Tag Archives: purification

Water Pollution

Water pollution is an important issue effecting man parts of the world, some places a lot more often than others. Polluted water can cause a variety of health and environmental problems, starting from stomach pains and upsets to as much as even death and destruction of natural eco-systems. Polluted water is any water source that is contaminated with hazardous materials or agents, water pollution can arise in large natural water bodies such as lakes, rivers and even the sea, groundwater aquifers and reservoirs, in small water environments, in general or domestic water supply systems etc.

In general, most water pollution globally is due to some sort of human activity, it can be a direct polluting activity or something indirect that eventually reaches the water. Water pollution can be in drinking water, treated wastewater that is used again for a specific purpose or disposed if back to nature, industrial wastewater that penetrates water supply, toxic materials entering the water etc.

Drinking Water Standards

How to identify water pollution

In public potable water supply systems, the water company or governmental supplier will detect the pollution and notify residents. In developing countries one must test the water before drinking it and the same is recommended for any water source that there is a doubt regarding its safety. In severe cases of water pollution it’s clear from the start that there’s a problem, the water will smell bad, they will be cloudy or murky or greasy, the taste will be bad and/or it will have particles in it.

The best and most common ways to test water pollution levels is either sending samples to a lab to scan for chemicals, biological, non-biological and other contaminants or using chemical indicators that tell in an easy and fast way if the water contains certain contaminants. If we are talking about a water source in the wild, we can examine the wildlife and plants around it to look for any sign of water pollution.

Drinking water pollution

This is by far the most dangerous type of water pollution. Drinking polluted water poses serious health risks and it is also the quickest way for someone to be contaminated if consuming polluted water. In many parts of the world high levels of water pollution prevent access to safe water and cause numerous death or illness cases annually.

In order to be able to drink the water, water purification is required. This is acheived through various water purification techniques and by using water filters and water disinfection methods.

Origins of water pollution

Water pollution can be a point source pollution where the contamination came from one clear place or source or it can be a non-point source pollution where the contamination source is unknown or from multiple places/sources. The overall origins of most cases of water pollution are:

  • Untreated wastewater or improperly treated wastewater.
  • Biological contaminants in the water source or supply system.
  • Industrial waste and wastewater.
  • Deliberate water pollution by chemical, physical or biological agents.

Common types of water contaminants

  • Pathogens: Bacteria, viruses, micro-organisms, viruses, parasite worms and more.
  • Chemicals and others: These can be organic or inorganic contaminants
    Organic chemicals: detergents, food processing waste, disinfection chemicals, herbicides, pesticide, insecticide, petroleum products, plant debris, and industrial solvents; Inorganic: Acidity forming pollutants, Ammonia, Chemical products and waste, fertilizers and heavy metals.
  • Large contaminants that cause water pollution, such as plastic, glass, paper, hygiene products etc.

Water Purification using Organisms

Water purification and treatment systems are relevant for fresh drinking water, water that are made suitable for drinking, wastewater treatment and reuse and other uses. The variety of methods that exist to treat water and improve its quality are used globally today in a very widespread manner – not only in large scale water treatment plants but also in private domestic use with small designated systems. Water purification using organisms is a great natural method to treat mainly used water.

The implementing of purification using organisms is known and works in practice for many years now, the principals of the method are natural and occur in nature all the time regardless of human intervention. But the use of this type of biological water treatment method is becoming more known and also more common due to the overall understanding that mankind needs to find more sustainable and ecological ways to live, treat our waste and co-exist with other systems on the planet.

The participants of purification using organisms

Basically, 3 types of organisms participate in water purification using organisms:

  • Water plants – special species that act as purifying agents.
  • Bacteria – colonies of “good” bacteria contribute to the process.
  • Fish – These are used mainly to keep the purification environment in a maintained and optimal state.

Fish are not always used in biological water purifier systems, their use depends on the actual system used, the water quality coming into the treatment system etc. But whenever fish are used in water systems (fresh water and used water), if there is a sudden high contamination, the fish will die and be an indication for the problem.

Creating a biological purification system using organisms

In most cases, a water purification using organisms system will be in the form of a natural wetland, green basin or lake, it is also possible to have the system in a regular treatment pool or reservoir site or even specially designed tanks. The most common way by wetland will either be a constructed wetland that is built specifically to be a purification using organisms system or an existing environment where water purification takes place – It can also be water to improve or support and existing eco-system or water environment.

