Water Treatment for Reuse
Published on by Peter Petersen, Water chemist II (water quality) at Milwaukee Water Works (Retired 2021) in Technology
What is the relationship between treated wastewater, water reuse and drinking water?
What are the best treatment methods for treating wastewater so it is reused as drinking water and what are the best treatment methods for wastewater reclamation in agriculture?
How does the treatment process differ for treating water from the aquifer to drinking water and treating wastewater to drinking water?
Taxonomy
- Irrigation
- Treatment
- Treatment Methods
- Drinking Water Treatment
- Water Reuse & Recycling
- Water Treatment & Control
- Waste Water Treatments
- Water Reclamation
- Wastewater Treatment
- Water Treatment Solutions
- Industrial Water Reuse
- Waste Water Reclaimation
21 Answers
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Potable water reuse is a question of need and cost, but it is also a sustainability issue. It costs less than desalination, too. So, its applications will continue to grow over time . There are well established technologies with clear performance capabilities, including for pharmaceuticals. The systems perform better than conventional surface water treatment processes. The analytical technology continues to be improved. Real time on line monitoring for key performance indicators is readily available. There are also technologies capable of identifying essentially all of the microbes that are in the source water and their removals at the various unit process stages. So, the science and technology exist and the produced water is better quality than many current conventional drinking water systems. It is very appropriate to have good control of inputs to the wastewater, as well as very good secondary and tertiary treated wastewater and that reduces the demands on the advanced treatment system. Of course, other less than potable reuse is also highly desirable and less controversial and less costly and it allows an offset from the 'natural' water.
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Hello Peter: Your vision or quest to be off the grid is really quite simple. All things for life are free if you follow natures rules. 1. Rain water system, pipes storage tanks (2 years supply), underground cistern you decide how much. 2.energy. try to wire up each building for separate grid, but connect to a central grid for back up. a) solar, b) wind, c) water::: metal slant roof mini hydro turbines, tidal wave generator, small water fall generator, d) bio generator. black and gray water processing using RNA microbes release electrons which can be collected and used. All trash reused, repurposed, recycled. = compost for field, green house, lawn trees etc. Grow your own veggies and fruits. Learn the art of canning/long term storage. Depending on your location farm animals. Goats, sheep, pigs, cows, chickens, others. Hint: elevated greenhouses have an average out put of 2#s of food per cubic foot. . e.g. [40 acre/120 ft tall put out 360 million #s a year. Off the grid is great. Learn the secrets and share with your neighbor. The pioneering spirt is alive.
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I would not recommend reusing wastewater for drinking water unless you have tight control on your waste stream. The amount of pharmaceuticals in municipal wastewater that cannot be broken down easily is of concern for water recycling.
What is the source of your wastewater stream? E.g. abattoir or food processing effluent? Or is it municipal?
Is it economical to recycle? Treatment to drinking water standard would require tertiary treatment in the form of advanced media or membrane filtration and associated disinfectant technology.
If you can control the amount of synthetic chemicals in the waste stream then I could suggest an MBR process followed by mechanical cavitation and disinfection, activated carbon, UV and chlorine dosing. This would produce WHO drinking water quality.
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Dear Peter,
water reclamation for reuse is just driven by water scarcity, nobody is reclaiming water for fun or for profit.
Regarding your question, treatment methods differ according to the intended use. Water quality requirements for agricultural use are less stringent than for indirect potable use (aquifer recharge). Reclamation for direct potable use is not a common practice, and in such a case the treatment would be the same that for drinking water.
You will find pretty interesting reference documents here:
http://ec.europa.eu/environment/water/reuse.htm
or refer to the experience in California.
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i think the treatment of water for re-use is somewhat snapped up by intent to produce profit, by providing a solution for sale.
treatment of water perhaps needs to be looked at by example. i.e how does nature deal with the process.
it could be the evaporation cycle perhaps, and can this be replicated. does it need to be on large scale process or can it be done on an individual level as in a collective of many.
I think we need to be aware that most or all functions that happen within nature on this planet are within a cycle or regenerative process. this does not mean that the process returns to an original state for what it was intended for but as a key component of the overall purpose still.
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The thing that I can never understand is why people are so =obsessed in water recycling of doing like alchemists and 'turning manure into gold' . There are many forms of waste water and many uses for recycled water that do not require full potable quality/. Better to concentrate on these larger volume areas than the niche 'urine recyc' end that is so challenging and ultimately not worthwhile except in deep space.
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Conventional activated sludge plus advanced water technology like MBR,AOP[advanced oxidation]plus microfiltration and other pressure driven processes in vogue.
MBR plus Ultra filtration combo very common,followed by disinfection using chllorine.
