Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Eco friendly ideas & concepts
User avatar
SAMPATH S
Posts: 132
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

Sediment Filter:
Virtually in every water purifier, sediment filter is the first stage. This generally a Polypropylene filter of about 5 microns. Most of the un-dissolved particles are removed at this stage.

RO (Reverse Osmosis) membrane:
The heart of RO purifier is its RO membrane. This RO membrane is made up of a Triple Layer Composite (TLC) filter membrane. The filtration efficiency of this membrane is finer than 0.001 micron. This membrane is capable of removing even the dissolved impurities in water. Thus salts, etc., in hard water are removed and the output water becomes soft water. In this process, the input water is filtered under pressure generated by a pump fixed to the unit. It also pumps out the water (waste water) that this not filtered through the membrane.

UV (Ultra-violet) Lamp:
This is the heart of a UV Purifier. Here, the water to be purified is made to pass around a UV Lamp. The UV rays alter the DNA of bacteria and viruses, decapacitate them and make them incapable of multiplication.

UF (Ultra fiber) filter:
This stage involves passing the water through fine fibers (Ultra fiber) with holes of 0.01 micron and less. Ultra fiber filter is capable of filtering out bacteria and viruses.

Activated carbon:
Activated Carbon filter is used to remove CTO (Chlorine, Taste & Odor) by the process of adsorption. There are broadly two types of Activated Carbon filters, one Carbon Granules and the other Carbon Block. In granules, the water is made to pass through small granules of activated carbon. In Carbon Block filters, fine carbon powder is mixed with a paste and a block is made. Carbon block filters generally have fine holes of about 10 microns and hence is preferable over carbon granules filters, but at the same time block filters can get clogged earlier.
User avatar
SAMPATH S
Posts: 132
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

Commercially available water purifiers can be broadly classified into two categories:

1. RO Purifiers, mainly for water with high TDS
2. UV Purifiers, mainly for water with low TDS.

Besides these, there are also UF Purifiers, but it is used by very few.

RO Purifiers are costly, probably in the range of Rs.5000 to Rs.20,000.
As seen above, the RO Membrane has holes less than 0.001 micron and is able to remove even the dissolved solids/salts (removing TDS-Totally dissolved solids). When this is the case, all bacteria and virus are also removed at this stage itself, besides the colour and smell, if any (as these cannot pass through the minute holes). When this is the case, post RO membrane, activated carbon filter, UF Filter, etc., are added. If the RO membrane functions properly, there should be no necessity for subsequent stages. Thus the annual maintenance charges are jacked up artificially for unwanted stages, besides resulting in avoidable waste generation.

UV Purifiers generally have an Activated Carbon filter stage, which is to remove CTO (chlorine, taste and odour). Post this stage, the Ultra Violet lamp stage is used to deactivate the bacteria and virus. All of us who use this kind of purifiers would have observed that the UV Lamp is never tested for working nor is replaced over the years. UV lamp is enclosed in an opaque metal case, as exposure to UV lamp even for a moment can cause loss of vision and skin cancer. UV lamps use certain pigments for generating UV rays, which deteriorate in quality over a period of about a year or two. But there is no way to check this nor do the service personnel bother about it. The standard reply is UV lamp need not be replaced forever. What if the UV lamp got fused? Hence whether the UV lamp works or even if it works, whether it works effectively, there is no way to ascertain it. But maintenance is carried out regularly with hefty charges.

Coming to UF purifiers, they use Ultra Fibers which have holes less than 0.01 microns, which do not allow bacteria and virus to pass through. Many of the UF filters also have activated carbon filters. The UF filters (along with carbon filters) are generally replaced once every 6 months.

Most of the urban households generally use piped water supply (mostly obtained from river or lake), which is chlorinated to remove bacteria and viruses to make it potable.

However, urban households to employ some kind of a purifier, mostly UV purifiers (since TDS is generally less than 200) and the water is potable.

