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Using Nualgi to grow Diatoms is the most economical and sustainable solution to sewage treatment,growing fish and fuel and sequester carbon.



Sewage contain nutrients Nitrogen and Phosphorus and removing these is very difficult and expensive. If tertiary treatment or Biological Nutrient Removal (BNR) is used the cost is very high.

Using the nutrients in sewage to grow something useful is the best solution to deal with them.

What is the most useful organism that can be grown using the nutrients in water?

Diatom Algae.

Diatoms are the dominant group of phytoplankton in nature and they are the best food for Zooplankton, newly hatched fish and shrimp, small fish, etc. Diatoms account for about 40% to 50% of primary production in lakes and oceans. ( ‘Global Significance’ para on ).

Others working on use of Algae for wastewater treatment advocate harvesting of the algae. Harvesting algae is difficult and expensive. Allowing fish to consume the algae and harvesting the fish is viable and profitable.  

We will use a unique product called Nualgi – Nutrition for Algae, to grow Diatom Algae in wastewater treatment plants, ponds, lagoons, lakes, etc.

Nualgi is invented by Mr T Sampath Kumar of Bangalore, India in 2004 and we have an exclusive agreement with him to use Nualgi to treat sewage.

The US Patent # is 7585898 ‘Composition for growth of Diatom Algae’ granted in 2009.

Nualgi is certified to be non-toxic by Indian Institute of Toxicological Research, Lucknow.

Any other certificates required will be obtained.

Diatom Algae consume huge amount of CO2 and in oceans, dead diatoms sink and sequester carbon for long time. Prof John Martin’s Iron Hypothesis is based on this. ( Ref 1 ).

Nualgi uses Nano Silica to deliver micro-nutrients to Diatom Algae in large waterways. No other product uses Nano Silica to be consumed by living organisms and no other product can grow Diatom Algae ( or any other specific group of micro-algae ) in an large waterways and WWTPs.

Category of the action

Reducing emissions from waste management

What actions do you propose?

In nature Diatoms are responsible for consumption of about 23 Billion tons of Carbon per year. Anthropogenic carbon emissions are about 10 Billion tons of Carbon per year.  So increasing Diatom growth by about 40% would result in consumption of all the anthropogenic carbon emissions.

The total amount of Nitrogen in the urine of all the people in the world is about 20 million tonnes per year, and of Phosphorus in the urine is about 2 Million tonnes. In addition to this large amounts of fertilizer run off, animal dung, etc., is available. These are regarded as problems to be dealt with, we regard these as resources to be used.

Diatom Algae require CO2, Nitrogen and Phosphorus for photosynthesis.

We will use Nualgi to grow Diatom Algae in sewage and sewage polluted lakes and coastal waters. Nualgi works in both fresh water and sea water.

Nualgi can be used in water of any type or volume, since Diatoms grow in any type and volume of water from a Goldfish bowl to the oceans.

We will market Nualgi for use in wastewater treatment plants, Facultative Lagoons, polluted ponds, lakes, rivers, estuaries, coastal waters, etc.

We will market Nualgi for use in fish ponds on farms, to consume the fertilizer in the runoff from farms. At present this run off is flowing into rivers and lakes and polluting them.

Septic tank runoff too can be released into ponds and Nualgi dosed in the ponds to grow Diatom Algae and Fish. At present septic tank runoff is seeping into the soil and sometimes it flows into wells, ponds and streams.

Most of the sewage treated in modern Wastewater Treatment Plants is not reused but is released into lake and rivers or even into oceans. For e.g., in California, Los Angeles treats and releases about 350 MGD of treated sewage into the Pacific via a long Ocean outfall and San Diego releases about 240 MGD of treated sewage into the Pacific, .

These WWTPs spend millions of dollars and consume huge amounts of electricity and in the end the treated wastewater is dumped into the ocean. Proper treatment using Diatom Algae would enable reduction in the amount of electricity used to treat the wastewater and use of the treated wastewater.

It is estimated that about 3% of the total electricity consumed in USA is used for Water and Wastewater, pumping and treatment. Using Diatom Algae to treat wastewater would save huge amounts of electricity and reuse would save huge amount of electricity consumed for pumping water from long distances.

There are reports that Diatom Algae are declining in the oceans due to sewage.

"Until recently, photosynthetic diatoms supported the Arabian Sea food chain. Zooplankton grazed on the diatoms, a type of algae, and were in turn eaten by fish. In the early 2000s, it all changed."


"As the study authors point out, Mumbai’s population has doubled to 21 million in the last decade. The region now sends 63 tons of nitrogen and 11 tons of phosphorus into the Arabian Sea each day. Karachi’s 15 million people send 70 percent of their wastewater into the sea untreated. "

Nualgi can be used to grow Diatom Algae to treat the sewage from Karachi and Mumbai, to keep the Arabian Sea clean, well oxygenated and with plenty of fish.

