Filtration of Fluoridated Water

Transcription

1 Filtration of Fluoridated Water There are two effective methods of filtering fluoridated water: Reverse Osmosis (R/O) and Distillation. Both methods are effective, convenient and affordable. This paper has been written to help those people living in areas which are already fluoridated and who pay a fixed amount for their water charges. If you pay according to the amount of water you use, see the discussion at the end of this guidance. If you live in the Southampton and Manchester areas where fluoridation is threatened, read on, since the information in this web-page can help you to make informed decisions. Equipment which will not remove fluoride Fluoride cannot be removed by using a home water-softening system, sediment filters, long column carbon filters, a filter jug system (such as Brita) or by boiling the water. Equipment which will remove fluoride Fluoride is removed by (A) distillation units and by (B) reverse osmosis filtration units (ROFUs). Both processes give peace of mind because they not only remove fluoride but remove other hazardous elements, such as chlorine, silica, iron, lead and arsenic from tap water. Since all minerals - even the beneficial essential minerals - will be removed during filtration and distillation it is advisable to supplement with occasional glasses of bottled natural mineral water (NMW) unless your diet is otherwise rich in these essential minerals (magnesium, zinc, calcium, iron, etc). Note that NMW from the Pennines or Derbyshire regions are not recommended since they contain fluoride and/or uranium. 1 A. Distillation. Produces 4 litres of distilled water in 5-6 hours. The suppliers claim a 99.8% efficiency. Replacement filters would cost extra. Disadvantages: they take up space on a work surface, and you have to remember to fill them and switch them on. You also have to remember to order replacement filters. Advantages: they don t waste water so are suitable for people with water meters. The product water is great for use in steam irons. 1 Joy Warren, Rev. Sept

2 Suppliers: J D Harris Domestic Distillation Unit 151 inc. VAT + 8 pp Replacement 5 per pack of 6 - should be changed monthly. Plastic bottles: one is supplied with the unit. Additional 12 + pp Filter Housing for plastic 4 each Glass 30 each + pp - optional for presentation purposes. Filter Housing for glass 4 each. Cleaner 8 + pp. Sort Life Out Holistic Health Shop, UK oscsid=6111b2c2484c9e d001a3f2cd1. Replacement filters are extra. Domestic Distillation Unit AQWSAFE - Countertop Water Distiller inc VAT Joy Warren, Rev. Sept

3 B. Reverse Osmosis (R/O) produces enough purified drinking water for everyday use and will remove up to 97% of the fluoride. Disadvantages: they waste water (2.4 litres for every litre of product water) so are not completely suitable for families with a water meter. You need to check the quality of the product water with a total dissolved solids (t.d.s) gauge for peace of mind. You may need to employ a plumber if you can t do D.I.Y. You need to remember to order filters and membranes every 6 months. Advantages tucked away out of sight and you don t need to remember to fill them and switch them on. The product water is for use in steam irons. Suppliers: Air and Water Centre SFE/productdetails.htm The current model (which I have installed) is called Domestic RO (Reverse Osmosis) Water Purifier inc. VAT and includes initial filters and membrane. Delivery is free if it s ordered via the Internet. Change filters every 6 months ( 22 for the pair). Change the membrane every year ( 46.60). ROFU Freshly Squeezed Water This company sells or leases ROFUs. According to the web site, their engineers visit the customers to replace the filters and membranes. This is ideal for those customers who are unable, due to frailty, to change the filters themselves. ROFU There are other suppliers Google Reverse Osmosis Filtration Units Retailers UK. Joy Warren, Rev. Sept

4 The filtered water should be used for making hot drinks and soups, (although tea is not recommended since it contains natural fluoride), for making up baby formula, for diluting soft drinks, for cooking vegetables (especially if boiled), for adding to anything that you cook which requires water in the recipe. Take a bottle of filtered water to work so that your coffee can also be fluoride-free. This will probably mean that you need to provide your own kettle which should be labeled to prevent others filling it with tap water. Since I do not have a distillation unit, the rest of this paper talks about ROFUs although some of the information is applicable to both distillation and ROFUs. ROFUs are gradually reducing in price. They re quiet, efficient and unobtrusive since the majority of the equipment (apart from the slim-line swivel tap) is installed underneath the kitchen sink. The costs and procedures below apply to a ROFU supplied by the Air and Water Centre but there are other systems on the market. The ROFU is quite easy to install but for those who are not good at DIY, the cost of a plumber must be added to the initial outlay. The unit needs to be attached to the inside of the kitchen unit carcass and a hole bored through the sink top surround for the swivel tap. The cold water feed is intercepted (but not diverted) so that when the ROFU tap is turned on, water flows from the ROFU s reservoir bottle, and water from the cold water system automatically enters the filtration part of the unit. While the water is filtering, rejected water containing fluoride etc. is expelled from the system to the outside drain. It is essential that the system rejects water to the outside drain since this water contains contaminants, including fluoride, which would otherwise clog up the filter. (See Appendix for calculation of amount of water which is wasted by the unit.) Air and Water recommends that two replacement filters should be fitted ( 25 inc. VAT + carriage) during month 6 and a membrane and two further filters fitted ( 80 inc.+ VAT) during month 12. This cycle is repeated every year. Fitting the filters and membrane does not need a plumber and is quite easy. However, depending on water hardness, etc. such frequent replacements may not be necessary. A total dissolved solids (t.d.s) gauge will tell you when the filters and membranes need changing. If the t.d.s of the ROFU water is less than 40 t.d.s, then changing the filters and membrane may not be necessary. The t.d.s of a unit when new filters and membrane have been fitted is approx. 14 t.d.s. A t.d.s gauge costing approx. 25 can be obtained from: Joy Warren, Rev. Sept

