  Insoluble matter suspended in water is the most common form of physical pollutant.
FROTH
          Froth or foam consists of a dispersion of gas bubbles in water. The formation of foam is a physical phenomenon, arising due to lowering of surface tension of water  by impurities.
THERMAL POLLUTION
             Thermal or temperature pollution refers to the discharge of heated water from electricity generating plants in to water resourses.

PHYSIOLOGICAL POLLUTANTS
               Physiological pollution is always a secondary phenomenon, arising from the presence of trace quantities of chemicals.
TASTE
           Industrial wastes contain many chemical compounds which impart characteristic and unpleasant taste to water, even when present in extremely small quantities.
ODOUR
           Under the influence of microorganisms, proteins undergo putrefaction giving intermediates having offensive odours.
BIOLOGICAL POLLUTANTS

                     The aquatic organisms which either multiply excessively or are otherwise undesirable, harmful or injurious are classified as biological pollutants.
WEEDS
           Excessive growth of fresh water weeds is because of discharge untreated sewage or effluents in to water.
ALGAE
           Algae multiply at an accelerated pace, causing odours in water.
BACTERIA
           The faecal contamination of water can introduce a variety of pathogenic bacteria into waterways.
VIRUSES
           Viruses are introduced into natural waters through faeces. Although these organisms are present in water in much lower members than bacteria, yet they pose a considerable health hazard because they possess a greater resistance to disinfection.
PROTOZOA
            Faecal contamination of drinking water is the major sourse of transmission of pathogenic protozoa.
 TESTING
           The content was tested by an expert teacher in the subject. The way of expressing the topic, the language used, spelling mistakes, content errors, clarity of pictures was checked and suggestions were given. The testing was also done on how much the content was applicable and understandable to the readers.
IMPLEMENTATION
                  Finally the content was uploaded in a learning management system where the students can easily get access to the knowledge they want and they can get  a clear idea on the topic that they want to learn.
EVALUATION
                   The Feedback from the learners and instructors are considered for further evaluation. After checking the feedback, the content is re-designed for effective delivery of the topic.       

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