How to make a homemade water filter. How to make a homemade water filter? Water filter from a plastic bottle

Water purification is required not only when using plumbing, but also when taking fluid from other sources. It could be a well, a river or a lake. In such water, inclusions are often found that are not useful to humans. In addition to mechanical suspension, which makes the water cloudy, but usually harmless, there are also more dangerous components. Among them are bacteria, dissolved salts, including nitrates, heavy metals and much more. To use such water, it must be purified. However, most modern filters are designed for the presence of a water supply with a certain water pressure. In a dacha or outdoor recreation, plumbing is not always the case. In this case, filter jugs or homemade devices are suitable. Let's take a closer look at how to make a water filter with your own hands.

Rice. 1 Do-it-yourself camping water filter device

To assemble a homemade water filter, you need to pick up two main parts. Container for laying the filter material and a container for collecting purified water.

A plastic bottle is suitable for laying the filter material. Its volume is selected depending on the required performance. The best options would be five, ten or twenty liters.

The bottom of such a bottle is cut off, holes are made in the cork or a mesh is installed instead. Filler is placed inside the bottle.

Such a filter is fixed above a bucket or tank to collect water. It is convenient to use a container with a lid in which a hole is made for the neck of the bottle. Such an installation can effectively purify quite large volumes of water.

Rice. 2 The easiest filter made from a plastic bottle

Filter media options

The principle of operation of any filter is simple. Water passes through the filter material, which traps contaminants. There are several options for filter media. For homemade filters, it is convenient to use the following:

• Fibrous - fabrics, gauze, cotton wool, non-woven material, for example, lutraxil. They effectively trap mechanical impurities, but are short-lived, quickly become contaminated. They are hard to clean and much easier to replace. The most convenient non-woven materials, which are more durable and easier to wash.
• Sand and gravel - sand and gravel backfill also effectively retains mechanical inclusions. Bacteria that absorb nitrogen compounds and dissolved organic matter settle on their surface.

Rice. 3 Silica sand for filters

• Activated or charcoal is an effective natural absorbent. In its pores, coal retains substances that cause an unpleasant smell and taste of water, eliminates color, and makes the liquid transparent. Coal retains a significant amount of dissolved salts. To fill the filter, you can use both ready-made granular filler and prepared yourself. Making charcoal for the filter is not difficult. The hardwood is placed on a metal sheet, covered to restrict air entry, and heated.

Rice. 4 Coal - a filler that effectively purifies water

• Zeolite is a mineral absorbent that retains iron, pesticides, nitrates and other contaminants well.

DIY carbon filter

Charcoal is the optimal filter material. It is efficient and affordable. If necessary, the filler can always be made independently by calcining hardwood logs in a metal container. Those coals that remain in a fire or stove are also suitable. Their size should not exceed three centimeters and be at least one centimeter.

The cooled coal is wrapped in gauze and placed in a container in which water will be filtered. This filter option is easy to make in field conditions.

For home use, for example, in a country house or in a private house, a more complex design can be made. It is better to choose a large container, the volume of which is at least twenty liters. A hole is cut from below, used to install the crane. To prevent the tap from leaking, a sealant is used and all seams are carefully glued.

Rice. 5 In-line carbon filter

A smaller container with a laid filter material is installed in the neck. For this purpose, a container of ten liters or less is suitable.

The filter material is placed in a homemade cartridge. For him, they take a piece of plastic pipe, which is suitable for the necks of the vessels with a diameter. Usually plastic bottles are used. Coal wrapped in gauze is tightly packed into the pipe. The resulting filter element is installed at the junction of two containers. Water should not seep past it, but only through the coal.

There may be charcoal in the first portion of the filtered water. There is nothing wrong with that. The first water is drained, and in the future only pure liquid will pass.

Pros and cons of homemade filters

Self-made filters have a number of positive characteristics and some negative points. These devices are convenient and functional. They are made from improvised materials, so the cost is minimal. You can get by with virtually no cost. The efficiency of homemade filters is high, and due to the large volume of filter material, they are productive.

However, we should not forget that a self-made filter in terms of technical characteristics and durability will be somewhat worse than factory-made models. They are more reliable and last much longer.

Rice. 6 Homemade water filters

The disadvantages of homemade filtering devices are the following features.