In terms of household water treatment, purification using organisms is very common for greywater recycling and in a less common practice for ecological clean swimming pools. For a greywater recycling system a small wetland or “green basin” is created in a pool or tank and the same process happens on a small scale.

How the organisms purify the water

All the participants in the purification using organisms process act together and live as a living, breathing and changing eco-system. The process is natural and basically involves no chemicals disinfectants; it can include a filtration process to maximize the results.


water plants contribute to purification using organisms by absorbing toxins into their root systems as nutrients and releasing important oxygen to further purification and for he bacteria colonies.


Bacteria colonies develop independently and are of course encouraged, these “eat” various contaminants and also remove the sludge from the bottom of the wetland.


The fish are not essential to the actual purification using organisms process but they are important in keeping the wetland in optimal condition for the purification process. Fish eat the algae from the surface and inside the water, they reduce mosquitoes and pests. There’s a need to use different species of fish to cover all the depth zones in a water purification using organisms system.

Water Disinfection Methods

Water disinfection methods describe a large variety of cases and methods, some relevant to large scale drinking water or wastewater treatment plants, others relevant for personal water use in contaminated or uncertain environments and some methods are meant for swimming pool disinfection. In general, water disinfection methods aim to eliminate and remove harmful contaminants from the water so it is suitable for the specific use its intended for.

Personal water disinfection methods

These are mainly relevant for people travelling to developing countries where water quality is poor, it’s polluted or its safety is uncertain. The main water disinfection methods used in these cases are water boiling, iodine tablets or tincture and portable water filters using activated carbon. Read more about water treatment methods.

Domestic water disinfection methods

Sometimes the general water supply from the local water company gets contaminated and the residents are advised to use water disinfection methods before drinking the water. In other cases a household’s water supply might be permanently in poor quality and needs disinfection.

Common domestic water disinfection methods are:

  • Boiling: the simplest method, it kills many contaminants.
  • Ceramic filters: special filters with very small micron penetration surface, stops most pollutans.
  • Chlorination: in tablets or other soluble solutions
  • Chemical compounds: compounds containing chlorine with other chemicals.

Ultra violet light disinfection

The UV light is an effective and clean water disinfection method, it inactivates cysts and other harmful contaminants. UV light as a disinfection method is non residual so is actually doesn’t leave any disinfectant in the water – can be an advantage or a disadvantage.

Disinfection using Chlorine

This is part of the water disinfection methods utilizing chemicals, but it is so common that it deserves a category of its own. Chlorine is a dangerous gas that is a very powerful oxidant; this oxidizing ability is what makes it so effective in terms of water disinfection methods. The actual use of Chlorine is usually as a compound with other chemicals or minerals that only allow the gas to release when it is in the water. It’s used a lot for drinking water treatment and disinfection, for swimming pools and other purification / disinfection methods.

Chlorine kills bacteria but does not eliminate certain cysts and other chemicals. Other water disinfection methods based on Chlorine or similar products are Chlorine dioxide water disinfection and Chlormine disinfection (a weaker disinfectant than free Chlorine but does not produce carcinogenic THM or HAA).

Ozone water disinfection

water disinfection methods also include the use of Ozone (O3), this is a very unstable molecule which is a powerful oxidant that’s toxic for organisms living in water. Ozone offers a very wide spectrum disinfection ability, the Ozone must be produced on site using oxygen and a UV light normally. Ozone disinfectant produces less hazardous by products that Chlorine does (THMs and HAAs). It’s mainly used in Europe for drinking water treatment plants.

Additional Methods

Other water disinfection methods use Hydrogen peroxide, ehich is similar in operation to Ozone, passing the water through an activated carbon (charcoal) filter and a new development that’s still in research – water disinfection using solar disinfected water.

Water Treatment Methods

As travelers to far away and exotic places know, drinking from the local water supply isn’t recommended.   In many countries, local water, whether piped, from a well or a river, may well be polluted with a host of contaminants that can, at a minimum, cause stomach upsets, perhaps sickness, vomiting or diarrhea and in the worst case scenario, severe dehydration and possibly even death.  That’s why, whenever travelling you need to first find out the quality of local drinking water and secondly, be aware of the various water treatment methods available to you.

Do not assume that just because the local population drinks the water that there is no risk and no need to use any form of water purification.  Remember, the local population is used to using their water supply and may have built up a resistance to the contaminants.  What for them is harmless, for you could be very painful!  Also, just because the water appears clean, doesn’t mean that it is safe to use – even for brushing your teeth!

