E.J. Rajasekaran

First meeting
2010, October 21st
Last update
phycoremediation, microalgae, seaweeds, training programs

“Our belief is that waste is a resource at the wrong place. If we handle it carefully, the waste can be converted into a commodity.“


How to transform a costly industrial effluent treatment process in a new source of income and employment? Using algae!

In October 2010, I visited the factory of SNAP Natural & Alginate Products. The company harvests and exploits seaweeds for extraction of phycocolloids such as carrageenans, alginates, all kind of seaweed activities in link with the Algonauts Project. But we barely focused on that ! The visit was mainly about what is behind the factory: a full industrial effluents treatment plant!

Driven by the philosophy that waste is a resource at the wrong place, the team has implemented a process for transforming waste in benefits and jobs. Discover this zero waste factory in the video below!


I’m Rajasekaran, Factory manager in SNAP Alginates Natural Products Limited, Ranipet, Tamil nadu, South India. We manufacture alginates brown algae and carrageenans from red algae and other agri inputs from various seaweeds.

We get brown and red algae from the coastline of Tamil nadu during the harvesting season. After drying seaweeds, we preserve them and store them in the warehouse for the usage for the rest of the year. Then we convert them into various products.

The cell wall matrix of the brown algae contains about 20% of alginic acid. We extract them by alkaline process and they are then converted into various sorts of alginic acid. We make varied grades of alginate: food grade, pharmaceutical grade textile grade, metal grade for various applications (as per international standard).

Waste management

We have been operating here for the past 30 years, manufacturing alginates. In the manufacture process of alginates, we get 2 streams of wastes :

  • solid waste: mainly the residues of seaweeds after extraction of alginates
  • liquid waste: essentially the wash water of the seaweeds, which is acidic and contains organic TDS, sea salts and sea sand.

Solid waste

The solid waste is taken to a composting yard. There, it is scientifically composted using concentration of bacteria and converted into organic manure and its further derivatives like liquid fertilizers, gel-type fertilizers. It is converted in various products for agri inputs, as per international standard.

Liquid waste

For liquid waste, we were conventionally neutralizing them with sodium hydroxyde. It was handled in the solar evaporation ponds. Sodium sulfate were formed and we were generating enormous amount of solid waste which was further classified by the Pollution Control Board as hazardous waste. And we had the problem of disposing that solid waste. And we have to take it to the place that Pollution Control Board tells us and we have to landfill the things as per their norms.

Phycoremediation plant

But, later on, in 2003 or so, we wanted to identify a biological method to treat our wastes. And we worked with various research institutions (University of Madras, Vivekanda Institute, IIT Chennai). With this research inputs, we identify a new methodology: a phycoremediation plant. The final part of this was worked out and found at Vivekenanda Institute of Algal Technology by identifying the various microbes that can be used in our wastewater treatment system.

Chroococcus turgidus

We are discharging our wastewater effluents at a pH of 1.8. Previously we were using sodium hydroxide for neutralizing. Now we are not using any sodium hydroxide, we are just putting the acidic effluent water from the process into the tank where a community of bacteria and algae present. According to the scientists, it is Chroococcus turgidus which is doing the neutralization part. Chroococcus turgidus is generating alkalinity and neutralizing the acidity of our effluents. Our effluents contain about 30 000 TDS1 of inorganic salts and about 20 000 TDS of organic matter. Algae and bacteria utilize the nutrients such as organic TDS and minerals, produce alkalinity and neutralize the water.

We have been operating this for the past 5 years and so far we have not generated any sludge. It’s a sludge-free water treatment system, we are not using any chemicals for that.

Description and operation

  • The effluent water is discharged over a drying platform made of AC sheet black painted, so that the water can runs evenly over it. Because of solar energy, the water can evaporate. It is stuffed with algal beds. These algae will neutralize the acidic water.

  • The water is collected at the end of the charging platform and pumped over the AC sheet roof of the tank.

  • There are green fences around this and it is elevated from the ground level, so any seepage will be immediately identified.


In our phycoremediation, we really took a risk in identifying and putting this new system which was not proved in any other place of the world, that’s what we heard about. It was the first of this kind in the world, we have tried this at the commercial scale. Initially it was a commercial risk for us, but we studied the system for nearly 3 years now in the pilot plant, in normal conditions and varying seasonal conditions, then we found that it was going to work and we invested about 40 lakhs2, 5-6 years before. Now the savings from the algae treatment alone is about 40 to 50 lakhs per annum and the major part of it, we are not generating any acidic waste we used to generate in the past, so it’s a totally sludge-free phycoremediation. We save money on it and we harvest rainwater, we run out the process plant for 3 months in a year with the rainwater harvested from the phycoremediation plant. And we also harvest algae and convert to useful manure and aquaculture products so that is become a commodity for us. We become a zero discharge unit, zero waste, in our area. We don’t waste anything.


Now with this biological system, we are not generating any solid waste and we are totally free from waste generation. The biomass that we are cultivating, which is growing in our phycoremediation plant, we collect it, harvest it and use it for various aquaculture purposes and land uses. It was tested for various heavy metals and other things, so that toxics can not enter into the food chain.