1. A relatively short service life is more of a temporary option for the summer season. Periodically, a new design will have to be made.
2. The resource of the filler is small. Filter materials require frequent replacement, otherwise bacteria, microorganisms and algae settle in them, which further pollute the water.
3. Getting a filter takes time and effort. Some options can be quite laborious to execute.

A homemade filter is a convenient solution, but only for temporary use. For permanent use, it is better to choose a factory-made device that is optimal in terms of characteristics.

Water from a well or well is often the only source of water.

From any well, well, or even a spring, one should not drink unpurified water. But there is not always a filter at hand.

The article offers several options for homemade filters for this case.

Universal plastic bottle filter housing

In order for water to be filtered, it must move (in our case, by gravity).

To ensure gravity flow, we make a watering can from an empty plastic bottle. We make a hole in the lid (larger), cut off the bottom of the bottle, turn it over and fix it over the bucket.

Now, filling the “watering can” with various filter materials, pour dirty water through the cut-off bottom, and get purified water from the neck.

Making a quartz sand filter

This is the case when civilization got one plastic bottle.

Pure river sand, poured into the filter, will purify the water from mechanical impurities and brighten it.

We make a filter from cotton wool and paper napkins

A filter is created from alternating layers of cotton wool and napkins in a "watering can". Cloth can be used instead of napkins, and activated charcoal can be added to cotton wool.

Such a filter in a bottle has its pros and cons. A plus can be considered the simplicity of design and at least some possibility of water purification.

The disadvantages of such a filter are its very low throughput, bulky design and insufficient degree of water purification.

carbon filter

Charcoal is an excellent sorbent that absorbs many contaminants at the molecular level (especially long chains). It is even released and used in the form of tablets.

An approximate replacement for activated charcoal tablets can be charcoal for barbecues. Using it in conjunction with a fabric filter, you can get a sufficient degree of water purification for consumption.

If there are no activated charcoal tablets or charcoal in bags, it is prepared from improvised wood (as for barbecue), burning it in a fire.

The resulting charcoal is wrapped in a cloth and placed in a funnel to filter the water. In this way, a carbon filter cartridge is obtained, which should be changed after 2 to 3 days.

After being filtered and boiled, water from a well or well can be considered safe to drink.

Filter in a cap

When civilization did not even share a plastic bottle with the traveler, the simplest filter for purifying well water can be made from a cap (a piece of any fabric) and a handful of quartz sand.

other methods

The design of the filter from improvised materials can be as follows:

1. A recess (pit) in the ground, at the bottom of which there is a vessel for collecting "purified" water.
2. The pit is covered with branches or paws of coniferous trees.
3. On the branches of grass and leaves, a “nest is paved”.
4. Sand and charcoal are poured into the "nest" (after the fire).

If it is possible to put a layer of fabric on the branches, then less litter from branches and leaves will get into the water.

Water must be boiled or additionally purified with antimicrobial agents.

Water Filtration Materials

Various materials are used to filter water in homemade filters, but the main ones are coal and sand. The list may expand depending on the items and materials that are at hand.

Sand. The main function of this material in water filtration is mechanical cleaning. Sand traps suspended particles.

The most suitable type of sand for filtration is quartz. The reason for this is the special shape of sand grains (they are sharp-angled and angular), such sand does not stick together, which is important for effective water purification.

Before use, the sand must be washed until the water is clear. If possible, it is advisable to boil it for an hour for disinfection.

Coal. This substance acts as an adsorbent. Coal retains chlorine, ozone, pesticides, oil products, organics, helps to clarify water, remove turbidity, tastes and odors.

If there was no special coal for water purification at hand in field conditions, its likeness can be made independently. To do this, you need to burn the wood in a fire, spread the coals, and when they cool down, collect them, grind them and rinse them under running water.

Coal is undesirable to grind into powder, it is desirable that the particles were about 1 mm in size.

You can also use activated charcoal tablets. In this case, it is important to calculate the proportions and "resource" of a homemade filter - one tablet can purify no more than one liter of water.

If you continue to filter water with one charcoal tablet over the resource, you will end up with worse quality water than it was before treatment. The reason is that coal begins to “give” the adsorbed particles back to the water.