In case of rainwater, the TDS is negligible. The only possibility is the presence bacteria and viruses if any. But because of the Positive ORP (Oxidation Reduction Potential) property of rainwater, which has the characteristic of inhibiting the growth of bacteria and decay of organic matter, if any, the rainwater by itself (if it had been collected with precautions) remains potable without the need for any treatment or chlorination. If precautions are observed for proper storage of rainwater, it will remain in the same pristine condition over several months/years.

As already mentioned, if rainwater is collected with care using EFFECTIVE RWH Filters, it will not have any colour or smell and even bacterial contamination.

I am presently using a self assembled purifier for my rainwater for drinking and cooking purposes. It consists of a sediment filter followed by Activated Carbon Block filter and finally a UF Filter. Each of these stages is enclosed in a transparent housing (10 inch container), which allows a clear view of the condition of water as it passes through various stages.

When the sediment filter acquires some sediment, the filter can be backwashed to clean it. If necessary, the filter cartridge itself can be removed, cleaned and put back. Further need be, the filter cartridge itself can be replaced, and spun PP filters can cost as low as Rs.40 to 50.

The Activated Carbon Block filter stage itself is for precaution only, as rainwater has no chlorine, taste or odour. Hence the carbon block can be used over several months/years. Even the replacement cost of this filter is about Rs.150 to 200 only.

The last stage is UF Filter. Here also, the UF can be removed from the housing and cleaned periodically, depending upon the need. I presently clean it once a month. The Ultra fiber itself costs about Rs.900 presently and in my opinion it can carry on for years, subject to proper maintenance.

UF Filter, together with its transparent housing is available for about Rs.1500.

The transparent 10 inch housing costs about Rs.350.

Thus every stage of my filter can be self serviced, saving the cost of the technician, no need to be dependent on any one, besides negligible maintenance cost. Added to this is the satisfaction of pure drinking water on which we can keep a constant watch.

In case of rainwater, I strongly advocate using an Alkalizing cartridge at the last stage of the purifier, to alkalize the water to a pH level of about 8.5 to 9 (for drinking purposes), which can be periodically confirmed using the liquid (Phenolphthalein) available for this purpose or using a litmus paper. Alkalization also turns the ORP (oxidation reduction potential) from positive to negative, which is necessary for drinking purposes.

Link for Alkaline cartridge, along with ORP tester and PH tester (for information only):
https://www.amazon.in/Shapure-Alkaline-Cartridge-Purifiers-Standard/dp/B08H1724FS/ref=sr_1_5?keywords=alkaline+cartridge&qid=1637820461&qsid=258-6118794-4032066&sr=8-5&sres=B07HKP3LL5%2CB075SSHVQK%2CB08H1724FS%2CB074RDT84G%2CB09F6T2GGG%2CB0848JY6B9%2CB07XBKJF7F%2CB092R5RLWL%2CB08H154337%2CB09GF9JD9R%2CB08JM59939%2CB097C1JJG5%2CB08FNPMZ2Z%2CB09M3ZGJGP%2CB079F6ZSV5%2CB093TGFYFV

Pictures of 10 inch transparent housing, PP sediment filter cartridge, carbon block cartridge, 10 inch transparent filter housing, Ultra Fiber filter membrane and my present water purifier set up would be posted shortly.
User avatar
SAMPATH S
Posts: 132
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

Picture of 10 inch Transparent housing for sediment cartridge and carbon block:

Transparent housing for filter cartridge 10 inch.jpg
Transparent housing for filter cartridge 10 inch.jpg (9.9 KiB) Viewed 9683 times
Picture of Sediment filter cartridge:

Sediment filter cartridge.jpg
Sediment filter cartridge.jpg (6.77 KiB) Viewed 9683 times
Picture of 10 inch Carbon Block Filter cartridge:

Carbon block filter.jpg
Carbon block filter.jpg (12.14 KiB) Viewed 9683 times
User avatar
SAMPATH S
Posts: 132
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

Picture of Ultra Fiber (UF) Housing:

UF Fiber Housing.jpg
Picture of Ultra Fiber (UF) Filter cartridge:

UF Membrane.jpg
UF Membrane.jpg (5.24 KiB) Viewed 9681 times
Picture of my Ultra Fiber Water Purifier (non-electric):

My rainwater Purifier set up.jpg
My rainwater Purifier set up.jpg (161.03 KiB) Viewed 9681 times
Stages from left to right: Sediment Filter; Carbon Block Filter; Ultra Fiber (UF) Filter.
Final stage at the bottom is the Alkalizer cartridge.
User avatar
SAMPATH S
Posts: 132
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

The last stage is UF Filter. Here also, the UF can be removed from the housing and cleaned periodically, depending upon the need. I presently clean it once a month.
In addition to periodic cleaning of the UF filter membrane, it can also be chlorinated further, may be once in 6 months, by the use of good quality bleaching powder.
User avatar
SAMPATH S
Posts: 132
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

Using Grey water for watering plants:

Even though at present water is not scarce in Bengaluru, the difficulty is felt more by residents who do not have a BWSSB water connection or have insufficient water in borewell, and generally in summer by many.

Large number independent houses have plants / garden in their premises. After rainy season, it is necessary to water them to keep them growing.

Waste water generated from bathwater, kitchen, washing machine, wash basin and the like is called grey water. Due to the use of large quantity of chemicals in washing powder, shampoo, cleaning agents for vessels, etc., the grey water generated is harmful to the plants and also the environment. The use of plant based organic solutions to substitute the chemical laden cleaning/washing agents could turn the grey water to environment friendly and can be used to water the plants.

By the use of citric fruit peels and discarded citric fruits, it is easy to make bio-enzyme at home, which is an organic, non-toxic, environment friendly cleaning agent and by the use of soapnut, which either independently or together with bio-enzyme makes a good organic washing/cleaning agent, the grey water can be made not only plant friendly, but also become a plant nutrient.

Moreover, discarded citric peels are a strict no-no in wormi-compost and also in bio gas plants. Large quantity of citric peels is also not welcome in compost bins. The leachate generated from decaying citric fruits and peels can harm the soil fertility and even contaminate ground water. Hence converting this citric waste into bio enzyme (it is an easy process) is helpful from all points of view.

Directing the grey water to plants (without storing the grey water) is much easier for houses located above the ground floor. It is necessary to have separate waste pipe for grey water and closet (toilet). A valve can be installed to stop the grey water from flowing to the sewage and divert it to plants by installing a flexible pipe to route the water.

I am following this method and am able to save precious rain water for my regular domestic use. The use of bio-enzyme also helps me to save a lot on purchase of cleaning agents and also help avoid the generation of plastic waste (containers / packaging).

For the last many years I am composting wet waste and for the last nearly 4 years also composting large quantity of dry leaves and garden waste in addition to wet waste to generate large quantity of compost to sustain my garden.
User avatar
SAMPATH S
Posts: 132
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

FIRST RAIN SEPERATOR

First rain separation, also called first flush, is an important part of rooftop rainwater harvesting for the purpose of storage and use.

Normally, the rainwater carrying pipe from the terrace has a valve near to the ground level to allow the first rain to flow into the groundwater recharge pit or to the storm water drain. After allowing the initial rainwater with dirt and impurities to flow out for a few minutes, the valve is closed to allow the rainwater to the filter unit. A simple T junction a little above the valve would serve as a diverter to the filter.

In this arrangement there is a possibility of some initial rainwater entering the T junction and thus to the filter unit. To avoid this possibility, a slight improvement in the piping is made. At the T junction, two elbows are used to raise the height of the outlet pipe to the filter.
First rain seperator valve.jpg
Piping to Filtration unit.jpg
In this picture of my piping, some additional outlets are seen. I have made certain arrangements, which are specific to meet my requirements. Just for information, the pipes in my installation are not actually pasted, but are just assembled (push fit) so that they can be dismantled without any damage and modifications may be effected as and when felt necessary. I have been continuously making experimentation to find the best option and hence this arrangement. I do not find much of any leakage due to the non-pasting of the pipes and if at all any, it has been very insignificant.