Available Water Treatment Methods

The first water treatment method is really very simple – use bottled mineral water from a trusted source.  This is a fairly safe alternative and strictly speaking isn’t a water treatment method.  Bottled water is usually available at even the remotest of locations.  A word of warning – check to make sure that the bottle is sealed properly.  If not, don’t buy it as it could have been refilled with local and possibly contaminated water.

Boil your water!

This is perhaps the safest and easiest of water treatment methods.  In order to be sure that the boiling process destroys all bacteria etc, follow this procedure:

  • Strain the water through a clean towel to remove any particles.
  • Boil the water for at least one minute.  This must be a “rolling boil” – lots of steam and bubbles.
  • Let the water cool to room temperature.  Don’t add ice cubes – if they are made with local water…
  • If you’re at a height greater than 6,562 feet or 2,000 m, then be aware that the boiling water treatment method needs to be adapted as air pressure is lower and the boiling point of water is lower.  So, you need to boil the water for at least 3 minutes or use a chemical disinfectant (see next section) after the water has been boiled for one minute.

Chemical disinfectant Water Treatment Methods


Available in tablet form, this is a convenient water purifier.  Always follow the manufacturer’s instructions exactly as tablets do differ.  If, after use, the water is cloudy, then double the dose and the waiting time between adding the iodine and drinking the water should be increased.  At temperatures lower that than 5° C (41° F) try and warm the water slightly and increase the time between adding the tablets and using the water.

Tincture of Iodine as a water treatment method

Add five drops of tincture of iodine to a liter of clear water.  If the water is cloudy, double the dose.  Wait at least half an hour before drinking if the water temperature is 25°C or 77°F.  For every 10 degree drop in water temperature, double the waiting time.

Portable water filters

Some water treatment methods rely on portable water filters.  While these can remove most bacteria, they cannot eliminate viruses.  Therefore, whenever using a portable water filter as a water treatment method it must always be followed up by a chemical water treatment method.

Well Water Purification

Due to the increasing encroachment of industrial society, the widespread pollution being spewed out by factories 24/7 , it is now necessary for all those using well water for their water supply to install a water well purification system to remove harmful, and even potentially fatal, pollutants from the water.  Put simply, no matter where you live – you are constantly exposed to water pollutants and need to find ways to eliminate them.

Types of water well purification systems

There are many different types of well purification systems but not every system is suited for every type of pollution.

That’s the purpose of this article, to give you some basic information regarding the various systems and technologies used for water well purification systems.  From there on in, the rest is up to you, we won’t be addressing budget considerations or possible future developments but we are sure that using the information provided here, you’ll be able to make an informed decision.

Testing your water

Step one is to get your well water tested by a certified laboratory.  In order to know which type of water well purification system you need, you must know which pollutants appear in your water and their density.  Without taking this preliminary step, any choice for a water well purification will be a shot in the dark.

Reverse Osmosis

Reverse Osmosis is by far the most common form of water well purification systems and also the most well known.

Most filtration systems include a reverse osmosis stage which is often used to reduce excess concentrations of calcium or sodium and other water suspended particles.  Reverse osmosis will also remove above permitted levels of lead and, according to some sources, prevent infections from water borne parasites.

Reverse osmosis has two main drawbacks: 

  • It can also filter out vital trace elements which, unless replaced, can be detrimental to your health.
  • The system works using a series of membranes.  According to the particle density of your water, these membranes need to be changed.  This isn’t a cheap process and many reverse osmosis systems also include a pre-filtration system to remove particles.

Ion Exchange water well purification

These water well purification systems use a membrane or bead shaped resin to achieve a balance in mineral content and the pH level of the water.  They can also reduce lead, copper or cadmium content by up to 99%!   Ion exchange resins cannot remove chlorine concentrations and are often used with an activated charcoal filter to remove excess levels of chlorine.

GAC, Carbon Block, Resins and Activated Aluminum

Well water purification systems such as these are used to reduce chemical concentration, chlorine for example. The carbon block is especially effective as it manages purify almost 100% of the water.  Special resins are utilized to remove chemicals such as THM’s and MTBE as they are not affected by carbon.

Even though carbon can be used to effectively remove fluoride compounds, activated aluminum is far more efficient and widely used.  One drawback of this system is that activated aluminum can only be used on a one tap.  A “whole house” water purifier is by and large used for household wide purification and fluoride elimination.

Particle Filtration

This water well purification method makes use of extremely absorbent materials to catch and remove impurities. This system does not, however, remove the essential minerals and salts from the water.   In areas where there is a danger of solid particle contaminants (asbestos fibers, cysts, parasites etc.) this type of system will, if maintained properly, perform a more than adequate job.