A water filter is a necessary and demanded thing in everyday life. It is no secret that purified water is more beneficial for health, since boiling is not able to rid it of harmful substances and impurities. A home-made filter is no worse than a production one, it is able to purify water from precipitation. Making a filter with your own hands is quite simple. Moreover, there are a variety of ways to solve this problem that do not require significant financial costs.

What materials will be required?

You can make a filter for purifying water from harmful impurities with your own hands. The most primitive water filter is sand. At home, a homemade water filter can be made from paper napkins or gauze. With their help, well and tap water is cleaned quite well, but such filters have one very significant drawback - they are very short-lived and require constant replacement.

Cotton wool and cotton fabric are quite effectively used to purify water. The cotton filter will last longer. It can be placed in a large strainer or colander. Earlier in Russia, shreds of linen were used for such purposes.

Charcoal is no less popular as a filter. It can be purchased today at almost any department store or grocery store. And there are those craftsmen who prefer to make charcoal themselves, and then use it not for the purpose of cooking barbecue, but as a filter for water purification. If you want to make charcoal to filter water yourself, this operation is very simple.

Pieces of wood are placed in a metal container, calcined in it - and charcoal for water purification is ready. However, it should be remembered that not every wood is suitable for such an operation. For the manufacture of activated carbon, pieces of coniferous wood are not used, since they contain resin and it prevents the production of this product.

What is the role of lutraxil and what impurities will it help get rid of?

A water filter can be made without problems from improvised materials. For those who are concerned about the problem of high-quality water purification and who have a desire to purchase any additional components for these purposes, experts usually recommend paying attention to lutraxil.

It has been used for filtering relatively recently, it is a new product on the Russian market. Lutraxil provides a high level of water purification for drinking and household needs due to the presence of special polypropylene fibers in it, which trap impurities and substances harmful to human health in the filter.

Filters allow you to purify water from the following negative impurities and properties:

• sulfates;
• chlorine;
• nitrates;
• nitrites;
• gland;
• chromaticity;
• turbidity.

About the secrets of making simple filters

What is the best homemade water filter? The answer is simple - multi-layered. Each of the listed materials used for water filtration has its own properties.

If the filters are combined, water purification is carried out at a higher level. Pitcher filters purify water slowly enough, for a faster solution to this problem, you can use a plastic bottle, with which a home filter is made.

To make a homemade filter you will need:

• five-liter plastic bottle;
• plastic bucket;
• small stones;
• gauze or thin cotton cloth;
• charcoal;
• sand.

How to make a filter that purifies water? It is better to take an ordinary five-liter plastic bottle for water purification. Its bottom must be carefully cut. The other part of the filter is a plastic bucket. A hole is cut in its plastic cover. Insert a plastic bottle upside down into it, make small holes in the cork, 5 pieces. It is better to clean the edges of the plastic with sandpaper. And now it only remains to fill the homemade filter with filler.

First, at the bottom of the bottle, we put washed small stones, about 2-3 cm, on top of a bandage folded four times, or cotton fabric. This is necessary to separate stones from coal.

The main filter element is coal.

You must first prepare it. If there is no ready-made coal, then for this you need to make a fire in advance, in which it is good to ignite the wood. Then we break it so that the pieces are not too small and not too large, and we fall asleep from above to about half the capacity.

Again we take gauze, fold it four times and cover the coals well with it so that there are no gaps. This is done so that, putting sand on top, it cannot seep to the coals. If the sand goes to the coals, they will clog. The sand must first be washed and slightly ignited for disinfection.

The function of sand is to enhance filtration. It should leave in itself small particles of dirt and foreign inclusions. Sand falls asleep approximately 2-2.5 fingers. On top of the sand again gauze in 4 layers, so that when pouring water, a funnel does not form. Approximately 1/3 of the free space must be left at the top in order to pour the water to be filtered.

If it is necessary to purify a larger amount of water, it is enough to take other containers in size and repeat the algorithm.

The water purification system is a necessary thing in everyday life. After boiling, water does not get rid of all contaminants, it remains hazardous to health. Each person cannot afford to buy a filter, prices sometimes “bite”. You should not despair. You can make a water filter with your own hands, it will turn out to be no worse in efficiency than store units.

Advantages of handmade filters:

• structures effectively cope with large impurities (iron, rust, silt, sand);
• filter eliminates unpleasant odor, taste of water;
• economical systems;
• you can make a filter even while on a hike, with a minimum amount of materials.