Baltic Sea develops a huge dead zone each summer. The Helsinki Convention ( HELCOM ) has set targets for each country. These are available on

The total target is 118,134 Tonnes of Nitrogen and 15,178 Tonnes of Phosphorus per year.

The amount of Diatoms required to be grown to consume this N and P would be about 1.4 Million tonnes and the amount of Nualgi required to grow this quantum of Diatoms in the Baltic Sea and in all tanks, ponds, lakes, rivers, etc. in the watershed of the Baltic Sea is about 1,400 Kilo liters per year. 

Centralised vs Decentralised Sewage Treatment:

The advantage of using Nualgi and Diatoms is that sewage can be treated in both a decentralized manner and in large ponds. Conventional WWTPs are large and hence require large land at one place. Decentralised plants require less space and can be fitted into buildings and neighbor hoods, like roof top solar panels as an alternative to large power plants. Photobioreactors to grow Diatoms using sewage can even be built on roofs and just outside toilets and the water reused for toilet flusing,etc. Thus in multi storied building Sewage from the 10th floor can be treated on the 9th floor and reused for toilet flushing on the 8th floor. This will result in tremendous savings in both pumping cost and water consumption.

Land Requirement

The total land required by a Diatom Algae and fish based sewage treatment solution should be compared with the total land required for water storage and wastewater treatment. Since sewage treated with Diatoms can be reused after further processing at a reasonable cost.

At present most of the treated sewage is being released into ocean and rivers and flows away and is not being reused. Reuse of treated wastewater would reduce the power cost of pumping water.

Why grow fish?

Fish are a better food source than Algae, since they do not require any further processing. Fish have, over millions of years, evolved the ability to consume Diatoms and digest them and convert them into food suitable for human consumption. Fish in lakes and oceans are the only thing that declined in the 20th Century. Everything else has increased – Human population, Cattle population, food production, fuel consumption, N P K fertilizer use in agriculture, etc..        

Does Nualgi contain any Diatom spores?

Nualgi does not contain any Diatoms, it contains 10 micro-nutrients – Iron, Zinc, Manganese, etc. It does not contain any organic matter or living organisms or spores.

What is the dosage of Nualgi?

The dosage is very low, just 1 liter per 1 to 2 million liters of sewage ( 1 ppm ) or 10 million liters of eutrophic lake water ( 0.1 ppm ).

Are there any unforeseen consequences?

Nualgi is being used to grow Diatom Algae in large lakes since 2005 and 1000s of liters has been used in 100s of ponds and lakes and there are no unforeseen consequences.

What happens if the Diatoms are not consumed by fish?

In nature Diatom Algae are consumed by Zooplankton and Fish, the question of the Diatoms not being consumed does not arise. There are no reports of lakes and ponds turning brown with Diatom blooms, but there are 1000s of reports of lakes and even oceans turning green with Cyanobacteria blooms and red due to Dinoflagellate blooms ( Red Tides). These blooms indicate that these algae are not consumed by zooplankton and fish.  

Diatoms that are not consumed sink due to the heavy silica shell. In a WWTP or Lagoon the sinking of diatoms is very useful, since there would be no fish. The dead diatoms would become part of the sludge along with the dead bacteria and can be transported out of the tanks in the same manner at the sludge is being disposed off at present.

When Diatoms sink the water above is clear and light is available for more diatoms to grow. But when other algae die off they float on the surface of the water, these can be seen as algal blooms in ponds and lakes and this cuts off sunlight to the water blow and this reduces growth of other algae.

Differences between Diatoms and other algae:

Diatoms have a silica shell, this is transparent and thus more light enters the diatoms, so they are able to carry on photosynthesis even when less light is available, such as on a cloudy day or at greater depths in large lakes and oceans. So they produce more oxygen than other algae.

Diatoms grow well in winter and even beneath ice in Arctic and Antarctic

Arctic -

Antarctic -

Lake Erie -

There are many other differences between Diatoms and other algae, all together make Diatoms the best type of algae. This can be best understood by noting the point that Diatoms are the last group of microalgae to have evolved, about 200 million years ago and they now account for about 40 to 50% of all photosynthesis in water on Earth (Lakes and Oceans).

Is there any danger of algal blooms?

Nualgi does not cause algal blooms, in fact It is used to prevent algal blooms. The concept of growing one type of algae to prevent bloom of other types of algae is very novel and hence difficult to understand. The concept of good algae vs bad algae is not discussed in scientific literature and text books. Diatoms are known as ‘grasses of the oceans’, by inference other algae are weeds. Obviously growing grass is better than weeds.