5 The disadvantages of R/O filtration units (ROFU) Yes there is a disadvantage. If you are an environmentalist with a strong conscience, ROFUs may give you a few sleepless nights. This is because they waste water. Approximately 2.4 litres of water containing the fluoride and other chemicals and minerals are wasted for every 1 litre of purified water produced (see appendix). The waste water exits the system under low pressure so it is difficult to harvest it for washing the car. It may also not be a good idea to use the rejected water for watering vegetables and fruit trees/bushes, because plants uptake fluoride. Although the volume of water wasted is not very high, for families who pay for the volume of water which they use (instead of as a fixed annual charge), water charges will be higher. But this is not significant since it is only the water passing through the kitchen tap which is wasted, and not water used throughout the household. On the other hand, some people have whole house ROFUs installed and since these waste a lot of water, being on a water meter is inappropriate in their case. Those families with water meters would probably find that an electric distillation unit is a better choice. In this case, and in order to economise on electricity, it is advisable to ask the electricity supplier to install a meter which gives you an Economy 7 tariff during the night. The distillation unit can be switched on after midnight. Since they switch off automatically, filtered water will be ready for drinking the next morning. If all those who are fluoridated were to install ROFUs, water companies would not be able to supply the additional water needed. But it is unlikely that an entire population of fluoridated people will go down this path. At the time of writing, discarded filters and membranes are not recyclable. Consumers on water meters Once you are on a water meter, that s it there s no turning back! So seriously consider the option of allowing the water company to install a water meter: it may prejudice a future house sale, especially if the house is a large family house which would otherwise be attractive to families with children. It is really important not to give way to pressure by water companies to get you to fit a water meter if fluoridation is threatened or if you are already fluoridated, since this reduces your bargaining power. Those who already have a water meter will find themselves spending more money than previously if they install a ROFU. However, for those with water meters, there are ways of reducing the amount of water drawn off. If your family finds it difficult to economise on water usage, try turning saving water into a game which will challenge the whole family. Joy Warren, Rev. Sept

6 With-holding money from your water charges If you re fluoridated or if fluoridation is imminent and if you ve paid for Reverse Osmosis or distillation equipment, if you re regularly buying bottled water or if you intend buying filtration equipment because of the fluoride content of your water, it may occur to you that you should not be paying the whole amount of your monthly water charges. Before taking any drastic steps, you re welcome to contact for advice. Joy Warren, Rev. Sept

7 Appendix: Amount of water wasted during the operation of a ROFU To calculate how much waste water an RO unit creates, you need to work out a product to waste ratio, which is done as described below. You need to calculate the waste water flow rate into gallons per day, whilst calculating how many gallons per day your system is producing. To calculate the amount wasted follow these steps: 1. Close off the saddle valve and open the tap until all water within the system is spent. Ensure the reservoir tank is empty. 2. Remove the waste pipe from the drain trap and lead into a receptacle of a known volume ie a bucket or bottle that can hold a set amount of water. A measuring jug will do, but this would mean that a close eye needs to be kept on the experiment. 3. When the waste pipe is in its receptacle, and the tank is definitely empty, open the saddle valve and sit back and wait for a while. 4. When your waste pipe has filled the container it is leading to or an hour or other exact amount of time has passed, close off the saddle valve. 5. Measure how much water has passed through the waste pipe, and reattach the pipe to the drain clamp and secure. This volume of water is now known as the reject GPD volume. 6. You then need to open the tap to draw water from the system, and measure how much water comes out of it. This volume is now known as the product GPD volume. This being what volumes would pass through the system in a 24 hour period should it be able to operate as such. 7. Then convert all measurements of water into gallons per day. 8. Then divide the gpd reject volume by the gpd product volume and the answer becomes a ratio. Water engineers training booklets list examples of 456 reject gpd and 193 product gpd and in this case this becomes a ratio of 2.4 to 1 (approx.), i.e. a ratio of 2.4 litres of waste water for every 1 litre of product water. However, the performance of each RO unit will vary according to feed pressure and water temperature. Furthermore, this figure will be affected by the incoming TDS levels as well as the age of the system and membrane etc. So the above is a rough guide to work out the rejection rate, and because of the variants at each site, these figures could vary over the course of a day and even from hour to hour. Another thing to take into account is the pressure within the vessel, and because this can decrease daily, this can also affect the ratio. Some people divert their waste water to their garden water butts, and some people store this water and then recycle it through use of UV sterilisation and further filtration, but this can cause technical difficulties and further costs. Before considering whether or not to water vegetable and fruit with the rejected water, please be aware that plants do uptake fluoride. Joy Warren, Rev. Sept