There is only one drawback of the structures - they do not remove bacteria and microbes from the water. It turns out that the liquid will carry a danger to human health. After filtering water through such a device, it must be boiled.

home filter

Every person wants to use high-quality, tasty, healthy water. If it is not possible to purchase a cleaning structure, you can make it yourself. Such a filter will perfectly cope with impurities of rust, sand, make the water “softer”, get rid of pathogenic bacteria.

For the "recipe" of the simplest design, you need to prepare:

• ordinary charcoal;
• cotton fabric;
• a plastic bottle (the cap must be screwed).

Initially, charcoal is "activated". It is crushed in such a way that the diameter is no more than 5 mm. Next, the product is poured into a saucepan, poured with cold water. Coal is brought to a boil (boil for 5-7 minutes). Water is drained, the product is left in the container until it cools completely. To make a water filter with your own hands, you need an amount of charcoal that will cover 30% of the capacity of the bottle.

System build process

1. A hole with a maximum diameter of 3.5 mm is carefully made in the bottle cap.
2. The bottom needs to be cut off.
3. A piece of prepared fabric is carefully placed in the neck, then coal is poured.

The service life of a homemade water purification system is long. If over time the liquid has become unpleasant in taste, the filter is made anew. It is recommended to "update" it once every 30-40 days.

Homemade cleaning design for a well

Having a well in the country, you need to take care of filtering the liquid. Pesticides, nitrates, and other harmful impurities seep through the ground. They get into the consumed water, then into the human body. Cleaning well systems are expensive; for a small cottage, it is more reliable to make a bottom water filter with your own hands.

Prepared for work:

• river ordinary pebbles;
• crushed stone (it is strictly forbidden to use construction);
• shungite;
• zeolite (effective against viruses, bacteria);
• gravel.

A shield for the well is knocked together from the boards, wrapped in geotextile, then sinks to the very bottom. Large stones are also added there at the first stage. After that, you can proceed to the manufacture of the filter (reverse, direct).

If the bottom of the country well "sparkles" with soft clay, a direct filter is needed. First, a fraction of a larger diameter is laid, then a smaller one. It is necessary to adhere to the optimal thickness of each layer. The average is 15-20 cm. The minimum number of layers is 3. First, crushed stone is laid, then small pebbles, and lastly, thoroughly washed river sand.

For a country well with a sandy bottom, a reverse system is suitable. Initially, a small fraction is laid, then a larger one. It is necessary to adhere to the same layer rules as in the previous case.

Over time, the filter will become clogged with sand, clay particles, and other impurities. It needs to be updated annually. The sand is replaced, the stones are well washed, then laid back.

How to make your own cleaning structure for a well

How to make a do-it-yourself water filter for a well? The device of the cleaning system is simpler than it might seem.

The following materials and tools are being prepared:

• pipe made of durable plastic;
• stopper made of wood;
• mesh with the smallest holes (cells), preferably brass;
• drill, drill.

Important! The length of the pipe is calculated individually based on the depth of the well. The diameter is taken less than the diameter of the well.

How to make a water filter: process description

1. Initially, the total length of the sump is measured.
2. At an angle of up to 60 degrees (minimum 35), it is necessary to drill small holes in a checkerboard pattern, leaving a minimum distance of 2 cm between them.
3. The pipe is thoroughly cleaned from the remnants of chips, the zone “with holes” (25% of the total length) is wrapped and fixed with rivets.
4. A plug (plug) is installed.

Passing through the mesh, small particles of dirt and sand will linger. Impurities of larger diameter settle in the sump. The water that has passed such filtration must be additionally boiled before use, since the purification system does not remove harmful substances (microbes, bacteria).

Filter "in haste" on a hike

It often happens that during a trip a person is sorely lacking drinking water. There is no well, especially a grocery store nearby. It is much easier to find a natural reservoir. The liquid in it is dirty, not suitable for drinking. A homemade water filter is a real salvation. You can easily make it from improvised materials.

Method 1

Activated charcoal, cotton wool, bandage are always taken on a hike. There is also a plastic regular bottle.

1. The bottom of the bottle is carefully cut off, the container is turned over.
2. A layer of cotton wool (2-3 cm) is placed in the neck.
3. A bandage is folded in 4-5 layers, located on top of the cotton wool.
4. The next layer is crushed activated carbon.
5. Next - another layer of cotton, bandage. Cleaning design "in haste" is ready.