Conventionally any algae may grow ( bloom ) in large natural waterways and particular species of algae are grown in controlled environment in laboratories, shrimp hatcheries, ponds, photobioreactors, raceways, etc. These were liable for contamination by unwanted species.

Nualgi is an unique solution to grow a particular group of algae in a controlled manner in an uncontrolled environment.

If the Diatom growth is excessive then dosing of Nualgi can be stopped and the number of diatoms will decline to the earlier levels in a few days or weeks.

Is further research required ?

No further research is required – Nualgi has gone through many versions, initially the micro-nutrients were sold separately, then they were combined, then there were two versions for sea water and for fresh water and then one product was made for both, it was earlier a moist powder and is now a liquid ( powder in suspension ).

The actual results on the ground are to be noted and understood. Nualgi and Diatoms are the cheapest solution to treatment of sewage. Conventional WWTPs are much more expensive and do not treat the wastewater fully that is why most of the treated wastewater is discharged into sea or lakes and is not being reused and one of the reasons why lakes and coastal waters are eutrophic.

What is unique about Nualgi?

Nualgi is to water and fish, what Urea is to land and agriculture.

Farmers use N P K fertilizers like Urea to grow crops on land to feed people and animals and they have to replenish the soil with more N P K.

Excess nutrients in water due to sewage from the higher population, manure from animals, fertilizer runoff, etc., is causing problems of eutrophication of waterways.

Excess nutrients have to be balanced with micro-nutrients to restore the Nutrient : Micro-nutrient balance.

Nualgi is an unique solution to deliver Micro-nutrients to Diatom Algae in water.

Another version of Nualgi is used as Foliar Spray in Agriculture to deliver the micro-nutrients to all plants.

The use of Nano Silica to deliver micro-nutrients is an unique concept, no one else has thought of this.

On land, silica and micro-nutrients ( mainly metals ) are stable and water and macro-nutrients ( N P K ) is less stable. So farmers use N P K fertilizer and irrigation to grow crops.

In water, water and macro-nutrients are available, since N and P are easily soluble and stable in water but silica and micro-nutrients ( metals ) are less stable and hence less available.

Therefore, a silica based micro-nutrient product is a good solution to the problem of enhancing beneficial photosynthesis in water and sewage.

Dr William Oswald wrote about ‘Photosynthesis in Sewage Treatment’ in 1955 ( Ref 6 ) and ‘The coming industry of controlled photosynthesis’ in 1962 ( Ref 7 ) but photosynthesis is not being used to the extent desirable and algae grows in sewage tanks and polluted lakes in an uncontrolled manner, since no technology gives control over the type of algae that is grown in large sewage treatment plants and lakes. Nualgi is the only product that gives this control, by using Nano Silica.

Who will take these actions?

Nualgi Nanobiotech will manufacture Nualgi and we will distribute it to all users worldwide.

We will market Nualgi to all the potential users.

Wastewater treatment plants can buy and use it in their plants to improve the treatment and reduce consumption of electricity.

Municipalities, Councils and other Government agencies can buy to use in lakes and estuaries and coastal waters to remove nutrients from the water.


  • The Massachusetts Water Resources Authority can use Nualgi to treat sewage from Boston fully and reuse it and also keep the River Charles, River Mystic and Boston Harbor clean, nutrient free and well oxygenated.
  • At present the waters in these waterways are eutrophic.
  • This is In spite of treatment and discharge of about 350 MGD of treated wastewater into the ocean via a 10 mile long tunnel.
  • If the wastewater if properly treated there would be no need to discharge into the sea and if all water is properly treated, no river, lake or ocean need be eutrophic.


Farmers can use Nualgi in ponds on their farms to consume the nutrients in the fertilizer runoff.

Groups of house owners can use it to treat sewage / wastewater onsite and reuse the water and thus reduce the cost of wastewater treatment and pumping of water over long distances.

Permission of International Maritime Organisation ( IMO ) would be required under the London Convention / London Protocol to use Nualgi in Oceans.

Where will these actions be taken?

Nualgi Nanobiotech will manufacture Nualgi in India and consumers all over the world can use it in their respective wastewater treatment plants and polluted waterways.

Nualgi is already being used on a small scale in India and USA and trials are on in many countries.

An e.g.  In Boston the Massachusetts Water Resources Authority can use Nualgi to treat sewage from Boston fully and reuse it and also keep the River Charles, River Mystic and Boston Harbor clean, nutrient free and well oxygenated. 




What are other key benefits?

Diatoms are the natural food for fish, so fish production will improve and this will help feed the growing population.

In fact, fish in the oceans have declined drastically in the 20th century, perhaps by about 75%, since we have been catching fish from the oceans, but have not done anything to grow fish in the oceans.

Proper treatment of sewage / wastewater will enable reuse of the water.

