Nualgi - Diatom Algae for Sewage Treatment by Nualgi-Diatom Algae

Questions of the Judges and our answers Judge 1: As a geologist with an understanding of diatoms in the fossil record, there is no doubt that using them to sequester carbon is a reality as nature has done it exceptionally well. The idea of utilizing a nutrient source for the growth of algae, while not novel, is commercially feasible and has a broad range of possibilities. Our solution Nualgi is a micro-nutrient on a Nano Silica base, this is an absolutely novel solution. No one else has thought of using Nano Silica to deliver micro-nutrients to any living organism. In fact our product is perhaps the only one to use a Nano material for consumption by any living organism i.e., Diatom Algae. All other nano products are used in chemical reactions or as coating material, etc. Harvesting fish in lieu of algae is an interesting variation. Harvesting algae while difficult is also an additional food source. I think the proposal has merit on small-scale commercial operations and small waste-water treatment facilities. Large waste-water treatment facilities process 10s of millions of gallons of waste water per day and storage of that water for algae and fish growth would take too much land. Answer: 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. Nualgi is intended for use in large volumes of water. It is quite easy to grow Diatoms in small volumes and there are many other solutions for this and these are used in all Shrimp hatcheries all over the world and in laboratories, Photobioreactors and raceway ponds. Nualgi is the only product that can grow Diatom Algae in large waterways, size is quite irrelevant. Only dosage changes with volume of water and a boat has to be used to do the dosing in a large waterway. Land required to build the wastewater treatment ponds is certainly more than the land required for conventional Wastewater Treatment Plants but is less than the reservoirs currently being used to store irrigation and drinking water. Today most of the treated wastewater is being released into oceans by coastal cities and rivers and lakes by inland cities. Nualgi and Diatoms can be used even in sea water and also in the natural lakes and rivers. The treated water would be fit for reuse, hence the land requirement should be compared to the drinking water reservoir size and not to the WWTP size. Cities hold 6 months or more of drinking water requirement in the reservoirs, but Diatom Algae based sewage treatment ponds need to hold only upto 30 days of sewage flow. Large scale implementation in large lake and rivers has potential unforeseen consequences. I feel is questionable without significant additional research into the possible outcomes of major algal blooms not consumed. I would have to see more detail into the potential upside of the increase in fisheries to make this feasible, especially at the extraordinary cost proposed. I definitely think is has potential for smaller scale implementation but the cost per unit has to be reduced dramatically. Nualgi is being used to grow Diatom Algae in large lakes since 2005 and there are no unforeseen consequences. Nualgi does not cause algal blooms, in fact It is used to prevent algal blooms. The basis of our proposal is that Diatom Algae are consumed by Zooplankton and Fish, the question of the Diatoms not being consumed does not arise. 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. 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. Cost of nutrient reduction in the Baltic sea is estimated in this paper - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3888655/ Cost is Euro 4.7 Billion for 675,000 tonnes of N, this is about Euro 7 per kg of N. If Nualgi is priced at Euro 100 per kg ( all inclusive ) and 1 kg removes 80 kgs of N, cost of N removal using Nualgi is Euro 1.25 per kg of N. Nualgi can be dosed directly into the Baltic Sea and also in all the waterways in the watershed. Judge 2: This is a great proposal, a little technical / wonky, but understandable. Wastewater treatment is certainly an industry that could benefit from some paradigm shift and this proposal is interesting in moving wastewater treatment towards a more sustainable pathway. Any revolutionary new technology would be technical / wonky, until people understand it. The concept of growing a particular group of algae in large waterways is a paradigm shift in the way algae is grown. 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. Answer Nualgi is an unique solution to grow Diatom Algae in large natural waterways, in a simple and economical manner. Thus we have achieved control over the type of algae even in an uncontrolled environment, this is why we are presenting it as a solution in this competition. 