Method 2

If you don’t have a first aid kit with you, don’t despair. To make a water filter, you can use:

• plastic bottle;
• coal from a fire (small);

Initially, holes are made in the lid (2-3 large), a piece of fabric is placed in it, previously folded 3-4 times. Now the bottom of the bottle is cut off, the cap is screwed into place. Alternately, the resulting containers are filled with moss, then with coal. The more such layers there are, the cleaner the water will be at the exit. The last layer is definitely moss.

A homemade water filter on a hike is an indispensable thing. It must be remembered that the cleaning system removes only turbidity, large particles of dirt from the liquid. Pathogenic microbes, dangerous bacteria will remain in the composition of the water. If it is possible to boil additional liquid, this is very good.

Filters for water purification in houses, in the country are sometimes inaccessible at a cost to a person. If there is a desire, it is not difficult to make a system on your own. The main thing is to clearly follow the sequence, use the “right” materials.

As you know, any paper is a plant fiber, interconnected in the form of a web. In fact, any paper is a very fine sieve with cells of various sizes. This is what paper looks like under a microscope:

It's beautiful, right?

It is because of this structure of the paper web that paper can be used (and is used!) To separate liquids from particles suspended in it. The thicker the paper, the smaller particles it will hold.

The paper that is used in real laboratories by real chemists has very tiny pores, the size of which, moreover, is carefully controlled at the production stage. Such paper is called filter paper and allows you to retain even the smallest impurities (up to 1 nm).

Filter paper - what is it?

Filter paper is a semi-permeable barrier made of plant and/or synthetic fibers designed to separate a dispersion medium (liquid, gas) and a solid dispersed phase (dust, aerosols, suspensions). The separation process itself is called filtering.

Simply put, if a liquid with various insoluble impurities is passed through such paper, then all these impurities will remain on the paper, and the liquid will become clean and transparent. Sometimes the target is the liquid itself, and sometimes it is the sediment that is of interest.

In the manufacture of filter paper, the manufacturer tries to give it certain properties:

Most often, filter paper consists of pure fiber, although synthetic fibers are sometimes added to its composition. It should not contain dark or translucent places, wood impurities, amyloids, chlorides, iron salts, etc.

During the production of the filter. papers use carefully selected polymer binder additives that do not react with most chemical compounds. To maintain a given and uniform distribution of pores, special technologies are used.

Thus, true filter paper is a complex composite material with rigidly defined properties.

Table 1. Characteristics of filter paper

Variety	Specifications	Density, g / m 2	Thickness, mm	Pore ​​size, µm	Filtration rate, s/10 ml	Typical Application
3w		65	0,15	10	15	Protection, ventilation
51	fast filtration speed, smooth	65	0,14	12,0	13	Analysis of water, dyes, alcohols
3m/N	medium filtration speed, smooth	65	0,12	4	30	Vacuum and pressure filtration of high turbidity extracts and dyes, for use in large clarification filters
4b	medium filtration speed, smooth	75	0,15	8,0	22	Fast filtration of large quantities of liquids with coarse sediments, emulsions, alcohols, dyes, solutions
53		70	0,15	7-10	18	Embossed paper, medium filtration rate, for general laboratory use.
49	fast filtration speed, embossed	78	0,17	10-15	11	Embossed filter paper, ideal for salt solutions and sugar juice
1300	medium filtration speed, smooth	90	0,19	7-10	30
1350	medium filtration speed, embossed	90	0,25	7-10	30	adsorption, protection
62	medium filtration speed, smooth	95	0,20	7,0	17	Essential oils, emulsions, essences, dyes
94/N	medium filtration speed, smooth	100	0,22	7,0	25	Juices, essences, tonics, must, wine, herbal extracts
100/N	medium filtration speed, smooth	85	0,18	6,0	30	Specially designed as a belt filter for the sugar industry
1310	medium filtration speed, smooth	135	0,26	7-10	30	Adsorption, protection, filtration of oils
1360	medium filtration speed, smooth	135	0,31	7-10	30	adsorption, protection
C 160	medium filtration speed, smooth	160	0,30	5,0	40	Filtration of a large amount of liquid with precipitation in the form of small flakes; tonics, alcohols
57/N	medium filtration speed, smooth	190	0,40	7,0	32	Filtration of large quantities of liquid, especially for weak acids and hot alkaline solutions
69/K	paper containing activated carbon	160	0,42	5,0	65	Paper containing activated carbon with 30% cardboard content for filtering electroplating baths and for cleaning colored liquids

Paper is produced in various forms: in rolls, in sheets or in the form of finished filters, round shapes of various diameters.