Methane emissions are expected to increase in areas like the Arctic, due to the melting of the ice cap. Diatoms create aerobic conditions and thus reduce methane production by methanogen bacteria and higher DO will support growth of methanotrophs. Thus even Methane emissions will be taken care of.

Anthropogenic CO2 emissions are balanced by anthropogenic wastewater and fertilizer runoff and using the nutrients to promote photosynthesis and consume the CO2 is a balanced solution.

The cost of growing Diatoms in oceans can be recovered from the increase in fish catch. 

How much will emissions be reduced or sequestered vs. business as usual levels?

Emission reduction per liter of Nualgi:

The efficiency of electric aerators is about 2 kgs of Oxygen for 1 kwh of electricity consumed. 1 liter of Nualgi can grow upto 1,000 kgs of Diatoms and these produce about 1,200 kgs of Oxygen. So 1 liter of Nualgi will eliminate upto 600 kwhs of electricity.

Coal fired power plants emit about 0.75 kgs of C for each kwh of electricity generated.

So 1 liter of Nualgi can reduce upto 450 kgs of Carbon.

Global impact:

Sequestering of 25 to 100% of all Anthropogenic emissions, i.e., about 2.5 to 10 Billion tonnes per year, is possible by growing Diatom Algae in all waterways in the world.

Natural Diatom biomass growth per year is about 23 Billion tons, so an increase of about 40% i.e., 10 Billion tons is adequate to consume ( not necessarily sequester) ALL anthropogenic carbon emissions.

This can be achieved in 10 to 25 years from the time permission is granted by the regulatory agencies for large scale use of Nualgi.


What are the proposal’s costs?

Cost of Sewage treatment:

The Hyperion WWTP in Los Angeles treats about 350 MGD at a cost of $77 Million per year.

This is $ 600 per Million Gallon.

But this treated water is now being released into the Ocean and is not being reused.

Total cost of Nualgi would be about $100 per liter and 1 liter would treat 0.25 to 0.5 Million Gallon. So cost would be at most $ 400 per MG and may be as low as $100 per MG, once technology matures and costs reduce due to economies of scale. And the water would be fit for reuse after this treatment, so it need not be dumped into the ocean.

The Terminal Island WWTP does treat wastewater to drinking water standards but the cost is $9.6 Million for 4.5 MGD. The cost per MG is about $5,845, almost 10 times more than the cost at Hyperion WWTP. This is perhaps the reason why more such plants are not being built. So a lower cost solution would be very useful.

The distance over which needs to be transported can be reduced if wastewater is treated fully and recycled. This would result in tremendous savings in energy consumption for pumping water.

Cost of carbon sequestration:

The total amount of Nualgi required to consume 5 Billion tons of Carbon per year is estimated to be about 10 Million kilo liters per year.

The cost at $ 50,000 per kilo liter is $ 500 Billion.


Most of this cost would be recovered from the increase in fish catch and in fact, there could be a profit if the increase in fish catch is more than this.

Increase in Fish growth would be upto 1 Billion tons per year for 10 Million kl of Nualgi. Value of this at $ 1.5 per kg of fish is $1,500 Billion.

FAO statistics indicate that the ocean fish catch value is about $ 200 billion per year

"Capture fisheries and aquaculture supplied the world with about 148 million tonnes of fish in 2010 (with a total value of US$217.5 billion),.."


Time line

Short Term:

Nualgi was invented over 10 years of research from 1994 to 2004 and has been in commercial use since 2005.

Its effectiveness and safety and economics has been proven in normal commercial use.

So it can be used on a large scale as soon as regulatory agencies approve, this may take 5 years.

Scaling up the manufacturing capacity is quite easy, since all the raw material are available. 

Had we received necessary support, we could have cleaned up all the waterways of the world and solved the problem of excess CO2 in atmosphere and oceans about 5 years ago.

Medium and Long term:

No new actions would be necessary beyond 15 years, we will continue to manufacture and sell Nualgi and WWTPs, etc., will continue to buy and use Nualgi. 

Further development of the product and achievement of economies of scale and competition from similar products will help reduce the cost.

Related proposals

Nualgi - Diatom and Oxygen' in the Water and Energy category 


1. Iron Hypothesis. Prof John Martin

2. The possible importance of silica in marine eutrophication.

C B Officer and J H Ryther.

3. The Economic Importance of Diatoms. Albert Mann.

4. The dependence of the fishes on the Diatoms. Albert Mann.

Ecology Vol. 2, No. 2 (Apr., 1921), pp. 79-83

5. The life of the Diatoms in the World's oceans.  Dr Armburst.

6.Photosynthesis in  Sewage Treatment. 1955 William J Oswald, et al. Paper No .2849

7. The coming industry of controlled photosynthesis. William Oswald, 1962