Our belief was that waste is a resource at the wrong place, so if we handle it carefully the waste can be converted into a resource. Our solid waste now become normal resource, now it becomes a product and commodity, we are selling it. So if you put mind and efforts we can eliminate the waste, we can eliminate pollution and we can convert all of these things into resources.

The products we are producing replace many chemical fertilizers. So, now by using our seaweeds products people are eliminating chemical fertilizers. So the pollution is removed from the fields, for everything there are possibilities.

Sustainability of the resource in Gulf of Mannar

The considerable amount of raw material, we take it from the sea, from the Gulf of Mannar. Gulf of Mannar is declared as biosphere reserve. So it’s very sensitive, it’s a sensitive area and it’s biosphere so the people, nearly 56 villages, people from 56 villages along the coastline of Rameshwaran district are engaged in this work. They are all fishing tribes, traditionally they are doing the seaweed collection.

Now to maintain the sustainability of the seaweeds, since they are interacting with the important ecosystem area, we want them to educate how to do their seaweed cultivation in this sensitive area. We work with scientist and took their inputs for knowing during what season we should collect seaweeds so that the sustainability of the seaweeds is maintained. We documented the time-schedule : during which time we have to collect the seaweeds and how to collect the seaweeds, how to avoid any impediments during collection of seaweeds.

Then we formed groups, what they call environmental committees. This was formed jointly by the Gulf of Mannar Biosphere Reserve Trust, a governemental organization, working along with the Forest Department. They form 56 environmental committees in these villages. We conduct training programs once a month in these villages to tell them how to collect seaweeds and maintain sustainability.

Mainly the women are engaged in the seaweed collection business so we teach them how to go, how to not disturb these things. Seaweeds are growing mainly out of the coral area so they are not interacting with the corals but even then, they should not collect other unwanted other species of seaweeds. They should select and collect only the useful seaweeds so that others species would be not disturbed. By doing this for the last past ten years or so, the seaweeds is now, especially the Sargassum abundantly available and we don’t have any problem with the availability of the seaweeds. What we invested in the training program : our time, efforts, money, everything, it’s paying us back for the availability of the raw material. Not only we, we have an association: the entire association follows this schedule and the association we meet twice a year and we’ll see that the norms fixed by the scientists are strictly implemented, that no industry is exploiting or collecting off season, etc. All the things are now monitored and maintained. We take the leadership in maintaining all this sort of activities.

We invest money for training these fishing tribes for collection of seaweeds to maintain sustainability. It gave us 2-3 benefits like: 1. the sustainability of seaweeds is maintained, 2. they harvest during the right, the correct season so that we get mature plants and the yield has gone up and the quality of the product has gone up, 3. we harvest and we taught them how to preserve the weeds after, post harvesting system. After harvesting, how to preserve the seaweeds so that wastes are avoided. The traditional spoiling of seaweeds is avoided. So whatever we harvest we carefully collect it and we carefully store it in our facilities for the rest of the year. This would improve the product, avoids wastes and it saves cost for us. And it also ensure the sustainability of the seaweeds, and people are interested in getting in the business, it’s also paying the more.

About 5000 families are benefiting from this industry, from this factory alone.

About women’s empowerment in the seaweed industry

We maintain the gender ratio, we simplify the technology so that the women can handle this process. Now in the factory we have the gender ratio 50% women, 50% men, which is normally very difficult to manage in this kind of industry, normally the men dominated. I’m talking about 30 years before, we were the first industry to introduce equal wages for women here in Ranipet. There was a lot of opposition, we were able to overcome.

Now we help fishing women, so they can also earn 300-350 Rs. per day. They became now self supporting. There are women entrepreneurs, there are women cultivators, women self help groups (SHGs), women traders, so in this industry we are able to achieve that, that’s one of our pride when we achieve the gender ratio here.

Message for the Youth

Anne-Gaëlle: What would you say to an 8 year old child who is affected by the prospect of a future with climate change, pollutions, biodiversity loss, energy crisis and overpopulation?

Yeah, my son also asks. He studies at school. That’s something he is worried about, always wondering “How long the world is going to be”.

For every problem there are solutions, we are working towards pass these solutions. Yeah there is about global warming, pollutions, various other problems, depletion of resource, etc. But when you set your mind, we are able to set up solutions. Now in the factory, we found solutions, we are not generating any waste. In fact, the products we are producing replace many chemical fertilizers, and they are more environmentally-friendly. By using our seaweeds products people are eliminating chemical fertilizers and the pollution is removed from the fields. For everything there are possibilities.

You, young people, you can innovate in new scientific ecofriendly methods so that you’ll be able to look after the world, the world is for us, we can enjoy it, we can be healthy nothing to worry about. Yes there are some negative things but it’s not going to be a major problem if we set our minds towards solutions. If you set well your mind, you are going to be great scientist and have a long life in the world.

Update 2016

Some recent updates about SNAP NAtural and Alginate Products and phycroremediation from Dr. Sivasubramanian (interview recorded in Chennai in December 2016):

See also

For more information


  1. TDS: Total Dissolved Solids, concentration of the dissolved particles. 

  2. 40 lakhs = 4,000,000 INR (Indian rupees) = about 60,000 USD