Combinations with AOP like ozonation,hydrogen peroxide,as well as UV treatment in vogue.
The link below describes a typical case of municipal waste and sewage recycle for drinking
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http://blogs.ei.columbia.edu/2011/04/04/from-wastewater-to-drinking-water/
From waste water to drinking water..A case from San Diego,US.
Direct and indirect potable water[use after storing in reservoir]from waste water.
Toilet to tap recycle of waste water also in California,New Mexico,and in countries like Singapore,Australia,Namibia,Spain etc
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As you know, potable water from wastewater is not permitted in the most of the countries.
Agriculture or Industrial use are very common in Spain and specially in the Canary Islands.
This is my experience after installing and operating several tertiaries.
First thing to consider as usual, is the quality of the treated wastewater and the target quality.
There are two points to consider: For granular filtration, the best choice is the up flow, continuous backwash type (Dynasand, Dualsand and other brands) because their efficiency is much higher than standard ones and remove phosphates, which is very important if a desalination stage is needed, to avoid a big expense of acid to eliminate the formation of calcium phosphate scaling.
If desalination is needed, do not use Reverse Osmosis, but Electrodialysis Reversal (EDR) due to the high level of dissolved organics present in the feed water.
Reverse osmosis get fouled very rapidly, needing a very high CIP frequency, which makes the operation anti economical and a nightmare for the operator. (Some RO Plants have been shut down or transformed in Electrodialysis due to the high cost of the produced water)
The big advantage of EDR versus RO is due to two main factors.
EDR can work with chlorinated water and is not a filter like RO (Product water do not pass through the membrane)
Resuming:
If desalination is not needed, use "Dynasand" type filter alone or "Dynasand" followed by MF or UF stage depending on the water quality. (Do not make the big mistake of using MF or UF without the previous "Dynasand" type filter stage).
If desalination is needed, the design must be:
"Dynasand" type filter, followed by MF-UF, followed by Cartridge Filters and finally Electrodialysis Reversal (EDR)
1 Comment
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Bonjour
Je suis désolé mais dans votre présentation vous ne proposez aucune méthode d'épuration et de purification.
La filtration n'est pas une méthode d'épuration des eaux usées et encore moins de purification.
Et ce qui est encore plus grave c'est que dans votre post on ne voit nulle trace d'un quelconque lien à la caractéristique -biologique- des eaux usées.
La majorité des eaux usées perdent ou on perdue les caractéristiques biologiques nécessaires voir même indipensable à un éventuel recyclage immédiat d'arrosage de la biodiversité et encore agronomique
Toutes les pollutions dissoutes, invisibles seront transmises au plant et on les retrouvera automatiquement dans nos assiettes.
Il faut des années à MERE NATURE pour faire une eau potable, comment l'homme ose t il vouloir faire mieux qu'elle avec sa technique.?
Hello I'm sorry but in your presentation you are proposing no method of cleansing and purification.
Filtration is not a method of purification of sewage and even less of purification.
And what is even more serious is that in your post there is no trace of a any link to the - organic - characteristic of wastewater.
The majority of wastewater lose or we lost the necessary biological features see same proficiency in any immediate irrigation of biodiversity and even agricultural recycling all impurities dissolved, invisible will be transmitted to the plant and we'll automatically find them on our plates.
It takes years for mother NATURE to make drinking water, how man can t he want to do better with his technique.?
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Cost (i.e., the present worth, which includes capital and operating costs) should be the key determining factor for selecting a technology that sustainably meets treatment goals.
- Treated wastewater is simply sewage that has been processed to meet a regulatory target (COD only, COD and N, or COD, N and P removal).
- For water reuse, the cost of treating the water and making it suitable for reuse should be cheaper than the cost of getting potable/drinking water. That is what allows the approach to make sense, an be sustainable.
- The first question to ask in determining the treatment method to be used is what the reuse water will be applied for. Watering lawns, cleaning factory floors, cooling industrial applications, flushing toilets, or drinking. Those applications determine the treatment required. E.g., water for drinking water purposes must be low in pathogens, Nitrates and TDS. Water for agricultural reuse should still have decent levels of N and P to augment the nutrient requirements of crops, and can possibly tolerate high TDS.
