PISA BASED QUESTIONS

                       PISA BASED QUESTIONS

                                       Topic: Water Hyacinth

                                

                  Eichhornia, water hyacinth, is a genus of aquatic flowering plants the family Pontederiaceae. The genus is native to South America. E. crassipes has become widely naturalized in tropical and subtropical regions and is a significant invasive species. It was named in honour of Friedrich Eichhorn, an early-19th-century Prussian minister of education. Since the water hyacinths are so prolific, harvesting them for industrial use serves also as a means of environmental control. In north-east India, the Philippines, Thailand and Vietnam the water hyacinth's stems are used as a braiding material and a source of fibers. Strings of dried fibers are woven or interlinked together to form a braid or cord used for making bags, footwear, wreaths, hats, vases, Christmas lanterns, and more decorative materials. Dried stems are used for baskets and furniture. Water hyacinth fibers are used as a raw material for paper. Since the plant has abundant nitrogen content, it can be used as a substrate for biogas production and the sludge obtained from the biogas. However, due to easy accumulation of toxins, the plant is prone to get contaminated when used as feed.

        Water hyacinth removes arsenic from arsenic contaminated drinking water. It may be a useful tool in removing arsenic from tube well water in Bangladesh. Water hyacinth is also observed to enhance nitrification in wastewater treatment cells of living technology. Their root zones are superb micro-sites for bacterial communities. Water hyacinth is a common fodder plant in the third world especially Africa though excessive use can be toxic. It is high in protein (nitrogen) and trace minerals and the goat feces are a good source of fertilizer as well. People consider water hyacinth is a most nuisance plant and cause death of lake.

Answer the following questions:

a)    What do you mean by Eutrophication?

b)   Define Hypertrophy and Eutrophy.

c)   For what purpose dried stems are used and How biogas can be produced by the use of water hyacinth?

d)   How Eichhornia is useful tool for removing impurities and for treatment of wastewater ?

e)   Why water hyacinth is called most nuisance plant ?

f)     Water hyacinth is abundant in:

1)   Nitrogen           2) Protein           3) 1 & 2 both         4) None of them

g)   Which chemical element helps Water Hyacinth in removing bacteria from Contaminated water ?

1)   Nitrogen            2)Dried fibres     3) Arsenic             4) All of them

By: Shubham Gupta :D