Table 2. Classification of paper filters (color coding)

Variety	Oud. weight g/m2	Filter time, sec	Properties	Main Applications
black tape	80	10	Coarse-pored, soft paper with a loose structure, very high filtration speed	Chpope-like and coarse precipitates, colloids: hydroxides of iron, aluminum, chromium, sulfides of copper, bismuth, cobalt, iron, various organometallic precipitates; determination of silicon in the analysis of steels. The variety most widely used for analytical work.
white ribbon	80	20	Medium pore size, high filtration rate	Coarse precipitates: sulfides of silver, arsenic, ammonium, cadmium, lead, iron and manganese, lead chromate, alkaline earth metal carbonates, etc.
yellow ribbon	80	20	Medium pore size, high filtration rate, low fat content	Coarse precipitation. Particularly suitable for the determination of fat in natural raw materials
3 green ribbon	80	100	Narrow pores, dense, low filtration rate	Filtration of fine precipitates: barium sulfate, lead molybdate, lead dioxide, calcium hydroxide, calcium fluoride, nickel sulfide, tin sulfide, etc.
blue ribbon	80	180	Finely porous, very dense, very low filtration rate	Fine precipitates: cold-precipitated barium sulfate, copper oxide, etc.
Red ribbon	80	50	Medium density, moderate filtration rate	Fast filtration of fine precipitates: magnesium ammonium phosphate, magnesium ammonium arsenate, etc.
purple ribbon	100	250	Lowest filtration rate, extra fine pores and high density, most efficient filtration of the finest sediments	Particularly difficult filtration conditions, fine-grained sediments: barium sulfate, copper oxide, etc.

Where can I buy?

They say that it is sold in some pharmacies. But when I wanted to filter the wine from the sediment using filter paper, I did not understand where to buy it in a pharmacy. I traveled, probably, with a dozen pharmacies in my city, but to no avail.

You can probably get a filter. paper in some laboratory or some chemical production, but this requires certain acquaintances, which I cannot boast of.

As a result, I got on the Internet and immediately googled hundreds of stores where to buy filter paper. It is sold by weight, in sheets and rolls, or in packages with cut disks of any diameter. Ashless filters are also on sale, which may be needed to filter solutions that are particularly demanding on purity.

The cost of filter paper is cheap. For example, a package of 100 discs will cost you 40 rubles. This is if it is retail.

How to increase strength?

Real filter paper, of course, is much stronger than ordinary blotting paper, but it still sometimes breaks. Especially when you need to filter a large volume of liquid. The paper processing method suggested below increases its tensile strength by 10 times! At the same time, the filtering qualities do not deteriorate.

So, all you have to do is wet the paper with 70% nitric acid (density 1.42 g/cm3) and immediately rinse with plenty of distilled water.

After thorough washing, the paper should be dried and used as needed. Such paper does not introduce any contaminants into the filtered solution and is suitable for drug preparation or use in analytical chemistry.

The paper treated in this way becomes so strong that its 5 cm wide strip can easily withstand the weight of a 1.5 kg weight. While ordinary filter paper is already torn at a weight of 150 grams.

Filter paper from different manufacturers has a pore diameter of 1.5 to 35 µm. At the same time, it is practically achievable to clean liquids from impurities with a particle size of 1-2 nm (large pores in the paper become clogged, and the filtration becomes finer).

The smaller the pore size of the paper and the greater the amount of sediment in the liquid being purified, the slower the filtration process. In some cases, the end of the process has to wait for hours. Things move especially slowly if the liquid has an increased viscosity (something like syrup).

What can be replaced?

If you don’t know where to get filter paper, pharmacies don’t have it, and you don’t have the strength to wait until they send it from some online store, then you can try to do without it. Let's see what can replace the filter paper.

