Biological Water Purification
Palatable clean drinking water is becoming scarce in the present-day world. Water table is decreasing day by day and the river water, even after treatment on a community basis, contains many contaminants. The levels of many pollutants like selenium, chromium, cadmium and arsenic have increased in water to dangerous levels. A long-term consumption of these pollutants may damage kidneys, liver and our nervous system. These also could lead to deadly diseases like cancer.
Of late we have different kinds of purifiers available in the market which are available at a very wide range of prices. These purifiers are associated with their own disadvantages, like, some of them consume energy in the form of electricity, some are made up of non biodegradable materials, some are very costly etc.
Some plants have been proved to be excellent for water purification. Plants like the Prickly pear cactus (Opuntia ficus-indica) or Moringa (Moringa oleifera) have the capacity to purify water. The Prickly pear cactus was used for water purification by Mexican communities long back during the 19th-century. As man marched ahead on the roads of civilization these facts were forgotten by him. He started his hunt for high technology methods of water purification.
A group of scientists from the University of South Florida in Tampa rediscovered the natural method of water purification using prickly pear cactus in 2010.
Norma Alcantar and her colleagues have used sophisticated microscopic analysis to prove the effects of cactus on dirty water.
Mucilage is glue like gummy substance secreted by plants which acts as a flocculant in water. It can precipitate substances into flakes and hence can remove substances like heavy metals (selenium, chromium, cadmium and arsenic) and even bacteria from water . This thick gum is used by the plant to store water. When this magical mucilage is added to water, it sticks to the sediment particles and bacteria, which later drops down to the bottom of the water samples. According to Alcantar 98% of added bacteria, Bacillus cereus, was removed from the water sample. However, experiments are yet to be carried in natural water.
Many rural and underdeveloped countries have no access to the conventional water purification devices due to which people dwelling there are forced to drink contaminated water. Cactus plant can be grown at many places at a lower cost. This plant can serve as a natural and renewable material for water filtration and at the same time save the lives of many people. It is a cost-effective alternative and also saves a lot of energy.
1. Buttice AL, Alcantar NA et al. Removal of sediment and bacteria from water using green chemistry. Environ Sci Technol. 2010 May 1;44(9):3514-9.
Anna Purna is a freelancer writing articles about her favourite interest, Health and Nutrition. She also works on home-based jobs. Before this, she has worked fulltime for about 2 and a half years in the annotation of Biological databases in various organizations. She holds a Post Graduate Degree in Biochemistry and a PG Diploma in Bio-informatics. For more information, please visit her website on http://purnasrinivas.webs.com