So, there we have it! Hopefully, you will be able to use the information here in order to evaluate your water well purification needs and make a final decision as to the best water well purification system to provide you with fresh, unpolluted water.

Further reading: Drinking Water Standards

Water Treatment Systems

In the past, most of us in the developed world opened the tap and drunk the water without putting too much thought into the matter. The same goes with regards to what happened to the water after we or other, more industrial, users used it – We also didn’t really think about it and in fact huge amounts of wastewater was flowed untreated to the ocean, to rivers and other water bodies.

Water treatment systems had always existed to some extent, also wastewater treatment systems. But it is only in recent decades that both domestic pre-use treatment systems and wastewater treatment systems became more common and now the importance of some of these systems is clear in so many ways.

Water treatment systems can refer to household or single tap treatment systems meant to improve the quality of water coming mainly from the local water company. It can refer to large scale drinking water treatment systems meant to purify and improve water coming from various sources or even produce drinking water from sea water (Desalination). The last major type of water treatment systems is designed for wastewater treatment, to clean and purify all sorts of wastewater according to a desired end use.

Domestic water treatment systems

These systems come in all shapes and sizes; they utilize a variety of technologies or scientific approaches. Some domestic water systems are installed before the water mains entrance to the house, some are physically on the tap or under it on the general plumbing and other very common systems are countertop purification systems also known as water “mini-bars”.

The technologies implemented in these various domestic or household water treatment systems are sometimes similar in nature to large scale treatment plants but in the majority of cases it is a filtration system. Systems use physical water filters to block particles and contaminants and also activated carbon filters and reverse osmosis to eliminate chemical and biological contaminants.

There are also domestic water treatment systems that are meant for wastewater – mainly greywater recycling.

Large drinking water systems

These treat water coming from different possible sources of fresh water designated for drinking and general use. It is treatment before the water goes to consumers. The most common water treatment systems for potable water use a treatment method that removes particles and possible contaminants using coagulation, sedimentation, filtration and disinfection – mostly done in special tanks or pools.

Wastewater treatment systems

This is the most widespread type of water treatment systems. These systems are designed to clean and purify wastewater coming from domestic sewage, industrial waste, commercial wastewater and all other used water. The systems need to remove numerous contaminants and pollutants, some very hazardous to man and the environment. There a lot of treatment methods used, they can be physical treatment, chemical or biological – mostly a combination of all.

The most common method is built from a few stages similar to drinking water treatment: Raw filtration of large debris and objects, coagulation and sedimentation of solids, removing and treating the created sludge, heavy-duty filtration stage using physical, chemical and/or biological filters, aeration, tertiary purification and then transfer to consumers.

Another method to implement a water purification system is purification using organisms such as plants, bacteria and fish.

Water Treatment Process

Water is a vital resource for life it self and a variety of other uses. But unfortunately water doesn’t always come in abundant so it needs to be produced; its quality isn’t always suitable for its required use so it needs to be treated; after we use it for various needs it needs to be disposed of properly or reused after treatment. Water pollution is a serious issue for many parts of the world. All these reasons and factors make water treatment processes vital.

A water treatment process can be done domesticaly, as part of household water treatment; it can be in large scale treatment plants that serve entire cities or it can be individually to purify water and drink it while travelling. Here we will go over the water treatment process mainly in regards to wastewater treatment and drinking water.

Drinking water treatment process

Naturally, drinking water requires much less treatment and generally a simpler process than wastewater of any kind – especially opposed to sewage or industrial wastewater. Drinking water may require different treatment methods in different areas, or even no treatment at all. The water treatment process type depends on water quality from the source – groundwater, lakes, rivers, streams, rain collection etc. We are talking about drinking water from a fresh potable source and not desalination water for example which are produced in a completely separate treatment process.

A water treatment process for drinking water can include all or some of the following stages:

  • Coagulation: This part of the water treatment process removes dirt and grit from the water coming into the plant, a coagulation agent such as Alum is added to the water and this creates sticky particles known as “Floc” – This makes dirt, grit and other solids come together and settle to the bottom of the tank/pool. Also called flocculation.
  • Sedimentation: simply, most of the solid and other heavy substances sink to the bottom and then the clear water can move on to the next stage.
  • Filtration: There are different types of water filters used, they can be physical, chemical or biological. A common filtration method is filters made from layers of sand, gravel and charcoal (activated carbon).
  • Disinfection: Mostly done using chemical agents, Chlorine or compounds of it is very common. The disinfection kills bacteria and micro-organisms left in the water. The chemical is residual and normally stays in the water when it reaches consumers.

