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  1. Treatment of Sewage:
    Adequate sewage treatment must be carried out in sewage treatment plans before released any to water bodies. They are usually of 3 steps.
    1. Primary treatment: It involves removal of large objects and suspended un-dissolved solids.
    2. Secondary treatment: Proper aeration is supplied for the growth of decomposing micro- organisms to decompose organic compounds into harmless sulphates, water, COetc.
    3. Tertiary treatment: It involves removal of nitrate and phosphates. The treated water is then released.
  2. Treatment of Industrial effluents:
    Industrial effluents can be removed by filtration and selective absorption. It also involves neutralization of acids and alkalies and removal of heavy metals by chemical treatment.
  3. Control measures of pesticide pollution:
    Excessive use of pesticides and herbicides should be avoided. Biological control of pest may be encouraged.
  4. Control measures of oil pollution:
    Proper care must be given to cause minimum pollution during oil extraction. Skimmers, vacuum pump or absorbent materials should be used.
  5. Control measures of thermal pollution:
    The temperature of heated waste from thermal plants must be reduced. This can be done by dilution of air.
  6. Ozone treatment of drinking water:
    Treatment of polluted water with ozone can oxidize the pollutants, disinfect the water and improve its taste and odour.
  7. Biological control:
    Certain plants and micro-organisms can help in controlling water pollution eg. Water hyacinth or Eichhornia are useful in absorbing nitrogen, phosphorus, heavy metals and radio- active elements.
  8. Modification of Manufacturing Processes:
    To reduce the production of harmful byproducts.
  9. Recycling wastes:
    Industrial effluents sewage, agricultural wastes, thermal pollutants may be recycled to generate cheaper fuel, gas and electricity.
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