Low cost household level solution to remove fluoride from drinking water
Article Low cost household level solution to remove fluoride from dr...
Dear Zinabu,
The water treatment methods that can remove fluoride from drinking water include reverse osmosis, distillation, anion exchangers and activated alumina adsorption or other filter materials.
Calcium salts such as Ca (OH)2; CaCl2 and CaSO4 are most used to precipitate the fluoride ions in the form of an insoluble product CaF2 (fluorspar).
On an industrial scale, usually it is recommended the use of chemical precipitation with lime; coagulation-flocculation with aluminum sulfate and membrane processes. All these processes are simple, but they have each of them advantages and disadvantages.
With my best regards
Prof. Bachir ACHOUR
Methods of water purification from fluorine compounds can conditionally be devided into four groups:
1. Water filtration through the inorganic bulk which is chemically interacting with fluorine anion. These are fine granulated aluminum oxide, magnesium oxide, and also calcium phosphate et al.
2. The special ion-exchangers possessing a certain selectivity in sorption of fluoride anion. These are magnesium-ferrouse slags of nonferrous metallurgy, the modified zeolites, and also the annealed bone flour.
3.Dosed addition in water Al-Si coagullants and flocculants which are filtrated after extraction of fluoride.
4. Reverse osmosis and an electrocoagulation methods.
Dear Ali A R Aldallal,
I thank you very much for your answer but, still the article is not clear to me. Please look the following copy sentences from the article and my questions are listed here based on article in general. I have three questions regarding to this article……
The Table shows that fluoride content has been efficiently decreased from 2.35mg/l to 0.33mg/l with 1.0g of Tulsi leaves and 30 min as time of operation whereas 0.5g of Tulsi leaves required comparatively greater time i.e. 45min. to decrease 2.35mg/l of fluoride to 0.48mg/l. Similar experiment was also performed with 1.5g of tulsi leaves but no significant decrease in fluoride content was found.
1. Why no significance decrease in fluoride content was found in 1.5g? if 1.0g of Tulsi leaves better fluoride removal than 0.5g of Tulsi leaves in the same time (Because efficiently decreased from 2.35mg/l to 0.33mg/l with 1.0g of Tulsi leaves and 30 min as time of operation whereas 0.5g of Tulsi leaves required comparatively greater time i.e. 45min. to decrease 2.35mg/l of fluoride to 0.48mg/l.)
2. In the paper if it was aimed to find a suitable low cost environmental friendly method for removal of fluoride in the drinking water that could be used by common man, easy to understand and can be adopted in rural as well as urban background throughout the year. How the rural community easily accesses the chemicals used for the titration because the use of titration tells in the discution part? (my be if there is any miss understanding pls tell me)
3. If chemicals are used for this study how can they improve the possible chemical residuals to avoid in household level (in the rural community)?
Refer to the following paper. Column studies and upscaling processes are underway
Article Kinetics and equilibrium studies for removal of fluoride fro...
Dear Zinabu.
Treatments to remove fluorides from drinking water to drink know the following:
-Employee granular activated carbon filters bone (bone char), which can be regenerated using saturated solutions of calcium or magnesium chloride.
-Inverse osmosis
-Desmineralización Using ion exchange resins.
-The Distillation
-Adsorción Using natural zeolites.
Water treatments I have used from experience to remove fluoride from drinking water to drink are:
Filters with granular bone char, which allows use water with salt content as supply comes from.
Reverse osmosis, only water quality is not suitable for human consumption by low salt concentration, as a balance of salts for human consumption is required, and must regulate the amount of dissolved CO2 and pH.
Demineralization can be used to remove fluoride, but it is convenient to add the minimum required sales pra human consumption.
The use of aluminum salts such as alum are used to flocculate in the cal system was suspended by the presence of aluminum in the drinking water.
Sincerely
IQ. De los Santos Jorge Luis Rovira.
From my practical and research experience...adsorption where an adsorption is packed in a column and the fluoride rich water pushed through, proven adsorbents that can be used include born char, activated alumina, other upcoming adsorbents include smectite rich clay soils raw or modified with high charge metal cations
hydroxyapatite have also be utilized in fluoride removal from water
Dear Zinabu,
It has been recently published by a research group in Australia an interesting study about removing fluoride from brackish waters by capacitive deionization (CDI). CDI is a low-pressure emerging water technology specially recommended for brackish water desalination applications. Please take a look at the attached file.
Hope this can help you.
Julio J. Lado
Try Distillation, Reverse Osmosis or Activated Carbon
Distillation will be cheaper in Laboratory Studies
A brief account on fluoride removal based on some literatures:
Various techniques and materials were explored throughout the world for defluoridation of groundwater.
The techniques can be broadly classified into four categories:
Adsorption technique, Ion-exchange technique, Precipitation technique, and Other techniques, which include electro chemical defluoridation and reverse osmosis.
