The foam in the Bangalore Lake caught fire and a TV Channel ( TV9 English Channel ) did a program on lake pollution, this is available on youtube, 47 minutes -

Hello Arno

The inventor of Nualgi never worked in a laboratory, he always tested Nualgi in large waterways, since the challenge was to grow Diatoms in a large waterways, in a simple manner.

"So maybe this is what you mean when writing that micronutrient changes can alter the species composition."

Not quite. Diatoms grow well in winter and spring and dominate the water, the water quality is good when they dominate. Diatoms require more micro-nutrients, so all the micro-nutrients available are consumed and once the micro-nutrients are consumed diatoms decline and cyanoabacteria and weeds take over in summer and autumn. So dosing micro-nutrients enables diatoms to grow even in summer and autumn and water will be as clean as in winter and spring.

"Do let me know how much Nualgi you need to add (dose size per liter)"

1 liter per 10 million liters of eutrophic lakes once a week and
1 liter per 1 to 2 million liters of sewage - daily, since sewage flows daily.
The dosage is based on the nutrient level - about 1 liter of Nualgi for 80 kgs of N and 11 kgs of P.

"and over what length of time before you see stimulation of diatoms in eutrophic ponds?"

Diatoms start to grow within minutes of dosing.
Increase in DO and stop of foul odor due to Hydrogen Sulfide can be seen in 1 day.
Decline in BOD, COD, TN and TP can be measured in 1 week to 1 month.

"What happens to weed species like Chlorella or attached filamentous species like Stigeoclonium that can choke the pond with doubling times of only a few hours."

Diatoms can grow as fast as any other micro-algae, pico diatoms can grow faster than most other species in the water.

"Adding silicate in low amounts will not kill these weed species."

Only silica or only Iron is not the solution, that is why we are using Iron on a Silica base.

"Are these outcompeted or do you need to eradicate them first?"

It will take a long time - 6 months to 1 year for the large weeds like water hyacinth or rooted weeds like milfoil to wither and die off. Since people are impatient such large weeds may have to eradicated or physically removed first, this is only for customer satisfaction and not for scientific reasons.

"Are you using your systems to clean up eutrophic water bodies?"

Yes.

"Are the treatments short term or do they require continued applications?"

Depends on the nutrient inflow. If there is regular inflow continuous application is required, if not a 1 month treatment will last for 6 months or so.

"Are you using copper sulphate to first kill the resident algae?"

No.

But alum, silica and bacteria are dosed along with Nualgi to set right the N : P ratio, facilitate Diatom growth, decompose sludge, i.e., to speed up the process.

Copper sulfate and other short term solutions may be used, only for customer satisfaction to show quick results, scientifically speaking this is not required.

A slow and steady growth of Diatoms will solve all the problems, but it may take a long time in some lakes.

The dead BGA will be decomposed by the bacteria that grow due to the oxygen that is available from the Diatoms.

Hello Bhaskar
Interesting work you are doing. I cultured algae in laboratory batch monocultures for about 10 years, producing the nutrient culture medium from scratch. I have also grown algae for about 5 years in 8 m³ outdoor model ecosystems including transplanted species from natural systems in order to test the impacts of additions like N and P and toxic compounds interfering with N and P metabolism like arsenate and chlorate. Such additions (at ug/g levels) restructure the species composition of the ecosystem and often this can look like eutrophication since one or two weed species take over but the macro nutrient levels remain the same. So maybe this is what you mean when writing that micronutrient changes can alter the species composition. I have spent many years diving in polluted coastal zones along the trajectory of sewage effluents, carrying out benthic algal surveys. Algal communities reflect the water quality and grazing impacts of invertebrates and fish species.

Do let me know how much Nualgi you need to add (dose size per liter) and over what length of time before you see stimulation of diatoms in eutrophic ponds? What happens to weed species like Chlorella or attached filamentous species like Stigeoclonium that can choke the pond with doubling times of only a few hours. Adding silicate in low amounts will not kill these weed species. Are these outcompeted or do you need to eradicate them first? Are you using your systems to clean up eutrophic water bodies? Are the treatments short term or do they require continued applications? Are you using copper sulphate to first kill the resident algae?

Hi Arno

We have been growing Diatom Algae using micro-nutrients, for the past 10 years, since 2005. This is even in Eutrophic ponds and lakes and even in raw sewage.

Specific answers to your points -

"It is most often that the macro-nutrients steer what dominant algal species take over and most certainly the amount of biomass."

Macro-nutrients determine the quantum and micro-nutrients the species. Have you ever tried dosing micro-nutrients in eutrophic water and observed the results. It appears that your comments are based on book knowledge and not direct personal experimentation.

"In freshwater systems phosphate is ususally the element that is limiting in terms of biomass and opportunistic species - usually green or blue-green algae are selected for if nutrient levels are high. If grazing by invertebrates cannot keep up, algal blooms can occur."