- Water from the aquifer tends to be low in organics (COD of
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As expected the answers to your question just complicate the issue even further. Hopefully some of the issues can be simplified. The best way of dealing with wastewater is to treat it to a standard (Solids, BOD and NH4) as set down in regulations and then discharge it back to the environment with a dilution factor of at least 10 to 1. This makes the water available for abstraction for any other use i.e. agriculture, industry or, following further treatment, potable. If the water is not put back into the environment and taken directly for potable use then it will (again) require two stages of treatment. The first is roughly the same as before but is designed as pretreatment simply to make it suitable as feedwater to an advanced process such as RO. As others have said this produces water which is akin to distilled water and, whilst great as industrial process water, it requires blending in order to make it suitable for potable uses. Wastewater can be used almost directly for agricultural purposes but poses threats to both to workers and consumers if precautions are not taken. Most countries have regulations requiring quality standards to be met. Most aquifers produce water which is suitable for direct consumption with just disinfection using chlorine.
2 Comments
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Cher Peter
Comme si le traitement de l'eau était aussi facile que vous le décrivez.
Que faites vous des diverses pollutions bio chimiques et chimiques dissoutes.
Chacune ne peut être traitée qu'individuellement car personne encore au monde n'a inventé de processus aussi pointu pour une telle performance.
Non la seule solution pour le traitement d'eau c'est la biotechnologie en préservant l'eau souillée de toute pollution chimique ou bio chimique
Dear Peter
As if the water treatment was as easy as you describe.
What do you of organic pollution chemical and chemical dissolved.
Each can be treated as individually because nobody even in the world invented process also pointed to such a performance.
No the only solution for the treatment of water it's biotechnology in preserving water contaminated from pollution chemical or bio chemical
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A concern that is in discussion in the academic world, how to detect the small amounts of new compounds such as phthalates and primarily, what is the safe concentration for human beings.
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Please establish the facts re (a) Composition of water as available for intended use (b) Regulatory values of various parameters ( Periodic range if these values change with time of the year) and their comparative with that of available water (c) Established need for bringing various water composition factors with in the regulatory or desired range...(c) will lead you to the treatment processes as may be required.. Better still to do a Pilot Project and than scale up.
1 Comment
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Bonjour
la problématique ne vient pas de là. On sait tous que les eaux usées contiennent différentes pollutions et que ces pollutions ont une origine.
Une fois que l'on a déterminé ceci on est toujours à la même place :comment effectuer un traitement? quel traitement? pour quel objectif?
Si le seul traitement consiste à filtrer l'eau, on ne fera que retenir les MES.
Si le traitement consiste à traiter la pollution diffuse dissoute, on est dans l'imaginaire. il faudrait un dispositif ciblant le type de pollution et adapter un traitement d'épuration spécifique.
Mais chaque traitement d'épuration adapté va générer des pollutions peut être encore plus difficile à épurer.
C'est ce qui se pratique de nos jours: l'alternance de traitement qui produit plus de pollution résiduelle.
On va très vite vers l'obligation d'effectuer des traitements de purification de l'eau potable contaminée par diverses pollutions chimiques invisibles mais hélas bien présentes.
Hello the problem is not from here. Everybody knows that wastewater contain different impurities and that these impurities have an origin.
Once it has been determined that we're still in the same place: how to do a treatment? what treatment? for what purpose?
If the only treatment is to filter the water, we can't make that hold the M.E.S
If the treatment is to treat the pollution dissolved, it is in the imagination. It should be a device targeting the type of pollution and adapt specific purification treatment.
But each sewage treatment will generate pollution may be even more difficult to purify.
That's what happens these days: the alternation of treatment that produces more residual pollution.
We will very quickly towards the obligation to perform treatments of purification of drinking water contaminated by various chemical pollutions invisible but unfortunately present.
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Unfortunately, there is no best treatment method for any sources of raw water existed. The best method would be under a typical condition, via with certain quality or characteristic of the raw water. If there were the best way to treat any kind of raw water, how could the other method have existed?
1 Comment
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Hello
Bravo et merci pour votre réponse. enfin quelqu'un qui pense comme moi d'une façon réaliste. A ce jour énormément de gens impliqué sur le sujet de l'eau pense qu'avec un coup de baguette magique on peut résoudre la problématique de l'eau potable.
Cette problématique est intimement liée à la problématique de la gestion des eaux usées sa principale source de pollution.
La seule et unique solution qui démontre une certaien efficacité c'est d'aller agir à la source de la pollution.
C'est ce que nous faisons dans l'assainissement -biologique-.
Les utilisateurs/consommateurs de l'eau dans l'usage qu'ils en font au quotidien pour leur besoin domestique adhèrent à la protection -biologique- de l'effluent. Un effluent -biologique- peut être épuré par un dispositif -biologique- et son produit de rejet peut servir immédiatement à l'arrosage de la biodiversité.
Rejeter le liquide des Stations dans les milieux hydrauliques naturels avec la pollution chimique qu'il contient fini par contaminer toutes les eaux de surface et souterraines
Hello
Bravo and thank you for your response. Finally someone who thinks like me in a realistic way. To this day a lot of people involved on the subject water think we can solve the problem of drinking water with a magic wand.