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. Similarly Nualgi is used to grow an useful algae in sewage and sewage and fertilizer polluted water to consume the nutrients and grow fish. On land, soil and micro-nutrients ( metals ) are available and water and macro-nutrients (N P K ) are less available, so farmers use irrigation and fertilizers and manure to provide the inputs required. In water, water and macro-nutrients are available and silica and micro-nutrients are less available so Nualgi with Silica and micro-nutrients has to be used. As with all new technologies that promise a solution to a problem the long term impacts of this approach to wastewater treatment need to be assessed. Are there any forseeable negative externalities associated with shocking water bodies with large quantities of this type of algae? While this project is novel in terms of what happens at a wastewater treatment plant, I would have liked to see an intervention further upstream in the wastewater treatment system. Nualgi is in use since 2005 i.e., for 10 years in many aquaculture ponds and polluted lakes and there no problems of any kind have been reported. We do not shock waterbodies with large quantities of Diatoms. We grow the required quantity of Diatoms. I think there is a misunderstanding, 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 and 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 ). The quantum of Diatom growth depends on the amount of nutrients in the wastewater, 1 gram of N enables growth of about 11 grams of algae and these produce about 14 grams of Oxygen, this is based on the Redfield Ratio. The Nualgi dosage is decided based on the nutrient content of the sewage and the Oxygen required to satisfy the BOD and COD and maintain DO at a high level. Also, most of the energy consumption that occurs at WWTP (in the states at least) is for heating. Can these algae survive in cold waters? The impact is clearly stated and definitely presented as a scale-able technology pending questions above. The presentation could benefit from some more clearly and succinctly packaged information. I do not think that most of the energy consumption at WWTPs is for heating, most is for aeration (about 50% ) and most of the total energy consumption for Water and Wastewater is for pumping the water and the sewage. The distance over which water and wastewater is pumped is increasing due to increasing urbanization. 1 Liter of Nualgi can grow upto 1,000 kgs of Diatom Algae and these can produce about 1,300 kgs of oxygen, thus all the oxygen required to satisfy all the BOD and COD can be produced utilizing the nutrients in the sewage, so there would be no need for use of electricity to run aerators. If wastewater is fully treated it can be reused and the need to pump water over long distances will diminish, thus there would be savings in energy consumption for pumping too. If small decentralized algae based treatment facilities are installed in all buildings and communities then the need to pump sewage to large centralized sewage treatment facilities too will diminish. Thus energy savings are possible in many ways. Judge 3: Interesting proposal; may want to ask for more information related to life cycle of diatoms, especially at project level. Answer This paper has a very good review about Diatoms - http://www.nature.com/articles/nature08057 Most of the Diatoms that grow in natural waterways are consumed by Zooplankton and small fish, these in turn are consumed by the bigger fish. Diatoms are the best food for newly hatched fish and also for shrimp and crustaceans like Oysters. Diatoms are the easiest to digest phytoplankton / microalgae. Diatoms are grown in Shrimp hatcheries since newly hatched shrimp consume only Diatoms for the first 3 days and their survival rate depends on the availability of Diatoms. Thus when Diatoms are available in natural waterways the survival rate of newly hatched fish too will improve. Diatoms are brown and not green like Green Algae or Blue Green Algae or red like Dinoflagellates ( Red Tides). I am sure that not many have seen waterways brown with Diatom blooms, this is because diatoms rarely accumulate in the water, they are consumed as rapidly as they grow and 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. 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. 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). These answers are also incorporated into the edited proposal.

Tengeya Thanks. The answers are incorporated into the main proposal on the description forum. Bhaskar

An example of use of sewage to grow fish. https://www.facebook.com/takeprideineastkolkatawetlands "Sewage before entering the pond and the sparkling clean water in the fish ponds displays the efficiency of a natural biological reactor. The local fishermen are the only ones in the world to have understood and used this ecosystem approach for the mutual benefit of the fishermen as well as the city people. Photo credit: Dhrubajyoti Ghosh" Kolkata is the largest city in the world that does not have any large modern sewage treatment plants. All the sewage is sent to a wetland of about 12,500 hectares and used to grow fish. This is the process that needs to be refined and used by all cities and villages worldwide. The refinement required is to reduce the land requirement and speed up the process and make it more reliable.

Video about our proposal - 

https://www.youtube.com/watch?v=HF0YEwsPPgI&feature=youtu.be