When phosphate is high BGA is favoured due to their N fixing ability.
BGA are not grazed by invertebrates, that is why they bloom and cause problems.
That is why growing Diatoms is good, since they are the natural food for invertebrates.

"Once a small lake has become eutrophic it is almost impossible to reverse the trend unless effluents and agro runoff are stopped and benthic sediment (which is rich in nutrients) dredged."

We have been reversing the trend in eutrophic lakes since 2005 using our patented product Nualgi. This is a Nano Silica based micro-nutrient mix. It contains 10 micro-nutrients on a Nano Silica base. Since only Diatoms require silica, they consume it and grow rapidly and out compete other micro-algae, weeds and grass.

"Using ponds and coastal zones to grow weeds and algae and then herbivorous fish that graze on this biomass (eg carp and tilapia) is not a new practice."

We are specifically growing Diatom Algae, this is simpler and more beneficial. Additional land is not required - Diatoms can be grown directly in the eutrophic water, they are better food for fish - so fish grow better.

"I don't think we can play God and determine what microalgae are going to grow and where in natural systems."

We have been doing this since 2005.

"But micro plankton in natural systems are difficult to manipulate with small innocula."

We are NOT using innocula, we only dose Nualgi - it only contains micro-nutrients on a silica base and does NOT contain any Diatoms. All natural waters have diatoms ( aquariums to oceans), the native diatoms grow when Nualgi is dosed.

We are selling directly to customers who accept our views, we find that scientists like you do not believe that this is possible and do not even agree to do a systematic trial.

Growing Diatoms is the simplest answer to excess CO2 in atmosphere ( Climate Change / Global Warming ) and water ( Ocean Acidification ) and excess nutrients in water ( Eutrophication ).

Joe

If micro-nutrients are dosed the nutrient boundary can be pushed back quite a bit.

Possibly also worth saying that nutrient runoff in water courses is considered to be one of the 9 'planetary boundaries' as suggested by the Stockholm Resilience Centre, defined as the 'safe operating space for humanity', and one of four boundaries which have recently been assessed as having been exceeded, leading to what leading scientists argue could be "abrupt or irreversible environmental changes."

See here: www.stockholmresilience.org/21/research/...ew-and-improved.html

A 2011 paper specifically on P says:

The planetary boundary for freshwater eutrophication has been crossed while potential boundaries for ocean anoxic events and depletion of phosphate rock reserves loom in the future. The solution to this problem is widespread adoption of better practices for conserving P in agricultural ecosystems, so that P is cycled effectively among soil, crops, livestock and people without contributing to eutrophication of surface waters

see here: iopscience.iop.org/1748-9326/6/1/014009/fulltext/

Hi Bhaskar
The algal and plankton ecosystem composition reflects the water quality eg N/P ratio, micro nutrient levels, structural ecosystem changes due to fishing and toxic compounds that in turn affect ecosystem structure and function, etc. It is most often that the macro-nutrients steer what dominant algal species take over and most certainly the amount of biomass. In freshwater systems phosphate is ususally the element that is limiting in terms of biomass and opportunistic species - usually green or blue-green algae are selected for if nutrient levels are high. If grazing by invertebrates cannot keep up, algal blooms can occur. Blue-greens that can fix gaseous nitrogen (ie they are not nitrogen limited) are specially adapted such that if there is a spate of phosphate from runoff or from upwellings and if the temperature is sufficiently high, these algae can be selected for. In marine systems algal blooms can occur when there is enough nitrogen to support the growth since phosphate is usually not limiting in seawater. This can be triggered by different critical factors for a species eg temperature or even micro-nutrients.

When you write that an ideal algal population like diatoms can be selected for by manipulating the ratio of micro to macro nutrients, this can mainly be true for systems that are not already eutrophic (rich in nutrients) and that are instead so-called oligotrophic (low in nutrients). Once a small lake has become eutrophic it is almost impossible to reverse the trend unless effluents and agro runoff are stopped and benthic sediment (which is rich in nutrients) dredged. For larger systems the pelagic area can show signs of recovery once the coastal zones are cleaned up and there you might be able to see some of the algal indicators of good water quality but that can take many decades depending on the residency time of the water body. Rivers will recovery quickly if they are not overly dominated by connected upstream lakes that are eutrophic.

Using ponds and coastal zones to grow weeds and algae and then herbivorous fish that graze on this biomass (eg carp and tilapia) is not a new practice. This was standard practice eg in Chinese villages for many centuries. Sewage/septage added to fish ponds will produce fish like carp that can tolerate low oxygen levels. But if too much sewage is added the fish (or the plantlife) won't be able to tolerate the anaerobic conditions.

I don't think we can play God and determine what microalgae are going to grow and where in natural systems. This is possible for submergent and emergent macrophyte species where shore and costal zones can be seeded. But micro plankton in natural systems are difficult to manipulate with small innocula. Of course growing them in cultures and fermentors is possible for biotech products.