This issue is intimately linked to the problem of wastewater management his main source of pollution.
That's what we do in sanitation - biological-.
The users/consumers of water in the use they make on a daily basis for their domestic need adhere to - organic - protection of the effluent.
A - biological - effluent can be purified by a device - biological - and its product of rejection can be immediately used to watering of biodiversity.
Reject the liquid Stations into natural water environments with pollution chemical it contains eventually contaminate all surface water and groundwater
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There is no difference at all. You can bioremediate any waste. Solid, liquid. or gas. When using the Archaea microbes the compounds will be reduced into their elemental/nutritional state. 40+ years of monthly testing has never had a single pathogen or toxic anything. In addition the Oxygen content is increased. It does not create more Oxygen. It makes the Oxygen more available. Great for cleaning up dead zones.
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Unfortunately, there is no relationship between the treatment of wastewater, reuse water and drinking water.
Initially it is important to clarify the word treatment which means everything and especially to say nothing.
When you're studying very closely the methodology of wastewater management we can realize that there is no treatment to own Senna of the word.
We have to find the qualification of treatment: sewage, purification. Off she doesn't appear anywhere.
Wastewater management is limited to a splitter function of suspended solids in the liquid.
Filtered by all means possible until you get a liquid get rid of everything, including bacteria.
Then one rejects this liquid in the environment in multiple forms that remains all the same the way to get rid of this liquid.
Except that this liquid contains a lot of dissolved impurities: urinates it, chemicals, disinfectant sanitizer and other body of dead bacteria.
By this principle this liquid cannot be recycled in a food need. But it can not be recycled for another use because it will end up in the environment by polluting nearby natural water environments.
It is pretty oblivious to bind water to wastewater. It is well know the drinking water. Before drinking it undergoes a very long chain of property and at the same time to load elements including the living on Earth in need.
We can but at an exorbitant price and always without any insurance certainly drinking water, to clean the sewage completely. Except that this water will be an inert product empty. It will bring nothing to the living to grow.
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DPR
It is complicated but well established. There are 2 relatively standard treatment trains that are most interesting. One involves RO and advanced oxidation, the other involves ozone biologically activated carbon. The former is very expensive and essentially produces distilled water, the latter is less expensive but will have higher TDS. The oldest operating system is in Windhoek that has been successful since the 1960s. It is a very complicated aggregation of treatments that was added to over time. They should reexamine it and can substantially simplify it. The WHO is about to release its Guideline for potable reuse, which is very practical. It will be available for free download very soon. The difference between Direct Potable Reuse and planned Indirect Potable Reuse is that the treated water is put through either a surface reservoir or a groundwater to distinguish it from recycled water, mostly in the public sense. Putting highly treated water in the environment sounds like a good idea, but actually it can recontaminate it and require another stage of drinking water treatment. Some regulators do not seem to understand that. See:
Cotruvo, JA, Direct Potable Reuse: Then and Now. World Water: Water Reuse and Desalination . Volume 5, Issue 1, pp 10-13. Spring, 2014.
http://edition.pagesuite-professional.co.uk/Launch.aspx?EID=192226ee-85e9-4277-9129-9ff8272ac622
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It is a general question and answer is very complex because it involves many factors. It should be better addressed.
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You have to go for tertiary treatment and polishing process.
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Hi Peter,
As others have eluded, this is a complicated question. Legislation aside, testing is your primary means of determining potential reuse. Wastewater treatement varies heavily on the design of the plant, and required treatment quality, but for reuse, you must consider nutrient content, bacteriologocal removal, heavy metal content and other toxins, hormones and polishing of the effluent to accomplish safe reuse.
All the best.
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You have to check the regulation in your country regarding raw water quality in order to be treated and reuse it for drinking water. In Jordan have such regulation and it is not allowed to use wastewater as raw water to be treated for drinking water, as still you have choice to find better quality of resource water.
If you have choices of much better raw water quality than wastewater this is good for everybody in your country.
For treated wastewater reuse it depend what type of crops you are going to irrigate- e.g. raw eaten vegetables, cooked vegetables, parks, fruit trees, flowers...etc. You have first to read WHO wastewater reuse guideline in order to determine what type of treatment you need, which mainly depend on E.coli counts and other parameters.
Best luck
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You ask a question with similar depth to "what is the origin of life?" It all really depends on what kind of waste water, and what you want to use the "re-use water" On drinking water while the WHO gives guidance on the quality of drinking water this may have different legal requirements depending where in the world you are. I would invest some time in finding a experienced, capable and honest service provider to help you through discovering a sustainable, lowest total cost solution to your question. Good luck