The objective of the Green Bridge Technology in water treatment is / are __:
1. To Reduce the turbidity of the flowing water
2. Absorption of heavy metals from water
3. Decrease the Chemical Oxygen Demand
4. Increase the aesthetic value of water resource
Choose the correct option from the codes given below:
[A]Only 1 & 2
[B]Only 2, 3 & 4
[C]Only 3 & 4
[D]1, 2, 3 & 4

1, 2, 3 & 4
Green Bridge Technology The high BOD (biochemical oxygen demand) values, COD (chemical oxygen demand) and alkalinity in Ahar, in turn, badly affected the ecology of Udaisagar Lake. The Green Bridge technology, however, proved a life saving measure. Green Bridge technology uses filtration power of biologically originated cellulosic / fibrous material in combination with sand and gravels and root systems of green plants. It is an innovative approach to minimize the cost of pollution treatment wherein the cellulosic / fibrous materials like coconut coir or dried water hyacinth or aquatic grasses are compacted and woven to form a bridge / porous wall like structure strengthened by stones and sand with various consortia of microorganisms specially seeded there for that purpose. All the floatable and suspended solids are trapped in this biological bridge and the turbidity of flowing water is reduced substantially. The green plants growing there help in absorption of soluble substances including heavy metals. It uses filtration and purification power of biologically originated cellulosic/fibrous materials in combination with root system of plants, sand and gravel. The fibrous materials like coconut coir or dried water hyacinth or aquatic grasses are woven to form a porous wall-like structure or bridge. It is further strengthened with sand and stones. Thus turbidity of flowing water is substantially reduced. Planting of shrubs and grass helps in absorption of soluble substances, including heavy metals and helps in regeneration of aquatic life.