In my arrangement, above the first separator valve, a pipe branches out which leads to a tank to store unfiltered water, which is mainly used to water the plants and for other non-domestic usage. Here, the water which is otherwise flushed out through the first rain separator, is stored. On closing the valve leading to this storage, the water rises up the pipe.

Another pipe branches out just above, which leads to a drip pipe around the house for watering the plants and also for absorption by soil to recharge ground water. This is used to drain some excess water when all the storages are full. When this outlet valve is closed, water rises and moves to the filtration unit.
User avatar
SAMPATH S
Posts: 132
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

WORLD WATER DAY is observed on 22nd March every year.

In tune with my efforts to promote rooftop rainwater harvesting for storage and direct use, I propose to conduct a demo of my setup at my residence, along with practical info on making and installation of the DIY Effective RWH Filters.

To enable enthusiasts to attend the session, it is proposed to be held on Sunday the 20th March 2022.

Since there is a limitation on the capacity, those interested may send a private message or email me at sampaths144@gmail.com. On confirmation, the Google location would be sent.

For such of the enthusiasts who require help in cutting the buckets, the same is proposed for Sunday the 27th March 2022. This also needs prior confirmation. For details regarding buckets, etc.; to be brought, the same would be informed on request.

Both the demo session and the help in cutting buckets would be completely FREE.
User avatar
SAMPATH S
Posts: 132
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

This has reference to the pre-production TV shooting held at my residence on 13th September 2021 by the Team of EPIC TV (from Mumbai) featuring me and my Innovative Low-cost, High Efficiency, Do-it-yourself Effective Rainwater Harvesting Filter.

I now understand that a series of episodes named JUGAAD MANIA is to be telecast by EPIC TV Every Monday at 9 pm, beginning this 28th February.

I am given to understand that I would be featured in the first episode itself.

Message from EPIC TV:

We're excited to present you the teaser of 'Jugaad Mania' a new show on Epic Tv channel produced by The Filmsters which will soon be aired on the Epic Tv and Epic On:

https://www.youtube.com/watch?v=e8La99c0GH0
https://www.instagram.com/p/CZPKqcBrbce/?utm_medium=share_sheet
User avatar
SAMPATH S
Posts: 132
Joined: October 28th, 2014, 1:00 pm

Re: Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

Post by SAMPATH S »

SAMPATH S wrote:
February 12th, 2022, 6:32 pm
WORLD WATER DAY is observed on 22nd March every year.

In tune with my efforts to promote rooftop rainwater harvesting for storage and direct use, I propose to conduct a demo of my setup at my residence, along with practical info on making and installation of the DIY Effective RWH Filters.

To enable enthusiasts to attend the session, it is proposed to be held on Sunday the 20th March 2022.

Since there is a limitation on the capacity, those interested may send a private message or email me at sampaths144@gmail.com. On confirmation, the Google location would be sent.

For such of the enthusiasts who require help in cutting the buckets, the same is proposed for Sunday the 27th March 2022. This also needs prior confirmation. For details regarding buckets, etc.; to be brought, the same would be informed on request.

Both the demo session and the help in cutting buckets would be completely FREE.
The visitors will also have an opportunity to see for themselves, high quality rainwater stored in sumps which are several months old, without any kind of treatment / purification, which is still pristine (except for some settled sediment). Also an opportunity to check the TDS of rainwater, Oxidation Reduction Potential (ORP), and if necessary, the pH.

As on date, I have sufficient water available to meet my requirements till April and may be beyond.

They can also see the use of grey water for watering plants. Also can see the Composter being used by me for composting wet waste, dry leaves and garden waste, which forms an excellent manure for the plants / garden. Also an opportunity to understand the making of Citrus Bio-Enzyme, which is an excellent organic non-toxic cleaning agent and know the numerous other household uses, made out of the citrus peels / discarded citrus fruits, and costs much less than Rs.10 per liter to make, which is sold in the market anywhere from Rs.300 to Rs.3,000.

The number of seats are limited and will be on first come first served basis, and the next opportunity may be available only after a year.
Post Reply

Return to “Solar and wind power”