If anyone does not know, earlier a piece of very thin and porous paper was invested in every school notebook. Its main purpose was to blot ink blots (hence the name).

In fact, the blotter was used in any way, but not for its intended purpose: they chewed a piece of paper in the mouth and spat the resulting crumb from the tubes (or sent it to the target using a ruler), seeds were germinated in the paper, cheat sheets and notes were written on it, wet a blotter was placed under the base of a light bulb to disrupt a lesson, small airplanes were rolled up, physical experiments were set up (a glass, a blotter and a mirror), soaked in potassium nitrate and used as rocket fuel or a fuse cord, etc. etc.

Sometimes this leaf had a jagged edge on one side, sometimes not.

By its properties, a blotting paper is the same filter paper, only thinner and with larger (not standardized) pores. But being rolled up in two or three layers, the blotter did a very good job of filtering solutions. And it did not tear under the weight of sediment, even in ordinary glass funnels (not to mention Buchner funnels).

Unfortunately, somewhere in the early 90s, blotters completely disappeared from school notebooks and now live only in our memory.

2. Filter suede

In cases of filtration of non-aggressive media from large mechanical impurities (more than 30 microns), the filtration process can be significantly accelerated if filter paper is replaced with suede.

To do this, suede must be prepared in a certain way.

Take a piece of suede of the required size and soak it thoroughly in a weak solution of sodium bicarbonate (baking soda) to remove the fats contained in it. Then washed in cold running tap water, then rinsed in distilled water and dried.

Suede prepared in this way is used as filter paper. Not only all kinds of tinctures are filtered through it very cleanly and at the same time, but also very thick syrups, as well as viscous, slimy vegetable juices.

The speed of the filtration process can already be judged by the fact that 1000 ml of the thickest syrup is filtered in about 15 minutes.

Filter suede is also good because it can be used repeatedly. Just make sure to rinse it thoroughly after every use.

3. Funnel with porous glass

To filter various chemically aggressive media (strong acids, alkalis), a special funnel with a glass filter is used - a Schott funnel.

Such a filter is made from glass powder of a given grain size, which is sintered together into a continuous porous plate. Glass powders themselves are obtained by spraying molten glass, so they look like very small balls.

After cooling, the powders are sorted by size and baked into plates. The porous glass plates are then soldered into glass funnels or other holders.

Immediately after use, such a funnel must be rinsed with water in the opposite direction of filtration. If it is not possible to completely wash out the precipitate, then they resort to washing with chemicals that destroy or dissolve the precipitate, for example:

Pollution	Solvent
Oxides of copper and iron	Hot hydrochloric acid with the addition of KCl.
silver chloride	Solutions of ammonia or sodium thiosulfate.
barium sulfate	Hot concentrated H 2 SO 4 .
mercury sulfide	Hot royal vodka.
Residues after filtering mercury	Hot concentrated HNO 3 .
Residues containing silica and alumina	2% hydrofluoric acid followed by concentrated H 2 SO 4 , then distilled water and finally acetone. Rinse until traces of acid are detected.
Fats	Carbon tetrachloride.
Proteins, viscose, glucose	Hot ammonia solution, 5-10% NaOH solution. A mixture of hot and concentrated sulfuric and nitric acids.
Other organic matter	Chrome mixture or preferably hot H 2 SO 4 with the addition of NaNO 3 , KNO 3 or HNO 3 .

4. Paper towels, napkins, etc.

Yes, all this can be used instead of filter paper. I am sure that everyone has at hand something from this list:

• paper towel;
• napkins;
• toilet paper (preferably white, multi-layered and unflavored);
• coffee or tea filters;
• cotton wool, cotton pads;
• repeatedly folded gauze or other fabric;
• at worst - a replaceable water filter (from jugs) or a tank with activated carbon from a gas mask. But in this case, a large amount of the filtrate will remain inside the filter and will be irretrievably lost.

It all depends on your resourcefulness. The only restriction is that the filter material itself must not contaminate the filtrate, must not react with it, and must have sufficiently small pores to retain sediment.

Toilet paper and napkins are very fragile, so it is better to put some kind of sieve or colander under them. The most ideal option is a special chemical funnel for vacuum filtration - a Buchner funnel.

Also, do not forget about an extremely effective way to separate liquids from various suspensions - settling and decanting. But this method takes a lot of time.