Materials used as defluoridation agents in these four techniques are:
Adsorption: Carbon materials, Activated Alumina, Magnesia, Tricalcium phosphate, Calcite, Hydroxy apatite, Wood, Lignite, Activated char coal, Fish bone char, Processed bone, Nut shells, Avaram bark, Paddy husk, Coffee husk, Tea waste, Jute waste, Coir pitch, Fly ash, Bauxite, Serpentine
Ion-exchange : a) Anion exchange resins- NCL poly anion resin, Tulsion A27, Lewatit-MIH-59, Amberlite IRA-400, Deacedodite FF-IP, Waso resin-14, Polystyrene. b) Cation exchange resins: Defluoron-1, Defluoron-2, Carbion.
Precipitation: Lime, Alum, Lime & Alum (Nalgonda technique), Alum flock blanket method, Poly Aluminium Chloride (PAC), Poly Aluminium Hydroxy Sulphate (PAHS), Brushite.
Others: Electrochemical method (Aluminium electrode), Electro dialysis, Electrolysis, Reverse Osmosis.
The basic characteristics of an ideal defluoridation process are the following:
o Cost-effective
o Independent of input fluoride concentration, alkalinity, pH, temperature
o Easy to handle/operate by rural population - the major sufferer
o Not affect the taste of water
o Not add other undesirable substances (eg. Aluminum) to treated water
Defluoridation can be introduced at two organizational levels; as household defluoridation for consumption of single household members, and as community defluoridation for the public use in a village.
The domestic defluoridation processes available today are not totally successful. Nalgonda and Krass processes for defluoridation have some merits.
This is for your kind information that at CSIR-CMERI, Durgapur, India we are working on the defluoridation of groundwater. We have already developed a process (adsorption technique) for defluoridation and filed a patent in April, 2016.
We have also designed and developed a Domestic Defluoridation Unit for reducing the fluoride content in water. In addition to the removal of fluoride, the Unit also arrests other common contaminants found in the groundwater. This unit is suitable for domestic purposes in the fluoride affected rural areas.
Specifications
· No electricity
· No chlorine, no bromine, no iodine used
· No running water required
· Flow rate: 5 L / hour
· Adsorbent life (proposed): ~2000 L
· Storage capacity: 18 L
Techno- Socio-Economic analysis
· Adsorbent replacement cost: Rs. 600/-
· Maintenance cost/month: 150/- (~500 L p.m.)
· The commercial filtration unit addressing the defluoridation of water for domestic purposes is not available in the market. The developed filtration unit could be promising for commercialization.
· Unit can be deployed in the fluoride rich regions of India through Govt./ NGO support
We are conducting a research project entitled “Geochemical modelling of fluoride contamination in groundwater of the Birbhum District, West Bengal, India” which primarily aims to explore the origin and enrichment mechanism of fluoride in groundwater. This study has encouraged us to undertake the work on defluoridation of groundwater.
Depending on the scale that you want to carry out defluoridation, the technique employed will differ, but studies have shown that sub-urban and rural communities in most sub-saharan and Asian countries that dont have access to clean municipal rely heavily on groundwater for their domestic use and often has high concentration of fluoride beyond recommended limits by WHO, these communities require to defluoridate their water at low cost and with very simple technology to operate. Adsorption has been observed by many researchers to be the best option but the challenge is availability of low cost, high capacity adsorbents based on locally available and abundant materials. My research group at University of Venda South Africa is experimenting with smectite clay rich soils found locally in Limpopo province either in their raw form or modified with metal oxides in an attempt to develop high capacity fluoride adsorbents.
Dr. Gitari, I appreciate your initiative - experiment to develop fluoride adsorbents with smectite rich soil. Next to arsenic, fluoride contamination in groundwater is a great problem for the rural parts in the world where groundwater is the prime source of drinking water. So, a cost effective technology suitable for rural people (domestic/community purposes) is highly required.
thank you Asif, we have gained alot of experience working with smectite rich clays soils, modifying them with metal oxides and testing their ability for fluoride removal. we also venturing into testing the same materials for arsenic removal in a our new project.
could i also ask you how i could get information on your patent registered in India for the fluoride removal that you registered in 2016
Dr. Gitari, I may kindly be excused for delay in reply. Today only I have seen your question.
We have filed the application for patent entitled " Spinel magnesium ferrite impregnated activated alumina adsorbent for effective defluoridation of water and a process for the preparation thereof" in India on 28 April, 2016.
Now, it is under process. Generally, the patent office takes long time to grant a patent. It can be seen when it will be uploaded in the website for public notice. However, you can see the 'abstract of the work ' in my profile.
With regards - Asit
Kindly advise on the cheapest and and readily accessible method of fluoride removal from borehole water which has 17mg/L of fluoride in the borehole water which is for drinking.
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