Now the drinking water can be sent to storage or to consumers via pipes.

Wastewater treatment process

This water treatment process is relevant to sewage purification and general wastewater treatment. The treated water is reused in agriculture or industrial uses or it is flowed back into water bodies in nature.

  • Initial screening: meant to catch and remove large debris from the water system – Using simple metal bars.
  • Grit removal / Coagulation: using either gravity alone or by coagulation chemicals, large and heavy particles come together and sink to the bottom.
  • Sedimentation: in large tanks or lagoons, other heavy particles settle to the bottom creating sludge that is removed.
  • Sludge treatment / Biosolids: the sludge from the bottom of the sedimentation pools can be “eaten by bacteria to some extent or mainly removed and treated further to usually become fertilizer.
  • Filtration: similar to the water treatment process in drinking water, may involve more “heavy duty” filters and more stages.
  • Aeration: adding oxygen to the water by mixing it, adding chemicals and other methods (activated sludge). This helps purify the water further.
  • Lagoons: an optional stage, similar to the disinfection stage of drinking water treatment process. Also encourages aeration.
  • Advanced treatment / Tertiary treatment: achieves high purification levels. Removing remained harmful nutrients and contaminants.  

Household Water Treatment

In terms of water treatment and wastewater or sewage treatment, we generally think of large scale municipal or regional plants with huge equipment, tanks, pools, lagoons etc. But in recent years, following the overall “green” agenda that’s being raised to “center stage”, household water treatment systems are also something that needs attention to and it’s a subject that is developing fast – Both in terms of installed solutions globally and in terms of technological advancements.

Further more regarding household water treatment – Some governments are already applying legislation and regulation to encourage the use of household water recycling systems. This field is widely known as greywater or wastewater recycling or reuse.

Of course household water treatment is not all about recycling wastewater, it is also about improving the fresh water supply that is used domestically and privately for drinking or any other overall use. This common area exists due to health and quality concerns of water supplied by government or private water companies; it involves household water filtration systems, water purifiers, countertop water “mini-bars” and other, more “exotic” methods to treat water.

So in general, household water treatment can refer to what we do with the water after we first use it – recycle and reuse it – or it can refer to the treatment the water goes through before we use it fro the main supply.

Household wastewater treatment

Treating domestic wastewater is normally done using the regular sewage system in the area that delivers the wastewater to the relevant treatment plant. But it can also be done within the household – on site treatment. This practically means that some of the wastewater created by the household is treated and recycled in favor of various uses by a designated domestic system. This can be done to a single private home or apartment or to a complete building.

The relevant wastewater created by a household is called greywater – as opposed to black water from the toilets. Greywater that can undergo household water treatment is the water that comes from dishwashing, bathing and laundry – basically any domestic water that doesn’t involve human waste such as in toilets or very toxic chemicals.

Household water treatment of greywater needs a different plumbing system than the normal pipes leading strait to the sewage, the process is done in a special water recycling system that is normally installed in the yard or garden. A wastewater treatment system can work according to a few methods; it can be quite small and also very large and complex. The principals of this type of household water treatment are that all the solids need to be screened or removed from the water and then the water needs to be purified to a level where it can be used for garden irrigation, toilet flushing etc.

The process of household water treatment and recycling can involve different types of filters, sedimentation tanks, biological water purification processes using technological systems or a wetland basin to eliminate pathogens and contaminants. The treated greywater can be used with a pump, undergo another household water treatment process with carbon filters and similar equipment. Overall this is an economic, sustainable, water saving solution for household water treatment.

Relaimed Water (Water Recycling)

Water is one of the most important and critical factors required to sustain human life – if not the most important alongside air to breath and sunlight. It is also a natural resource that is a major problem in many countries and is expected to become a problem in the future. Water shortage is something more and more countries across the world suffer from and many say that future wars and conflicts will revolve around control of water sources.

Water shortage can be the result of dry climate, a specific climate crisis and also improper water management in a local, national or cross-national level. Also, water is expansive to produce, the production sometimes creates other problems and overall the trend is to reduce consumption of natural resources and to find better, wiser ways to sustain human life and growth.

All of the above reasons lead us to the importance and implementation of water recycling and the use of reclaimed water.