Regarding the question of the foam again, it is the surfactant component in the sewage that is causing this phenomenon. For the Varthur case there may be several surfactants coming into play, urine being one of them. If there have been some experiments on what levels of urine are required to cause this sort of mammoth foaming, it would be interesting to see these results.

Please tell us more about your work with diatoms.

Best wishes

Hi Arno

Are you open to discuss other reasons why Urine ( and fertilizer runoff ) in water is causing problems.

Soil has micro-nutrients ( mainly metals ) but has less macro-nutrients ( Nitrogen and Phosphorus ), that is why farmers have to use N P K fertilizers, either manure, urine or chemical ( Urea, Super Phosphate, etc.)and use less micro-nutrient supplements ( Iron Sulfate, Zinc Sulfate, etc).

Water has a higher capacity to hold macro-nutrients, since N and P that enter water remain in the water, however micro-nutrients - mainly metals like Iron, Zinc, etc., are less stable in water.

Human action is resulting in input of N and P into waterways but not of micro-nutrients, so the Nutrient : Micro-nutrient balance of water is upset and the wrong type of organisms grow - Cyanobacteria / Blue Green Algae instead of Diatom Algae, this results in low DO and this results in Anaerobic bacteria instead of Aerobic bacteria and decline in Zooplankton and Fish.

So we believe that adding micro-nutrients to water in required ratio to balance the nutrient input from sewage or fertilizer runoff balanced the nutrient ratio and enables Diatom Algae to grow. When Diatoms grow the water is clean and well oxygenated with plenty of fish.

What if farmers used Fertilizer or Manure and grew weeds instead of grass and grass instead of grain.

What is the best phytoplankton / micro algae to grow in water ?
Have you ever thought of this ?

Diatoms are know as grasses of the Ocean.
Conversely Cyanobacteria are weeds.

The report in Deccan Herald gives details about the Varthur Lake foam - the Huffington Post article refers to it but does not quote fully from it -
www.deccanherald.com/content/474713/urin...-behind-varthur.html
Commenting on the accumulation of foam and the stink, M A Khan, Principal of K K school, said: “The smell is an indication that it is hydrogen sulfate and the foam is not because of any detergent soap but due to the phosphate getting into the lake. The urine content is so high that the phosphate in the urine turns into the foam.”

It appears that some research has been done on the issue of whether the foam is due to urine or detergents.

I have seen similar foam in other locations too and it is unlikely that there was a large detergent input in those areas - the sewage was mainly from slums - too poor to use detergents.

Hi Bhaskar
Having worked with the impacts of treated and untreated sewage in steams, rivers and lakes, for over 40 years I can say that it is highly doubtful that it is urine that could cause the extreme surfactant effects shown in the video creating large banks of pure white foam.



The "article" in Huffington Post shows no basis for the headline that urine is causing this effect. Detergents are much stronger surfactants than urine and are the most likely cause for this. But to address your question as to why urine is on one hand an effective fertilizer on land and a pollutant when added to water has more to do with the much higher capacity that soil has to deal with urine and excreta from terrestrial animals including humans compared to the capacity that water has to take on such compounds. Air contains 100s of times the amount of oxygen than what can be dissolved in water. So water becomes anoxic and thus organic materials like urine and faeces putrify and create noxious odours like hydrogen sulfide. Urine when added to soil and growing plants is a near perfect fertilizer. Thus Agriculture Minister Eknath Khadse's recent statement about collecting urine at Multiplexes does make a lot of sense. www.mid-day.com/articles/agriculture-min...elp-farmers/16196181

One day of urine from an adult contains sufficient fertilizer to produce a kg (fresh weight) of food in the form of maize cobs over about 3 months of growth.


This from Peter Morgan's work in Zimbabwe. www.ecosanres.org/pdf_files/PM_Report/Ch...lness_of_urine_a.pdf

But when urine gets into lakes, it is regarded as a pollutant -
www.huffingtonpost.com/2015/05/04/varthu...eetlnkushpmg00000048
Urine, Not Detergent Causing Disgusting Foam On India's Varthur Lake

Why is urine a resource on land but a pollutant in water ?

A senior minister in Govt of India is using urine as fertilizer in his garden.

economictimes.indiatimes.com/news/politi...cleshow/47170657.cms

NEW DELHI: After former Prime Minister Morarji Desai, India now has another politician rooting for the beneficial effects of urine. While Desai is said to have used it for personal fortification, road transport minister Nitin Gadkari has vouched for the magical transformation in his plants after a little dose of urine therapy.

Gadkari, who as a Cabinet minister lives in a sprawling bungalow in the capital's Lutyens' zone with space to spare for a spot of farming, has claimed that he experimented watering plants with urine at his official residence, opposite the house of Congress president Sonia Gandhi. He said he used his own urine on the plants and they grew one-and-a-half times more.