Some of the successful traditional purification methods (Biological purification Technologies or Green Technologies) being used by rural and tribal communities:
Nelli/Amla : Branches of Phyllanthus emblica (dumped in wells for purification of water and for removing salinity in water). Woods of Phyllanthus emblica are capable of reducing the hardness of water and the amount of magnesium and sulphate in drinking water. Our ancestors used the woods of this tree in all drinking water wells, ponds and tanks in villages invariably.
Tamarai Nelumbium or Nelumbo nuciferaintroduced in wells, ponds and in biowastes to cleanse all impurities in water and to remove bad odor. Our ancestors introduced the lotus in all wells and ponds in villages where drinking water is drawn.
Cardamom is used as a natural coagulant by sprinkling the powder on water surface.
Drumstick (Moringa oleifera) one of the common trees in Tamilnadu is a medicinal tree. Green leaves, barks, roots, flowers, seeds and the drumstick are invariably used by local people in Tamilnadu. In preliminary research, moringa seed powder is being assessed for its potential to make river water potable. Research showed that filtering with seed powder may diminish water pollution and bacterial count. The seeds can be used to purify turbid and muddy water. Dr Samja Alazharia, a German scientists proved the presence of an efficient coagulant in the seeds of Moringa oleifera. The seeds of drumstick can be used as an alternative to alum because aluminum sulphate is used as a conventional chemical coagulant to treat water in large scale. The seeds kernels contain water soluble proteins and when the powdered seed is added to water, they attract clay, silt and bacteria and toxic contents in the water. Researchers found out that the seeds can be used as an antimicrobial flocculent. The seed kernels of Moringa oleifera contain significant quantities of water-soluble proteins. When the crushed seeds are added to raw water, the proteins produce a positive charge which acts like a magnet attracting particles like clay, silt, bacteria, and other toxic particles. The proteins bind the particles by forming flocs which can be easily removed using filters. It is used for detoxification and as an antibiotic.
Thethankottai (Strychnos potatorum)is a wonderful seed found abundantly in the Western Ghats mountain ranges in Tamilnadu and still indigenous communities use the seeds as a natural coagulant to clean impure water. Traditional Medicinal Uses: According to Ayurveda, seeds are acrid, alexipharmic, lithotriptic and cure strangury, urinary discharges, head diseases etc. Roots cure Leucoderma whereas fruits are useful in eye diseases, thirst, poisoning and hallucinations. The fruits are emetic, diaphoretic alexiteric etc. According to Unani system of medicine, seeds are bitter, astringent to bowels, aphrodisiac, tonic, diuretic and good for liver, kidney complaints, gonorrhea, colic etc.
Cherankottai (Semecarpus anacardium) The deciduous tree is used for medicinal purpose. The seeds are powdered and a paste is made to be dissolved in water. We get a pure drinking water instantly. Tribal communities still practice the method.
Vettiver (Vetiveria zizanoides). This aromatic grass is grown on the banks of river and near ponds. Roots can be used to purify water and for a fragrance.
Tulsi (Ocimum sanctum): Leaves are dropped in drinking water for purification and for medication. In all Hindu temples, water mixed with Tulsi leaves are offered to devotees every day since the herbal plant is an excellent medicinal plant found all over India and is considered sacred.
Vilamichhamver (Andropogon muricatus) Flavoring water
A maxim from Sanskrit literature (2000 BC) states that the foul water can be treated by boiling and dipping seven times a piece of hot copper into it and then filtering the water.
Bio Filtersusing sand, mud and natural resources. (Bio-sand water purification methods can be used for large scale purifications of water.
Neem (Azadirachta indica) and Tulsi: Leaves are crushed and mixed in water and kept in sunlight for hours. The water is used for bathing sick patients, and people suffering from small pox.
(In ancient Sanskrit literature (1500 BC) Neem regarded as life saving and disease preventive plant. Leaf, bark, seed and all part of Neem tree contain useful substances that can be taken as tee, oil and prepared medicine remedy dust allergy, fever, skin diseases, rheumatism etc (Roemmming, 1999, Nature). Professor Heinz Rembold, of famous Max-Planck Institute of Biochemistry, Germany found any side effects of the use of Neem on human and soils do not contain any hazardous substance as a residue after being used as pesticides. Research conducted by, among others, United States Department of Agriculture (USDA) has shown that Azadirachtin A offers protection against more than 130 insects, while it is partly active against more than 70 other insects. Since the potential value Neem-based pesticides was recognised, commercial interests have been increased).
Banana Peels: Banana peels can be used to purify drinking water contaminated with toxic heavy metals such as copper and lead, according to a study.
Copper and Bronze vessels:Water is stored overnight and rural people still use the purified water in the morning. The copper/bronze vessels are coated before making use of the vessels.
Indian Bael (Aegle Marmelos) Used in temples to offer devotees a purified water mixed with the leaves of Indian Bael. The leaves are well known for their insecticidal activity.
Clove is also capable of removing total coliforms
Nannari roots can remove calcium in water and purifies water.
Gooseberryis capable of removing fluoride from water. The walls on the periphery of wells in villages were constructed with the help of gooseberry wood in the past.
Leaves of Ocimumsp have a capacity to remove total coliforms and E coli.
Barrikngtonia acutangula Ficus glomerata
Ficus glomerata (athi) : DOOMAR Trees: The tree species is found near wells, ponds, rivers and water sources. They are capable of purifying water. The tree not only purifies water but also enriches it with medicinal properties. The fruits have wonderful medicinal properties.
(Neer Marudhu) Terminalia arjuna: The tree species were also planted in and around water bodies to purify water.
(Hibisicus sabdariffa) (Pulichakeerai)
Grape fruit seed extract can purify water.
Seeds, trees and herbs used in traditional/biological water purification found in ancient literature in Tamilnadu:
Sources: Palm Leaf Manuscripts (Tamil)( Indigenous Documents), data available with the traditional medical practitioners, agrarian community, indigenous tribal community and ancient literature available in classical Tamil language.