Reclaimed water or recycled water can be treated wastewater, treated sewage or water from ordinary domestic water use that does not involve the toilet – What is commonly known as Greywater. Reclaimed water can also refer to recovery and storing of rain water. Its reclaimed water as after a treatment and purification process the used water can be reclaimed and used for various purposes.

Water recycling or water reclamation requires the removal of solids and a variety of impurities. Water recycling and the use of reclaimed water are done for economic, sustainability and water conservation purposes. All these different process to treat wastewater and reuse it for various uses comes to replace less sustainable and environmental customs that are still used and were much more common in the past – mainly discharging and flowing the wastewater (before or after treatment) into rivers, wetlands or the oceans. Of course that sending untreated wastewater to water sources and eco-systems is extremely not ecological.

Reclaimed water and water recycling processes can be used to produce water for more sustainable landscape and agricultural irrigation, industrial needs, recharging underground water aquifers or other water habitats and reuse for domestic uses with regards to greywater recycling or rainwater collection.

Reclaimed wastewater and reuses

The majority of reclaimed water and water recycling processes performed globally is wastewater that was treated in various methods to make it suitable for reuse. This referrers to domestic and industrial wastewater mainly that flows to water treatment plants through sewerage systems. The method of recycling this water and reclaiming it for a diverse variety of uses is complex and involves physical, chemical and biological processes that eliminate solids, pathogens and other materials.

Common uses of reclaimed wastewater are:

  • Agriculture irrigation
  • Constructing or improving wetlands and water habitats
  • Drinking in very rare cases and countries
  • Industrial needs

Domestic water recycling and collection

Grey water is all the water from sinks, showers, bath, laundry machine etc. from domestic or commercial use – basically anything but toilet water. Water recycling of greywater uses various household systems and methods and the water is used to flush toilets, irrigation, cleaning. Same goes for reclaimed water from rain collection into tanks or pools.

Sewage Purification

Sewage is the wastewater that is produced by domestic water use, industrial uses and every other use or water source that eventually ends up in sewage pipes or transfer systems. Sewage purification is a process that is most widely performed in wastewater treatment plants that operate globally, using various technologies and methods and that can be in very large municipal plants or smaller solutions for a specific house, farm, plant or area.

The process of sewage purification entails removing various contaminants that are domestic and human waste and also effluents or runoff. Sewage purification is done using physical, biological and chemical methods. The purpose of sewage purification processes is mainly to produce water or fluid waste that can be reused for various uses or disposed of ecologically. In some methods also a solid waste (sludge) solution that can be reused as fertilizer or that can be disposed of with minimal ecological and health hazards.

The main use of treated water from sewage purification is for irrigation in agriculture, but with certain methods and complex processes the water purification level is so high that they can be used as drinking water.

Technical details about sewage purification

Sewage wastewater contains both water or liquids and solids of different sorts and origins, sewage purification needs to remove as much as possible or needed of the solids, other obstructions and of course biological and chemical contaminants.

Sewage purification involves a few stages and has a lot of methods by which it is done globally, main stages are:

  • Pre-treatment: screening and removal of solids (mainly inorganic solids) from the wastewater, sometimes also by sedimentation. After this grit removal is next.
  • Primary treatment: mainly done by sedimentation in large basins or tanks, this separates sludge and other materials such as fat from the wastewater. The primary treatment stage of sewage purification is complex, has a lot of methods and is the longest.

Sewage purification methods

Wastewater treatment and sewage purification can achieve various levels of purification, some plants produce water that reach the secondary (biological) treatment level while others produce very pure water at the tertiary level – this can be used to a variety of uses, including agricultural produce irrigation.

In general, all common methods of sewage purification use sedimentation processes by which solids (sludge) sink to the bottom – in some cases this primary sludge is removed for further treatment. After this comes the secondary or biological treatment of sewage purification, this involves biological processes and the use of bacteria that “eats” away a lot of the hazardous contaminants. Use of oxygen by various implementation techniques is very important. After the secondary stage of sewage purification comes final settlement of biological solids and then a tertiary treatment that removes even better the rest of the biological and organic materials in the water. Tertiary treatment uses filters of various types.

Other methods or technologies that take part in the above general sewage purification processes are:

  • Anaerobic or aerobic digestion of contaminants – mainly for sludge.
  • Constructed wetlands that have plants that oxygenates the water and absorbs toxins.
  • Sedimentation and oxygenation lagoons
  • Incineration of treated sludge.
  • Producing fertilizers from treated sludge.
  • Filter and/or oxidizing beds.
  • Nutrient, Nitrogen, Phosphorus removal.